Engine PT6A-60 SERIES. TRAINING MANUAL (2007)

ENGINE INDICATING SYSTEM

Function:

- Provide the pilot with indications concerning the

engine parameters during flight

- Provide the required data for engine condition trend

monitoring and performance

Engine Indicating Systems:

- Ng / Np Tachometer-Generators (Pulse pick-up probes

on the PC12)

- Oil temp/ Oil pressure indication

- Chip detector

Indicating Systems Built Into Engines:

- Inter turbine temperature system (T5)

- Torque indication system

PT6A-60 SERIES

TRAINING USE ONLY

ENGINE INDICATING SYSTEM 7.2

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

ENGINE INDICATING SYSTEM

COMPRESSOR SPEED

OIL TEMPERATURE (C˚)

ITT

TORQUE

PROPELLER SPEED

NG (%)

AND PRESSURE (PSIG)

(C˚)

(FT-LBS)

Np (RPM)

OIL

START

PROP RPM

ITT

TORQUE

RPM

FTLB

X 100

˚c x 100

x100

PSI

X 100

x 10

-2

Np TACHO

GENERATOR

Ng TACHO

OIL PRESSURE

GENERATOR

TRANSMITER PORT

OIL TEMPERATURE

BULB

PT6A-60 SERIES

TRAINING USE ONLY

ENGINE INDICATING SYSTEM 7.3

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

INTER-TURBINE TEMPERATURE (T5)

Function:

Provides an indication of the Inter-Turbine Temperature

(ITT), between the compressor turbine and the first stage

power turbine vane ring (station 5).

Description:

- 10 individual thermocouples (chromel-alumel)

- 1 positive bus bar (chromel-small terminal)

- 1 negative bus bar (alumel-large terminal)

- 1 trim probe

- 1 T5 wiring harness

Note:

Engine operation at or above maximum temperature may

damage or shorten hot section component's life

PT6A-60 SERIES

TRAINING USE ONLY

ENGINE INDICATING SYSTEM 7.4

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

TEMPERATURE INDICATING SYSTEM (ITT)

Operation:

Maintenance:

- Check system loop resistance (continuity)

As temperature increases, an increasing voltage is gener-

- Check resistance of individual probe

ated at the chromel/alumel junction of each thermocouple.

- Check insulation resistance (harness, probe and trim

probe)

Uneven heat distribution within the gas path causes individ-

- Check probes for heat response

ual thermocouples to see different temperatures and gener-

- Check Trim thermocouple adjustment

ate different voltages.

To obtain an average reading, the thermocouples are con-

Troubleshooting:

nected in parallel. The indication generated is the average

temperature of 10 specific locations (thermocouple tips)

Problem Area

Symptom

within the gas path and therefore does not necessarily rep-

resent the exact average temperature at station 5. The

Burnt Probes

T5 drops due to loss of probes

exact average temperature is calculated at engine test and

in hot spots

is used to determine engine acceptance.

Short Circuit To Ground

T5 drops due to complete or

partial loss of T5 signal

A trim probe located over the inlet case is connected in par-

allel with the 10 thermocouples to bias the average temper-

Trim Probe Open Circuit

T5 increases due to loss of

ature reading. The resultant corrected temperature is read

trimming function

in the cockpit. The indication generated by the 10 probes at

station 5 is trimmed down using the trim probe internal

High Resistance On T5

T5 drops due to reduction of

resistor. The smaller the resistance the greater the down-

Circuit Between Engine

T5 signal

trim (the lower the ITT).

And Aircraft Gage

Trim Probe Resistance

T5 increases if trim resistance

The amount of trimming is a function of the trim probe inter-

Drifting

increases

nal resistance. The resistance of the trim probe is adjusted

T5 drops if trim resistance

at engine test to match the required temperature trim.

drops

PT6A-60 SERIES

TRAINING USE ONLY

ENGINE INDICATING SYSTEM 7.6

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

TORQUE SYSTEM

Function:

Maintenance:

Provide an accurate indication of the torque applied to the

Check/calibrate the airframe torque transducer and gage

propeller.

(ref. to airframe maintenance manual).

Description:

Troubleshooting:

- Hydro-mechanical system

- Floating first stage ring gear with helical splines

Problem Area

Symptom

- Piston

- Cylinder

Control Valve

Torque goes off scale (high)

- Spring loaded oil control valve

Stuck Open

Worn Piston

Torque indication low

Operation:

Seal Rings

Set oil pressure to max limit

Torque applied to the propeller induces a small rotational

Defective Trans-

Torque may indicate high or low

and rearward movement of the first stage ring gear. This

ducer/Gage

movement is due to the helical splines on the ring gear.

The ring gear pushes the piston and the control valve.

Oil In RGB

Torque fluctuation

Static Line

Moving the control valve to the rear, opens the metering ori-

fice and allows more oil pressure to push on the piston

Reference:

against the ring gear mechanical force.

A52, A64

1 psi = 30.57ft/lb

The movement of the ring gear only stops when metered oil

pressure in the torque meter chamber exactly balances the

A60, A65

1 psi = 83.63ft/lb

rearward force of the ring gear. Static air pressure inside the

A66

1 psi = 37.04ft/lb

reduction gearbox acts on the torquemeter piston and

would cause incorrect (higher) torque reading. For this rea-

A67

1 psi = 86.63ft/lb

son, static pressure is sent to the transducer and subtracted

from the torque reading.

Hydrostatic lock is prevented by continuously bleeding oil

from the pressure chamber.

PT6A-60 SERIES

TRAINING USE ONLY

ENGINE INDICATING SYSTEM 7.8

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

CHIP DETECTOR

Function:

Maintenance:

- Inspect chip detector at interval specified by aircraft

Provides an indication of metal particle contamination of the

maintenance manual

engine oil system.

- Functionally test chip detector

- 100hrs -> Check Continuity

- 600hrs/12Mo. -> Function Check

Description:

- Two magnetic poles

- Normally open circuit

Warning:

- Wired to a light in the cockpit (optional)

- Self closing valve allows chip detector verification with-

DO NOT OVERTORQUE THE CHIP DETECTOR

out draining the RGB (except A64/66)

Operation:

When metal particles accumulate on the two magnetic

poles and bridge the existing gap, the circuit closes.

Some installations use an indicator in the cockpit to warn

the pilot or maintenance people that contamination is

present. Other models rely on visual inspection and conti-

nuity check of the chip detector to detect contamination.

Particles found on the chip detector can be analyzed and

identified. Refer to chapter 70 of the Engine Maintenance

Manual.

PT6A-60 SERIES

TRAINING USE ONLY

ENGINE INDICATING SYSTEM 7.10

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

IGNITION SYSTEM

Function:

Exciter Box Specifications:

Input voltage

9-30 VDC

Provide the spark to ignite the fuel/air mixture.

Input current

3.5 amp

Operating Altitude

0-50000 feet

Description:

Spark rate 10 VDC

1 spark/sec

- Airframe mounted ignition exciter

30 VDC

4 spark/sec

- Two high tension cables

Stored energy

4.7 joules

- Two spark igniters

Output voltage

8000 volts

Exciter Box:

Operation:

A sealed unit which transfers a DC low voltage input to a

Activated by the pilot for engine start. The system can

pulsed high voltage output. When the unit is energized, the

operate continuously during adverse weather conditions to

capacitor progressively charges until the voltage can ionize

allow the engine to re-light in the event the of engine flame

the spark gap then the capacitor discharges through the

out.

igniter plugs.

Maintenance:

Ignition Cables:

- Ignition plugs are not life limited.

Two cables carry the electrical energy from the exciter box

- Inspect cooling holes of spark igniters for blockage.

to the igniters. Each cable consists of an electrical lead sur-

- Inspect igniter shell and electrode for erosion.

rounded by an insulating tube contained in a flexible metal

- Carry out functional test by disconnecting one ignition

braiding.

cable at the exciter box. Switch ignition on and listen

for the spark.

Spark Igniters:

- Replace igniter plugs if dropped.

Located at 4 and 9 o'clock positions on the gas generator

- Check for fretting wear @ combustion chamber junc-

case, the spark igniters are in the form of threaded plugs

tion.

with a central electrode enclosed in an annular semi-con-

ducting material. When the voltage reaches a certain level,

Warning:

the air between the central electrode and the plug outer

shell ionizes a high energy spark discharges from the elec-

Wait six minutes after switching ignition off before

trode.

handling any ignition components.

PT6A-60 SERIES

TRAINING USE ONLY

IGNITION SYSTEM 8.2

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERFORMANCE CHECK

Function:

Permits verification of engine condition over a wide range of

- From appropriate curves (Airframe M/M), determine:

ambient temperatures without exceeding torque or T5 lim-

Target Torque.

its.

ITT

Fuel Flow

Performance Check Should Be Performed:

- Determine parameter limits using tolerance from the

- After engine installation.

Airframe Maintenance Manual applied to the graph val-

- Before and after hot section inspection.

ues.

- After FCU change.

- Start engine and stabilize at idle for 5 min.

- At regular interval.

- No generator or pneumatic loads during performance

test.

- Set torque and Np as per chart.

Description:

- Stabilize engine at that power for 5 min.

- Record actual ITT, Ng and Wf.

Performance check curves establish engine parameter lim-

- Compare recorded values of ITT, Ng and Wf to chart

its for an acceptable engine at different atmospheric condi-

parameters.

tions. The check is performed at a given power where Tq

- If values deviate from chart limits, troubleshooting

and Np are constant and the values obtained for Ng, ITT

action should be undertaken to restore engine perfor-

and WF are compared to the limits obtained from the chart.

mance.

Pre-H.S.I. Checklist:

Procedure:

1. Calibrate engine gauges.

- Ensure engine indicating system is properly calibrated.

2. Check for F.O.D. and wash compressor if needed.

- Determine Outside Air Temperature (OAT).

3. Check the oil filter/screens and chip detectors.

- Determine Pressure Altitude (Pa) or Barometric Press

4. Borescope (optional)

5. Carry out a ‘before’ and ‘after’ Performance run.

Set altimeter to 29.92 ^inHg to obtain Pressure Alti-

tude

Set altimeter to 0 ft altitude to get field barometric

pressure

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.2

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERFORMANCE CHECK (SHORTS INSTALL)

General:

Static Maximum Take Off Power Check:

Shorts installations use two types of performance checks.

A Static MTOP check is required upon replacement of an

1. Static Reduced Power Check.(Static RTOP)

engine after the Static Reduced Torque Check has been

2. Static Maximum Take Off Power check (Static MTOP)

carried-out, or if a loss of performance is noted.

3. Reserve Power Check

1. Determine OAT and pressure altitude

Static Reduce Power Check:

2. From POH, determine target torque and corresponding

Ng, Wf and ITT target values.

This check is performed on both engines after;

3. Start and stabilize engine at target torque (1 min.)

a) installing an engine.

4. Check that observed values of Ng, Wf and ITT agree

b) a rigging adjustment.

with the graph values within tolerance.

c) a propeller or engine component change.

5. If unacceptable, refer to PWC EMM for performance

d) if requested by the flight crew.

troubleshooting flow chart.

Reserve Power Check:

Procedure:

1. Determine OAT and pressure altitude

The Reserve Power Check is a ‘follow-up’ to a satisfactory

2. From POH, determine target torque and ITT limit.

MTOP/RTOP check.

3. Start and stabilize engine at target torque (1 min.)

4. Record ITT and compare it to pre-determined limit. Must

a) Set power as per POH, (2^nd engine must be at Idle/

be within POH tolerances (approx +10 / -50°C). If out of

off.)

limit, carry-out a Static MTOP check.

b) Activate Power Reserve Switch, confirm Static MTOP is

achieved.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.4

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

ENGINE CONDITION TREND MONITORING (WEBECTM)

Function:

Data Acquisition:

- Maintenance tool

The accuracy of the WebECTM process depends on the

- Allows user to monitor the engine performance

quality of the data entered into a computer system. Cruise

- Permits early detection of engine deterioration

condition is the only flight configuration where engine reac-

- Helps determine trouble area

tion can be predicted.

- Increase dispatch reliability

- Allows to perform repairs at the most economical time

To ensure validity of WebECTM data:

- Allows to be on (soft time) for hot section inspection

- Record data once per day, or every 6 hours

Description:

- Select the flight with the longest cruise that is at a rep-

resentative altitude and airspeed

WebECTM is a process of periodically recording engine

- Allow the engine to stabilize 3 to 5 minutes without

and aircraft instrument parameters and comparing them to

ANY power lever movements

a computer reference model.

- The same flight configuration must be repeated (i.e.

electrical load, bleed air extraction)

Under specific ambient conditions, engine parameters such

- Record data within a reasonable time frame

as compressor speed (Ng), Inter-turbine Temperature (ITT)

and fuel flow (Wf) are predictable. The difference between

Data entry and Calculation:

the actual engine parameters and the computer model val-

ues will be plotted as 3 deltas using a graphical chart

Via PWC WebECTM

method as illlustrated below.

Plotting and Trend Analysis:

Once a trend is established by the plotting of these deltas,

any deviation would indicate some engine deterioration.

Once the deltas are calculated, the computer does the plot-

Analysis of the trend reveals extent of deviation and possi-

ting and displays the result on screen or prints it. Analysis of

ble need for corrective action.

the trend can reveal extent of deviation and possible need

for corrective action.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.7

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

WEBECTM (CON’T)

Plotting:

Guidelines for interpretation of trend:

Following computation, DELTA Ng, DELTA ITT, and DELTA

Wf should be plotted on a continuous sheet. Flight log

Net change of 10 to 15°C ITT:

number may be used as the abscissa, although the trend

Early sign of deterioration, that should be investigated when

could also be recorded as a function of date or, preferably,

convenient.

as a function of engine running time in hours.

Net change of 20 to 25°C ITT:

Deterioration becoming more serious. Further running

Definition Of Terms:

could result in replacement of high cost hot section compo-

nent. Corrective action should be taken as soon as possible

Base Line:

A straight line, derived from the average of the first 15 delta

Net change of 30°C ITT:

points for a particular engine with known conditions, which

At this level, whether or not ITT is redlined, deterioration

include a recently completed HSI, inspection of compres-

has progressed to a point where serious engine damage is

sors and a compressor wash. New or newly overhauled

imminent

engines also meet these conditions.

Net change of .75 to 1% Ng:

Net Change:

Early signal of some deterioration should be investigated

The change from the base line to a line passing through a

when convenient

delta point at a specific location on the graph.

Net change over 1.5% Ng:

Revision of Base Line:

Action should be taken as soon as possible

In the event the initial base line position improperly esti-

mated, a revision of the base line values needs to be done.

Note:

A fault or change in the instrumentation calibration or an

WebECTM courses are available. Please contact P&WC

engine repair/H.S.I. will require the baseline to be re-estab-

Customer Training department for the schedule

lished.

Analysis:

The analysis of the trend graph should be carried-out on a

daily basis if possible, but not deferred for more than five

days.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.8

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

TBO AND HSI INTERVAL

• SB 13003 for PT6A-65

• SB 13303 for PT6A-52/60/61

Engine

TBO

H.S.I.³

• SB 13203 for PT6A-60AG, A-65AG

• SB 14003 for PT6A-67R, 67D

PT6A-52/60/61

3600

1800

• SB 14303 for PT6A-67AF, F

PT6A-65

6000

1200²/2000¹

• SB 14603 for PT6A-64, 66, 66A/B/D, 67, 67A/B/P/T

• SB 14503 for PT6A-67AG

PT6A-64/66/66A/66D/67/67A/67T

3000

1500

PT6A-67B/P, PT6A-64 ( post SB

3500

1750 to 2000

TBO Industry:

14089 or 14112 and 14261, 14308 )

Initial TBO applicable to all operators.

PT6A-66B, PT6A-66 ( post SB

3600

1800 to 2000

14112, 14274 and Piaggio Post-

TBO Fleet:

SB80-0194 )

TBO attained by individual operators for engines of the

same model in their fleet only.

PT6A-60AG/65AG/67AF/67AG/F

3000

1500

PT6A-67D/R

6000

2000

TBO Extension:

1) A65’s operated as airliners.

Operators desiring TBO extension can submit a formal

2) A65’s operated as executive transports.

request in writing together with details of sample engine log

3) N/A if operated under an approved WebECTM program

book to: Manager, Technical Support, PT6 engines.

HSI interval may be based on engine condition trend moni-

Recommendations for time between-overhaul take into con-

toring with borescope inspection at 2000 hours and every

sideration the average effect of the many variables that

500 hours subsequently. (Ref SB 14003).

affect overhaul life. These variables are average flight dura-

tion, percentage of time at any given power level, climatic

Modular Concept:

conditions and environment, maintenance practices and

An engine may be operated as 2 distinct modules, each

engine utilization.

having a logbook. This allows an operator to return the

power section or gas generator for repair (or overhaul) and

Under extreme conditions of very low utilization coupled

keep the remaining module in service. Any spare module of

with continuous operation in salt water atmosphere or

the same model can be installed and operated as long as

heavy sand environment periodic inspections in accordance

each logbook reflects the applicable data.

with the applicable maintenance instructions may indicate

that maintenance actions are required prior to the recom-

mended overhaul life.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.10

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS*

Description:

Operating limits define the upper and lower boundaries for

all engine parameters observed in the cockpit during nor-

mal operation for each specific engine model.

Excursion beyond these limits may accelerate engine wear

and possibly lead to component malfunction.

For current operating limits, refer to applicable aircraft pilot

operating handbook.

*Operating limits, listed here, are for reference only. They

can be found in each Maintenance Manual in Section 71-

00-00.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.11

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS

PT6A-52

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

PSI

°C

Take-off/Max Cont

850

2230

72.95

820

39000

104

2000

90 to 135

0 to 110

Max Climb

850

2230

72.95

775

39000

104

2000

90 to 135

0 to 110

Max. Cruise

850

2230

72.95

800

39000

104

2000

90 to 135

10 to 99

Normal Cruise

850

2230

72.95

775

39000

104

2000

90 to 135

10 to 99

Min. Idle

750

21000

-40 to +110

Starting

1000

200 (max)

-40 (min)

Transient

2750

89.73

850

39000

104

2205

40 to 200

0 to 110

Max. Reverse

800

760

90 to 135

0 to 99

PT6A-60A

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

PSI

°C

Take-off

1050

3625

43.34

820

39000

104

1700

90 - 135

0 - 110

Maximum Continuous

1050

3625

43.34

820

39000

104

1700

90 - 135

0 - 110

Takeoff / Climb

1000

3625

43.34

785

39000

104

1700

90 - 135

0 - 110

Max. Cruise

1000

3625

43.34

820

39000

104

1700

90 - 135

0 - 110

Normal Cruise

1000

3625

43.34

775

39000

104

1700

90 - 135

10 - 99

Min. Idle

750

19000

60 (min)

-40 - 110

Starting

1000

200 (max)

-40 (min)

Transient

850

39000

104

1870

40 - 200

-40 - 110

Max. Reverse

900

760

1650

90 - 135

0 - 99

PT6A-60AG

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

PSI

°C

Take-off

1050

3625

43.34

820

39000

104

1700

90 - 135

0 - 110

Maximum Continuous

1050

3625

43.34

775

39000

104

1700

90 - 135

0 - 110

Takeoff / Climb

1050

3625

43.34

775

39000

104

1700

90 - 135

0 - 110

Max. Cruise

1050

3625

43.34

775

39000

104

1700

90 - 135

0 - 110

Min. Idle

750

21750

60 (min)

-40 - 110

Starting

1000

200 (max)

-40 (min)

Transient

850

39000

104

1870

40 - 200

0 - 110

Max. Reverse

900

760

1650

100 - 135

0 - 104

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.12

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS

PT6A-61

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

PSI

°C

Take-off/Max Cont.

850

2230

72.95

800

39000

104

2000

90 - 135

0 - 110

Max. Cruise

850

2230

72.95

800

39000

104

2000

90 - 135

10 - 104

Normal Cruise

850

2230

72.95

775

39000

104

2000

90 - 135

0 - 99

Max Climb

850

2230

72.95

775

39000

104

2000

90 - 135

0 - 104

Min. Idle

715

19000

60 (min)

-40 - 110

Starting

1000

200 (max)

-40 (min)

Transient

2750

89.73

850

39000

104

2250

40 - 200

0 - 110

Max. Reverse

800

760

90 - 135

0 - 99

PT6A-64

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

PSI

°C

Take-off

700

2230

72.95

800

39000

104

2000(90.7%)

100 - 135

0 - 110

Max. Continuous

700

2230

72.95

800

39000

104

2000

100 - 135

0 - 104

MaxClimb/Cruise

700

2230

72.95

785

39000

104

2000

100 - 135

10 - 104

Min. Idle

715

19000

60 (min)

-40 - 110

Starting

1000

200 (max)

-40 (min)

Transient

2750

89.96

870

39000

104

2205(100%)

40 - 200

-40 - 110

Max. Reverse

700

760

1900

100 - 135

0 - 104

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.13

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS

PT6A-65B

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

@ OAT

lb-ft

°C

RPM

PSI

°C

Take-off

1100

3625

43.34

820

39,000

104

1700

90 to 135

0 to 110

Maximum Continuous

1100

3625

43.34

810

39,000

104

1700

90 to 135

0 to 110

Maximum Climb

1000

3625

43.34

800

39,000

104

1700

90 to 135

0 to 110

Norm cruise

1000

3625

43.34

750

39,000

104

1700/100%

90 to 135

10 to 99

Min. Idle

700

21,750

60 minimum

-40 to 110

Starting

1000

200 max

-40 minimum

Transient

5100

870

39,000

104

1870/110%

40 to 200

0 to 110

Max. Reverse

900

760

1650/97%

90 to 135

0 to 99

PT6A-65AR

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

°C

RPM

PSI

°C

Take-off

1424

4400

52.61

855

39,000

104

1700/100%

90 to 135

10 to 110

Maximum Continuous

1220

3825

45.74

840

39,000

104

1700

90 to 135

10 to 110

Maximum Cruise/

956

3625

43.34

770

39,000

104

1700

90 to 135

10 to 105

climb

Min. Idle

715

21,000

60 minimum

-40 to 110

Starting

1000

200 max

-40 minimum

Transient

5100

61.00

870

39,000

104

1870/110%

40 to 200

-40 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 105

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.14

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS

PT6A-65AG

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

°C

RPM

PSI

°C

Take-off

1300

4017

48.03

810

39,000

104

1700/100%

90 to 135

0 to 110

Maximum Continuous

1220

3825

45.74

810

39,000

104

1700

90 to 135

0 to 110

Maximum Cruise/

956

3625

43.34

800

39,000

104

1700

90 to 135

0 to 110

climb

Min. Idle

750

21,000

60 minimum

-40 to 110

Starting

1000

200 max

-40 minimum

Transient

5100

60.98

870

39,000

104

1870/110%

40 to 200

-40 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 110

PT6A-66A

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

°C

RPM

PSI

°C

Take-off

850

2230

60.21(72.95)

830(800)

39,000

104

2000/90.7%

90 to 135

0 to 104

Maximum Continuous

850

2230

60.21(72.95)

830(800)

39,000

104

2000

90 to 135

0 to 104

Maximum Cruise/

850

2230

60.21(72.95)

820(785)

39,000

104

2000

90 to 135

0 to 104

climb

Min. Idle

750(759)

19,000

60 minimum

-40 to 110

Starting

1000

200 max

-40 minimum

Transient

2750

74.24(89.96)

870

39,000

104

2205/100%

40 to 200

0 to 110

Max. Reverse

800

760

1900/86.2%

90 to 135

0 to 104

PT6A-66D

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

°C

RPM

PSI

°C

Take-off

850

2230

72.95

850

39,000

104

2000

90.7

100 to 135

0 to 104

Maximum Continuous

850

2230

72.95

840

39,000

104

2000

90.7

100 to 135

0 to 104

Maximum Cruise/

850

2230

72.95

840

39,000

104

2000

90.7

100 to 135

0 to 104

climb

Min. Idle

750

19,000

60 minimum

-40 to 110

Starting

1000

200 max

-40 minimum

Transient

2750

90.0

870

39,000

104

2205

100

40 to 200

0 to 110

Max. Reverse

800

780

1900

86.2

100 to 135

0 to 104

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.15

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS

PT6A-67A

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

°C

RPM

PSI

°C

Take-off

1200

3708

44.34

850

39,000

104

1700/100%

90 to 135

10 to 110

Max Cont

1200

3708

44.34

840

39,000

104

1700

90 to 135

10 to 110

Max. Cruise / Climb

1000

3625

43.35

840

39,000

1700

90 to 135

10 to 105

Norm Cruise / Climb

1000

3625

43.35

820

39,000

1700

90 to 135

10 to 105

Min. Idle

750

19,000

60 minimum

-40 to 110

Starting

1000

200 max

-40 minimum

Transient

5100

60.98

870

39,000

104

1870/110%

40 to 200

0 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 105

PT6A-67AG

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

°C

RPM

PSI

°C

Take-off

1350

4170

49.87

800

39,000

104

1700/100%

90 to 135

10 to 110

Max Cont/ Cruise/

1220

3770

45.07

800

39,000

104

1700

90 to 135

10 to 110

climb

Min. Idle

750

19,000

60 minimum

-40 to 110

Starting

1000

200 max

-40 minimum

Transient

5100

60.98

870

39,000

104

1870/110%

40 to 200

0 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 105

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.16

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS

PT6A-67B

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

psig

°C

Take-off

1200

3708

44.34

800

39000

104

1700/100%

90 to 135

10 to 110

Maximum Continuous

1200

3708

44.34

800

39000

104

1700

90 to 135

10 to 110

Maximum Cruise/

1000

3090

36.95

760

39000

104

1700

90 to 135

10 to 110

climb

Min. Idle

750

19000

60 min.

-40 to 110

Starting

1000

200 max.

-40 min.

Transient

5100

61.00

870

39000

104

1870/110%

40 to 200

0 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 105

PT6A-67D

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

psig

°C

Take-off

1279

3950

47.23

800

39000

104

1700/100%

90 to 135

10 to 110

Maximum Continuous

1214

3750

44.84

780

39000

104

1700

90 to 135

10 to 110

Maximum Cruise/

1106

3750

44.84

760

39000

104

1700

90 to 135

10 to 110

climb

Min. Idle

750

19000

60 min.

-40 to 110

Starting

1000

200 max.

-40 min.

Transient

5100

61.00

870

39000

104-

1870/110%

40 to 200

-40 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 105

PT6A-67F

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

psig

°C

Take-off

1600

4943

60.25

870

39000

104

1700/100%

90 to 135

10 to 110

Maximum Continuous

1600

4943

60.25

870

39000

104

1700/100%

90 to 135

10 to 110

Maximum Climb/

1550

4789

58.37

815

39000

104

1700/100%

90 to 135

10 to 110

Cruise

1350

4634

56.48

795

Min. Idle

750

19000

50.7

60 min.

-40 to 110

Starting

1000

200 max.

-40 min.

Transient

6092

74.25

910

39000

104-

1870/110%

40 to 200

-40 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 105

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.17

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OPERATING LIMITS

PT6A-67P

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

psig

°C

Take-off

1200

3708

44.34

850

39000

104

1700/100%

90 to 135

10 to 110

Maximum Continuous

1200

3708

44.34

840

39000

104

1700/100%

90 to 135

10 to 105

Maximum Climb/

1200

3708

44.34

820

39000

104

1700/100%

90 to 135

10 to 105

Cruise

1000

3090

36.95

820

Min. Idle

750

19000

60 min.

-40 to 110

Starting

1000

200 max.

-40 min.

Transient

5100

61.00

870

39000

104-

1870/110%

40 to 200

-40 to 110

Max. Reverse

900

760

1650/97%

90 to 135

10 to 105

PT6A-67R & T

Power Setting

SHP

Torque

Max ITT

Oil Pressure

Oil Temp.

lb-ft

psig

°C

RPM

psig

°C

Take-off

1424

4400

52.61

855

39000

104

1700/100%

90 to 135

10 to 110

Alt. take-off (R only)

1281

3960

47.35

825

39000

104

1700

90 to 135

10 to 110

Maximum Continuous

1220

3825

45.74

840

39000

104

1700

90 to 135

10 to 110

Maximum Cruise/

1020

3760

44.96

790

39000

104

1425

90 to 135

10 to 105

climb

Min. Idle

755

21000

60 min

-40 to 110

Starting

1000

200 Max

-40 min.

Transient

5100

61.00

870

39000

104

1870/110%

40 to 200

0 to 110

Max. Reverse

900

760

1650

90 to 135

10 to 105

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.18

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

ROTOR COMPONENTS - SERVICE LIFE

Description:

Flight Count Factor:

Certain rotating components are subject to low-cycle

This is an index of severity. An indication of how much a

fatigue due to cyclic operation of the engine. Additionally,

component is affected during the engine operation. This is

other factors such as high frequency fatigue and metallurgi-

a multiplier and will change for a given component if

cal changes related to time rather than flight cycles are con-

installed in a different engine.

sidered. As a result, these parts must be removed from

service when the cycle limit is reached.

If your missions include more flights than starts, component

cycle life may be calculated in accordance with the following

Reference:

formula:

- SB 13002 for PT6A-52/60/61/65

- SB 13202 for PT6A-65AG

Total Cycles =

- SB 14002 for PT6A-64,66,67, 67B/D/P

[Starts + ( Flights-Starts

) ] x Flight Count Factor

Abb. Cycle Factor

- SB 14302 for PT6A-67AF

- SB 14502 for PT6A-67AG/67F

Operators having missions, which include many touch-and-

go flights or a frequency of scheduled in-flight shutdowns

(such as used during pilot training) or which include more

Airworthiness Regulations Require The Operator To:

than 10 flights per hour must submit their mission profiles to

- Log engine hours, starts and aircraft flights

Pratt and Whitney Canada for life cycle analysis.

- Calculate and record these hours and cycles

Definition Of A Cycle:

A flight preceded by a start and followed by a shutdown.

Abbreviated Cycle:

A flight, from wheels up to wheels down, but without a start

or shutdown.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.19

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

ENGINE TROUBLESHOOTING

Effective engine troubleshooting infers monitoring engine

Troubleshooting of problems related to internal engine com-

parameters on a regular basis, using performance check

ponents is generally divided in 2 areas:

and engine condition trend monitoring.

- Compressor section

- Hot section.

Effective troubleshooting can be divided into four steps:

The compressor section refers to all the components of the

1. Evaluate the symptoms

main gas path. This starts from the aircraft inlet and

2. Logically isolate the possible cause of the problem

includes the gas generator where P3 air fills the cavity

3. Try quick fixes when possible.

around the combustion chamber liner.

4. Determine the corrective action required to solve the

problem

The hot section is composed of all the components starting

from the combustion chamber liner down to the exhaust

Remember that troubleshooting is done by comparing

duct including all the vane rings and the turbines.

engine parameters with a set of reference values for a good

engine or by looking at the trend of the parameters of one

engine over a period of time.

Propeller speed and torque are the indication of power pro-

duced by an engine. Any serious troubleshooting should

begin with the calibration of the instruments used in the pro-

cess.

Note:

Chapters 10 and 11 cover troubleshooting of fuel and pro-

peller systems.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.22

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERFORMANCE TROUBLESHOOTING

Introduction:

Systematic Approach:

- The following information is a guide only.

- Preferred approach

- Refer to the appropriate aircraft or engine mainte-

- Gathering of all applicable information

nance manual as necessary.

- Analysis of engine symptoms

- Determination of most probable cause

- Corrective actions

Troubleshooting:

- Confirm results

- Technique used to logically isolate the cause of an

engine problem .

This method requires a good knowledge of normal and

- Determine the corrective maintenance action(s).

abnormal engine operation, systems operation as well as

- Resolve the problem in a timely manner.

the ability to use technical manuals efficiently.

The systematic approach increases the chances that you

Shotgun Approach:

are looking in the correct area for the problem, so that pre-

- Based on a "Trial and Error" method.

cious man-hours and material are not wasted on tasks that

- Used by personnel with minimal knowledge of engine

provide no resolution to the problem.

operation and troubleshooting techniques.

- This time consuming method is not cost effective and

indicates that some form of training is required.

By The Book Approach:

Effective but time consuming method used by maintenance

technicians who follow all necessary troubleshooting proce-

dures from technical manuals. This method requires some

knowledge of engine construction and operation.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.23

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERFORMANCE TROUBLESHOOTING (CONT’D)

The Basics:

tance limits on compressor FOD. The extended limits are

- Understand the problem

approximately double the previous ones but are acceptable

- Simultaneous review of ECTM* and recent past history

providing that engine performance remains acceptable.

- Pilot reports, and maintenance logs

Therefore, if the FOD is towards the high side of the

A review of the ECTM plots for the past three to six months

extended limits, heavy erosion is visible or the engine is

in conjunction with a review of the past thirty days of pilot

having performance difficulties then it is likely the compres-

write-ups and maintenance actions are the two most useful

sor has reached the refurbishment point. Further attempts

tools to be employed in defining the problem and setting a

to repair the engine on-wing would be futile.

plan for corrective action. It is recommended these records

be available on-site where the aircraft maintenance is being

Compressor Wash:

performed and not in a locked office a few hundred miles

- How long since last wash

away where the individual has gone home for the night. If

- Does ECTM show extended gradual shift right of all

this is not the case, then the maintenance crew should have

parameters

some way of accessing the information.

- Experience has shown 15 to 20 °C recovery when

washed

ECTM has the ability to tell you if the problem is in the cold

- A wash may be all you need

section or hot section of the engine. A step shift of only one

parameter is a likely instrumentation problem.

If it has been some time since the last wash and the com-

pressor looks dirty, it is recommended a ground perfor-

Pilot write-ups and maintenance logs can offer very valid

mance run be carried out, followed by engine wash, and

clues; for example if the pilot report has been repeated sev-

then finally by another ground performance run. A compar-

eral times dated back to seven days previous. One could

ison of the pre and post wash run data will indicate how

go back and review the maintenance actions carried out just

dirty the engine was and if any further troubleshooting is

prior to the first pilot report to see if the problem was intro-

required. We have seen reported "major performance loss"

duced by the maintenance action.

being rectified by nothing more than two successive engine

washes.

Compressor Health:

* Inspection for FOD and erosion

Note:

* Increased manual limits

ECTM = Engine Condition Trend Monitoring

* Compressor may have reached refurbishment point

One of the first areas that one should look at on the engine

is the compressor intake. PWC has extended the accep-

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.24

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERFORMANCE TROUBLESHOOTING (CONT’D)

Instrument Calibration:

From the previous example, the importance of instrument

- How long since last calibration.

calibration can not be overemphasized.

- Accurate calibrations are worth the effort.

- OAT, PA, and IAS are used in normalization process

and thereby affect ECTM accuracy .

Intake Deviations:

- Erroneous OAT, PA, and TQ affects targets for the day.

- Actual running data has shown up to 35° C ITT differ-

- If ECTM data shows a step jump in ITT only, one

ential between separator deployment and retraction

should suspect an instrumentation problem in the ITT

- Ice vane drop/out of adjustment will also cause perfor-

system.

mance deterioration and parameter fluctuation

- Similarly if all parameters are high, a torque indication

problem is likely.

Eliminate Cabin Bleed Leaks:

Remember ECTM plots are produced by normalization pro-

- Ground run with cabin bleeds blanked at engine flange

cess of certain inputs and then comparing the normalized

- Compare blanked and un-blanked run data

data with actual recorded. Outside air temperature, pres-

- Leaking P3 pre-coolers and defective temp control

sure altitude, prop speed, and airspeed are inputs to the

valves have caused up to 60°C rises in ITT

normalization formula. If these parameters are out of cali-

bration, the ECTM plots will be unreliable as a trouble-

shooting tool.

Carry out a ground performance run with the cabin bleed

systems in the normal off position. Follow this with a

Outside air temperature and pressure altitude are used to

ground performance run with the bleeds blanked at the

determine target torque for the day in doing ground perfor-

engine flange. It is important to blank the system at the

mance runs. Errors in these instruments will lead to selec-

engine flange rather than at some other convenient loca-

tion of the wrong target torque for the day. If the torque

tion.

transducer calibration is low, the actual engine torque will

be higher than what is indicated. This is perceived as the

engine being temperature limited, as well, fuel flow and gas

generator speed will be higher than normal.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.25

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERFORMANCE TROUBLESHOOTING (CONT’D)

Eliminate Cabin Bleed Leaks (Cont'd):

Trim Determination:

- Trim on/off runs to determine if trim compensation is

Compare the results of the two runs. If the parameters of

correct.

the run with the bleeds blanked appear lower, you have a

- Not a "dial as required system"

leak or component malfunction in the bleed system that

- Do not readjust existing trim probes.

requires rectification.

At the same time as the bleeds blanked run is done, it is

Do two ground runs at take-off power, one with the trim

also a convenient opportunity to do a bleed valve closing

compensator connected and one with it disconnected and

point check and a T5 trim determination check.

compare the results. It is recommended to use a precision

tester (i.e. Barfield) to monitor ITT during these runs rather

Bleed Valve Closing:

than the cockpit gauge. The delta in ITT between these two

- Is the BOV closure point correct ?

runs should be within ±10% of engine data plate trim value.

- Late closing bleed valve results in high ITT.

- Sticking bleed valve results in intermittent power.

If the delta is greater than ±10%, the T5 trim compensator

- Regular scheduled BOV checks.

should be replaced. Previously installed or adjusted trim

- Closure point shifts with time.

compensators must not be readjusted.

- Some engines have classified CT baffle.

- Controls BOV closing pressure air.

- Facilitates seat adjustment.

- Mixing pre and post SB hardware results in BOV clos-

ing problems.

Some engine models have a classified baffle bolted to the

number two bearing cover. The size of the inner diameter

of this baffle controls the air to the bleed valve, therefore,

when working in this area pay particular attention not to

intermix pre and post SB hardware. Intermixing of hard-

ware results in BOV timing difficulties.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.26

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERFORMANCE TROUBLESHOOTING (CONT’D)

Borescope Inspection:

Engines are assembled; performance tested and trimmed

- Borescope engine to confirm hot section distress.

with a particular set of CT and first stage PT vane classes.

- Does what you see with the borescope agree with the

It is important to know what these classes were as a refer-

ECTM plots.

ence point for future on-wing maintenance.

- Do you want to run to extended borescope limits.

When it becomes necessary to replace a CT or Power Tur-

If the ECTM plots show typical hot section deterioration (ris-

bine (PT) vane on-wing, one must go back to the last test

ing ITT and decreasing NG) you should see distress of the

cell performance run vane class matching as a reference for

Compressor Turbine (CT) vane and/or CT blades when you

replacement, not necessarily the class that was removed.

borescope the hot section.

PWC recognize that it is not always possible to obtain the

Some maintenance manuals have the extended inspection

exact same class vane as required on short notice. To

limits incorporated (72-00-00). A number of factors must be

allow some flexibility, PWC recommends that one stays

taken into consideration when opting to run to the extended

within ±0.03 of a class on CT and ±0.1 of a class on PT of

limits. The two factors are whether there is a large ITT delta

those installed at last test cell run.

upshift in the ECTM plots and how long the engine has

been operating this way. If the borescope inspection

Maintaining a small spreadsheet for your complete fleet is a

reveals a burned through vane airfoil one must carefully

useful tool and worth the effort. The spreadsheet should

assess the decision to continue in service. As this condition

contain engine serial number with what class vanes were

excites the CT blade that can lead to blade cracking and

installed at last test cell run and what classes are currently

possible failure.

installed. It can give ready picture of what engines may not

be ideally matched. It can also speed up the process in hot

Engine Matching:

section planning.

- Has engine performance been questionable since last

HSI.

- What classes of CT and PT vanes were installed at

last test cell run.

- What vane classes are installed now.

- Use same class within ± .03 CT and ± .1 PT

- Keep a log of important engine data, BOV seat, CT

baffle, vane class etc.

PT6A-60 SERIES

TRAINING USE ONLY

PERFORMANCE 9.27

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

POWER MANAGEMENT

- 3 lever control system

Propeller Lever:

- 2 levers on PT6A-66 and A-67B/P

- Connected to the propeller speed control lever on the

top of the propeller governor (CSU).

Power Lever:

- Controls the propeller speed in the governing mode.

- Controls the compressor speed in forward as well as

- Allows feathering of the propeller.

reverse thrust mode.

- Controls the propeller pitch in reverse.

Manual Override (Power Lever):

- Connects to a cam cluster located on the accessory

- Single engine aircraft only.

gearbox.

- Controls Ng directly in the event of a loss of P3 air

- Cam cluster transmits power lever movement to the

pressure at the FCU.

fuel control unit.

- Controls fuel flow from minimum to maximum flow

- The FCU controls Ng.

stops.

- Used in forward mode only.

Below idle, movement of the power lever affects both Ng

and the beta valve to change the propeller blade angle from

Note:

positive pitch to reverse pitch as power is gradually

Engines operated with two levers have a ‘single speed’ pro-

increased in reverse.

peller governor. (Pilatus PC-XII aircraft PT6A-67B/P).

Fuel Lever (Condition Lever):

- Cut-off position stops fuel flow to the combustion

chamber and causes the engine to shut down

- Allows to set Ng from low idle to high idle

- Low idle is the minimum Ng allowed

- High idle is the minimum power used in flight

When the correct Ng is reached, the low idle position is

selected to allow fuel into the combustion chamber.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.2

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL SYSTEM

Function:

Alternate/Emergency Fuels:

Provides the engine with clean fuel at the required pressure

Minimize use of AVGAS. AVGAS may contribute to acceler-

and flow to permit control of engine power.

ate hot section deteriorations. Run AVGAS a maximum of

150 hrs between overhauls.

Components:

- Fuel heater

Operating time on AVGAS is computed on the basis of

- Fuel pump

quantity used versus average engine consumption. The

- Fuel control unit

operation of P&WC commercial engines, covered by this

- Flow divider

training manual, on fuel other than the approved jet fuels is

- Fuel nozzles (14)

not permitted without the express permission of P&WC.

- Fuel drain valves (2)

Fuel And Additives:

- SB 13044 for A-52/60/61/65.

- SB 13244 for A-65AG.

- SB 14004 for A-64/66/67.

- SB 14504 for A67AG/F

- SB’s indicated above list minimum requirements for

acceptable engine fuel.

- Additives such as;

anti-corrosion.

anti-icing.

thermal stability additives.

Anti-microbial

- Use of Aviation Gasoline (AVGAS) is limited to 150

hours per engine between overhaul periods (TBO).

- Diesel fuel is permitted for agricultural use only.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.4

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL SYSTEM

Description:

Fuel from the aircraft tank is sent to the fuel heater via one

or more airframe boost pumps. From the fuel heater, fuel is

directed to the fuel pump. The fuel pump sends the fuel to

the fuel control unit (FCU) which determines the quantity of

fuel required by the engine to produce the power requested

through the power lever and according to the ambient con-

ditions.

The excess fuel is returned to the inlet of the fuel pump and

the fuel flow going to the engine goes through the fuel flow

meter to indicate the fuel consumption in the cockpit. Then,

the fuel reaches the flow divider where it is directed to the

primary and secondary fuel manifolds to supply all the noz-

zles. The fuel nozzles atomize the fuel in the combustion

chamber to sustain the combustion.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.6

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL HEATER

Function:

Maintenance:

- Heat the fuel to prevent ice crystal formation

- Replace unit if defective.

- Heat the FCU housing to prevent condensation from

- Repair the coating on fuel heater as per engine Main-

freezing in the bellows assembly

tenance Manual.

- Preheat the fuel for FCU calibration

Troubleshooting:

Description:

- Verify operation by touching the fuel filter bowl after

- Housing

shutdown. Should be warm but not hot (≈27°C / 80°F).

- Fuel passages

- A template temperarure recorder can be used to deter-

- Scavenge oil passages

mine if thermal element is good (refer to the Mainte-

- Thermal element sensing fuel temperature

nance Manual).

- Internal damage may cause oil to mix with fuel and

result in high oil consumption when engine is running.

Operation:

- Internal damage may also cause fuel to mix with the oil

in static conditions.

Cold fuel from the aircraft boost pump enters the fuel heater

and surrounds the thermal element. The cold thermal ele-

ment contracts and allows scavenge oil from the accessory

Symptom

Cause

Effect

gearbox to travel across the heat exchanger. Heat from the

oil transfers to the fuel raising it's temperature.

Fuel Too Hot

Thermal element or

Fuel pump

control valve

cavitation

At 21°C the thermal element begins to expand and moves

Fuel Too Cold

Thermal element or

Possible filter

the valve to the right. In this position, scavenge oil from the

control valve

blockage (ice)

accessory gearbox progressively bypasses the fuel heater

and the fuel temperature begins to stabilize. The spring

High Oil Con-

Heat exchanger

Oil leak in the

located at the back of the valve pushes it back to the left

sumption

internal leakage

fuel

(heating position) when the fuel temperature drops. During

operation, the thermal element constantly reacts to adjust

fuel outlet temperature.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.8

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL PUMP

Function:

Outlet Filter Bypass Valve:

- Bypass fuel if filter gets restricted

Provide clean fuel under pressure to the fuel control unit.

- Set to open at 15-25 psid

Description:

- Single stage

Bypass Pressure Regulating Valve:

- Gear type pump

- Maintains bypass pressure above a minimum to mini-

- Brass bushings loaded against pump gears

mize fuel leakage at the brass bushing

- Carbon seals prevent fuel leak

- Set to open at 10 - 35 psid

- Inlet and outlet fuel filters

Operation:

Pump Capacity (Typical):

From the fuel heater, fuel enters the fuel pump housing and

passes through the inlet filter, then through the pump. Fuel

is filtered a second time through the outlet filter before being

Pressure

delivered to the fuel control unit. Two carbon face seals

pph

psi

prevent fuel from leaking out of the pump. A bypass pres-

13 %

200

175

sure regulating valve is mounted on the FCU bypass return

line to ensure a minimum amount of pressure is maintained

100 %

1600

800

on the brass bushings to reduce fuel leakage when pump

Typical engine Wf at 1000 SHP ≈ 500 pph

pressure increases.

Inlet Filter:

Maintenance:

- 74 micron screen.

- Inspect inlet and outlet filters at specified intervals.

- Cleanable (600hrs)

- Inspect for reddish-brown stain in drain port of fuel

- Bypass feature

pump (Sundstrand pumps only).

- Bypass at 1.5 psid

- Replace fuel pump if the engine is operated without

airframe boost pressure for more than 10 hours.

Outlet Filter:

- 10 micron non-metallic type filter

- Disposable (600hrs)

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.10

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL CONTROL UNIT (MAIN FLOW)

Function:

Minimum Flow:

- Provides minimum fuel to start engine and prevents

Deliver the required amount of fuel at the required pressure

flame out during rapid deceleration

to the fuel nozzles.

- Factory set at ≈90 pph

Pressure Relief Valve:

Pump Unloading Valve:

- Prevents system over pressurization

- Pilot operated to start or shutdown the engine

- Dumps excess fuel to the bypass

- Opens when pilot shuts down the engine

- Factory set to open at 1350 psid

- Dumps P2 fuel to P0

- P2 becomes equal to P0

- Shutdown valve closes

Bypass Valve:

- Factory set

- Maintains delta pressure P1-P2 constant at 53 psid

- Bypass fuel in excess of engine requirement

- Fuel pump delivers more fuel than required

Minimum Pressurizing And Shutdown Valve:

- Bypass fuel returns to the pump

- Allows the fuel control to pressurize before providing

- Factory adjusted to limit engine acceleration rate

fuel to the engine

- Improves fuel metering on start

During acceleration, more fuel is required in the P2 line. To

- Works in conjunction with the pump unloading valve

supply the need, less fuel is dumped to Po by the bypass

for engine shut down

valve. During deceleration, the opposite applies.

- Opens at 100 psid

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.12

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL CONTROL UNIT (METERING)

Function:

Fuel Valve And Bellows Section:

Determines fuel flow to the engine in response to the follow-

The Fuel Valve rotates and moves up and down to deter-

ing inputs:

mine the amount of fuel going to the engine by varying the

- Power Lever Position (PLA)

opening between the inner rotating valve and the static

- Compressor discharge pressure (P3)

outer valve.

- Compressor speed (Ng)

Cockpit movement of the PLA causes the 3D cam to rotate.

Rotation of the 3D cam makes the Cam Follower move

3D Cam And Follower:

which in turn rotates the Fuel Valve (Initial accel or decel).

Rotates around it's centerline and up and down in response

Up and down movement of the Fuel Valve depends on the

to power lever movement and compressor speed (Ng). The

bellows position (P3 air pressure).

3D cam is rotated by moving the power lever in the cockpit.

The face of the cam is shaped to move the cam follower and

- More Wf

rotate the fuel valve, thus changing fuel flow and Ng.

Increasing P3 moves the Valve Seat down, allowing Pz

pressure to diminish, resulting in a downward movement of

The 3D cam also senses Ng speed via a flyweight governor.

the Fuel Valve.

Variation of Ng speed causes the Po orifice to open or close

causing the 3D cam to translate up or down. The cam fol-

- Less Wf

lower and fuel valve move in response to the 3D cam there-

Decreasing P3 moves the Valve Seat up, allowing Pz pres-

fore changing fuel flow and Ng.

sure to increase, resulting in an upward movement of the

Fuel Valve.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.14

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

COMPRESSOR DELEVERY AIR LINES

Function:

To provide clean P3 air to the FCU.

Description:

Compressor discharge air (P3), derived from the diffuser

section of the gas generator case, is routed to the metering

section of the FCU through external lines and a fine-screen

filter. The system consists of two tube assemblies, one on

each side of the air filter housing.

Maintenance:

Replace P3 filter

- SB’s 13175 and 14054 introduce a P3 air pressure

sensitive drain valve to the air filter housing. During

compressor wash, P3 air pressure is low, and the

valve is spring-loaded open to allow cleaning fluid to

drain. As engine speed builds, P3 air pressure

increases and closes the valve.

Note:

The filter element is normally a permanent (stainless steel)

type and is intended to be cleaned ultrasonically at an

approved overhaul facility. However, the filter may be

cleaned (washed) electronically at field level.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.18

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FLOW DIVIDER WITH DUMP VALVE

Function:

Operation:

Provides a means to separate the starting flow (primary)

When the condition lever is moved to the "fuel on" position,

from the normal engine running flow (Pri & Sec). Allows the

fuel enters the flow divider and pushes against the primary

fuel flow to be ported to a collector can during the shutdown

and secondary valve and spring. At a fuel pressure of 9 -

(dump) sequence.

13 psi, the primary valve moves to the right and allows fuel

to flow to the primary manifold only.

Description:

As Ng speed increases, fuel pressure increases (17-22

- Two concentric valves spring loaded to the closed

psid) in the flow divider and the secondary valve moves to

position

the right. At this point, Ng is at approximately 35% and fuel

- Fuel pressure operated

flows through all the nozzles.

When the fuel lever is moved to the "cut-off" position, the

Primary Flow:

fuel pressure drops rapidly and the two springs push the

primary and the secondary valves toward the closed posi-

Allows fuel to flow through primary manifold for starting. Pri-

tion. This allows the fuel to drain by gravity into a collector

mary valve opens at fuel pressure of 9 - 13 psi

can, preventing contamination (carbon deposits) of fuel

nozzles due to fuel residue.

Secondary Flow:

Maintenance:

Combined with the Primary flow, allows enough fuel flow to

- No maintenance at field level

operate the engine. Secondary valve opens at fuel pressure

- Visually inspect for cracks and leaks

of 17 - 22 psid.

Dump Position:

Allows fuel to dump into a collector can. Springs move the

Primary and Secondary valves to the cut-off position, port-

ing both manifolds to dump.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.20

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FLOW DIVIDER WITH PURGE VALVE

(SB 13074, 14065)

Operation:

Function:

When the fuel lever is moved to the "fuel on" position, fuel

enters the flow divider and pushes against the primary and

Provides a means to separate the starting flow (primary)

secondary valves.

from the normal engine running flow (Pri & Sec). Allows the

fuel flow to be purged (blown) back to the Combustion

At a pressure of 9 - 13 psi, the primary valve moves to the

Chamber to be burnt during the shutdown sequence.

right and allows fuel to flow in the primary manifold at a

pressure providing optimum fuel atomization.

Description:

- Two concentric valves spring loaded to the closed

As Ng speed increases, fuel pressure goes up and at 17 -

position

22 psid, the secondary valve moves to the right. At this

- A P3 purge check valve separates the fuel side from

point, Ng is spooling through 35% and fuel flows through all

the air side

the nozzles.

- Fuel/Air pressure operated

When the fuel lever is moved to the cut-off position, fuel

Primary Flow:

pressure drops and the two springs push the primary and

Allows fuel to flow through primary manifold for starting. Pri-

secondary valves into the purge position. P3 air, accumu-

mary valve opens at fuel pressure of 9 - 13 psi, and forces

lated in a purge can, pushes the check valve open and

shut the P3 purge check valve.

blows the remaining fuel in the manifold and fuel nozzles in

the combustion chamber where it is burned. This may

Secondary Flow:

cause a small Ng and T5 spike during shutdown.

Combined with the Primary flow, allows enough fuel flow to

operate the engine. Secondary valve opens at fuel pressure

Maintenance:

of 17 - 22 psid.

- No maintenance at field level

- Visually inspect for cracks and leaks

Purge:

- Verify airframe check valves and purge canister.

- P3 air accumulator (airframe).

- Opens the check valve.

- Purges the fuel from transfer tubes and nozzles into

the Combustion Chamber.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.22

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

SIMPLEX FUEL NOZZLES (A52/60/61, A64, A65)

Function:

Maintenance:

- Clean or replace nozzles every 400 hours

Deliver and atomize metered fuel into the combustion

- New operator clean every 200 hours

chamber.

- Alternate cleaning method, in situ cleaning every 200

hours to extend intervals between removals

- Leak test if nozzles tips are removed

Construction:

- Check for erosion and fretting wear on nozzle sheaths

- 14 fuel nozzle adapters, 7 primary, 7 secondary

- Upgrades from Simplex to Duplex type nozzles:

- 14 sheaths

SB 13182…….A65’s

- 14 fuel nozzle tips

SB 14053…….A64

- 28 transfer tubes (manifolds)

SB 14067…….A66/67,A,R,AF

Warning:

Operation:

Badly Spraying Nozzles Will Reduce Hot Section Compo-

On start, fuel flows through the primary manifolds and the

nent Life

seven primary fuel nozzles. The position of the primary fuel

nozzles is such that fuel is sprayed circumferentially

towards the spark igniters in order to facilitate ignition.

An increase in Ng causes fuel pressure to increase and the

secondary fuel nozzles to spray fuel into the combustion

chamber.

During operation, all 14 fuel nozzles receive fuel from the

flow divider and deliver it to the combustion chamber.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.24

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

DUPLEX FUEL NOZZLES (A67B/D/F/P AND POST SB FOR OTHERS)

Function:

Maintenance:

- Clean or replace nozzles every 400 hours.

Deliver and atomize metered fuel into the combustion

- New operator should clean every 200 hours.

chamber.

- Alternate cleaning method, in situ cleaning every 200

hours to extend intervals between removals.

- Leak test if nozzles tips are removed.

Construction:

- Check for erosion and fretting wear on nozzle sheaths.

- 14 fuel nozzle adapters

- 14 fuel nozzle sheaths

Warning:

- 14 fuel nozzle tips

- 28 transfer tubes

Badly spraying nozzles will reduce Hot Section compo-

nent life

Operation:

On start, the flow divider sends fuel to the primary mani-

folds. The 14 fuel nozzles will deliver fuel to the combustion

chamber through the Primary passage.

As Ng increases, the fuel pressure increases. The second-

ary fuel nozzle passages will spray fuel into the combustion

chamber.

During operation, both Primary and Secondary passages of

the 14 fuel nozzles receive fuel from the flow divider and

deliver it to the combustion chamber.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.26

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL CONTROL UNIT MANUAL OVERRIDE

Function:

The P1 to Pz pressure differential will move the fuel valve

down to increase fuel flow.

Allows the pilot to manually control the FCU fuel valve in the

event of a pneumatic (P3, Py) system malfunction.

A return spring below the P2 valve ensures the valve fol-

lows the bellows movement during normal operation. In the

event of a pneumatic failure (P3 or Py), it is easier to com-

Installed on the following:

press the return spring than the bellows; so less force is

- A-60AG

required to move the MOR and the Pz valve.

- A-64

- A-65AG

SB 13196

- A66A, A66D

Caution:

- A-67B/P

- A-67AG

Move manual override lever slowly

Operation:

In the event of a P3/Py air loss or metering unit malfunction,

Maintenance:

the pilot can manually control the position of the fuel valve

- Operate manual override system regularly to confirm

by simulating the action of P3 air pressure. A special lever

proper operation and familiarize with engine response

is provided in the cockpit to that effect.

in this mode

Movement of the Manual Override Lever (MOL) will

increase spring pressure on the rate piston, forcing it to

move. The rate of movement is established by the orifice

which dampens any abrupt MOL movement. The rate pis-

ton movement is transmitted to the Manual Override Rod

(MOR) that runs through the center of the fuel valve. The

MOR forces the P2 valve down allowing Pz pressure to

bleed to Po.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.28

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

POWER RECOVERY SYSTEM (PT6-A65R/AR AND 67R ONLY)

Function:

On twin engine aircraft’s, provides manual or automatic

power increase on one engine in the event of a severe

power loss from the opposite engine.

Description:

A solenoid valve activated by a low torque reading on the

failed engine allows P3 air to push on a piston located at the

back of the FCU. The piston then rotates an eccentric shaft

changing the position of the cam follower on the 3D cam.

The movement of the follower on the cam is designed to

cause a rotation of the fuel valve and increases Ng by

approximately 4%. The system is used during take-off only.

A P3 bleed to atmosphere allows the servo piston to return

when power recovery is selected off (solenoid valve

closed).

Maintenance:

Check and adjust Ng increase as per Airframe Maintenance

Manual.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.30

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

OVERTORQUE LIMITER

Function:

A solenoid (deleted by SB 14185) valve is used on the A-

67B and A-67AF to disable the torque limiter when not

A back-up unit which prevents engine overtorques. The pilot

required. The solenoid valve closes when de-powered. It

is always responsible for operating the engine within limits.

controls the supply of Py to the torque limiter.

Description:

Maintenance:

- Adjust unit as per Airframe Maintenance Manual so

A oil bellows which senses torquemeter oil pressure and is

that the required torque value is not exceeded.

linked to a Py bleed orifice. Found on the following engines:

- Pressure check unit to ensure Py does not leak.

- A-64

- Replace unit if defective.

- A-66B/D

- A-67AF post SB 14056

- A-67B post SB 14154

- A-67T

Operation:

Oil from the torquemeter chamber passes through a restric-

tor before entering the bellows. The restrictor dampens

torque pressure fluctuation and prevents damage to the bel-

lows assembly. When torque pressure reaches a specified

limit above maximum permitted torque, the bellows

expands and compresses the spring.

The flapper valve then moves to allow Py air pressure from

the fuel control unit to bleed to the atmosphere and there-

fore limit the fuel supply to the engine.

Bimetallic disks are mounted on the spring to compensate

for variation of spring tension caused by change in ambient

temperature.

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.32

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL CONTROL UNIT ADJUSTMENT

Deadband

- Adjust deadband first, by deadband adjustment screw.

- Clockwise increases the deadband angle.

- Always verify low idle after a deadband adjustment.

Low Idle

- Always adjust before high idle setting

- Loosen FCU lever clamping screw

- To increase Ng, loosen top screw, tighten lower one

- To decrease Ng, loosen lower screw, tighten top screw

- When adjusting Ng, turn screw in increments of 1/6 of a turn at a time

High Idle

- High idle can be adjusted at two location on the FCU

- Adjust at cam follower adjustment screw if there is no stagger in the condition lever.

- Adjust High idle stop screw if the condition levers are staggered.

- Clockwise rotation increases Ng 1.5% per turn

Maximum Ng,

- Adjust as per Airframe Maintenance Manual

Reverse Ng,

Reserve Power

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.34

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

FUEL SYSTEM TROUBLESHOOTING SUMMARY

Observed Problem

Verification

Engine Does Not Start / Hot

- Ensure that minimum cranking speed is achievable

Starts

- Verify igniters for proper operation

- Check for evidence of fuel flow to the flow divider while motoring the engine

- Ensure primary and secondary fuel nozzles are in their respective position (N/A

for engines equipped with duplex nozzles)

- Replace flow divider

- Replace fuel nozzles

- Weak batteries

Engine Hangs Below Idle

- Ensure starting procedure is carried out properly

(Hung Start 30-35% Ng)

- Flow divider secondary valve not opening

Engine Is Slow To Accelerate To

- Ensure starting procedure is carried out properly

Idle

- Check for possible restriction in the P3 air line to the FCU

- Possible Py leaks

- Replace flow divider

- Replace FCU

Sub-Idle Condition (40-45% Ng)

- P3/Py line leaking or broken. P3 filter blocked

- Prop. Governor or Torque Limiter leaking Py.

- FCU bellows broken or leaking

White Smoke On Shut Down

- Verify for proper operation of flow divider and dump/ purge valve

From Exhaust Duct

- Replace FCU

Ng Coupling Failure

- Engine will go to 85% power

Fuel Leakage Between FCU And

- Remove FCU from pump and replace o-ring at fuel bypass port

Fuel Pump

- Replace FCU and pump if fuel leakage persists

PT6A-60 SERIES

TRAINING USE ONLY

FUEL SYSTEM 10.36

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER SYSTEM

Function:

Change the power produced by the engine into thrust in

order to propel the aircraft through the air.

Description:

- Three to six bladed propellers

- Made of Aluminium or Composite materials

- Variable pitch, single acting type

- Propeller governor (CSU) controls:

Propeller Speed in governing mode.

Blade Angle in Beta mode.

List Of Topics:

- Propeller system

- Pitch change mechanism

- Governing mode

- Beta mode

- Primary blade angle

- Reverse thrust

- Feathering

- Propeller overspeed governor

- Np governor

- Propeller governor adjustments

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.2

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PITCH CHANGE MECHANISM

Function:

When oil pressure is decreased, the return spring and

counter weights force the oil out of the servo piston and

Allow varying the propeller blade angle in order to maintain

change the blade pitch to a coarser position.

a constant Np through various ambient conditions and

power settings.

An increase in oil pressure drives the blades towards a finer

pitch.

Description:

- Hollow spider hub supports the blades

CSU Action

Propeller Reaction

Max Position

- Feathering spring attached to the servo piston (dome)

- Centrifugal counterweights on each blade working with

Oil In

Finer Pitch

Reverse

the feathering spring drive the propeller blade toward

(lower pitch)

feather

(faster prop RPM)

- Oil pressure from the propeller governor drives the

Oil Out

Coarser Pitch

Feather

propeller towards reverse position

(higher pitch)

(slower prop RPM)

Operation:

Oil from the propeller governor feeds into the propeller shaft

Maintenance:

and to the servo piston via the oil transfer sleeve mounted

- Refer to the Airframe Maintenance Manual.

on the propeller shaft.

As oil pressure increases, the servo piston is pushed for-

ward and the feather spring is compressed. Servo piston

movement is transmitted to the propeller blade collars via a

system of levers.

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.4

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER GOVERNOR GOVERNING MODE

Description:

Speeder Spring:

- Opposes a mechanical force to the centrifugal force of

Is the range of operation where engine power is sufficient to

the flyweights

maintain the selected propeller speed by varying the blade

- Determines the propeller speed at which the flyweights

angle (pitch).

will be "on speed."

- The pilot controls spring tension through the propeller

The System Is In The Governing Mode When:

lever (not on A-67B/P).

- Indicated propeller speed matches selected NP.

- increase in Ng speed do not affect Np.

Operation:

- Moving the propeller lever results in a change in Np

Oil is supplied to the governor. A gear pump, mounted at

the base of the governor, increases the flow of oil going to

Components:

the CSU relief valve. When the oil pressure reaches the

desired level, the relief valve opens to maintain the pres-

Pressure Relief Valve:

sure.

- Opens to bypass oil when maximum pressure is

When the speed selected by the pilot is reached, the fly-

reached (450 to 720 depending on the model)

weights force equals the spring tension of the speeder

spring. The governor flyweights are then on speed.

Pump Gears:

When the engine output power is increased, the power tur-

- Supply oil pressure to control the propeller pitch

bines tend to speed up. The flyweights in the CSU sense

this acceleration. The flyweights go into an overspeed con-

Governor Flyweights:

dition because of the increase centrifugal force and force

- Rotation of the flyweights generate a centrifugal force

the control valve to move up and restrict oil flow to the pro-

proportional to the propeller speed

peller dome. The feathering spring increases the propeller

- Flyweight force pushes against a spring to move the

pitch to maintain the selected speed. Reducing power

control valve up or down

causes an under-speed of the flyweights, downward move-

ment of the control valve, more oil in propeller dome, result-

Pilot Valve:

ing in a finer pitch to control propeller speed.

- Moves up and down under the influence of the fly-

The propeller governor houses an electro-magnetic coil,

weights

which is used to match the rpm of both propellers during

- Controls the oil pressure going to the propeller

cruise. An aircraft supplied synchro-phaser unit controls

this function.

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.6

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER GOVERNOR

BETA MODE (FORWARD OPERATION)

Power Lever:

Description:

On the ground, movement of the power lever below the idle

gate causes the reversing cam to actuate the beta valve,

The beta mode corresponds to a range of operation where

thus causing the blade angle to reduce

the blade angle is between PBA (Primary Blade Angle) and

reverse. The propeller pitch is a direct function of the beta

valve position (power lever)

Operation:

At low power, the propeller and governor flyweights do not

turn fast enough to compress the speeder spring. In this

Function:

condition, the control valve moves down and high pressure

- Prevents the blade angle from going below minimum in

oil pushes the dome forward, moving the blades towards a

flight

(Primary Blade Angle, PBA)

finer pitch.

- Allows the pilot to manually control the blade angle on

The propeller dome in it's forward movement contacts the

the ground for taxiing and reverse operation

beta nuts. Any further movement pulls the beta rod and the

slip ring forward. The forward motion of the slip ring is

transmitted to the beta valve via the beta lever and the car-

You Are In The Beta Mode When:

bon block. Forward movement of the beta valve stops the

- Indicated Np is below selected Np

oil supply to the propeller. This prevents the blade angles

- A change in Ng speed causes a Np change

from going any finer. This is called "Primary Blade Angle"

- Propeller lever movement does not change Np

(PBA) and it is the minimum blade angle allowed for flight

operation.

Beta Feedback System:

From this point the propeller is in the beta mode. If the

engine power is reduced when the propeller is at the pri-

In low pitch operation, the beta nuts, beta rods, slip ring,

mary blade angle, the propeller speed will decrease since

carbon block and the beta lever, which compose the beta

the blade angle does not change.

feedback system, actuate the beta valve

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.8

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER GOVERNOR (CONT’D)

Lockpitch Solenoid Valve:

Prevents the propeller from going into reverse or below the

primary blade angle in the event of a Beta system malfunc-

tion in flight. The solenoid is energized by a switch (air-

frame supplied) mechanically connected to the propeller

slip-ring linkage via a second carbon block.

Any movement of the slip ring towards reverse blade angle,

prior to the pilot selecting reverse, energizes the solenoid

and stops the oil flow from the governor pump to the propel-

ler servo. This controls the blade angle from going any

finer.

As oil pressure leaks off around the propeller shaft oil trans-

fer sleeve, the blade angle slowly drifts back toward coarse

pitch. This will de-activate the low pitch solenoid valve and

restore the oil supply to the propeller servo. The low pitch

solenoid valve will cycle (close/open) as back-up to the beta

valve function.

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.10

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER GOVERNOR

BETA MODE (REVERSE OPERATION)

As Np increases due to the increase in engine power, the

governor flyweights begin to move outwards. Since the

Function:

reset lever is closer to the speeder spring cup, the cup con-

tacts the reset lever before the flyweights would normally

Allows the pilot to control the propeller with a negative blade

reach the on-speed position (95% Np instead of 100%).

angle. (Reverse thrust).

When the reset lever is pushed up by the flyweights/

speeder spring cup, Py bleeds from the Fuel Control Unit

(FCU) which lowers the Wf, engine power and thus propel-

Operation:

ler speed.

Moving the power lever backwards causes the reversing

In reverse Np remains 5% below the selected propeller

cam and cable to move the beta valve backward, allowing

speed so that the control valve remains fully open and only

more oil to flow into the propeller dome, causing the blades

the beta valve controls the oil flow to the propeller dome.

to go towards reverse pitch.

In this mode, the propeller speed is no longer controlled by

As the blades move to reverse, the slip ring is pulled forward

changing the blade angle ( i.e.: servo pressure). It is now

by the dome (beta nuts) and moves the beta valve outward

controlled by limiting engine power (i.e.: Ng speed).

restricting the oil flow. This stops the blade movement

toward reverse. To obtain more reverse thrust, the power

lever must be moved back more to reset the beta valve

inward and repeat the process.

The reset arm on the CSU is moved rearward by the inter-

connecting rod at the same time as the blade angle is mov-

ing toward reverse. This causes the reset lever and reset

post to move down in the CSU. This brings the reset lever

closer to the speeder spring cup.

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.12

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER FEATHERING

Function:

Maintenance:

Minimise propeller drag by streamlining the blades in the

Check feathering operation as per Airframe Maintenance

event of an in-flight engine shutdown.

Manual instruction.

Adjustment:

Description:

Adj. Feather screw CW -> Increases the time to feather

Bringing the propeller lever to the feather position causes

Adj. Feather screw CCW->Decreases the time to feather

the speed selection lever on the CSU to push the feathering

valve plunger and allows propeller servo oil to dump into the

reduction gearbox sump.

The pressure loss in the propeller hub causes the feather-

ing spring and the propeller counterweights to feather the

propeller quickly.

Note:

The A-67B/P propeller governor has no provision for speed

control. Feathering is done through a feather solenoid

located on the propeller overspeed governor.

The A-64 propeller governor has no feathering valve.

Feathering is done through physically lifting the control

valve by rotating propeller speed actuating lever completely

CCW.

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.14

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

NF GOVERNOR (OVERSPEED PROTECTION)

Description:

The movement of the reset lever around its pivot point

opens the Py air passage. Py bleeds into the reduction

The CSU contains a Py bleed orifice closed by a ‘flapper’

gearbox limiting the fuel supply to the engine. This will pre-

valve and reset lever. The ‘flapper’ valve/reset lever can be

vent the propeller/power turbines from accelerating beyond

opened by the speeder spring cup when the flyweights

106%.

react to an increase in centrifugal force caused by an over-

speed of the propeller/power turbines.

Maintenance:

- Adjust speed limit in reverse using the underspeed

In Forward Propeller Operation:

eccentric screw (max rev screw).

- Over-speed limit adjustment in forward propeller oper-

Provides Np overspeed protection (6% above selected

ation is not permitted.

prop speed) by bleeding-off Py air pressure from the FCU

- Check for Py leakage which will cause a loss of perfor-

thus reducing the power of the engine.

mance.

In Reverse Propeller Operation:

Limits propeller speed to a value approximately 5% below

the selected Np by bleeding-off Py air pressure from the

FCU thus reducing the power of the engine.

Operation:

In the event of a propeller overspeed not controlled by the

propeller overspeed governor (oil governor), the flyweights

in the propeller governor will move outwards until the

speeder spring cup contacts the reset lever.

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.16

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER OVERSPEED GOVERNOR

(AIRFRAME OPTION)

increase in blade pitch puts more load on the engine and

slows down the propeller.

Function:

To test the unit, the speed reset solenoid is activated and

Provides back up protection against propeller and power

servo oil pressure pushes against the reset piston to cancel

turbine over speeds (4% over max prop speed).

the effect of the reset spring. With less spring tension act-

ing on the flyweights, the overspeed governor can be tested

at speeds lower than maximum.

Description:

- Airframe supplied except on A-67B/P

On twin installation, a second solenoid valve is mounted on

- Flyweight governor actuating a control valve

the overspeed governor and is used in conjunction with the

- One solenoid valve to reset the unit during ground

aircraft auto-feather system. The system is switched on for

tests

take off and in the event of an engine malfunction will ener-

- One solenoid to feather the propeller

gize the solenoid valve to dump propeller servo oil into the

reduction gearbox sump. The feathering spring and propel-

On the PT6A-67B, the overspeed governor feather solenoid

ler counter-weights move the blade quickly to feather.

is the only way to feather the propeller and the speed reset

solenoid is replaced with a mechanical reset lever mounted

on the governor.

Maintenance:

- Test the unit on a regular basis.

- With the reset solenoid energized, verify the speed at

Operation:

which the overspeed governor controls Np.

A67B/P: No solenoid, rotate mechanical reset

The governor houses a set of flyweight connected to a con-

lever to test

trol valve that is driven by a bevel gear mounted on the pro-

- Refer to the Airframe Maintenance Manual for adjust-

peller shaft. The flyweight's centrifugal force is acting

ment.

against two springs, a speeder spring and a reset spring.

When the propeller speed reaches a specified limit (4%

over maximum Np) the governor flyweights lift the control

valve and bleed off propeller servo oil into the reduction

gearbox sump, causing the blade angle to increase. An

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.18

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER GOVERNOR ADJUSTMENTS

Maximum

- Set propeller lever at maximum position in the cockpit

Forward

- Ensure that max Np stop is contacted

Propeller

- Adjust screw CCW to increase maximum Np, CW to decrease.

Speed (Np)

- One flat alter Np 2% (A-67R/AF/AG), 4% (A-67/67A)

Maximum

- Set propeller lever at maximum Np position

Reverse

- Disconnect reset arm from interconnect rod

Propeller

- Secure reset arm against rear stop

Speed

- Move power lever forward until propeller speed stabilises

- Check that propeller speed stabilises within specified limits

- Adjust underspeed eccentric screw if required

- In some cases the FCU may not be adjusted to provide enough reverse power, this

requires an initial check/adjustment of the FCU before adjusting the CSU

Feathering Operation

- Set power lever at ground idle

Check

- Move propeller lever to the feather position note feathering time, adj. as req.

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.22

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PRIMARY BLADE ANGLE (PBA) CHECK

Function:

Troubleshooting:

- Indicated torque lower than target = PBA too fine

Provide equal flight idle torques for appropriate aircraft han-

- Indicated torque higher than target = PBA too coarse

dling. On twin engine applications the aircraft may yaw if

PBA is not the same on both engines. On single engine air-

Adjust the beta valve position by adjusting the reversing

craft, approach handling characteristics are dependant on

cable clevis end

PBA.

- Move clevis end forward to increase torque

- Move clevis end rearward to decrease torque

Procedure:*

- Record OAT

Adjust beta nuts as per airframe manual to rectify

- Record field barometric pressure

- Move beta nuts rearward to increase torque

- Set propeller lever at maximum position

- Move beta nuts forward to decrease torque

- Increase power until target Np is reached

- Target Np speed is always less than maximum speed

Note:

to ensure the beta valve is actuated

Some airframe or propeller manufacturers do not

- Stabilise engine and record torque

allow adjusting the beta nuts . The only option left is to

- Compare indicated torque with torque given by chart in

adjust the beta valve inwards only . This will give a finer

Airframe Maintenance Manual

PBA on the higher indicating engine .

*(For reference only, refer to aircraft maintenance manual

for specific procedure)

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.24

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PROPELLER SYSTEM TROUBLESHOOTING

Observed Problem

Action Required

Np And Torque Fluctuations At High

Max Np setting may be too high (interference with OSG)

Power

Overspeed governor test solenoid leaking. (interferes with prop.Governor)

(No Ng Fluctuation)

Np And Torque Fluctuation At Low

Verify Beta ring is not distorted

Power

Inspect carbon block for excessive wear

(In Beta)

Check beta nut adjustment (not equal)

Propeller Slow To Unfeather

Carbon block worn out or beta valve rigged too far out

Low servo pressure from prop. governor

Np, Tq And Ng Fluctuation

Ensure reset arm is positively sitting against forward stop

(Power Fluctuation)

Verify Py line for leaks

Replace FCU if problem is still present

Propeller Rpm Too High (Governing)

Check propeller speed gauge for accuracy

Adjust maximum stop on governor

Replace prop. governor if adjustment is not effective

Propeller Rpm Too Low (Governing)

Insure max stop is contacted

Adjust maximum stop on governor

Ensure Ng is not limited by any P3 or Py leak.

Replace propeller governor

Check/Replace overspeed governor

Propeller Rpm Too Low

Check Nf governor minimum adjustment in reverse

(Reverse)

Adjust FCU maximum reverse Ng stop

Propeller Rpm Too High

Check that maximum forward propeller speed is OK

(Reverse)

Check proper rigging of the reset arm. May not be bleeding enough Py

Check Nf governor minimum adjustment in reverse

PT6A-60 SERIES

TRAINING USE ONLY

PROPELLER SYSTEM 11.26

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERIODIC INSPECTION

The following table is for reference only, refer to your Engine

Maintenance Manual.

FREQUENCY

COMPONENTS

Routine : coincides with daily or pre-flight airframe inspec-

25 hours

2^nd Power Turbine Blades

tion.

50 hours

2^nd Stage PT Blades

Minor : coincides with a typical airframe inspection.

100 hours

Engine Oil

Notes:

Oil Filter Element

1)The intervals at which these inspections are per-

formed may be altered by the aircraft manufacturer’s

AGB Drive

maintenance program and approved by the opera-

P3 Air Filter

tor’s local airworthiness authority.

2)Engines operating in sandy or dusty environments or

P3 Air Filter Drain Valve

in smog or salt-laden atmospheres should be sub-

Chip Detector

jected to additional inspections for corrosion and

compressor erosion.

125 hours

2^nd Power Turbine Blades

Minor

Control Linkage

FREQUENCY

COMPONENTS

Fuel Control Unit

Routine

Oil Level

Manual Override FCU

Oil Filler Cap

Fuel Pump

Fuel System

Fuel Pump Outlet Filter

Fuel & Oil Lines

Oil-to Fuel Heater

Scavenge Oil Pump Housing

P3 Air Filter

Propeller Oil Shaft Seal

P3 Air Filter Bowl

Accessories

Oil Filter Element

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.2

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

PERIODIC INSPECTION (CON’T)

FREQUENCY

COMPONENTS

FREQUENCY

COMPONENTS

Minor

Tubing, Wiring & Hoses

250 hours

2^nd Power Turbine Blades

(Oil/Fuel/P3/Py)

300 hours

Fuel Pump Inlet Screen

Ignition Exciter

Oil Filter

Ignition Cables

400 or 600 hours

Fuel Manifold Adapter &

Sparks Igniters

Nozzle Assemblies

Accessories

600 hours

Sundstrand Fuel Pump only

Air Inlet Screen

Fuel Pump Inlet Screen

Air Inlet Case

Fuel Pump Outlet Filter

Gas Generator Case

600 hours or 12 months

Chip Detector

Fireseal Mount Rings

1,000 hours

Oil Filter

Drain Valves

Agb Scavenge Pump Filter

Flow Divider

P3 Air Filter

Exhaust Duct

At component

Accessory Gearshaft Spline

Replacement / Removal

200 hours

2nd Power Turbine Blades

Fuel Manifold Adapter &

Nozzle Assemblies

200 hours or 6 months

AGB Scavenge Pump Filter

200 or 400 hours

Fuel Manifold Adapter &

Nozzle Assemblies

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.3

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION

Purpose:

HSI Frequency:

- As per relevant SB

To optimize engine performance, fuel economy, safety and

- On condition (as per ECTM result)

increase components life. The condition of the hot section

parts has a direct effect on engine performance. Deteriora-

Pre HSI Actions:

tion of the hot section can be detected by using engine con-

dition trend monitoring (ECTM) and / or by doing

1. Do a performance check. The result of the performance

performance checks (refer to chapter 9).

check will be compared with a post HSI check to monitor

performance recovery.

Deterioration of hot section components may include crack-

2. Remove and inspect oil filter, magnetic chip detector and

ing, burning, buckling, erosion, fretting wear and corrosion.

RGB strainer for metal contamination.

3. Remove air inlet screen and inspect first stage compres-

Hot section distresses is usually attributed to malfunctioning

sor blades for F.O.D.

fuel nozzles, hot starts, running the engine beyond accept-

able ITT limits, continuous operation at maximum power,

Return engine to an overhaul facility if #2 check is beyond

doing rapid accelerations, or abusing reverse thrust or FOD.

limits.

Engine Disassembly:

Goals Of The HSI Include:

- Remove power section

- Maintaining CT blade tip clearance close to a minimum

- Measure Compressor Turbine blade tip clearance

- Optimizing lug to slot fits on CT vane

- Remove Compressor Turbine assembly

- Minimizing P3 air leaks, internal or external

- Remove fuel nozzles

- Ensuring that replacement compressor turbine vane

- Remove spark igniters

ring and power turbine vane ring classes are kept the

- Remove combustion chamber liners

same as installed during the last test-cell run.

- Remove CT vane assemble

- Remove large exit duct

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.4

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

BORESCOPE INSPECTION

Description:

Procedure:

- Remove one fuel manifold adapter.

The borescope inspection allows operators to visually

- Insert the guide tube through the open port.

inspect hot section components without disassembling the

- Install the holding fixture to the engine "C" flange.

engine.

- Connect the borescope to the light source.

- Insert the borescope into the guide tube with care.

The following components can be inspected with a bores-

Note:

cope:

Keep in mind that you are looking 125 degrees away from

- Compressor turbine blades.

the point of entry of the tip as shown in the figure.

- Leading and trailing edges of compressor turbine vane

ring. Inner and outer walls of vane rings.

All compressor turbine blades can be inspected through

- All CT vanes can be inspected when fuel nozzles are

one fuel nozzle adapter port. Using the proper tool in the

removed for inspection.

starter drive can rotate the compressor. Ensure borescope

- Turbine shroud segments.

tip does not interfere with compressor turbine blades.

- Cooling rings and dome section of the combustion

chamber.

The guide tube is not required for the inspection of combus-

tion chamber liner.

Use the borescope with care since it is a very fragile device.

A 35-mm, digital or a video camera may be mounted on the

viewer to record inspection of hot section areas (adapters

required).

Engine must be cool prior to using the borescope. Cool

down engine for a minimum of 40 minutes.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.6

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION TOOLS

1. Power Section Sling (Without The Propeller Installed On

The Engine) (PWC34673).

2. Compressor Turbine Holding Wrench (PWC30331).

3. Spacers (4) (PWC34478).

4. Spreader (PWC30335).

5. Compressor Turbine Puller (PWC30403).

6. Protector Sleeve (PWC30336).

7. Puller No. 2 Bearing Cover (PWC32823).

8. Dial Indicator (PWC 32280).

9. Shroud Grinder Adapter (PWC 32209).

10. Fuel Nozzle (PWC32811).

11. Grinder (PWC37918).

12. Crimper (PWC30458).

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.8

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

CT TIP CLEARANCE MEASUREMENT

Procedure:

- Measure tip clearance using a tapered or a wire feeler

gage, loading the CT disk in the direction of the mea-

surement.

- The tip clearance limits for each individual model is

listed in the Engine Maintenance Manual.

- No need to rotate turbine while taking measurements.

Limits Shown In The Maintenance Manual:

- Average clearance for new segments.

- Average clearance for used segment (that ran at least

5 minutes at take off power).

Amount Of Readings Taken:

- Average all readings and compare with limits stated in

Engine Maintenance Manual.

- For 10 segment types, take 3 readings per segment. (3

readings x 10 segments = 30 readings).

- For 20 segment types, take 2 readings per segment. (2

readings X 20 segments = 40 readings)

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.10

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION (CONT’D)

Inspection

CT Vane:

- Inspect vane ring for evidence of burning, cracking and

Gas Generator Case:

coating loss.

- Inspect case for cracks, distortion, corrosion and evi-

- Insure proper sliding fit (lugs to slots) with mating

dence of overheating.

parts.

- Inspect engine mount threads.

- Check air-cooling holes for blockage.

- Inspect P3 air supply holes at CT vane flange for

- Change ‘C’ & ‘W’ seal rings.

blockage.

- Inspect diffuser pipes for cracks and fretting wear.

- Inspect shanknuts at CT vane flange for security.

Shroud Housing:

- Inspect shroud housing for cracks, blockage of cooling

air holes, fretting wear at sealing ring contact area

Combustion Chamber Liners:

- Visually inspect the liners for evidence of burning,

cracking, buckling or metal to metal fretting wear.

Shroud Segments:

- Regap cooling rings if they are distorted.

- Inspect shroud segments for cracks, burning distortion

- Stop drilling of cracks and welding may be required

and metal buildup

(refer M/M for limits).

- Tip clearance

Small Exit Duct:

Compressor Turbine:

- Inspect for evidence of burning, cracking, buckling,

- Inspect CT blades for: tip rub, cracks, sulphidation,

coating loss or metal to metal fretting wear.

erosion, burning and coating loss.

- Stop drilling of cracks may be required (refer M/M for

- Inspect CT disk for damage.

limits)

- Wash turbine blades based on past sulphidation expe-

rience.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.12

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION (CONT’D)

Inter-Stage Sealing Ring:

Sealing surface restoration

- Inspect sealing ring(s) for fretting wear on sealing

diameter and face.

Purpose:

- Fit ring on sealing diameter for full contact.

To achieve best sealing of P3 in the gas generator case

area and keep leakage to a minimum.

Power Turbine Vane:

- Inspect vane ring for evidence of burning, cracking and

coating loss.

Description:

- Ensure proper sliding fit (lugs to slots) with PT stator

There are 2 sealing surface contacts that must be checked

housing.

for proper seating:

- Damage to the power turbine vane ring is not common

unless bad fuel nozzles caused damage to CT area.

1. Lock-plate to vane ring inner diameter.

2. Vane ring outer diameter to small exit duct.

Power Turbines:

Gas tight contact between these surfaces, depends on sur-

face finish and flatness. Surface finish should be better than

- Inspect the 1^st and 2^nd stage power turbines for:

32 micro-inches and .0005" max waviness. Lapping can be

cracks, burning, coating loss, corrosion, and impact

used to eliminate minor surface imperfections. When lap-

damage and blade shift.

ping is impractical, the assemblies should be machined at

- Return the power section to an authorized overhaul

an approved overhaul facility.

facility if either turbine needs to be replaced.

Exhaust Case:

- Inspect the case for general condition.

- Check the case for cracks near the flanges.

- Inspect flange -D- area for cracks around PT shroud.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.14

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION (CONT’D)

Fitting Of Hot Section Parts

Step 2:

Purpose:

Install the shroud housing on a bench with the slots upper-

- To achieve best fitting of the hot section parts for mini-

most. Install the vane ring lugs inside the shroud housing

mizing side play which can result in CT tip rub.

lugs.

- To allow thermal expansion to take place, without any

binding.

Rotate the vane in the direction it would want to turn, as the

gases flow through it. Hold the shroud housing still. This

will force the lugs to contact the slots on one side and to

Description:

have a loose fit on the other side. Measure clearance on

both sides with a narrow feeler gage, ref. MM for limits.

There are 2 lug to slot fit areas that must be checked for

proper fit:

If clearance cannot be achieved, re-index the parts and

measure. If clearance can still not be obtained, remove

1. Vane ring inner lugs to #2 bearing cover slots.

material lightly with a stone until fit is achieved.

2. Vane ring outer lugs to shroud housing slots.

Step 1:

Install the vane ring on a bench with the inner lugs upper-

most. Install the #2 bearing cover slots around the vane

ring lugs.

Rotate the vane in the direction it would want to turn, as the

gas flow through it. Hold the #2 bearing cover still. This will

force the lugs to contact the slots on one side and to have a

loose fit on the other side. Measure clearance on both

sides with a narrow feeler gage, ref. MM for limits.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.15

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION (CONT’D)

Shroud Segment Grinding

Preparations:

- Mask vane ring, #2 bearing and gas generator area

To achieve optimum Compressor Turbine tip clearance all

carefully.

around the shroud.

- Install the 4 rubber spacers with equal tension

between the large and small exit ducts.

- Install the grinder adapter on compressor stub shaft.

Hot Section Kit:

- Install the radius gage on the adapter and calculate

the tip clearance.

Operators who are equipped with the proper tooling can do

their own grinding. The preferred method is to send the hot

section kit to an approved P&WC service center, which can

Calculating Amount Of Metal Removed By Grinding

achieve a superior surface finish and concentricity control.

The hot section kit consists of the following:

The shroud inside dimension (radius) is measured by

- CT vane assembly (vane ring, small exit duct, shroud

comparing reference master tool to the shroud dimension.

housing and segments.

- #2 bearing cover and / or flange.

The dimension stamped on the master tool is the radius

- Lockplate.

from the center of the gage to the step on the master tool.

- Compressor turbine assembly.

Set gage dial to zero when it is on the master.

Grinding can be minimized by carefully selecting classes to

compensate for ovality or eccentricity of the shroud hous-

ing. The best fitting class segments is picked after measur-

ing the CT outside diameter and referring to a table from the

Engine Maintenance Manual. It is recommended to go 1-

class higher (thicker segments) to offset any excessive

ovality from the shroud housing.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.16

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION (CONT’D)

Calculate Actual Tip Clearance Before Grinding As Fol-

lows:

(the numbers used are for examples only)

- Dimension stamped on side of

- gauge (master).= 4.282"

- Dial gage reading.= -0.009"

(plus or minus sign is important)

- CT largest diameter / 2 (8.532 / 2).= 4.266"

Step 1 = Find the radius of the shroud:

(master + dial reading => 4.282" -.009")= 4.273"

Step 2 = Find actual CT tip clearance:

(shroud radius - disk radius => 4.273" - 4.266")

= 0.007"

Step 3 = Determine material to be removed, assuming

required tip clearance is .010".

(actual clearance - required clearance :

.007" - .010")

= -.003"

We need to grind .003" off the segments.

Note:

Refer to Maintenance Manual for proper grinding proce-

dure.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.17

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION (CONT’D)

Fuel Nozzle Functional Check:

Pressure Test:

Pressure test for leakage between nozzle tip and adapter at

Ensures the engine combustion chamber receives properly

500 PSIG fluid pressure or 200 PSIG air pressure, no leak-

atomized fuel.

age allowed.

Inspection Interval:

Fuel Nozzle Cleaning:

- 200 hours for new operators.

- When spraying, brush tip with a non-metallic brush to

- 400 hours max interval afterwards, depending of con-

loosen any possible carbon debris.

dition.

- If above method is not effective, ultrasonically clean

nozzles in carbon remover solvent.

- Always rinse nozzles in hot water after cleaning, since

Spray Pattern Check:

carbon solvent is corrosive.

- Flow test for spray pattern at 20 PSI. Check for drool-

ing and spitting (none permitted).

- There may be an onion or tulip shaped spray pattern.

Fuel Nozzle Sheaths:

- Flow test for spray pattern at 60 PSI. Check for spray

- Inspect sheaths for erosion on the dome top.

pattern streakiness, drooling or spitting.

- Inspect sheaths for wear at combustion chamber con-

- 20% max streakiness is allowed

tact area.

- Check gap between sheath and adapter flange.

- Check concentricity between sheath and adapter ori-

Note 1:

fice with a .020" drill.

All values are for reference only. Always refer to the appro-

priate Maintenance Manual for proper settings.

Note 2:

If a streaking nozzle is found during testing, a visual HSI or

borescope inspection of the hot section should be done.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.18

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

HOT SECTION INSPECTION (CONT’D)

T5 System Functional Check:

Heat Response Test: (T5 Probe Functional Check)

T5 system inspection should be performed during hot sec-

This check is done to verify proper functioning of T5 probes.

tion inspection with the engine split at flange "C" or when-

Ensures T5 probes respond to heat.

ever a T5 indication problem is suspected.

With engine split at "C" flange, connect test set to alumel

and chromel lead. Heat each probe individually and verify

Continuity Resistance (Loop) Check:

response. Replace faulty thermocouple probe.

Ensures continuity and proper resistance in the T5 probes,

bus-bars, wires and terminals.

Note:

- Each T5 probe can be checked for loop and insulation

Disconnect all leads from T5 terminal block on gas genera-

resistance if a fault is suspected.

tor case (use care, while disconnecting leads, to avoid

- Always clean connector carefully to ensure resistance

cracking the insulation material) and measure resistance

of the system is not disturbed

between Alumel and Chromel terminals.

Disconnect T5 probes from bus-bar and measure resis-

Trim Thermocouple Check:

tance between Alumel and Chromel terminals, refer to

Maintenance Manual for resistance limits.

This check is done to ensure proper resistance of the trim

stick.

Insulation (Ground) Resistance Check:

This check is done to ensure system is not grounded

(shorted). Ensures that neither Alumel nor Chromel bus

bars are contacting the casing.

Connect test set between alumel or chromel and ground

(gas generator case) and measure insulation resistance.

Minimum resistance must not be less than specified limit.

PT6A-60 SERIES

TRAINING USE ONLY

MAINTENANCE PRACTICES 12.19

P&WC Proprietary - Disclosure and use subject to the restrictions on page 2 of preface

BASIC ENGINE RIGGING

Purpose:

Provide the operator with a basic approach to engine rig-

ging. This section defines the logical sequence that should

be followed when rigging the engine. It also describes the

post run-up adjustments necessary to get an ideal cockpit

lever to engine response relationship. Use the airframe

maintenance manual for specific engine rigging information.

Pre-Rigging Verification:

- Ensure that cockpit levers and cables operate freely

and do not bind before connecting it to the engine.

- Ensure that the engine reversing cable is not damaged

and operates freely when disconnected from the beta

lever.

- Verify that the propeller reversing lever is connected to

the beta valve and make sure the carbon block is in

good condition.

- Verify that the beta valve is properly connected to the

beta lever.

- Verify run-out on beta feedback slip ring (.003 max)

- Check that beta valve slides freely.

You are now ready to rig the engine.

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.2

REAR LINKAGE RIGGING

One of the first steps prior to rigging the fuel control unit on

Note:

the PT6 is to carefully rig the cambox position. Once this is

A “rig pin" hole located on the cambox may be used to facil-

done, the fuel control unit and the reversing cable can be

itate the track point rigging. Ensure that the above proce-

rigged.

dure applies for a more precise rigging.

Cambox Rigging:

With the airframe power lever cable and the engine reverse

cable disconnected from the cambox, move the cockpit

power lever through the full range and verify motion is free

of binding and excessive friction.

- The next step is to find the track point.

- Cycle the power lever forward and back slowly until the

cockpit idle detent is contacted.

- Find the track point by rotating the cambox input lever

counterclockwise until the reverse cam moves back 1/

32 inch (apply light forward force on reversing cam

while measuring).

- Once the track point is located, position the cambox

input lever at the angle specified by the airframe man-

ufacturer.

- Cycle the cockpit power lever between maximum for-

ward and reverse position and ensure the power lever

cable terminal travel exceeds the required input l lever

displacement.

- Connect the airframe power lever cable to the cambox

input lever

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.3

WOODWARD FUEL CONTROL RIGGING

1. Disconnect the FCU interconnecting rod and set it's

length to 1/8 inch shorter than specified in the airframe

maintenance manual (the rod length will be rectified later

on).

2. With the rod disconnected position the fuel lever to con-

tact the idle stop without going into the deadband.

3. Connect the FCU inter connecting rod to the proper hole

on the FCU actuating lever. Connect the rear end of the

rod to the FCU arm using the serrated washer to posi-

tion the FCU shaft as marked in step 2 (at the idle stop).

4. Remove FCU interconnect rod and lengthen it 1/8 inch

(so it goes back to airframe manual recommendation).

This will provide some forward deadband (approximately

1/4 inch) on the pedestal before Ng picks up.

5. Move the power lever through the full range (make sure

the reverse cable is disconnected). The cam follower

pin should not bottom out at either end of the reverse

cam slot. In the maximum forward position, the FCU

maximum Ng stop screw should contact the FCU maxi-

mum stop.

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.4

FRONT LINKAGE RIGGING

Telescopic Interconnect Rod:

Rigid Interconnect Rod:

1. Disconnect the reverse cable at the cambox.

2. Move the Power Lever in the cockpit between Flight Idle

2. Move the cockpit power lever between idle and maximum

and Max Power setting to verify free movement.

power position to verify free movement

3. Pull on the Beta Lever and adjust the front clevis so that

3. Disconnect the propeller governor interconnect rod, pull

the Beta Valve clevis slot face is flush with the Beta Valve

on the beta lever and adjust the front clevis so that the

cap.

beta valve clevis slot face is flush with the beta valve nut.

4. Adjust the length of the interconnect rod to get the

4. Connect the reverse cable rear clevis to the required hole

required gap as specified in the Airframe Maintenance

in the reverse cam. Adjust the clevis so that the cable is in

manual.

light compression (pushed forward) when the clevis pin is

installed.

5. Cycle the cockpit levers from idle to max power to verify

smooth operation. Adjust the reverse cable pre-load at

5. Connect the CSU interconnect rod in the specified holes

the rear clevis connection if excessive friction is

and adjust it to get a sliding fit, then shorten thread by

observed. The reverse cable will be in tension since it is

turning one end 1/2 turn.

pushed forward by the Beta valve spring.

6. Cycle the cockpit power lever from idle to maximum to

confirm smooth motion. Adjust the reverse cable pre-load

at the rear clevis connection if excessive friction is

observed.

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.6

FUEL CONDITION LEVER

- Disconnect control cable from the fuel idle reset/cut-

Propeller Lever:

off lever

- Move the cockpit propeller lever fully forward. Ensure

- Insert rigging pin through the idle reset/cut-off lever

that speed select lever contacts maximum Np stop

- Place cockpit fuel condition lever to ground idle and

screw. Adjust console stop to comply.

adjust the aircraft cable to fit to the appropriate hole on

- Move cockpit propeller lever to feather. Ensure speed

the idle reset/cut-off lever

select lever fully depresses the feathering valve

- Remove rigging pin

plunger.

Ensure :

Note:

- Fuel condition lever moves freely throughout the entire

Speed select levers should be loaded slightly against the

range

maximum Np when maximum propeller speed is selected.

At Cut-Off Position :

Post Rigging Check:

- Ensure that there is a positive contact with the cut-off

stop.

Ensure the propeller feathers when the cockpit propeller

- Ensure that the unloading valve screw fully depresses

lever is halfway through the feather detent.

the unloading valve plunger.

At High Idle Position :

- Ensure high idle stop is contacted

Prior To Starting The Engine:

- Disconnect the fuel line going to the flow divider

- Perform a wet motoring run to confirm Positive fuel

cut-off

- Ensure cut-off happens when the fuel lever position is

halfway through the cut-off detent.

- Check low and high idle speed as per aircraft mainte-

nance manual

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.8

POST RUN UP ADJUSTMENTS

Prior to running the engine ensure that:

- The FCU maximum Ng stop is contacted when the cockpit power lever is advanced to the maximum position.

- The cut-off stop is contacted when the condition lever is at the cut-off position.

- The speed select lever on the CSU makes firm contact with the maximum speed stop.

Symptom

Fix

- Ensure rigging was done properly

Idle Ng Too High

- Adjust Ng speed as per manual’s instructions

- Ensure there are no P3 or Py leaks

Idle Ng Too Low

- Adjust as per manual instructions

Before adjusting make sure that:

- The deadband is the same on the two engines

- The power lever travel movement from idle to take off is the same on the

Ng Pick-Up Point Is Different On

two engines (stagger is constant).

The Two Engines

To Adjust:

(Constant Stagger)

- To move the pick-up point forward on the quadrant, turn the serrated

washer clockwise. (Do not change the rod length) NB: 2 teeth change on

serrated washer = .040" movement on the cockpit quadrant approximately.

Before adjusting

- Ensure low and high idle speeds are the same on both engines

Unequal Power Lever Travel

- Ensure maximum Np is the same on both engines.

Movement From Idle To Take Off

To Adjust:

Between The Two Engines

- To shorten the power lever travel, (PLA ahead) shorten FCU interconnect-

(Progressive Stagger)

ing rod

- Reposition the pick-up point by adjusting the serrated washer (counter-

clockwise in this case)

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.10

POST RUN UP ADJUSTMENTS (CONT’D)

Symptom

Fix

- Verify position of the beta valve is identical on the two engines when the

cockpit power lever is advanced halfway between idle and maximum

power.

Primary Blade Angle Check; Different

- Adjust beta valve position using the reversing cable clevis end (small

Torque On The Two Engines

adjustment) or adjust beta nuts if airframe maintenance manual permits

(big adjustment)

- Send propeller to an overhaul shop if beta nuts adjustment is not

allowed. Beta valve position has a limited effect on PBA.

- Confirm the beta valve position is flush with the beta valve cap nut.

- Ensure the reverse cable clevis is connected to the specified reverse

Propeller Zero Pitch Position (Np

cam hole.

Increase In Rearward Deadband) Is

- Ensure the cambox track point is rigged the same on the two engines.

Staggered On The Two Engines

- Perform primary blade angle check (Calibrate torque transducer). Adjust

PBA as required

- Verify track point rigging

Pilot Reports YAW During Approach

- Verify beta valve rigging

- Perform primary blade angle check

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.11

TWIN ENGINE RIGGING TROUBLESHOOTING

Condition 1

Ideal Condition.

Condition 5

Reverse Pick-Up Point Are Split

- Adjust deadband screw on the right hand engine

May vary from airframe to airframe. The Airframe Mainte-

(CCW) to reduce the band. This will change the dead-

nance manual provides a description of the required set-

band in forward as well.

tings after engine rigging.

- Reposition the deadband using the serrated washer

(.003” feeler gauge test). Start engine and re-adjust

the idle speed.

Condition 2

Ng Pick-Up And Target Points Are Split.

- Displace the pick-up point with the serrated washer.

This will also bring the power lever more or less in line.

Condition 6

Beta Valve Tracking Point Is Staggered

- Also the deadband must be adjusted.

(Np increases in Beta).

- Verify the Cambox reverse “track point” is rigged cor-

rectly.

Condition 3

Power Lever Stagger For Equal Torque

- Verify “pre-loading” of pin connecting the reverse cam

- Correct the stagger by lengthening the FCU intercon-

and the clevis.

necting rod on the right hand side engine.

- This will move the pick-up point forward which can be

corrected by adjusting the serrated washer on the right

Condition 7

Forward & Reverse Pick-Up Point Not

hand side engine.

Matched

- Move deadband using serrated washer (but do not

adjust angle) rearward on right engine

Condition 4

Ng Pickup Point Split But Equal At

- Use paper check to have both engines at same posi-

Power.

tion

- Lengthen the FCU interconnect rod on the right hand

side engine.

- Adjust deadband screw (.003” gauge test) and the ser-

rated washer to set the “deadband angle” and “pick-up

point position” the same on both engines.

- Start engine and verify the idle speed.

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.12

TRAINING MATERIAL CHANGE REQUEST

Date: ________________________________

Company Name and Address: ____________________________________________________________________________

Your Name: __________________________________

Job Title:_________________________________________

Training Aid Title:_______________________________________________________________________________________

Reference Page(s): _____________________________________________________________________________________

Recommended Change(s) and Reason(s) for Change(s):_______________________________________________________

_____________________________________________________________________________________________________

____________________________________________________________________________________________________

TMCR ID Number (P&WC Office Use Only): _________________________________________________________________

Send To:

Note: If you would like to be contacted regarding the

Pratt & Whitney Canada Customer Training

resolution of your request for change, please provide us

1000 Marie-Victorin (05CA1)

with your telefax number on the following line.

Longueuil, Quebec, Canada, J4G 1A1

Email: customer.training@pwc.ca

Telefax Number: _________________________________

PT6A-60 SERIES

TRAINING USE ONLY

RIGGING 13.14

Engine PT6A-60 SERIES. TRAINING MANUAL (2007) - page 2