Rolls-Royce Engine 250–C18, 250–C18A, 250–C18B, 250–C18C. Operation and Maintenance Manual (2003)

CAUTION: TO PREVENT POSSIBLE BLADE DAMAGE AND TO ASSURE ADEQUATE

RINSE AT THE BASE OF THE BLADES N₁ MUST NOT EXCEED 10% RPM.

IF N₁ RPM REACHES 10%, RELEASE THE STARTER AND CONTINUE THE

WATER SPRAY. PERMIT N₁ RPM TO REDUCE TO APPROXIMATELY 5%

AND THEN RE-ENERGIZE THE STARTER TO OBTAIN A FULL TEN

SECONDS OF ENGINE ROTATION WHILE WATER IS SPRAYED INTO THE

COMPRESSOR.

(d)

Spray water into the compressor inlet for 10 seconds while the engine is being motored

with the starter. Start the water injection three seconds prior to starter engagement. The

three second delay will reduce the tendency of the engine to accelerate above 10% rpm.

The spray must flow the water as close to the bullet nose of the compressor inlet as

possible to ensure that all of the spray is injected into the engine. Do not flood the engine

prior to starter engagement.

NOTE: Observe engine speed during the 10 second rinsing operatiion. The engine rpm

will generally stagnate at or just below 10%; but, when using a fully charged

battery or an A.P.U., the rpm may tend to exceed 10%.

(e)

Continue injection of water spray during coast down until N₁ stops, this improves the rinse

of the base of the blades. Do not continue spray after engine stops.

(f)

While engine drains, remove the bleed valve wedge.

(g)

Within 15 minutes of the water rinse, operate the engine at idle for five minutes to purge

and evaporate all residual water as soon as possible (actuate anti-icing system for one

minute).

NOTE: If exposure to excessive salt or other corrosive media has occurred, a repeat of

the rinse procedure may be necessary. In cases where the engine has not

been receiving regular daily water rinsing, double rinse may be required to

prevent corrosive attack of metals in the engine.

Cleaning Water-alcohol Residue From Engine

(1) Regular use of water alcohol augmentation may temporarily reduce engine power if impure

water has been used. Contaminants from impure water build up in the compressor airflow

path. Restore normal power by removing contaminants using the normal compressor cleaning

process (Brulin). If Brulin cleaning does not restore normal engine power, clean the engine

with 0-200 micron dry Arizona road dust (AC Spark Plug Coarse Air Cleaner Test Dust, or

equivalent) as follows:

(a) Start the engine. Load to power requirement just short of liftoff.

CAUTION: EXCESSIVE USE OF THE DUST CLEANING PROCESS CAN CAUSE

PERMANENT ENGINE POWER DEGRADATION DUE TO EROSION OF

COMPRRESSOR COMPONENTS.

(b) Feed 1/4 pound (113 grams) of dry 0-200 micron Arizona road dust into the inlet. Feed

the dust at a rate of 1/4 pound (113 grams) per 10-20 minutes.

cleaning procedure.

(d) When engine power has recovered satisfactorily, flush the engine with clean water

(distilled if available) using the same procedure as used for salt spray removal. (Refer to

Compressor Salt Water Contamination Removal.)

Corrosion Treatment and Surface Finish Repair

(1) Repair of Corrosion and Surface Finish Damage

(a) Touch up damaged paint on magnesium alloy parts other than the diffuser scroll with

engine gray enamel (AMS 2510).

Page 41

(b)

Touch up abrasion damage to the paint on the diffuser scroll as follows:

Thoroughly swab the area with trichloroethylene. Air dry five to ten minutes.

Apply heat resistant paint (Nubelon S No. 16473 Gray, mixed two parts by volume

with one part lacquer reducer No. 90l2, products of Glidden Co., Cleveland Ohio; or

equivalent). Heat cure at 425°F (219°C) for 30 min. or air dry for one hour before

handling.

(c)

On aluminum-alloy parts which were originally painted without anodizing, touch up

reworked areas with zinc-chromate primer (AMS 3110), then repaint.

(d)

On aluminum-alloy parts which were originally anodized, clean damaged areas with

mineral spirits and rinse the part with water. Treat the damaged area with chemical film.

(Chem-Rite A22 or equivalent manufactured by Hanson-Van Winkle-Munning Co.,

Matawan, N.J.). As an alternate use chromic acid. If the coating is soft and powdery, the

solution is too strong or the reaction time is too long; dilute the solution with water. If little

or no visible coating forms, increase either the solution concentration or the reaction time.

(e)

Use the following procedure on aluminum-coated steel parts. Apply corrosion-preventive

paint only forward of the turbine unit; the surface heat of the engine aft of the gearbox will

destroy the paint.

Clean the damaged surface with perchlorethylene and let dry five to ten minutes;

clean all welds with a stainless-steel brush.

Mask all vent holes.

Paint all surfaces with heat-resisting aluminum paint (Lankote P/N 620 or equivalent,

made by J. Landau Co. N.Y.). Apply and let dry for one hour.

NOTE: Do not paint compressor case vanes

(f)

Use the following corrosion treatment procedure for repair of the compressor case finish.

Degrease the affected area with trichlorethylene.

Use No. 300 grit sandpaper to remove oxidation and prepare the surface to be

painted.

NOTE: Keep the time interval between the sanding process and the application of

paint to a minimum.

Use a brush or spray to apply paint (Actithane WC 100 with H251 thinner or

equivalent, made by Saran Chemical Co., Detroit, Michigan) a minimum of one mil

thick, to the area. Air dry the paint for 20 minutes.

Apply a second coat of paint. Cure paint with a heat lamp at 450°F (232°C) for 20

minutes then 425°F (219°C) for 30 minutes or air dry at room temperature for 72

hours before engine operation.

Galvanic Corrosion Protection

(1) Specific engine areas shall be protected against galvanic corrosion by a protective paint seal

covering joints between dissimilar materials. The protective paint must be applied to the

specified area after the units are assembled when the area is accessible and not affected by

subsequent disassembly or loosening of affected parts. If it becomes necessary to disturb an

original paint seal, that area shall be resealed with paint.

(2) Specific areas requiring protective paint (areas joining dissimilar metals) are as follows:

(a) Front diffuser. Front diffuser to scroll splitline.

(b) Scroll

Around all mounting bolts at insert end.

All fittings and steel bushings.

Page 42

CAUTION: KEEP PAINT OFF THE COMPRESSOR MOUNTING INSERT FACE.

Rear diffuser-to-gearbox mounting pads.

(All fittings and steel bushings except plastic shipping plugs.

At steel accessory cover plates shipped on pads. Paint attachment fasteners and

interface splitline after cover plate installation (splitlines for plates with gaskets

excluded).

Splitline washers and/or studs and mounting bolts attaching engine mounting

brackets.

Around magnetic drain plugs and their inserts after plug installation.

Torquemeter support shaft nuts at interface splitlines after nut installation.

Turbine assembly mounting pads on gearbox cover.

Gearbox cover mounting face provided for the turbine. Paint the depressed

(fireshield) area bounded by the four adjacent turbine mounting bosses.

(3)

Use the following paint, or equivalent, for galvanic corrosion protection:

(a) Actithane WC100 (Saran Chemical Co., Detroit, Mich.)

(b) Actithane Thinner H251 (Saran Chemical Co., Detroit, Mich.)

(4)

Clean, paint, and cure the area requiring protection as follows:

(a) Immediately before application of paint, thoroughly clean the area using acetone,

methylethylketone, or toluene. Do not handle the area with bare hands or soiled gloves

during or after cleaning.

(b) Apply paint by spray or brush. Air dry for 30 minutes. Flow a continuous film of paint at

the interface area of all dissimilar metals so that the area is completely sealed against

moisture. This applies to all areas not previously protected and/or to areas on which a

previously applied film should need repair.

16.

Engine Preservation And Depreservation

A. Areas of the engine requiring preservation are the oil system, fuel system, and compressor.

B. Inactive Engine Preservation. Preserve stored engines (removed from container) or any engine

installed in stored aircraft as follows:

NOTE: See Preparation for Storage and Shipment, for container storage information.

(1) Preserve the oil system in accordance with Oil System Preservation if shutdown period will

exceed 45 days. Represerve at least each 90 days if stored outdoors (installed engines only)

and each 180 days if stored indoors.

(2) Preserve the fuel system in accordance with Fuel System Preservation, if the shutdown

period will exceed 45 days. Represerve at least each 90 days if stored outdoors (installed

engines only) and each 180 days if stored indoors.

(3) Preserve the compressor and engine gas path in accordance with Compressor Preservation if

warranted by local corrosive conditions. Represerve at least each 30 days if stored outdoors

(installed engines only) and each 90 days if stored indoors.

(4) Install compressor inlet cover. Attach No. 88 Absorbent Protective Dehydrating Agent, or

equivalent (MIL-D-3464) to exhaust collector stack covers and install. Ensure that desiccant

does not contact metal surfaces. Inspect desiccant periodically (based on local humidity

conditions) and rejuvenate as necessary.

(5) During storage, use a flagged wedge to hold the compressor bleed valve closed. Also, cover

the diffuser vent orifice hole and gearbox overboard vent.

Page 43

(6) Store engines indoors if not installed in an aircraft or engine shipping container. Rolls-Royce

recommends that installed engines be stored indoors if possible.

17.

Oil System Preservation

A. If the engines will be inactive for over 45 days, the oil system shall be preserved as follows.

(1) For engines not installed in airframe or shipping container:

(2) Remove oil filter cap and magnetic plug. Service as necessary.

(3) Using 6799790 adapter and speed handle, turn engine while supplying clean, approved engine

oil to the filter housing. Continue until fresh oil drains from gearbox.

(4) Install new filter cap and magnetic plug packings. Install cap and plugs. (See Engine Oil

Change.)

(a) For operable engines installed in airframe:

Service engine oil system. (See Engine Oil Change.)

CAUTION: DO NOT EXCEED AIRFRAME MANUFACTURER STARTER

ENGAGEMENT LIMITS.

Motor engine to ensure oil flow to all engine bearings.

18.

Fuel System Preservation

If the engine will be stored for over 45 days, the fuel system shall be preserved as follows:

(1)

For engines not installed in airframe:

(a) Remove the hose from the fuel nozzle; position the open hose end in a bucket.

(b) Loosen the clamp supporting the two tubes (P_o and P₁) between the fuel control and the

fuel pump. Remove the control bypass (P_o) tube and plug the P_o opening in the fuel

control.

31100 or equivalent) or alternate MIL-PRF-7870A oil (Gulf Oil Corp. Gulflite 6 or

equivalent) at 50 psig (345 kPa) to the fuel inlet of a static engine.

(d) Move the gas producer lever out of the FUEL OFF position.

(e) When oil is observed flowing into the container, remove the oil supply to the pump and

move the gas producer level to FUEL OFF.

WARNING: FAILURE TO PROPERLY INSTALL, ALIGN AND TORQUE FUEL, OIL, AIR

FITTINGS AND TUBES COULD RESULT IN AN ENGINE FAILURE.

(f)

Permit the excess oil to drain from the fuel system before removing the plug and

reassembling the fuel system components. Torque hose coupling to 80-120 lb in.

(9.0-13.6 N^.m); Torque P_o tube coupling nuts to 150-200 lb in. (17-23 N^.m); Torque

clamp nut to 35-40 lb in. (3.9-4.5 N^.m).

(2)

For operable engines installed in airframe:

(a) Remove the hose from the fuel nozzle; position the open hose end in a bucket.

(b) Supply MIL-PRF-6081 grade 1010 oil (Atlantic Refining Co. No. 31100 or equivalent) or

alternate MIL-PRF-7870A oil (Gulf Oil Corp. Gulflite 6 or equivalent) to the fuel pump

inlet.

CAUTION: DO NOT EXCEED STARTER LIMITATIONS WHILE MOTORING THE

ENGINE.

ignition). When oil is observed flowing into the bucket, move the twist grip to the FUEL

OFF position. Remove the oil supply to the pump inlet.

Page 44

Dec 15/97

WARNING: FAILURE TO PROPERLY INSTALL, ALIGN AND TORQUE FUEL, OIL, AND

AIR FITTINGS AND TUBES COULD RESULT IN AN ENGINE FAILURE.

(d) Permit excess oil to drain from the fuel control then reinstall the fuel line. Torque hose

coupling to 80-120 lb in. (9.0-13.6 N^.m).

19.

Fuel System Depreservation

Purging preservative oil and/or air from the fuel system. (Refer to Fuel System Purging.)

20.

Compressor Preservation

Application of preservative to the compressor shall be made as warranted by local corrosive

conditions encountered. In no case, when operating in a corrosive enviroment, shall the shutdown

period exceed 5 days without preserving the compressor.

(1)

For engines not installed in airframe:

(a)

Disconnect the fuel system pressure sensing (P_c) line at both end connections. Hold the

P_c filter while disconnecting the coupling nut. (On configurations without a P_c filter,

disconnect this line from the elbow at the scroll and from the governor fitting.) Cap the

line and the P_c filter.

(Plug the elbow at the scroll and at the power turbine governor tee

on configurations without the P_c filter.)

(b)

Disconnect the bleed control valve pressure sensing (P_c) line at both end connections.

Cap the line and the elbows.

(c)

Block the bleed control valve in the closed position using 6798861 compressor protector

cleaning kit.

(d)

Retain the anti-ice valve in the closed position.

(e)

Turn the compressor rotor using a splined adapter and speed wrench at the spare pad on

the rear of the gearbox (adjacent to governor). Spray the preservative (Rust-Lick No.

606, Rocket WD40, or equivalent) into the compressor inlet while the rotor is being

turned. Apply preservative using an aerosol pressure-type spray can. Hold the can 8 to

12 in. (20-30 cm) in front of the compressor. Allow the preservative to be drawn into the

compressor for 15 to 20 seconds while spraying in a circular motion which covers the

entire intake area.

(f)

Reconnect the control system and bleed control valve pressure sensing lines. Torque

coupling nuts to 80-120 lb in. (9.0-13.6 N^.m). On configurations having a P_c filter, hold

the filter while tightening the coupling nut.

(g)

Remove the wedge which was used to block the bleed control valve in the closed

position.

(h)

Install the inlet and exhaust collector covers and keep the engine in a static condition after

preservative application.

CAUTION: EXCEPTION TO THE RECOMMENDED WATER RINSE IS FOR PRESERVATION

REMOVAL ONLY AND DOES NOT ALTER THE REQUIREMENT FOR DAILY

WATER RINSE FOLLOWING EXPOSURE TO A SALT WATER ENVIRONMENT.

(REFER TO COMPRESSOR SALT WATER CONTAMINATION REMOVAL.)

(i)

Before starting the engine, remove the preservative and soft contaminants by water

rinsing and drying the compressor in accordance with the procedure Compressor Salt

Water Contamination Removal.

NOTE: Operation of the engine prior to removal of compressor preservative may contribute

to early contamination of the compressor blades with a resultant decrease in

compressor efficiency. The recommended water rinse may be omitted only if

available power is closely monitored and a compressor cleaning schedule is

established.

Page 45

(2)

For operable engine installed in airframe:

NOTE: To prevent the preservative from baking dry, be sure the compressor is cool to the

touch (bare hand) before application is made.

(a) Disconnect the fuel system pressure sensing (P_c) line at both end connections. Hold the

P_c filter while disconnecting the coupling nut. (On configurations without a P_c filter,

disconnect this line from the elbow at the scroll and from the governor fitting.) Cap the

line and the P_c filter.

(Plug the elbow at the scroll and at the power turbine governor tee

on configurations without the P_c filter.)

(b) Disconnect the bleed control valve pressure sensing (P_c) line at both end connections.

Cap the line and the elbow.

protector cleaning kit.

(d) Retain the anti-ice valve in the closed position.

CAUTION: DO NOT EXCEED 10% N₁ RPM MOTORING SPEED. DO NOT INJECT A

SOLID STREAM OF FLUID INTO THE COMPRESSOR.

(e) Spray one-quarter pint (0.12 liter) of preservative into the engine while it is being motored

with the starter and without ignition (ignition circuit breaker pulled). Use Rust-Lick No.

606, Rocket WD40, or equivalent for the preservation. Use a sprayer with a quick

opening valve and a nozzle sized to spray one-quarter pint (0.12 litre) of preservative in 1

to 3 seconds. Hold the can of sprayer 8 to 12 in. (20-30 cm) in front of the compressor.

Allow the preservative to be drawn into the compressor while spraying in a circular motion

which covers the entire intake area. As an alternate method of application use an aerosol

pressure-type spray can. Spray preservative from the can for 15 to 20 seconds while the

engine is being motored. Spray in a circular motion which covers the entire intake area.

(f)

Reconnect the control system and bleed control valve pressure sensing lines. Torque

coupling nuts to 80-120 lb in. (9.0-13.6 N^.m). On configurations having a P_c filter, hold

the filter while tightening the coupling nut.

(g) Remove the wedge which was used to block the bleed control valve in the closed

position.

(h) Install the inlet and exhaust collector covers and keep the engine in a static condition after

spraying with preservative.

(i)

Before starting the engine, remove the preservative and soft contaminants by water

rinsing and drying the compressor in accordance with the procedure in Compressor Salt

Water Contamination Removal.

CAUTION: EXCEPTION TO THE RECOMMENDED WATER RINSE IS FOR

PRESERVATION REMOVAL ONLY AND DOES NOT ALTER THE

REQUIREMENT FOR DAILY WATER RINSE FOLLOWING EXPOSURE TO A

SALT WATER ENVIRONMENT. (REFER TO COMPRESSOR SALT WATER

CONTAMINATION REMOVAL.)

NOTE: Operation of the engine prior to removal of compressor preservative may

contribute to early contamination of the compressor blades with a resultant

decrease in compressor efficiency. The recommended water rinse may be

omitted only if available power is closely monitored and a compressor cleaning

schedule is established.

Page 46

21. Lubricants

CAUTION: DO NOT USE MOLYBDENUM DISULFIED LUBRICANTS ON INTERNAL THREADS OR ON

ANY FUEL, LUBRICATION OR AIR SYSTEM TUBING, HOSE OR FITTINGS.

CAUTION: DO NOT USE SILICONE LUBRICANTS EXCEPT WHERE SPECIFIED. USE ONLY THE

LUBRICANTS RECOMMENDED IN THE ENGINE PUBLICATIONS.

A. The following lubricants shall be used for assembly of the engine and at regular periodic lubrication

of components.

NOTE: NOTE: Apply a light coat of lubricant by hand; wipe off any excess. Lubricate only the

male threads of fuel and oil lines; wipe the lubricant from the lead threads to prevent it

from entering the system. Do not mix synthetic lubricating oil with petroleum based

products.

Lubricants

Location

Lubricant

General use such as installation of bearings, oil

Engine oil

seals and O-rings

Accessory gear splines and splines of engine com-

Lubriplate 130A (or equivalent)

ponents

Gearbox seal lips and packing roller bearings for

Grease (Shell 6249 or equivalent)

ease of assembly

External spanner nut, nut, bolt and stud threads ex-

Silicon base molybdenum disulfide antiseize com-

cept male threads and attachments and plugs

pound: DC550R- protects up to 232°C (450°F).

installed in the outer combustion case, turbine sup-

CP-63- protects up to 760°C (1400°F).

ports and exhaust collector. Also, used on No. 2

bearing retainer spanner nut.

Male threads of plugs and attachments installed in

Nickel base antiseize compound, NS165, Never

the outer case, turbine supports or exhaust. Also

Seez Nickel Special--high temperature, high pres-

used on threads of bolts at splitlines between the

sure protection; DSL Super Hi-Temp.

outer case, turbine supports and exhaust collector.

Fuel system preservation

See Table 1.

Page 47

22. Troubleshooting

A. Troubleshooting, Table 6 provides for correction of potential engine malfunctions.

TABLE 6

Troubleshooting

Item

Trouble

Probable Cause

Remedy

Engine fails to reach 15%

Inadequate torque at starter

Check output of starter and battery.

cranking speed

pad.

Binding N₁.

Check inlet for foreign object damage. Ro-

tate N1 by hand and listen for abnormal

noise.

Engine fails to light off

Preservation oil fouling the

Try a second start.

spark igniter.

Air in the gas producer fuel con-

Purge air from the system. (Refer to para

trol and lines.

37.)

Faulty circuit to ignition unit.

Listen for ignition operation. Observe for

fuel vapor coming out of the exhaust.

Check input power to ignition unit. Isolate

and replace defective part.

Faulty ignition exciter.

Listen for igniter operation. Observe for fuel

vapor coming out of exhaust. Replace with

known satisfactory unit. (Refer to Ignition

Exciter, para

85.)

Faulty spark igniter.

Listen for igniter operation. Observe for fuel

vapor coming out of exhaust. Replace with

known satisfactory unit. (Refer to Spark

Igniter, para 85.)

Insufficient fuel in tanks.

Fill tanks with correct fuel.

Gas producer fuel control re-

Check linkage.

mains in cutoff.

Insufficient fuel pressure to fuel

Turn on aircraft boost pump.

pump.

Spark igniter firing intermittently.

Check input voltage to exciter. Check igni-

tion exciter by replacing temporarily with a

known satisfactory unit.

Fuel nozzle valve stuck.

Replace fuel nozzle.

Fuel pump inoperative (Fuel va-

Check pump for sheared drives or internal

por will not be observed leaving

damage. Check for air leaks at inlet or fluid

the exhaust.)

leaks at outlet.

Water or other contaminant in

Check a sample of fuel from the bottom of

fuel.

the tank, if contaminated, disconnect the

fuel line at the fuel nozzle, drain all fuel then

flush the system with clean fuel.

Fuel nozzle orifice clogged.

Check fuel pump filter, replace nozzle. (Re-

fer to Fuel System Filter and Fuel Nozzle,

Maintenance para 43 and 44.)

Early lightoff

Fuel control cutoff valve not

Make a fuel control cutoff valve operational

closed.

check. (Refer to Fuel Control Cutoff Valve

Operational Check, para 53.)

Page 48

TABLE 6

Troubleshooting - continued

Item Trouble

Probable Cause

Remedy

Engine lights off but will not

Loose pneumatic fitting, cracked

Pressurize the system to check for leaks.

accelerate to idle speed at

accumulator, or cracked pneu-

(Refer to Fuel Control System Pneumatic

a normal rate

matic line causing air leak in

Leak Check, para 42.)

control system.

Check for crack in air tubes or outer com-

bustion case. Check for air seal leaks.

Dirty P_c filter.

Clean P_c filter.

(Refer to Cleaning P_c Filter

Maintenance, para 45.)

Inadequate torque at starter

Check condition of battery and starter to de-

pad.

termine if sufficient N₁ cranking speed is

attainable.

Dirty compressor.

Clean compressor and bleed valve. (Refer

to Compressor Cleaning and Bleed Valve

Cleaning, para 15.)

Insufficient fuel supply to gas

Check fuel system to ensure all valves are

producer fuel control.

open and pumps are operative.

Insufficient fuel pressure to fuel

Turn on aircraft boost pump.

pump.

Gas producer fuel control by-

Disconnect the fuel line at the fuel nozzle,

pass valve stuck open.

flush system with clean fuel; then replace

control.

Fuel nozzle partially clogged

Clean fuel nozzle. (Refer to Fuel Nozzle,

with carbon.

Maintenance para 44.)

Fuel nozzle check valve stuck

Replace fuel nozzle.

partially open.

Gas producer fuel control incor-

Replace control.

rectly adjusted or calibration has

shifted.

Anti-icing valve open and cabin

Close anti-icing valve and turn off cabin

heat on.

heat.

Foreign object damage (FOD),

Replace the case or compressor assembly

eroded blades, vanes and/or

if damage or erosion exceeds acceptable

plastic coating.

limits.

(Refer to Blade Damage, Vane Dam-

age and Case Plastic Coating Inspection,

para 91, 92, and 93.)

Faulty power turbine governor.

Replace governor.

Gas producer fuel control start

Adjust start derichment. (Refer to Ad-

derichment too lean.

justments, para 46.)

Low power and high TOT Contaminated bleed valve jet.

Clean bleed valve (Refer to Bleed

Valve Cleaning, para 15.)

Page 49

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Acceleration temperature

Insufficient time allowed for

Purge the engine by motoring with the gas

too high during start.

draining after an unsuccessful

producer lever and ignition switch in OFF for

starting attempt.

approximately 10 sec. before attempting a

second start.

Reduced battery capacity. (This

Recharge or replace battery.

can produce low cranking

speed.)

High residual TOT in excess of

Motor engine with starter leaving gas pro-

150°C (302°F).

ducer lever and ignition OFF.

Depreciated starter which is not

Replace starter.

capable of dry motoring gas pro-

ducer (N₁) above 15 percent.

Gas producer lever (twist grip) in

Review starting procedure.

ground idle (start) position prior

to and during starter engage-

ment.

Dirty compressor.

Clean compressor and bleed valve. (Refer

to Compressor Cleaning and Bleed Valve

Cleaning, para 15.)

Fuel nozzle valve stuck full

Replace fuel nozzle.

open.

Excessive compressor air leak-

Check for leaks. Be sure that anti-ice valve

ing.

is fully closed.

Bleed control valve stuck

Replace bleed control valve.

closed.

Gas producer fuel control incor-

Replace faulty control if start temperature

rectly adjusted or calibration has

exceeds 927°C (1700°F).

shifted.

Gas producer fuel control start

Adjust start derichment. (Refer to Adjust-

derichment too rich.

ments, para 3-45.)

Acceleration temperature

Loose pneumatic fitting, cracked

Pressurize the system to check for leaks.

too low during starting

accumulator, or cracked pneu-

(Refer to Fuel Control System Pneumatic

matic line causing air leak in

Leak Check, para 42.)

control system.

Gas producer fuel control incor-

Replace control.

rectly adjusted or calibration has

shifted.

Gas producer fuel control start

Adjust start derichment. (Refer to Adjust-

derichment too lean.

ments, para 46.)

Engine speed cycles at idle

Gas producer fuel control by-

Disconnect the fuel line at the fuel nozzle;

pass valve not operating freely.

flush system with clean fuel. Inspect and

clean the fuel control fuel filter. (Refer to

Cleaning the Gas Producer Fuel Control

Fuel Filter, para 47.) If the same condition

still exists, replace control.

Page 50

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Engine instability above

Double check valve.

Replace double check valve.

idle speed

Contamination in the pneumatic

Remove air lines and check P_g port in the

section of the gas producer fuel

governor and the P_c port in both control and

control and power turbine gover-

governor. Replace control or governor if

nor.

contaminated.

Engine instability in power

Loose pneumatic fitting, cracked

Pressurize the system to check for leaks.

range

accumulator, or cracked pneu-

(Refer to Fuel Control System Pneumatic

matic line causing air leak in

Leak Check, para 42.)

control system.

Idle speed too low

Incorrect gas producer lever set-

Check lever position and rigging. (Refer to

ting.

Fuel Control Rigging Check, para 51.)

Malfunctioning tachometer.

Replace tachometer.

Excessive generator load.

Reduce electrical load requirement.

Dirty compressor.

Clean compressor and bleed valve. (Refer

to Compressor Cleaning and Bleed Valve

Cleaning, para 15.)

Gas producer fuel control idle

Correct the setting.

(Refer to Fuel Control

adjustment incorrectly set.

Idle Speed Setting, para 52.)

Loose pneumatic fitting, cracked

Pressurize the system to check for leaks.

accumulator, or cracked pneu-

(Refer to Fuel Control System Pneumatic

matic line causing air leak in

Leak Check, para 42.)

control system.

Idle speed too high

Incorrect gas producer lever set-

Check lever position and rigging. (Refer to

ting.

Fuel Control Rigging Check, para 51.)

Malfunctioning tachometer.

Replace tachometer.

Gas producer fuel control idle

Correct the setting. (Refer to Fuel Control

adjustment incorrectly set.

Idle Speed Setting, para 52.)

Oil pressure drops off se-

Oil supply low.

Check oil supply and refill as necessary.

verely

Oil pressure transmitter or indi-

Check transmitter or indicator and repair or

cator giving false indication.

replace if necessary.

Regulator valve sticking or bro-

Clean or replace spring.

ken spring.

Defective oil pump.

Replace pump or send power and accesso-

ries gearbox to an overhaul facility. (Refer

to applicable part of Gearbox Disassembly

and Assembly, para 123.)

Excessive oil pressure fluc-

Air in sensing line.

Bleed line.

tuation

Gage records inaccurately.

Check gage and transmitter.

Faulty pressure regulating.

Replace the valve.

Page 51

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Excessive oil pressure fluc-

Oil contamination.

Drain and replace filter. Inspect magnetic

tuation (cont)

chip detectors for metallic particles. Thor-

oughly flush with engine oil while motoring

engine. Drain and refill with engine oil.

Low oil quantity.

Check for excessive consumption.

Wear of filter housing due to

Replace O-rings on the of inlet and bypass

vibration of filter inlet and filter

tubes and/or replace the filter housing (as

bypass tubes.

required).

Oil filter inlet tube assembly too

Dimensionally inspect the tube assembly

short

per para 120.

Engine operating more

Low oil quantity.

Remove engine and send to Rolls-Royce

than 30 seconds without oil

Authorized Maintenance Center (AMC) for

pressure

investigation. (Refer to para 66.)

Improper servicing after oil

Same as above

change.

Oil pump failure.

Same as above

Low oil pressure

Lack of oil in reservoir.

Fill reservoir with correct oil.

Gage records inaccurately.

Check gage and transmitter.

Oil leaks.

Check all piping connections and the gear-

box splitline.

(Refer to Gearbox Cover-to-

Housing Assembly, para 121 for assembly

technique to prevent splitline leakage.)

Clogged oil filter.

Clean or replace oil filter.

Oil pressure not adjusted.

Adjust oil pressure regulating valve. (Refer-

to Pressure Regulating Valve, para 75.)

CAUTION: DO NOT MAKE A PRESSURE REGULATING VALVE ADJUSTMENT TO CORRECT FOR A

RAPID CHANGE IN OIL PRESSURE. THESE CONDITIONS ARE CAUSE TO SUSPECT OTHER

OIL SYSTEM PROBLEMS HAVE DEVELOPED.

Increase in oil pump internal

Replace pump or send power and accesso-

clearances or sheared drive.

ries gearbox to an overhaul facility. (Refer to

applicable part of Gearbox Disassembly and

Assembly, para 123.)

Oil contamination.

Drain and replace filter. Inspect magnetic

chip detectors for metallic particles. Thor-

oughly flush with engine oil while motoring

engine. Drain and refill with engine oil.

Wear of filter housing due to

Replace packings on the inlet and bypass

vibration of filter inlet and filter

tubes and/or replace the filter housing (as

bypass tubes.

required).

Oil filter inlet tube assembly too

Dimensionally inspect the tube assembly

short.

per para 123.

High oil pressure

Oil pressure gage and transmit-

Check gage and transmitter.

ter records inaccurately.

Page 52

TABLE 6

Troubleshooting - continued

Item Trouble

Probable Cause

Remedy

17 High oil pressure - contin-

Pressure regulating valve im-

Readjust oil pressure regulating valve.

ued

properly adjusted.

CAUTION: EXCEPT FOR INITIAL ADJUSTMENT ON NEWLY INSTALLED ENGINES, DO NOT ADJUST

THE PRESSURE REGULATING VALVE TO CORRECT FOR HIGH OIL PRESSURE. DO NOT

MAKE A PRESSURE REGULATING VALVE ADJUSTMENT TO CORRECT FOR A SUDDEN

INCREASE OR RAPID CHANGE IN OIL PRESSURE. THESE CONDITIONS ARE CAUSE TO

SUSPECT OTHER OIL SYSTEM PROBLEMS HAVE DEVELOPED.

Oil consumption exceeds

Loose fittings, connections, or

Check all fittings, connections, and splitlines

0.05 gal (0.19 liter) per

splitlines.

for sealant and proper torque. Wash entire

hour [1 quart (0.9 liter) per

engine and coat with whitener in suspected

5 hours]

area. Operate engine to locate source of

leakage (Refer to Gearbox Cover-to-Hous-

ing Assembly, para 123 for assembly tech-

nique to prevent gearbox splitline leakage.)

Oil leakage from power turbine

Replace seal. (Refer to Removal of the Oil

carbon face seal.

Bellows Seal, para 107.)

Leaking accessory oil seals as

Replace defective seals. (Refer to Replac-

evidenced by oil draining from

ing Oil Seals, para 99.)

weep hole (on gas producer fuel

control and power turbine gover-

nor) or from drainernor) or from

drain on fuel pump.

Oil consumption in excess

Coking and carbon buildup in

Clean power turbine support scavenge oil

of one quart (0.9 liter) per

power turbine support.

strut, power turbine support pressure oil

hour

nozzle and the external scavenge oil sump.

(Refer to para 81 and 82.)

Improper fit between the power

Send engine to an overhaul facility for re-

turbine inner and outer shafts.

pair.

Oil blowing from gearbox

Leaking accessory pad seal.

Replace seal.

vent or oil venting into ex-

haust (on aircraft installa-

tions in which gearbox vent

is connected to the exhaust

collector.)

Oil spewing from diffuser

Orifice improperly sized (smaller

Refer to Diffuser Vent Orifice Selection/

vent orifice

orifice needed).

Installation, para 126.

Oil spewing at compressor

No. 1 bearing seal failure.

Replace seal. (Refer to Compressor Front

bleed control valve

Bearing and/or Oil Seal Replacement, para

99.)

Oil temperature exceeds

Oil cooler fan inoperative.

Check fan, repair or replace. Inspect en-

107°C (225°F)

gine. (Refer to Oil Temperature Limit Ex-

ceeded, para 66.)

Oil cooler bypass valve inopera-

Check valve, repair or replace. Inspect en-

tive.

gine. (Refer to Oil Temperature Limit Ex-

ceeded, para 66.)

Page 53

TABLE 6

Troubleshooting - continued

Item Trouble

Probable Cause

Remedy

Low power with high TOT

Dirty compressor.

Clean compressor. (Refer to para 15.)

Foreign object damage (FOD),

Replace the case or compressor assembly

eroded blades, vanes, and/or

if damaged or erosion exceeds the accept-

plastic coating.

able limits. (Refer to Blade Damage, Vane

Damage and Case Plastic Coating Inspec-

tion, para 89, 90, 91.) Inspect turbine as-

sembly for secondary damage.

Engine air inlet blockage.

Remove objects causing blockage. (Refer

to Compressor Inlet Air Blockage para 27.

Excessive compressor air leaks.

Repair leaks.

Faulty TOT indicator.

Check calibration of TOT system. Replace

indicator as necessary.

Anti-icing valve leaking.

Check solenoid, tube fittings for leaks, re-

place valve as necessary.

Faulty torquemeter indicating

Check calibration of torque sensing system.

system.

Replace gage or transmitter as necessary.

Also refer to item 40.

Compressor air discharge tubes

Reposition the compressor air discharge

leaking air at the piston ring split

tubes or replace the piston ring split seals.

seals.

Inspect tubes for cracks. Check for worn

seal bore. Check outer combustion case

flanges for warping.

Compressor rotor-to-shroud

Repair or replace the compressor.

clearance excessive.

Compressor impeller rub caused

Clean or replace compressor.

by dirt. No. 1 Bearing failure.

Compressor scroll internal ero-

Repair or replace compressor.

sion, distorted elbow vanes or

air leaks at joints.

New compressor case misa-

If noise monitoring indicates rub, remove

ligned at instaltion.

and reinstall the case. (Refer to Case Re-

placement, para 96.)

Bleed control valve failed to

Check compressor discharge pressure

close.

sensing line for leaks and for security.

Clean valve nozzle, filter and jet.

(Refer to

Bleed Valve Cleaning, para 15.)

Replace bleed control valve.

Outer combustion case cracked

Repair crack or replace outer combustion

or distorted.

case.

Warped or cracked combustion

Repair or replace combustion liner.

liner.

1st-stage gas turbine nozzle

Replace 1st-stage nozzle.

cracked.

Page 54

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Low power with high TOT -

Burned or missing turbine rotor Replace turbine assembly.

continued

blades.

Turbine wheel or nozzle eroded

Replace turbine.

excessively.

Turbine wheel blade tip exces-

Replace turbine.

sive clearance.

No. 6 and 7 area labyrinth seals

Replace turbine.

excessive clearance.

Blocked or restricted exhaust

Remove blockage or replace turbine (eg.

outlet.

flow splitter damage).

Leaking heating/environmental

Cap or blank off customer bleed pad on

control bleed air system.

scroll to isolate cause.

NOTE: The effect of anti-icing air flow on engine performance is as follows:

Approximate Effect on PerformanceAvailable at Power Levels Above

Type of Operation

40,000 N₁ Speed*

Constant TOT 693°C

A 30 hp decrease and a 1000 rpm (1.95%) decrease in N₁ (gas producer)

(1280°F) Max Continuous

speed.

Constant N₁ speed 100%

A 7 hp decrease and a 45°F (25°C) increase in TOT.

(51,120 rpm)

Constant hp (270) and

A 300 rpm (0.59%) increase in N1 speed and a 60°F (33°C) increase in TOT.

constant collective pitch

(load) operation

*The effects at lower powers and speeds will be only slightly different but still immediate and definite.

Low power with TOT below

Gas producer control lever not

Clean and adjust linkage to the gas produc-

max limit

reaching control. Correct any

er fuel looseness, wear or lost travel. (Re-

maximum speed adjustment

fer to Fuel Control Rigging Check, para 51.)

stop.

Gas producer control lever max-

Correct the maximum speed adjustment

imum speed adjustment stop not

setting. Adjust cw to increase N₁ speed one

properly set.

turn equals approx 1%. (Refer to Checking

the Fuel Control Max Speed Stop, para 56.)

Loose pneumatic fitting, cracked

Pressurize the system to below max limit

accumulator, or cracked pneu-

check for leaks. (Refer to Fuel Control Sys-

matic line causing an air leak in

tem Pneumatic Leak Check, para 42.)

the control system.

Contaminated fuel control air

Clean air circuit.

(Refer to Fuel Control Air

(Pneumatic) circuits.

Circuit Cleaning, para. 55.)

L.P. fuel filter blocked.

Check bypass indicator. Replace filter ele-

ment.

Page 55

TABLE 6

Troubleshooting - continued

Item Trouble

Probable Cause

Remedy

Low power with TOT

Aircraft fuel system restriction,

Refer to aircraft manual for corrective ac-

below max limit (cont)

contamination or leakage.

tion.

Blocked fuel nozzle.

Clean or replace fuel nozzle. (Refer to

para. 44.)

Faulty gas producer fuel control

Replace gas producer fuel control assembly.

assembly.

Low measured TOT power

Faulty TOT indicator.

Check TOT system calibration. Replace

at normal or high

indicator as necessary.

Faulty TOT thermocouple as-

Check TOT system calibration. Replace

sembly.

thermocouple assembly as necessary. (Re-

fer to Thermocouple Inspection, para 86.)

Same as Items 24 and 25.

Correct as in Items 24 and 25.

Engine N₁ or N2 over-

Gas producer fuel control link-

Check linkage for proper operation and ad-

speeds

age not overspeeds properly

justment.

set.

Defective gas producer fuel con-

Replace defective control or governor.

trol or power turbine fuel gover-

nor.

Faulty N₁ or N2 tachometer.

Replace generator or indicator.

NOTE: During ground run after overspeed incident, note the idle speed with the twist grip at the 30°

position. If idle speed is normal, suspect the governor if idle speed is high, suspect the gas

producer fuel control as the faulty component.

Excessive NR droop at

Improper linkage adjustment.

Review beep motor adjustment and rigging.

takeoff, hover, or cruise

Fast decelerations

Dirty gas producer fuel control

Clean circuit.

(Refer to Cleaning the Gas

air Fuel Control Air Circuit,

Producer Fuel Control Air Circuit. para 55.)

Auto decelerations

Dirty gas producer fuel control

Clean circuit.

(Refer to Cleaning the Gas

air circuit.

Producer Fuel Control Air Circuit, para 55.)

Excessive exhaust torching

Fuel nozzle malfunction.

Replace fuel nozzle.

during transients

Excessively rich gas producer

Replace control.

fuel control.

Leaking accessory bleed lines.

Repair or replace lines.

Slow to accelerate from

Dirty compressor.

Clean compressor and bleed valve. (Refer

idle to power

to Compressor Cleaning and Bleed Valve

Cleaning, para 15.)

Page 56

TABLE 6

Troubleshooting - continued

Item Trouble

Probable Cause

Remedy

Slow to accelerate from idle

Foreign object damage (FOD),

Replace the case or compressor assembly

to power - continued

eroded blades, vanes and/or

if damage or erosion exceeds acceptable

plastic coating.

limits. (Refer to Blade Damage, Vane Dam-

age, and Case Plastic Coating Inspection,

para 91, 92, 93.)

New compressor case misa-

If noise monitoring indicates rub, remove

ligned at instalation

and reinstall the case. (Refer to Compres-

sor Case Replacement, para 98.)

Bleed control valve malfunction-

Replace bleed control valve.

ing.

Loose pneumatic fitting, cracked

Pressurize the system to check for leaks.

accumulator, or cracked pneu-

(Refer to Fuel Control System Pneumatic

matic line causing air leak in

Leak Check, para 42.)

control system.

Excessive generator load.

Reduce electrical load.

Excessive compressor air leak-

Check for leaks and repair.

age.

Gas producer control accelera-

Replace control.

tion schedule too lean.

Slow to accelerate to pow-

Same as in preceding trouble.

Correct as in preceding trouble.

er while in flight

Governor linkage incorrectly

Check rigging. Correct linkage as required.

rigged.

TOT approx 30°C (86°F)

Bleed control valve stuck

Replace bleed control valve.

lower than normal at idle

closed.

Compressor surge during

Dirty compressor.

Clean compressor and bleed valve. (Refer

starting or near the idle

to Compressor Cleaning and Bleed Valve

speed

Cleaning, para 15.)

Foreign object damage (FOD),

Replace the case or compressor assembly

eroded blades, vanes and/or

if damaged or erosion exceeds the coating.

plastic coating.

acceptable limits. (Refer to Blade Damage,

Vane Damage and Case Plastic Coating

Inspection, para 91 through 93.)

New compressor case misa-

If noise monitoring indicates rub, remove

ligned at installation.

and reinstall the case. (Refer to Compres-

sor Case Replacement, para 98.)

Excessively rich gas producer

Replace gas producer fuel control.

fuel control.

Bleed control valve stuck

Replace bleed control valve.

closed.

Page 57

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Compressor surge during

Bleed control valve stuck

Replace bleed control valve.

starting

closed.

Foreign object damage (FOD),

Replace the case or compressor assembly

eroded blades, vanes and/or

if damage or erosion exceeds acceptable

plastic coating.

limits.

(Refer to Blade Damage, Vane Dam-

age and Case Plastic Coating Inspection,

para 91, 92, 93.)

Excessively rich gas producer

Replace gas producer fuel control.

control.

Bleed control valve failed to

Replace bleed control valve.

open.

Excessively rich gas producer

Replace gas producer fuel control.

fuel control.

Compressor surge during

Foreign object damage (FOD),

Replace the case or compressor assembly

acceleration (cont)

eroded blades, vanes and/or

if damage or erosion exceds the acceptable

plastic coating.

limits. (Refer to Blade Damage, Vane Dam-

age and Case Plastic Coating Inspection,

para 91, 92, 93.)

New compressor case misa-

If noise monitoring indicates rub, remove

ligned at installation.

and reinstall the case. (Refer to Case Re-

placement, para 96.)

Compressor surge during

Bleed control valve failed to

Clean bleed valve filter, jet and strainer. If

low power operation

open.

condition still exists, replace bleed control

valve. (Refer to Bleed Valve Cleaning, para

15.)

Foreign object damage (FOD),

Replace the case or compressor assembly

eroded blades, vanes and/or

if damage or erosion exceeds the accept-

plastic coating.

able limits. (Refer to Blade Damage, Vane

Damage and Case Plastic Coating Inspec-

tion, para 91, 92, 93.

New compressor case misa-

If noise monitoring indicates rub, remove

ligned at installation.

and reinstall the case. (Refer to Compressor

Case Replacement, para 98.)

More than 20 drops per

Fuel pump drive shaft seal leak-

Replace fuel pump.

minute fuel leaking from

ing.

drain or weep holes

Gas producer fuel control fail-

Replace fuel control

ure.

Faulty torque meter indica-

Faulty airframe installed trans-

Replace transmitter.

tion

mitter.

Torquemeter supporting bearing

Replace power and accessory gearbox

failure.

Page 58

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Faulty torque meter indica-

Clogged torquemeter pressure

Disassemble power and accessory gearbox

tion - continued

sensing oil line.

and clean passage. (Refer to applicable

part of Gearbox Disassembly and Assem-

bly, para 122 and 124.)

Clogged torquemeter bleed ori-

Disassemble power and accessory gearbox

fice.

and clean orifice. (Refer to applicable part

of Gearbox Disassembly and Assembly,

para 122 and 124.)

Lack of antiicing air

Defective antiice air lines.

Check lines.

Antiicing valve stuck closed.

Replace valve.

Dirt collected in vane trailing

Remove anti-icing air lines at the compres-

slot.

sor front support, cap the bullet nose outlet

holes and blow through struts and out slots

at 40 psig (276 kPa) maximum.

Continuous exhaust smok-

Oil leakage from forward com-

If oil consumption exceeds limits, replace

ing

pressor bearing oil seal or power

faulty component(s) as necessary.

turbine carbon face seal

Compressor rear bearing

Seal vent orifice improperly

Replace or repair vent orifice. (Refer to Dif-

labyrinth seal vent smoking

sized or improperly seated.

fuser Vent Orifice Selection/Installation,

para 126.)

Engine power reset to the

Aircraft gas producer linkage

Replace linkage or reconnect.

takeoff setting

broken or disengaged.

Exhaust duct emitting

Combustion liner damage.

Inspect combustion liner and repair or re-

sparks

place. (Refer to Combustion Liner Inspec-

tion, para 109.)

Turbine or compressor blade,

Replace faulty component.

vane or seal damaged.

Excessive vibration

Loose engine mounts.

Inspect for security and condition of mounts.

Turbine wheel blade failure.

Inspect the turbine wheel blades. (Refer to

Turbine Blade Damage, para 103.)

Foreign object damage (FOD),

Replace the case or compressor assembly

eroded blades, vanes and/or

if damage or erosion exceeds the accept-

plastic coating.

able limits. (Refer to Blade Damage, Vane

Damage and Case Plastic Coating Inspec-

tion, para 91, 92, 93,)

Bearing failure or accessories

Check the magnetic inspection plugs for

section internal failure.

particles. if accumulated particles are found,

send engine to overhaul.

Cause uncertain.

Install engine in another aircraft or in test

stand for comparison. Send engine to over-

haul if excessive vibration persists.

Page 59

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Unable to stop engine

Gas producer fuel control fuel

Close the aircraft fuel shutoff valve to stop

cutoff valve not closed.

the engine. Then check control linkage rig-

ging or replace gas producer fuel control if

faulty.

Afterfire

Oil leak.

See “Oil Leakage during shutdown periods.”

Burner drain valve line obstruc-

Check the drain lines. Clean or replace as

tion.

necessary.

Sticking burner drain valve.

Replace valve.

Afterfire - continued

Fuel nozzle valve stuck open.

Replace fuel nozzle.

Gas producer fuel control cutoff

Check linkage or replace fuel control.

valve not fully closed.

Heavy smoking out ex-

Oil see page past No.5 bearing

If suspected, visually inspect for evidence of

haust following engine

oil bellows seal into hot exhaust

puddling in bottom of exhaust collector after

shutdown (light wisps of

and collector.

engine has been inoperative. If leakage is

smoke are normal and not

present, replace No. 5 bearing oil bellows

cause for engine rejection

seal (Refer to replacement para 107.)

unless oil consumption lim-

its are exceeded

Oil seepage past turbine oil

Remove and inspect turbine check valve.

check valve onto hot turbine.

(Refer to Turbine Pressure Oil System

Check Valve, para 78.)

Residual oil in No. 6 and 7 bear-

Remove external sump; inspect and clean

ing area, depositing on hot tur-

strut. (Refer to Inspection and Cleaning of

bine parts.

Power Turbine Support Scavenge Oil Strut,

para 81.)

Excessive clearance of rotating

This is usually accompanied by low power.

knife seals located in No. 6 and

If suspected, replace turbine.

7 bearing area.

Oil leakage in aircraft scavenge

Oil can be found leaking from the outer

oil check valve (Hughes H500).

combustion case after the engine has been

inoperative for an extended period.

Heavy smoking out ex-

Contamination or carbon buildup

Inspect and clean oil system and passages.

haust

in the turbine.

(Refer to Inspection and Cleaning of Power

Turbine Support Scavenge Oil Strut, para

81.)

Continuous exhaust smok-

Oil leakage from forward com-

If oil consumption exceeds limits, replace

ing

pressor bearing oil seal or power

faulty component(s) as necessary.

turbine carbon face seal.

Oil leakage at compressor

Insert loose.

Replace insert. (Refer to Compressor In-

attachment insert in the

sert Inspection, para 116.)

gear-box housing. (At in-

sert adjacent to compres-

sor oil supply fitting.)

Page 60

TABLE 6

Troubleshooting - continued

Item

Trouble

Probable Cause

Remedy

Static oil leakage from

Internal check valve stuck open.

Clean or replace the internal check valve.

power and accessories

(Refer to Replacing the Lube Oil Filter

gearbox breather

Housing, para 76.)

Remove filter housing and inspect housing

and transfer tubes (2) mating surfaces.

Check O-rings on housing end of transfer

tubes. Replace defective items.

Oil leaking from weep holes

Check engine oil seal.

Replace leaking seal. If oil leakage is blue

at power turbine governor.

in color, this is an indication of governor

Oil leakage may be blue in

drive bearing grease washout, therefore re-

color. governor.

place the power turbine

Oil or fuel leaking from the

Oil seal leaking at gearbox, fuel

Identify if the leakage is fuel or oil. Oil leaks

fuel control weep holes.

pump fuel seal leaking. or fuel

require replacement of the gearbox seal

Leakage may be blue in

pump drive O-ring leaking.

and/or the fuel pump drive O-ring. Fuel

color.

leaks require replace ment of the fuel

pump. If the fuel or oil leakage is blue in

color this is an indication of fuel control

drive bearing grease wash-out, therefore

replace the fuel control.

Starter unable to rotate en-

Turbine blade tip clearance.

If engine will rotate after cooldown, no cor-

gine immediately after

rective action required. If unable to rotate

shutdown

engine after cooldown, remove turbine for

further examination.

Starter unable to rotate en-

Binding of compressor, turbine

Determine which major component is bind-

gine

or gearbox.

ing; replace component or engine.

Main rotor (N₂) does not ro-

Turbine blade tip (N₂) rub.

Shut down. Repeat start procedure. If not

tate by 25% N₁ speed dur-

rotating after second attempt, walk the main

ing start wards before

rotor back (Refer to Item 58 NOTE.) Re-

again repeat ing the start

place turbine if condition persists.

procedure.

Carbon formation rotating

Ensure that the oil being used is MIL-

around labyrinth seals.

PRF-7808F or G. or MIL-PRF-23699.

Shut down. Repeat start procedure. If not

rotating after second attempt, walk the main

rotor backwards before again repeating the

start procedure. (Refer to Item 58 NOTE.)

If repeated walk-through does not free N₂,

clean carbon from rotating labyrinth seals.

(Refer to Cleaning Power Turbine Labyrinth

Seals, para 82.)

NOTE: To help alleviate turbine rub or carbon conditions which prevent the main rotor (N₂) from turning by

25% N1 speed, walk the main rotor backwards after a start attempt and/or while the engine is

cooling down. If chatter is encountered, stop the walk-through. Repeat the procedure at the next

convenient shutdown.

Page 61

TABLE 6

Troubleshooting - continued

Item Trouble

Probable Cause

Remedy

Main rotor (N₂) does not ro-

Aircraft power train seizure.

Refer to aircraft maintenance manual.

tate by 25% N₁ speed dur-

ing start wards before

again repeat ing the start

procedure. (cont)

Engine tubing cracked or

Excessive vibration.

Check the engine for possible vibration

broken at the flare

causes. (Refer to Vibration Inspection, 24.)

Bearing noise at compres-

Bearing failure.

Inspect and/or replace compressor No. 1

sor which may be accom-

and No. 2 bearings as required.

panied by looseness of the

impeller

NOTE: Inspect magnetic drain plugs to determine extent of contamination due to bearing failure. (Refer to

Magnetic Plug Inspection, para 3-154.)

Magnetic plug warning light

Engine metal generation.

Refer to Magnetic Plug Inspection, para 70.

illuminated

Loss of power sharing dur-

Incorrect aircraft rigging.

Check rigging and adjust in accordance with

ing acceleration or torque

aircraft manufacturer’s instructions.

split on multi engine ap-

plications.

Excessive collective/P.T. Gover-

Correct looseness, wear or lost travel. Re-

nor control system looseness,

fer to aircraft manufacturer’s instructions for

wear or lost travel.

corrective action.

Contaminated fuel control air

Clean circuit. See Item 25.

(pneumatic) circuits.

Engine undershoots ground

Dirty fuel control P_r-P_g valve.

Clean valve. (Refer to Cleaning the Bendix

idle setting during practice

Fuel Control P_r-P_g Valve, para 58).

autorotation

Oil leaking from weep holes

Check engine oil seal.

Replace leaking seal. If oil leakage is blue

at governor. Oil leakage

in color, replace the power turbine governor.

may be blue in color.

This is an indication of governor drive bear-

ing grease washout.

Oil or fuel leaking from the

Oil seal leaking at gearbox, fuel

Identify if the leakage is fuel or oil. Oil leaks

fuel control weep holes.

pump fuel seal leaking or fuel

require replacement of the gearbox seal

Leakage may be blue in

pump drive O-ring leaking.

and/or the fuel pump drive O-ring. Fuel

color.

leaks require replacement of the fuel pump.

If the fuel or oil leakage is blue in color, re-

place the fuel control. This is an indication

of fuel control drive bearing grease wash-

out.

High throttle shaft torque.

Binding of fuel control or gover-

Spray lubricant (WD-40 or equivalant) on

nor shaft due to corrosion build-

the shaft and bushing of the control and

up between shaft and bushing.

governor. Rotate throttle to assure penetra-

tion. Repeat spray application if necessary.

Page 62

23.

Inspections

The inspection requirements for the engine have been categorized into Preflight and Postflight

Inspections, Scheduled Inspections, and Special Inspections.

NOTE: Inspections may require using a bright light (flashlight or equivalent) and a mirror.

When applicable, review engine records for compliance with all mandatory Bulletins,

Inspections and Airworthiness Directives.

Review Engine Records for Time and/or Cycle Limited Parts. Review Components,

Accessories and Modules time between overhaul.

When local conditions dictate, it is the responsibility of the operator to increase the scope

and/or frequency of checks and/or inspections to assure an adequate level of serviceability

and safety.

Operating and maintenance personnel should be alert to recognize signs of engine abnormal operation

that may be indicative of an impending engine difficulty. Any or all of the following engine abnormalities

may be indicative of an impending engine difficulty and should be investigated to determine the cause

and the required corrective action.

NOTE: Cracks in the horizontal and/or vertical fireshield can be indicative of abnormally high engine

vibration.

Broken, cracked, or fretted fuel, lube, or air tubes can be indicative of abnormally high engine

vibration.

Polishing of tube assemblies in the tube clamping areas can be indicative of abnormally high

engine vibration.

N₁ rotor coast-down that is more rapid than what is normally experienced can be indicative of

an impending engine difficulty. (Example: Coast-down from idle in 4-5 seconds can be

indicative of binding in the N₁ rotor system.)

Preflight And Postflight Inspections

Inspections that must be made before flight and after the final flight of the day are given in Table 7.

(1)

Engine, General

(a) Inspect the entire engine for loose bolts, broken or loose connections, security of

mounting accessories, and broken or missing lockwire. Check accessible area for

obvious damage and evidence of fuel or oil leakage.

NOTE: Check the slippage marks on all accessible B-nut corrections for alignment.

(b) Check to ascertain that mounting and support bolts are tight, lockwired, and in good

condition.

(d) Remove all foreign material which might be drawn into the compressor inlet.

(2)

Control Linkage

(a) Check for freedom of operation and full travel. Check security of linkage. Check for

excessively loose or worn linkage and linkage bolts.

(3)

Compressor Blades and Vanes

(a) Any time the aircraft has been operated in an atmosphere known (or suspected) to be

corrosive, perform a water rinse of the compressor. (Refer to Compressor Salt Water

Contamination Removal.)

(b) Inspect for obvious foreign object damage.

(4)

Outer Combustion Case

(a) Inspect the weld joints of the outer cases that do not have the brazed screen

reinforcement in the armpit area.

Page 63

Dec 30/96

(5) Magnetic Drain Plugs

(a) If a warning light is received, inspect and clean the magnetic drain plugs. (Refer to

Magnetic Plug Inspection.) If the aircraft is not equipped with a cockpit indicating system,

electrically check the magnetic plugs for continuity. If required, remove and inspect

magnetic drain plugs.

(6) Oil Supply

(a) Check oil supply level.

(b) Check oil quantity immediately after shutdown (before oil drains into the gearbox).

(7) Fuel Control

(a) Check the fuel control by making a deceleration check during shutdown for the last flight

of each day. (Refer to Fuel Control Operational Checks.)

(8) Fuel System, General

(a) Check the accessible fuel system components, lines, and connections for evidence of

insecurity or leakage. Accomplish with the boost pump on if available.

Page 64

Dec 30/96

Table 7

Preflight and Postflight Inspections

Item

Component

Preflight

Postflight*

CAUTION:

BEFORE THE ENGINE IS OPERATED, MAKE CERTAIN THE COMPRESSOR INLET IS

FREE OF DEBRIS. ALSO, MAKE CERTAIN THE COMPRESSOR ROTOR IS NOT

FROZEN IF THE AIRCRAFT IS IN A FREEZING ATMOSPHERE.

ENGINE ASSEMBLY

Engine, general

(1)(a) and (b)

Control linkage

(1)(a)

COMPRESSOR

Blades and vanes

(3)(a) and (b)

COMBUSTION SECTION

Outer combustion case

(4) (a)

GEARBOX

Magnetic drain plugs

(5)(a)

NOTE:

If the aircraft is not equipped with a cockpit indicating system, electrically check magnetic

plug for continuity at Postflight Inspection.

LUBRICATION

Oil supply

(6)(a)

(6) (b)

FUEL

Fuel control

(7)(a)

Fuel system, general

(8)(a)

*Postflight inspection shall be made after the final flight of the day.

NOTE: The number and letter designations in the Preflight and Postflight columns refer to the

applicable Description of the Inspection.

Scheduled Inspections

Scheduled inspections are made at periodic intervals in an effort to prevent engine malfunction and

serve in the role of preventive maintenance for the engine. The component to be inspected, the

nature of the inspection, and the elapsed time after which the inspection is to be performed are

given in the Inspection Checksheet, Table 8. The inspection times are hours of engine operation.

Special Inspections

Special Inspections are required when the engine has been subjected to abnormal operating

conditions, when engine damage is suspected, or when associated parts are removed from the

engine. The special occurrence, the component or system to be inspected, and the nature of the

inspection are given in Table 9.

Gearbox Compressor-Mounting Insert Inspection

(1) Inspect the inserts for looseness anytime the compressor is removed from the gearbox.

(Refer to Compressor Insert Inspection.)

Power Turbine Outer Shaft Spline Inspection

(1) Inspect the power turbine outer shaft splines whenever the engine has been subjected to a

Sudden Engine Stoppage as defined in para 26. (Refer to Power Turbine Shaft Spline

Inspection.)

Page 65

F. Power Train Pinion Helical Gear Spline Inspection

(1) Inspect the power train pinion helical gear splines whenever the engine has been subjected to

a Sudden Engine Stoppage as defined in para 26. (Refer to Power Train Pinion Helical Gear

Spline Inspection.)

TABLE 8

Inspection Checksheet

Owner

Date

A/C Make/Model

S/N

Reg No.

TSN

Engine S/N

TSN

TSO

This inspection check sheet is to be used when performing scheduled inspections. This form may be local-

ly reproduced and/or expanded to reflect the aircraft operating environment. Keep the completed sheets as

a permanent part of the aircraft engine records. Detailed information regarding each inspection item is

contained in the referenced Operation and Maintenance Manual paragraphs.

CAUTION: BEFORE UNDERTAKING ANY INSPECTION OR MAINTENANCE ACTION, CONSULT

THE REFERENCED PARAGRAPHS OF THE OPERATION AND MAINTENANCE

MANUAL. FAILURE TO DO SO COULD RESULT IN EQUIPMENT DAMAGE OR

DESTRUCTION, POSSIBLY RESULTING IN PERSONNEL DEATH OR INJURY.

Item

Inspection/Maintenance Action

Ref. Para

Initial

100 Hour Inspection

Inspect the entire engine for loose or missing bolts, broken or loose

N/A

connections, security of mounting accessories and broken or missing

lock wire. Check accessible areas for obvious damage and evidence

of fuel or oil leakage. Loose connections also include the requirement

to inspect the slippage marks on all B-nut connections in the engine

control system.

Check mounting and support bolts to be sure they are tight, lockwired

N/A

and in good condition. Check security of screws and rivets. Remove

all foreign material which might be drawn into the compressor inlet.

Check accessible fuel system components, lines, and connections for

N/A

security, damage or leakage. Accomplish with the boost pump on, if

available.

Check fuel control and power turbine governor linkage for freedom of

operation, full travel and proper rigging. Check security of linkage and

for loose or worn linkage and linkage bolts.

Inspect compressor inlet guide vanes and visible blades and vanes for

N/A

foreign object damage.

Clean compressor with chemical wash solution as required if operating

in a smoggy area or with water alcohol.

Visually inspect the water-alcohol nozzles for build-up of contaminants

which could restrict flow or alter the spray pattern. Ultrasonic clean

nozzles if equipment is available.

Page 66

TABLE 8

Inspection Checksheet - continued

Item

Inspection/Maintenance Action

Ref. Para

Initial

100 Hour Inspection (cont)

Clean the 200 mesh screen (airframe part).

Inspect the compressor scroll for cracks or breaks at the anti-ice valve

and customer bleed ports. If cracks or breaks are detected, check en-

gine for possible vibration causes.

Inspect P_c filter for proper clamping and security.

Until 250 CEB-A-246 is complied with, inspect P_c filter assembly as

N/A

follows: Without disassembly or removal of the P_c filter assembly from

the mounting bracket, inspect using a 10x magnification glass and a

bright light to detect any signs of cracks, paying particular attention to

both of the end fittings at their junction with the end walls. If cracks are

detected, remove assembly and comply with 250 CEB-A-246.

Remove the scroll-to-Pc filter tube at both end connections and in-

N/A

spect for cracks using a 10X magnification. Pay particular attention to

the flared ends of the tube for cracks and to the areas beneath the

floating ferrules for excessive excessive fretting damage. Tubes found

to contain cracks and/or fretting damage are to be replaced by new

parts of the same part number as removed.

NOTE: Excessive fretting is present when the ferrule has chafed the tube sufficiently to wear a step

that can be felt with the thumbnail or other inspection aid.

With the scroll-to-P_c tube assembly still removed and using a 10x

N/A

power glass, inspect the elbow in the compressor scroll for distress/

cracks/proper alignment. No cracks are permissible.

Inspect for discharge air tube inserts that are cocked or backing out of

the scroll. If cocked or loose inserts are detected, check engine for

possible vibration causes.

Check anti-ice valve for security, worn parts and and proper operation.

Valve need not be removed or disassembled unless a problem is de-

tected.

Inspect compressor mount inserts for looseness or oil leakage. Re-

116

place if loose and check engine for possible vibration causes.

117

Inspect the turbine support assemblies and engine exhaust ducts for

121

condition of welded joints, for cracks and buckling. Check exhaust

duct clamps for proper installation, condition and torque.

Wet spline starter-generator gearshafts (new production or those re-

121

placed in accordance with the Rolls-Royce Commercial Engine Bulle-

tin 250-C18 CEB-179) do not need periodic inspection and lubrication.

Clean and inspect any other starter-generator gearshaft. Clean the

female splines of the starter-generator gearshaft and the male splines

of the starter-generator with mineral spirits and a soft brush. Inspect

splines in accordance with para 111, Starter-generator Gearshaft Fe-

male Spline Inspection. Lubricate acceptable splines with grease

(Aero-shell No.22, or equivalent). Before reinstallation of the starter-

generator, make sure torsional damper members of the the starter-

generator driveshaft are in hard contact with each other.

Page 67

TABLE 8

Inspection Checksheet - continued

Item

Inspection/Maintenance Action

Ref. Para

Initial

100 Hour Inspection (cont)

NOTE: Inspect the starter-generator brushes for wear in accordance with the Aircraft Manual at the

same time the spline inspection is made.

Remove, inspect and clean the oil filter. Note any accumulation of

metal chips, debris or carbon particles. Conduct further inspection of

the lube system and/or engine gear train/bearings if metal chips or de-

bris are found. See item 16 below if carbon particles are found.

If carbon particles are found in the oil filter, perform the following in-

spections:

Measure oil flow from the scavenge oil passage of the external sump.

External sump need not be removed for this check.

Visually inspect external sump. Clean internal carbonaceous deposits

N/A

from sump or replace if necessary.

Inspect scavenge oil strut in the power turbine support. Clean carbona-

ceous deposits from the strut.

Inspect No. 6 and 7 bearing pressure oil nozzle. Clean carbonaceous

deposits from the nozzle.

Inspect and clean magnetic chip detector plugs.

Inspect quick disconnect magnetic chip detector plugs and flanged in-

serts for wear (if installed).

Inspect the outer combustion case for condition. Inspect the weld joints

109

of cases that do not have the brazed screen reinforcement in the arm-

pit area.

Clean the burner drain valve.

110

Inspect the ignition lead for burning, chafing, or cracking of conduit and

loose connectors and broken lock wire.

Review engine records for compliance with all mandatory bulletins, in-

N/A

spections and airworthiness directives.

Review engine records for time limited parts components, accessories

N/A

or modules.

Enter component changes, inspection compliance, etc., in logbook as

N/A

required.

200 Hour Inspection

In addition to the 100 hour inspection items, perform the following:

WARNING: MANDATORY COMPLIANCE DATE FOR ROLLS-ROYCE 250-C18 CEB-A-161 WAS

NOVEMBER 1, 1989.

Perform fuel pump backlash inspection on Sundstrand dual element

250 CSL-61

pump P/N 6854292, 6857548, 6877719, 6856250, 6876803.

Page 68

TABLE 8

Inspection Checksheet

Item

Inspection/Maintenance Action

Ref. PARA

Initial

200 Hour Inspection (cont)

Drain oil system and refill.

Section 1

300 Hour Inspection

NOTE: In addition to the 100 hour and appropriate 200 hour inspection

items, perform the following:

CAUTION: INSPECTION FREQUENCY SHALL BE BASED ON THE NATURE OF THE EROSIVE

AND/OR CORROSIVE ENVIRONMENT. THIS ENVIRONMENT MAY DICTATE A MORE

FREQUENT INSPECTION INTERVAL. IN NO CASE SHOULD THE INSPECTION

INTERVAL EXCEED 300 HOURS OR 6 MONTHS.

Inspect the compressor case when operating in an erosive and/or cor-

rosive environment.

CAUTION: AIRCRAFT INSTALLED-ENGINE FUEL-PUMP FILTER DIFFERENTIAL PRESSURE

WARNING SYSTEMS AND/OR OPERATING EXPERIENCE MAY DICTATE REPLACEMENT

AT A LESSER TIME INTERVAL. IN NO INSTANCE SHOULD THE 300 HR REPLACEMENT

INTERVAL BE EXCEEDED.

Replace the fuel filter element.

CAUTION: WHEN THERE IS EVIDENCE THAT THE FUEL PUMP FILTER HAS BEEN BYPASSED, THE

GAS PRODUCER FUEL CONTROL INLET STRAINER, THE FUEL NOZZLE STRAINER,

THE GOVERNOR FILTER AND THE HIGH PRESSURE FUEL FILTER, IF APPLICABLE,

MUST BE CLEANED. (REFER TO TABLE 9 SPECIAL INSPECTIONS, SECTION III, PAGE

3-71, FOR DETAILS.) IF ANY CONTAMINATION IS FOUND IN THE FUEL NOZZLE

SCREEN, THIS WILL REQUIRE THAT THE FUEL CONTROL BE SENT TO AN

AUTHORIZED OVERHAUL/REPAIR FACILITY FOR INTERNAL CLEANING. REFERENCE

MUST ALSO BE MADE TO THE AIRFRAME MAINTENANCE MANUAL FOR FUEL SYSTEM

MAINTENANCE FOLLOWING FUEL CONTAMINATION.

NOTE: This filter is a throw-away item; it is not cleanable.

Perform a fuel pump bypass valve operational check whenever a fuel

filter is replaced.

Purge air from the fuel system.

Check the max. N₁ speed setting of the gas producer fuel control.

Inspect and clean the fuel nozzle. If no airframe mounted fuel filter is

installed, inspect the fuel nozzle screen.

Inspect and clean the No. 1 bearing oil pressure reducer.

Visually inspect external sump. Clean internal carbonaceous deposits

N/A

from sump or replace if necessary.

Inspect scavenge oil strut in the power turbine support. Clean carbo-

naceous deposits from strut.

Inspect No. 6 and 7 bearing pressure oil nozzle. Clean internal carbo-

naceous deposits from nozzle.

Page 69

TABLE 8

Inspection Checksheet - continued

Interval

Inspection/Maintenance Action

Ref. Para

Initial

Other Scheduled Inspections

500 hr/

Inspect all uncoated and coated P/N 6846278 and 6871338 power tur-

250-C18

1 yr

bine outer coupling nuts for corrosion.

CSL-88

NOTE: Compliance with Rolls-Royce Commercial Engine Bulletin 250-C18

CEB-193 and/or 250-C18 CEB-207 removes this inspection

requirement.

600 hr Check the fuel pump driveshaft on Sundstrand single element pumps

N/A

for spline wear.

NOTE: This inspection is not required for Argo-Tech (TRW) fuel pumps or

Sunstrand fuel pumps, P/N 23003114 and subsequent

600 hr Perform scavenge oil filter impending bypass function check per Facet

N/A

Service Bulletin No. 090589 (ref. Rolls-Royce CSL 168) for aircraft

equipped with this type of external scavenge filter system.

1000 hr Replace the fuel control strainer assembly (Bendix fuel controls P/N

2524463-3 or 2524527-2 and earlier unless 250-C18 CEB-185 has

been accomplished).

1500 hr Inspect the compressor case. Inspection frequency shall be as made

necessary by operating environment. In erosive environment, inspect

case at least every 300 hours. In any environment do not exceed 1500

hours without case inspection.

1500 hr Replace the fuel control strainer assembly. (All Bendix fuel controls that

have complied with Rolls-Royce Commercial Engine Bulletin 250-C18

CEB-185 and Bendix fuel controls P/N 2524463-4 or 2524527-3 and

subsequent.)

1500 hr Inspect the fuel nozzle screen for contamination.

Page 70

TABLE 9

Special Inspections

Item

Occurrence

Component or System

Required

Action

Engine removal from aircraft

Engine, general

Compressor removal from engine

Anti-icing valve

Gearbox compressor mount inserts

Turbine-to-compressor coupling

Spur adapter gearshaft

Turbine removal from engine

Combustion liner

Outer combustion case

Compressor discharge air tubes

Turbine pressure oil check valve

Burner drain valve

Power train drive helical gear

Turbine-to-compressor coupling

Turbine-to-pinion gear coupling

Power turbine outer shaft

Rigid tube and/or accumulators removal

Rigid tube and/or accumulators

e, ak

from engine

Hard landing (over 10g)

Engine, general

Sudden stoppage of rotor

Engine, general

Operation in erosive environment

Compressor

Snow or ice ingestion

Compressor

Foreign object damage

Compressor

Turbine

Operation with inlet restricted

Compressor

Overtemperature operation

Turbine

Thermocouples

Oil temperature limit exceeded

Oil system

Hot start encountered

Turbine

Thermocouples

Fuel filter bypassed

Fuel pump filter

Fuel control filter

Fuel nozzle strainer

Oil change

Oil System

Oil filter

15A

Engine operated for more than 30 seconds

Oil System

ac1

without oil pressure

Page 71

Rolls-Royce Engine 250–C18, 250–C18A, 250–C18B, 250–C18C. Operation and Maintenance Manual (2003) - page 5