Robinson R22 Helicopter. MAINTENANCE MANUAL (2018)

10.150 Throttle Correlation Rigging (continued)

NOTE

Before adjusting throttle connecting rod, ensure idle RPM and

engine shimming are correctly adjusted per §§ 2.210 and 6.130.

3. See Figure 10-8. If required, adjust length of throttle connecting rod for 0.020-0.050

inch gap between carburetor butterfly bellcrank and idle RPM adjustment screw when

performing step 2.

4. Tighten jamnut(s), check witness holes, and safety wire rod end, as required. (Note:

If A933-3 rod end is installed, B330-7 palnut is required.)

10.200 Track and Balance

10.210 Equipment Requirements

NOTE

Calibrate track and balance equipment per manufacturer’s

recommendation, at least once a year, or if equipment is

dropped, misused, or calibration is suspect.

NOTE

The Chadwick-Helmuth Vibrex system, the TEC ACES system,

the Dynamic Solutions Systems’ MicroVib system, or equivalent

equipment is required to perform dynamic rotor balancing and

in-flight track checks.

10.220 Equipment Installation

10.221 Main Rotor Equipment Installation

NOTE

Use the following track & balance procedures in conjunction with

approved equipment manufacturer’s balancing instructions.

CAUTION

Cable security is critical; helicopter will be flown at V_NE.

a. Refer to Figure 10-9A. Using appropriate hardware, attach brackets to vibration

transducer and attach assembly A359-1 panel as shown. Remove removable controls.

b. Install magnetic pickup bracket onto swashplate if not previously installed.

OCT 2018

Chapter 10 Rigging, Track and Balance

Page 10.21

10.233 Main Rotor Blade Trim Tab Adjustment

NOTE

To correct for a "climbing" blade condition (blade spread that

exceeds 3/8 inch with forward airspeed), bend high blade trim

tab down.

CAUTION

Do not use other helicopter manufacturers' trim tab bending

tools. Use of these tools will damage Robinson blades.

CAUTION

MT352-1 gage must contact trim tab trailing edge. If gage

does not contact tab trailing edge, tab is bent beyond limit.

CAUTION

Tighten MT526-1 or MT526-8 trim tab bending tool bolt to

bend tab; do not use tool as a lever.

CAUTION

Bend tab upward only when absolutely necessary; bending tab

upward can increase rotor vibration.

CAUTION

MT526-1 trim tab bending tool (for A016-4 [stainless steel

skin] blades) and MT526-8 trim tab bending tool (for A016-6

[aluminum skin] blades) are not interchangeable. Use of wrong

bending tool can result in blade damage. MT090-1 trim tab

bending tool (for earlier blades) is obsolete.

Using felt tip marker, ink mark main rotor blade trim tab per Figure 10-12. Mark

line with a measuring point in the center of the tab (approximate).

Position MT352-1 gage chordwise across blade upper surface and tab trailing edge.

Zero dial indicator on measuring point.

Position MT526-1 (trim tab bending tool (for A016-4 [stainless steel skin] blades)

or MT526-8 trim tab bending tool (for A016-6 [aluminum skin] blades) on tab per

Figure 10-12. Slide tool completely over tab until tool stops contact blade trailing

edge. Double-rib side of tool should contact tab upper surface to bend tab down.

Double-rib side of tool should contact tab bottom surface to bend tab up.

Tighten MT526 bending tool bolt to bend tab. Make slight bends and re-measure

tab with MT352-1 gage. Bend trim tab 0.015 inch (down) to effect dynamic

movement of main rotor blade tip approximately 0.2 inch (downward).

OCT 2014

Chapter 10 Rigging, Track and Balance

Page 10.32A

CHAPTER 11

ENVIRONMENT CONTROL

11-00 Description

Fresh air vents are located in each door and in the nose. Door vents are opened and closed

using the knob near the vent door hinge. On earlier aircraft, pushing in on the knob will

seal and lock the door vents closed. On later aircraft, a rotating knob is provided to lock

the vents. For maximum ventilation, open door vents wide during hover but only one inch

or less during cruise. The rotating knob can be used to hold vents partially open.

The fresh air inlet in the nose is opened by pulling the cabin air knob on the console face.

Air from the nose inlet is directed along inside surface of the windshield for defogging as

well as for ventilation.

A cabin heater is optional. It consists of an air outlet mounted on the left side of the engine

cooling fan scroll, a muffler heat shroud, a control valve at the firewall, an outlet grille

forward of the pilot’s seat or forward of the tail rotor pedals, and interconnecting ducting.

Earlier heaters used an electric blower, located on the left side of the engine compartment,

and a blower switch, located on the ledge forward of the pilot’s seat, for air. A push-pull

control, located on the ledge forward of the pilot’s seat, actuates a valve which directs

heat either into the cabin or out an overboard discharge on the cabin underside.

NOTE

For earlier heaters that use an electric blower for air, the heater

shroud may be removed during warm seasons (when heater is

not in use) to prolong muffler life. Current production heaters

provide constant cooling air to muffler via the cooling fan scroll

and are designed to remain installed.

OCT 2018

Chapter 11 Environment Control

Page 11.1

11-10 Ventilation

11-11 Nose Vent

A. Removal

1. Refer to Figure 11-1. Remove Aspen PFD per § 13-61, if installed. Remove

screws securing upper console to lower console and tilt upper console aft. Protect

instrument face with foam support or equivalent.

2. Remove battery per § 33-10 as required.

3. Remove and discard cotter pin securing clevis pin and A522-1 (air vent) control

inner wire to vent box flap assembly. Remove and retain clevis pin.

4. Remove hardware securing AN742-3 clamps and control housing to lower console

assembly.

5. Remove jam nut and lockwasher securing control (at knob) to lower console

assembly; remove clamps and grommet as required and remove control.

B. Installation

1. Refer to Figure 11-1. Position A522-1 (air vent) control in lower console, install

lockwasher and jam nut on control, and tighten nut against console support

assembly. Verify security.

2. Install MS35489-4 grommet in vent box flap assembly.

3. Secure control inner wire to vent box flap assembly using clevis pin and (new)

cotter pin. Verify security.

4. Install hardware securing AN742-3 clamps and control housing to lower console

assembly. Verify security.

5. Actuate vent and adjust clamp position as required for proper vent operation.

Verify control housing does not slip through clamp when opening and closing

vent. Verify clearance under knob is 0.03-0.10 inch with knob fully depressed

(closed).

6. Install battery per § 33-10 if removed.

7. Tilt console forward and install screws securing upper console to lower console.

Verify security. Install Aspen PFD per § 13-61, if removed.

OCT 2018

Chapter 11 Environment Control

Page 11.3

11-20 Cabin Heater

11-21 Heater Shroud

A. Removal

1. Loosen clamps and disconnect hoses from heater shroud. Temporarily cover

open hoses to protect system from contamination.

2. Remove exhaust system per § 6.510.

3. Remove screws securing shroud to muffler and remove shroud.

B. Installation

1. Install shroud on muffler and install screws. Verify security.

2. Install exhaust system per § 6.520.

3. Remove temporary covers and connect hoses to shroud. Tighten clamps and

verify security.

C. Configuration for Flight with Heater Shroud Removed (Earlier Helicopters):

NOTE

For earlier heaters that use an electric blower for air, the heater

shroud may be removed during warm seasons (when heater is

not in use) to prolong muffler life. Current production heaters

provide constant cooling air to muffler via the cooling fan scroll

and are designed to remain installed.

1. Remove electric blower per § 11-22 Part A.

2. Remove heater shroud per Part A.

3. Remove hoses and attaching hardware from inside engine compartment.

4. Pull out HEATER circuit breaker (10 amp) at panel, and placard as required.

OCT 2018

Chapter 11 Environment Control

Page 11.5

11-22 Electric Blower (Earlier Helicopters)

A. Removal

1. Remove hardware securing screen, spacer, and inlet to LH engine side skirt and

blower assembly, and remove screen, spacer, and inlet. Remove LH engine side

skirt.

2. Turn battery switch off and pull out HEATER circuit breaker (10 amp) at panel.

Disconnect blower assembly wiring from airframe electrical harness at connectors.

3. Loosen clamp securing hose to blower assembly and disconnect hose. Temporarily

cover open hose to protect system from contamination.

4. Remove hardware securing blower assembly and ground wire to frame and remove

blower assembly.

B. Installation

1. Install hardware securing blower assembly and ground wire to frame, but do not

torque.

2. Remove temporary cover and connect hose to blower assembly. Tighten clamp

and verify security.

3. Turn battery switch off and pull out HEATER circuit breaker (10 amp) at panel.

Connect blower assembly wiring to airframe electrical harness at connectors;

verify security.

4. Install LH engine side skirt; install hardware securing screen, spacer, and inlet

to LH engine side skirt and blower assembly (adjusting position of blower as

required). Verify security. Standard torque hardware securing blower assembly

and ground wire to frame, and torque stripe per Figure 2-1.

Page 11.6

Chapter 11 Environment Control

OCT 2018

CHAPTER 12

FUEL SYSTEM

12.000 Description

Fuel system maintenance is specific to either bladder or all-aluminum tank installations (current

production aircraft have flexible bladders in aluminum enclosures while earlier aircraft use

all-aluminum tanks). Mechanics are advised to identify fuel tank installation type, and to

follow the appropriate maintenance procedures. Maintenance procedures for the carburetor or

engine fuel system accessories may be found in the appropriate manufacturer’s technical data.

The fuel system is gravity-flow (no fuel pumps) and includes a main tank, an auxiliary tank

(optional for all-aluminum tanks), a shut-off valve control located behind the left seat, and

a strainer (gascolator). Fuel tank air vents are located inside the mast fairing.

Plunger-style drain valves are provided for the gascolator and for each fuel tank sump. The

gascolator is located on the lower left side of the firewall. The drain valves for the auxiliary

tank and bladder-style main tank are located inside the cowl door below the auxiliary tank.

Plastic tubes attached to the valves allow fuel to be drained overboard.

Fuel samples are taken by pushing on the plunger(s). For all-aluminum main tanks, the

drain is located on the left side of the fuselage and is opened by pushing in on the plastic

tube. On newer helicopters, a glass tube stowed inside the upper, aft cowl door is provided

which may be used to catch the fuel samples. Fuel should be sampled from all three

locations prior to the first flight of the day and after refueling to verify no contamination

and correct grade.

The fuel gages are electrically operated by float-type transmitters in the tanks. When the

gages read E the tanks are empty except for a small quantity of unusable fuel. The low

fuel caution light is actuated by a separate electric sender located on the bottom of the

main tank.

The auxiliary tank is interconnected with the main tank and is located somewhat higher so

it will become empty first while fuel still remains in the main tank. The fuel shutoff valve

controls flow from both tanks to the engine.

OCT 2018

Chapter 12 Fuel System

Page 12.1

12.100 Fuel Tanks

CAUTION

Flexible hoses kink easily; handle with care.

CAUTION

Temporarily cap fuel fittings when opened.

WARNING

Fuel vapors are explosive. Do not use electric tools in vicinity

of an opened fuel system.

12.110 Main Tank

A. Removal

1. Defuel helicopter per § 1.150.

2. Remove mast fairing. Open access doors, disconnect ELT antenna and ground

wire at connectors if ELT is installed, and remove tailcone fairing. Remove B423-1

channel assembly and B429 skins (cowling between tanks).

3. Remove left backrest assembly.

4. Loosen clamps, or cut and discard safety wire, securing vent tubes to main tank

assembly and pull tubes off of tank. Remove hardware securing A713-1 strap to

tank.

5. Cut and discard ty-raps as required and disconnect fuel quantity sender and low-

fuel switch assembly wiring from airframe harness at connectors. Remove nuts

securing wiring to fuel quantity sender if connectors are not installed.

6. a. Bladder Tank: Disconnect D205-32 (tank-to-fuel shut-off valve) hose assembly

from valve and D205-33 (tank interconnect) hose assembly from aux tank. Cut

and discard ty-raps attaching D205-34 (drain) hose assembly and D205-33

hose assembly to support, then disconnect hose from drain valve connector.

(Hose assemblies remain attached to main tank during tank removal.)

b. All-Aluminum Tank: Disconnect A726-2 (tank-to-fuel valve) and B141-1 (tank

interconnect; aux tank option) line assemblies and remove line assemblies.

7. Remove hardware securing tank's A028-7 frame (panel) to B428-1 frame (panel)

and A020-2 (steel tube) upper frame. Remove hardware securing tank outboard

corners to horizontal firewall vertical flange. Remove hardware securing tank forward

channel to underside of horizontal firewall (access from engine compartment).

8. Carefully remove tank assembly.

OCT 2014

Chapter 12 Fuel System

Page 12.3

12.110 Main Tank (continued)

B. Installation

NOTE

When positioning main tank in helicopter, verify vertical strip

attached to horizontal firewall is between tank’s D249-4 angle

(attached to stiffener on bottom of tank) and tank’s exterior skin.

NOTE

Electrically verify proper function of low-fuel warning switch

and fuel quantity sender prior to main tank installation. Perform

fuel quantity sender check per § 12.410 as required.

Bladder Tank: If not previously accomplished, connect D205-32 (tank-to-fuel

shut-off valve) hose assembly to main tank strainer assembly, D205-33 (tank

interconnect) hose assembly to main tank AN815-6D union, and D205-34 (drain)

hose assembly to main tank AN815-4D union. Special torque hose nuts per §

1.330 and torque stripe per Figure 2-1.

Position main tank assembly in helicopter, carefully routing attached hose assemblies

(bladder tanks) to appropriate locations.

Install hardware securing tank outboard corners to horizontal firewall vertical flange.

Install hardware securing A713-1 strap to tank. Install hardware securing A028-7

frame (panel) to B428-1 frame (panel) and A020-2 (steel tube) upper frame. Install

hardware securing tank forward channel to underside of horizontal firewall (access

from engine compartment). Standard torque hardware per § 1.320 and torque

stripe per Figure 2-1.

a. Bladder Tank: Connect D205-32 hose assembly to fuel valve elbow. Connect

D205-33 hose assembly to aux tank strainer assembly. Connect D205-34

hose to drain valve connector. Special torque hose nuts per § 1.330 and

torque stripe per Figure 2-1. Install two MS3367-5-9 ty-raps around D205-33

and D205-34 hose assemblies to stand-off ty-rap hoses to support, but do not

tighten. Maintain 0.25 in. minimum clearance for D205-33 hose with frame

assembly and firewall, and for D205-34 hose with firewall and support. Cinch

ty-raps until snug without over-tightening, and trim tips flush with heads.

b. All-Aluminum Tank: Connect A726-2 (tank-to-fuel shut-off valve) line assembly

to tank elbow or tee (aux tank option) and fuel valve elbow. Connect B141-1

line assembly (aux tank option) to aux tank nipple and tank tee. Special torque

line nuts per § 1.330 and torque stripe per Figure 2-1.

Connect fuel quantity sender and low-fuel switch assembly wiring to airframe

harness at connectors. Install nuts securing wiring to fuel quantity sender if

connectors are not installed; special torque nuts per § 1.330 and torque stripe per

Figure 2-1. Install ty-raps as required.

Connect vent tubes to tank and tighten clamps until snug, or wrap two turns

0.032-in. dia. lockwire and safety tubes tight to tank. Verify security.

Page 12.4

Chapter 12 Fuel System

OCT 2014

12.110 Main Tank (continued)

B. Installation (continued)

7. Check fuel quantity indication per § 12.420. Verify no leaks.

8. Inspect fuel cap alignment stripes per R22 Service Bulletin SB-107. Verify proper

installation and legibility of D682-44 decals.

9. Install left backrest assembly.

10. Install B423-1 channel assembly, B429 skins (cowlings between tanks), and A706-

1 tailcone fairing. Install mast fairing. Connect ELT antenna & ground wire at

connectors if ELT is installed. Secure access doors.

11. Perform pitot-static leak check if system was disturbed.

C. Bladder Replacement

NOTE

During disassembly, progressively tape bladder openings to

protect interior from foreign object contamination. During

assembly, progressively remove protective tape.

CAUTION

B028-1 bladder assembly temperature should be above 65°F

before removing, installing, or flexing bladder.

Remove main fuel tank per Part A.

Remove fuel quantity sender per § 12.410.

Remove screws securing D250-6 cover assembly to B028-1 bladder assembly and

tank. Carefully remove cover, with low-fuel switch assembly attached. Remove

o-ring, and discard if condition warrants.

At vents, remove screw securing bladder to tank.

At fuel filler neck, remove fuel cap and screws securing bladder to tank.

At forward inboard corner, remove B254-3 strainer assembly, AN815-4D union, &

AN815-6D union and discard o-rings. Remove screws securing bladder to tank.

Remove hardware securing B578-1 bulkhead assembly, B575-4 channel, and

B575-5 stiffener to tank. Detach hook-and-loop tape and remove bulkhead.

Detach hook and loop tape and carefully remove bladder.

Carefully insert new B028-1 bladder assembly inside main tank assembly. Align

bladder and tank fastener holes and press hook-and-loop tape together.

10.

Install hardware securing B578-1 bulkhead assembly, B575-4 channel, and B575-5

stiffener to tank. Verify security.

OCT 2014

Chapter 12 Fuel System

Page 12.5

12.110 Main Tank (continued)

C. Bladder Replacement (continued)

11. At forward inboard corner, apply A257-9 anti-seize to screw threads and install

screws securing bladder to tank. Lubricate new o-rings with A257-6 grease and

install o-rings on B254-3 strainer assembly, AN815-4D union, and AN815-6D

union. Install strainer and unions; special torque per § 1.330 and torque stripe per

Figure 2-1.

12. At fuel filler neck, apply A257-9 anti-seize to screw threads and install screws

securing bladder to tank. Install fuel cap.

13. At vents, apply A257-9 anti-seize to screw threads and install screw securing

bladder to tank.

14. On bottom, lubricate (new) o-ring with A257-6 grease and install o-ring in bladder

ring groove. Carefully insert D250-6 cover into bladder, with attached low-fuel

switch assembly. Apply A257-9 anti-seize to threads and install screws securing

cover to bladder and tank.

15. Install fuel quantity sender per § 12.410.

16. Pressure check assembled fuel tank by plugging vents and fittings and pressurizing

bladder to no more than 1 psi. Check for leaks with a mild soap and water solution

applied to all seams.

17. Install main fuel tank per Part B.

Page 12.6

Chapter 12 Fuel System

OCT 2014

12.120 Auxiliary Tank

A. Removal

1. Defuel helicopter per § 1.150.

2. Open right side of mast fairing. Open access doors, disconnect ELT antenna &

ground wire at connectors if ELT is installed, and remove tailcone fairing. Remove

B423-1 channel assembly and B429 skins. Remove B430 door and skin.

3. Remove right backrest assembly.

4. Loosen clamps, or cut & discard safety wire, securing vent tubes to aux tank

assembly and pull tubes off tank. Remove hardware securing pitot-static line

clamp to tank channel.

5. Cut & discard ty-raps as required and disconnect fuel quantity sender wiring

from airframe harness at connectors. Remove nuts securing wiring to sender if

connectors are not installed.

6. Remove hardware securing rotor brake cable assembly to B112-1 lever. Cut &

discard heat shrink and disconnect bead chain from cable at connector.

7. Cut & discard ty-rap securing drain tube to angle (bladder tank), or remove hardware

securing drain tube clamp to firewall clip.

8. Disconnect hose or line assembly from tank fitting.

9. Bladder Tank: Above right seat, gently lift foam from bulkhead and remove fasteners

securing tank to bulkhead.

10. Remove screws securing tank channel to frames.

11. Remove perimeter screws securing tank to bulkhead. Remove tank.

OCT 2014

Chapter 12 Fuel System

Page 12.7

12.120 Auxiliary Tank (continued)

B. Installation

Position aux tank assembly in helicopter. Install perimeter screws securing tank to

bulkhead.

Install screws securing tank channel to frames.

Bladder Tank: Above right seat, gently lift foam from bulkhead and install fasteners

securing tank to bulkhead.

a. Bladder Tank: Connect D205-33 hose assembly to aux tank fitting, special

torque hose nut per § 1.330, and torque stripe per Figure 2-1. Verify 0.25 in.

minimum clearance with frame assembly and firewall (reposition hose assembly

angle as required).

b. All-Aluminum Tank: Connect B141-1 line assembly to aux tank fitting, special

torque line nut per § 1.330, and torque stripe per Figure 2-1.

a. Bladder Tank: Install MS3367-5-9 ty-rap securing drain tube to angle. Cinch

ty-rap until snug without over-tightening, and trim tip flush with head.

b. All-Aluminum Tank: Install hardware securing drain tube clamp to firewall clip.

Install hardware securing rotor brake cable assembly to B112-1 lever. Slip length

of B158-6 heat shrink over rotor brake chain, connect chain and cable, and activate

heat shrink over connector. Verify security.

Connect fuel quantity sender wiring at connectors. Install nuts securing wiring to

fuel quantity sender if connectors are not installed. Install ty-raps as required.

a. Bladder Tank: Connect vent tubes to tank and tighten clamps until snug. Verify

security.

b. All-Aluminum Tank: Connect vent tubes to tank, wrap two turns 0.032-in. dia.

lockwire and safety tubes tight to tank. Verify security.

Install hardware securing pitot-static line clamp to tank channel.

10.

Check fuel quantity indication per § 12.420. Verify no leaks.

11.

Inspect fuel cap alignment stripes per R22 Service Bulletin SB-107. Verify proper

installation and legibility of D682-44 decals.

12.

Install right backrest assembly.

13.

Install B430 door and skin. Install B423-1 channel assembly and B429 skins.

Install tailcone fairing, connect ELT antenna ground wire at connector if ELT is

installed, and close access doors. Close right side of mast fairing.

Page 12.8

Chapter 12 Fuel System

OCT 2014

12.120 Auxiliary Tank (continued)

C. Bladder Replacement

NOTE

During disassembly, progressively tape bladder openings to

protect interior from foreign object contamination. During

assembly, progressively remove protective tape.

CAUTION

B028-2 bladder assembly temperature should be above 65°F

before removing, installing, or flexing bladder.

Remove aux fuel tank per Part A.

Remove fuel quantity sender per § 12.410.

Remove screws securing D250-8 cover assembly to B028-2 bladder assembly

and tank. Carefully remove cover, with strainer, siphon, and union attached.

Remove and discard o-ring.

At vents, remove screw securing bladder to tank.

At fuel filler neck, remove fuel cap and screws securing bladder to tank.

Remove hardware securing B579-1 bulkhead assembly and B577-2 stiffener to

tank. Detach hook-and-loop tape and remove bulkhead.

Detach hook-and-loop tape and carefully remove bladder.

Carefully insert new B028-2 bladder assembly inside aux tank assembly. Align

bladder and tank fastener holes and press hook and loop tape together.

Install hardware securing B579-1 bulkhead assembly and B577-2 stiffener to

tank. Verify security.

10.

At fuel filler neck, apply A257-9 anti-seize to screw threads and install screws

securing bladder to tank. Install fuel cap.

11.

At vents, apply A257-9 anti-seize to screw threads and install screw securing

bladder to tank.

12.

Lubricate new o-ring with A257-6 grease and install o-ring in bladder ring groove.

Carefully insert cover into bladder, with strainer, siphon, and union attached. Apply

A257-9 anti-seize to threads and install screws securing cover to bladder and tank.

13.

Install fuel quantity sender per § 12.410.

14.

Pressure check assembled fuel tank by plugging vents and fittings and pressurizing

bladder to no more than 1 psi. Check for leaks with a mild soap and water

solution applied to all seams.

15.

Install aux fuel tank per Part B.

OCT 2018

Chapter 12 Fuel System

Page 12.9

12.130 Fuel Cap(s)

WARNING

Fuel cap alignment stripes are required by regulation and

necessary for the pilot to verify fuel caps are properly secured.

An improperly secured cap may come off in flight.

1. Refer to Figure 12-1A. Paint fuel cap stripes (in two places 180º apart) and A250 neck

if stripes have deteriorated (in one place facing outboard) per the following:

a. Clean surfaces to be painted using a lint-free, clean cloth dampened with acetone.

Allow surfaces to dry.

b. Apply D257-7 black (Imron AF400/AF700) for light-colored ships or D257-5 white

(Imron AF400/AF700) for dark-colored ships, mixed in accordance with paint

manufacturer’s recommendations, to surfaces.

2. Attach D682-44 decal to A689 fuel cap as shown.

OCT 2018

Chapter 12 Fuel System

Page 12.9B

12.200 Fuel Vents

12.210 (Vent Line) Rollover Valve Assemblies

R22 rollover valves contain one brass ball. In normal conditions, air flows around the vent

ball from the bladder expansion spaces. In the event of inadvertent over-filling or in-flight

fuel sloshing, the ball will float and seal the vent. If the aircraft is inverted, the ball seals

the vent to minimize fuel spillage. There are no internal packings.

A. Removal

1. Open right side of mast fairing.

2. Above lower rib, remove D277-6 (spring) clamp securing A729-61 tube to D251-1

rollover valve assembly and pull tube off of valve. Pull valve downward, through

rib grommet.

3. Loosen B277-4 (worm gear) clamp securing A729-48 or A729-62 tube to rollover

valve and pull tube off of valve.

Installation

1. Observe orientation markings and push A729-48 or A729-62 tube onto D251-

1 rollover valve assembly and tighten B277-4 (worm gear) clamp. Push valve

upward, through lower rib grommet.

2. Above rib, push A729-61 tube onto rollover valve and install D277-6 (spring)

clamp. Verify security.

3. Perform vent system check per Part C.

C. Vent System Check

1. Open right side of mast fairing. Verify main and aux fuel tank caps are installed.

2. Attach temporary hose to one A731-4 (vent) tube.

3. Blow into the temporary hose (do not use compressed air) and verify air blows out

the other vent tube. If air does not blow out the other vent, remove obstruction(s)

and repeat check.

4. Close mast fairing.

12.300 Drain Valves

A. Removal

1. Defuel helicopter per § 1.150. Remove engine right cowling, as required.

2. Cut & discard safety wire securing A729 tube to A761-1 drain valve, if installed, and

pull tube off of valve.

3. Remove valve from connector, tank, or gascolator assembly. Tape fuel system opening.

4. Actuate valve to expose stem, then remove & discard o-ring.

OCT 2014

Chapter 12 Fuel System

Page 12.11

12.300 Drain Valves (continued)

B. Installation

1. Actuate A761-1 drain valve to expose stem, and install new o-ring in stem seat.

2. Lightly coat valve threads using B270-6 sealant. Remove tape and install valve in

connector, tank, or gascolator assembly. Standard torque valve per § 23-32 and

torque stripe per Figure 2-1.

3. Push A729 tube onto valve. Wrap tube with two turns 0.032-inch diameter

lockwire and safety tube to valve, as required.

4. Fuel helicopter per R22 Pilot’s Operating Handbook Section 2 and inspect fuel

system for leaks. Install engine right cowling, if removed.

12.400 Fuel Quantity

12.410 Fuel Quantity Senders

CAUTION

Rotation of fuel sender center stud or base nut is not permitted.

WARNING

Do NOT apply system voltage to installed fuel quantity senders.

A. Removal

1. a. Bladder Tanks: If removing D252-3 fuel quantity sender, remove main fuel

tank per § 12.110. If removing D252-4 fuel quantity sender, defuel helicopter

per § 22-52.

b. All-Aluminum Tanks: Defuel helicopter per § 22-52 until level is below

fuel quantity sender mounting hole. Cut & discard ty-raps as required and

disconnect sender wiring from airframe harness at connectors. Remove nuts

securing wiring to sender if connectors are not installed.

2. Remove hardware securing fuel quantity sender to cover assembly or tank.

Carefully pull sender lever through opening, then tape opening.

B. Installation

1. Perform fuel quantity sender check per Part C.

2. Inspect condition of sender gasket and replace as required. Remove tape from

opening, position gasket on sender, and carefully insert sender lever through

opening. Install hardware, special torque bolts in criss-cross pattern per § 23-33,

and torque stripe per Figure 2-1.

3. Bladder Tanks: If removed, install main fuel tank per § 12.110.

4. Connect sender wiring to airframe harness at connectors. Install nuts securing

wiring to sender if connectors are not installed. Install ty-raps as required.

5. Check fuel quantity indication per § 12.420. Verify no leaks.

OCT 2018

Chapter 12 Fuel System

Page 12.13

12.410 Fuel Quantity Senders (continued)

C. Check

1. Remove fuel quantity sender per Part A.

2. Simulate mounting position of appropriate sender per Figure 12-3. Position float

arm as shown and measure the resistance with a multimeter. Verify resistance

is within tolerance in the four positions given.

3. If resistance is out of tolerance at any of the four positions given, bend the float

arm up for a sender with excessive resistance, or bend the float arm down for a

sender with too little resistance. Repeat steps until sender resistance is within

tolerance.

4. Install fuel quantity sender per Part B.

12.420 Fuel Quantity Indication

1. Defuel helicopter per § 22-52. Turn fuel shut-off valve off.

2. Fuel main tank with exactly 6.2 gallons (if equipped with main and aux bladder tanks),

5.6 gallons (if equipped with main bladder tank only), 6.3 gallons (if equipped with

main and aux all-aluminum tanks), or 5.4 gallons (if equipped with main all-aluminum

tank only) of fuel per R22 Pilot’s Operating Handbook Section 2. Wait five minutes

for fuel levels to equalize. Inspect for leaks.

3. Turn battery switch on and read fuel quantity gage. Verify fuel gage indicates one half

to one and one half needle-widths below a quarter of a tank, as shown in Figure 12-4.

4. If indication is beyond allowable limit, perform fuel quantity sender check per § 12.410.

If sender resistance is within tolerance, adjust fuel gage per § 14.440, or replace fuel

gage as required and repeat check.

Main Tank Gage

MINIMUM ALLOWABLE INDICATION

MAXIMUM ALLOWABLE INDICATION

1½ Needle-widths below ¼ of a tank

½ Needle-width below ¼ of a tank

FIGURE 12-4 FUEL QUANTITY INDICATION CHECK

Page 12.14

Chapter 12 Fuel System

OCT 2018

12.430 Low-Fuel Switch Assembly

CAUTION

Avoid contaminating fuel bladder or tank interior. Cover arms

with sleeves and use lint-free gloves when working inside interior.

A. Removal

1. Remove main fuel tank per § 12.110.

2. Remove A521 low-fuel switch assembly wiring pins from connector housing.

3. Remove fuel cap. Carefully capture switch assembly body with clean mechanical

fingers (avoid capturing movable float). Remove AN924-5D nut securing switch

assembly to cover or tank.

4. Carefully pull switch assembly through fuel cap opening, avoiding fuel quantity

sender. Install fuel cap, and tape fuel bladder or tank opening.

Installation

1. Lubricate new o-ring with A257-6 grease, and install o-ring over A521 low-fuel

switch assembly threads.

2. Tape switch assembly wiring to 30-inch length of lockwire.

3. Remove fuel cap and tape. Position tank upside down. Thread lockwire through

fuel cap opening and switch assembly mounting hole. Pull switch assembly wires

and threads through mounting plate and retaining nut.

4. Apply light coat B270-1 sealant to mating face of AN924-5D nut and install nut

securing switch assembly to cover or tank. Special torque nut per § 1.330 and

torque stripe per Figure 2-1.

5. Install main fuel tank per § 12.110.

6. Perform operation check per Part C.

C. Operation Check

1. Turn battery switch on. Fuel helicopter per R22 Pilot’s Operating Handbook Section

2 as required and inspect fuel system for leaks.

2. With a clean wooden dowel, gently depress low-fuel switch assembly float and

verify low fuel warning light illuminates after approximately 1 second delay.

3. If warning light does not illuminate when float is depressed, but does illuminate

when activating push-to-test switch, replace switch assembly.

OCT 2014

Chapter 12 Fuel System

Page 12.15

12.500 Gascolator Assembly

A. Cleaning Sediment Bowl

1. Turn battery switch off. Turn fuel shut-off valve off. Remove left side skirts. Electrically

ground helicopter. Drain fuel into an approved, electrically-grounded container using

A666-1 gascolator assembly drain valve.

2. Cut & discard safety wire securing gascolator collar to outlet fitting. Unscrew collar,

and remove collar, ring, and sediment bowl.

3. Remove gasket and screen from gascolator top. Inspect, then clean, sediment bowl

and screen.

4. Install screen and gasket in gascolator top. Apply light coat A257-6 grease to collar

threads and collar inner flange. Verify large diameter of ring contacts collar inner

flange. Slide ring and collar over bottom of sediment bowl so small diameter of ring

engages groove in bowl flange. Position sediment bowl drain valve thru hole in belly

panel, and hand-tighten collar, ring, and bowl onto gascolator top until snug. Verify

no threads exposed in gascolator top. Safety collar to outlet adapter using 0.032-inch

diameter lockwire.

5. Turn fuel shut-off valve on. Perform ground check and run up per §§ 2.205 & 2.210.

Verify no leaks; repair as required. Install left side skirts.

Page 12.16

Chapter 12 Fuel System

OCT 2014

12.600 Minimum Fuel Flow Check

Turn battery switch off. Turn fuel shut-off valve off. Electrically ground helicopter.

Remove right side skirts. Verify fuel tank cap(s) are installed.

Fuel main tank with exactly 3.0 gallons (bladder tanks) or 1.7 gallons (all-aluminum tanks)

fuel per R22 Pilot's Operating Handbook Section 2.

Disconnect B283 hose assembly from carburetor, turn battery switch and fuel shut-off

valve on, and defuel helicopter into an approved, electrically-grounded container until low

fuel light illuminates. Turn battery switch and fuel shut-off valve off.

Place electrically-grounded, calibrated container beneath hose, turn fuel shut-off valve on,

and record time required to fill container. Verify filling time does not exceed maximum

time listed below:

ALLOWABLE FUEL FLOW RATE

QUANTITY

MAXIMUM TIME

1 U.S. Gallon

2 minutes 25 seconds

4 Liters

2 minutes 33 seconds

1 Imperial Gallon

2 minutes 54 seconds

If filling time is exceeded, perform vent system check per § 12.210. Inspect fuel tank

outlet strainer, line assembly, and hose assemblies for obstructions. Remove obstructions

and repeat check.

Connect B283 hose assembly to carburetor, special torque nut per § 1.330, and torque

stripe per Figure 2-1.

Perform ground check and run up per §§ 2.205 & 2.210. Verify no leaks. Install right

side skirts.

OCT 2014

Chapter 12 Fuel System

Page 12.17

CHAPTER 13

INSTRUMENT SYSTEM

Section Title

Page

13-00

Description

13.1

13-10

Pitot-Static System

13.3

13-20

Primary Instruments

13.4

13-21

Vertical Speed Indicator

13.4

13-22

Airspeed Indicator

13.6

13-23

Dual Tachometer

13.7

13-24

Altimeter

13.9

13-25

Manifold Pressure Gage

13.10

13-26

Magnetic Compass

13.11

13-30

Engine Gages

13.12

13-31

Ammeter

13.12

13-32

Engine Oil Pressure Gage

13.13

13-33

Engine Oil Temperature Gage

13.14

13-34

Cylinder Head Temperature Gage

13.14

13-35

Fuel Quantity Gages

13.15

13-36

Carburetor Air Temperature Gage

13.15

13-40

Additional Standard Indicating Equipment

13.16

13-41

Clock

13.16

13-42

Outside Air Temperature (OAT) Gage/Voltmeter

13.17

13-43

Hourmeter

13.18

13-50

Instrument Markings

13.18

13-60

Electronic Flight Displays

13.21

13-61

Aspen PFD Installation

13.21

OCT 2018

Chapter 13 Instrument System

Page 13.i

CHAPTER 13

INSTRUMENT SYSTEM

13-00 Description

Standard primary instruments include an airspeed indicator, engine and rotor dual

tachometer, altimeter, manifold pressure gage, and magnetic compass. Engine gages

include an ammeter, oil pressure, oil temperature, cylinder head temperature, and fuel

quantity for main and aux (if installed) tanks. Also standard are a clock, a carburetor air

temperature gage, and a digital outside air temperature gage. An hourmeter is located on

the ledge just forward of the pilot’s seat.

For instrument panels with electronic flight displays, a P/N D327 light filter may be used to

reduce reflections in the windshield at night. The light filter is installed by clipping it to the

front of the display. Filter use is at pilot discretion.

The pitot-static system supplies air pressure to operate the airspeed indicator, altimeter,

and vertical speed indicator. The pitot tube is located on the front edge of the mast fairing.

The static source is located inside the aft cowling inboard of the cowl door hinge.

Water can be drained from pitot-static lines by removing the plastic drain plugs which are

accessible through the inspection panel on the underside of the cabin. Draining lines should

only be required if the airspeed indicator or altimeter appears erratic.

Pitot and static sources should be inspected frequently for bugs or other obstructions.

OCT 2018

Chapter 13 Instrument System

Page 13.1

13-10 Pitot-Static System

CAUTION

Do not apply suction to pitot system or pressure to static system.

A. Pitot System Leak Test

1. Open mast fairing.

2. Refer to Figure 13-1. Seal drain hole in elbow aft of pitot tube with pressure-

sensitive tape. Connect a medical syringe, with plunger withdrawn, to pitot tube

via flexible tubing.

3. Slowly apply pressure to pitot line by depressing syringe plunger until airspeed

indicator reads 70 knots (plunger will remain in place).

4. Gently tap airspeed indicator glass to remove friction effects.

5. If airspeed indication drops more than 10 knots in one minute, an unacceptable

leak is indicated. Slowly release pressure. Locate and repair any leak(s). Retest

after any repairs.

6. Remove tape from pitot tube drain hole and verify airspeed indicator has returned

to zero.

7. Remove test equipment. Close mast fairing.

B. Static System Leak Test

CAUTION

Airspeed indicator, altimeter, and vertical speed indicator may

be damaged if suction to static line is applied or removed rapidly.

1. Refer to Figure 13-1. Set altimeter to location elevation.

2. Connect a medical syringe, with plunger depressed, to static port tube via flexible

tubing.

3. Slowly apply suction to static port by withdrawing syringe plunger until altimeter

indicates 500 feet greater than location elevation (plunger will remain in place).

4. If altimeter indication drops more than 100 feet in one minute, an unacceptable

leak is indicated. Slowly release suction. Locate and repair leak(s). Retest after

any repairs.

5. Remove test equipment.

OCT 2018

Chapter 13 Instrument System

Page 13.3

13-20 Primary Instruments

13-21 Vertical Speed Indicator

A. Description

The vertical speed indicator indicates rate of ascent or descent. Check vertical speed

indicator for a zero-rate needle indication when rotorcraft is in a stationary hover.

B. Diagram

Refer to Figure 13-1 for pitot-static system diagram.

C. Removal

CAUTION

Protect instrumentation using foam padding or equivalent.

Handle instruments like eggs.

1. Turn battery switch off and pull out applicable circuit breaker(s).

2. Remove perimeter screws securing face to console and pull face aft.

3. Remove screws securing instrument to face.

4. Disconnect wiring as applicable.

5. Disconnect pitot/static lines and cap & plug instrument and system fittings, as

applicable.

6. Remove instrument and place on foam padding.

D. Installation

CAUTION

Protect instrumentation using foam padding or equivalent.

Handle instruments like eggs.

1. Turn battery switch off and pull out applicable circuit breaker(s).

2. Remove caps and plugs and connect pitot/static lines. Verify security.

3. Connect wiring as applicable. Verify security.

4. Install screws securing instrument to face. Verify security.

5. Install perimeter screws securing face to console. Verify security.

6. Perform pitot-static system checks as required per § 13-10.

7. Perform appropriate function checks per § 2.200.

Page 13.4

Chapter 13 Instrument System

OCT 2018

13-21 Vertical Speed Indicator (continued)

E. Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

F. Special Maintenance and Inspections

1. If vertical speed indicator displays climb indication but does not return to zero in

level flight, or if indication is erratic:

a. Inspect static system for water or obstructions, and remove water or

obstructions if found.

b. Perform pitot-static system checks as required per § 13-10.

2. Perform appropriate function checks per § 2.200. If vertical speed indicator still

displays erratic indication, or displays no indication, remove indicator per Part C,

and return to RHC for inspection.

3. Install airworthy indicator per Part D.

OCT 2018

Chapter 13 Instrument System

Page 13.5

13-22 Airspeed Indicator

A. Description

The airspeed indicator displays airspeed in knots and miles or kilometers per hour.

The airspeed indicator operates properly in forward flight only; backward or lateral

flight will not indicate correct airspeed. The airspeed indicator will indicate airspeeds

up to a maximum of 102 knots (red line).

Diagram

Refer to Figure 13-1 for pitot-static system diagram.

C. Removal

Remove airspeed indicator per § 13-21 Part C.

D. Installation

Install airspeed indicator per § 13-21 Part D.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. If airspeed indicator displays no indication:

a. Inspect pitot tube for obstructions and remove obstructions if found.

b. Inspect pitot tube connection, and tighten connection if loose.

c. Open upper console and inspect pitot line for kinks or bends.

d. Perform pitot-static system checks as required per § 13-10.

e. Perform appropriate function checks per § 2.200. If indicator still displays

no indication, remove indicator per Part C, and return to RHC for inspection.

f. Install airworthy indicator per Part D.

2. If airspeed indicator displays erratic indication:

a. Inspect pitot-static system connection(s), and tighten connection(s) if loose.

b. Inspect pitot-static system lines and verify no lines are cracked or broken.

c. Inspect pitot-static system for water, and remove water if found.

d. Open upper console and inspect pitot lines for kinks or bends.

e. Perform pitot-static system checks as required per § 13-10.

f. Perform appropriate function checks per § 2.200. If indicator still displays

erratic indication, remove indicator per Part C, and return to RHC for inspection.

g. Install airworthy indicator per Part D.

Page 13.6

Chapter 13 Instrument System

OCT 2018

13-23 Dual Tachometer

A. Description

CAUTION

Installation of electrical devices can affect accuracy and

reliability of electronic tachometers.

An electronic engine and rotor dual tachometer is standard. Engine tachometer

signal is provided by magneto breaker points. Rotor tachometer signal is provided

by two magnetic senders at the main gearbox drive yoke. Each tachometer is on a

separate circuit with its own circuit breaker. With battery and alternator switches

off, the tachometers continue to receive power from the battery through a bypass

circuit as long as the clutch actuator switch is in the engage position.

NOTE

Do not stow helicopter with clutch switch engaged. The

tachometers are powered with the clutch engaged and will

discharge the battery.

NOTE

Do not use magnetized tools.

CAUTION

Protect instrumentation using foam padding or equivalent.

Handle instruments like eggs.

B. Removal

1. Turn battery switch off and pull out TACHS E (2 amp) and R (2 amp) circuit

breakers at panel.

2. Remove perimeter screws securing instrument face to console and pull face aft.

3. Remove screws securing console harness connector to A792 dual tachometer

and unplug connector.

4. Supporting instrument, remove screws securing tachometer to face, and remove

tachometer.

OCT 2018

Chapter 13 Instrument System

Page 13.7

13-23 Dual Tachometer (continued)

C. Installation

1. Turn battery switch off and pull out TACHS E (2 amp) and R (2 amp) circuit

breakers at panel.

2. Install screws securing A792 dual tachometer to instrument face. Verify security.

3. Plug in console harness connector to tachometer and install connector screws.

Verify security.

4. Install perimeter screws securing face to console. Verify security.

5. Perform accuracy check and needle synchronization per Part D.

D. Adjustment

NOTE

Adjust rotor tachometer if engine and rotor tachometer needles

are not within 1% of each other at 104% RPM.

1. Remove screws securing instrument face panel to upper console and carefully pull

panel aft.

2. Run-up helicopter per R22 Pilot’s Operating Handbook (POH) Section 6 at 104%

engine tachometer indication.

3. Turn adjustment screw on back of tachometer (apply 1/8 turns) clockwise to

increase and counterclockwise to decrease rotor tachometer indication. Adjust

rotor tachometer to indicate 104%.

4. Shutdown helicopter per POH Section 6. Tighten screws securing instrument panel

to upper console.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Refer to § 1.102 for additional component maintenance.

Special Maintenance and Inspections

1. Perform adjustment as required per Part D.

2. If tachometer cannot be adjusted, remove tachometer per Part B, and return to

RHC for inspection.

3. Install airworthy tachometer per Part C.

Page 13.8

Chapter 13 Instrument System

OCT 2018

13-24 Altimeter

A. Description

The sensitive altimeter provides altitude information relative to mean sea level when

the barometric pressure correction scale is properly set. Check altimeter calibration

by setting correction scale to the current altimeter setting and checking the altimeter

reading against field elevation; they must agree within 70 feet.

Diagram

Refer to Figure 13-1 for pitot-static system diagram.

C. Removal

Remove altimeter per § 13-21 Part C.

D. Installation

Install altimeter per § 13-21 Part D.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. If altimeter displays no indication:

a. Inspect static lines for obstructions and remove obstructions if found.

b. Perform pitot-static system checks as required per § 13-10.

c. Perform appropriate function checks per § 2.200. If altimeter still displays

no indication, remove altimeter per Part C, and return to RHC for inspection.

d. Install airworthy altimeter per Part D.

2. If altimeter displays erratic indication:

a. Inspect static system for water, and remove water if found.

b. Perform pitot-static system checks as required per § 13-10.

c. Perform appropriate function checks per § 2.200. If altimeter still displays

erratic indication, remove altimeter per Part C, and return to RHC for inspection.

d. Install airworthy altimeter per Part D.

OCT 2018

Chapter 13 Instrument System

Page 13.9

13-25 Manifold Pressure Gage

A. Description

The manifold pressure gage provides an indicator of absolute air pressure in the

engine intake manifold. The red line on the gage indicates the maximum manifold

pressure that the rotorcraft is type certificated for at 104% rotor RPM. The manifold

pressure gage should indicate within 0.3 inches Hg of ambient barometric pressure

when engine is not running.

B. Removal

Remove manifold pressure gage per § 13-21 Part C.

C. Installation

Install manifold pressure gage per § 13-21 Part D.

D. Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

E. Special Maintenance and Inspections

Manifold Pressure System Leak Check

1. Disconnect A740-1 line assembly from engine fitting.

2. Connect a medical syringe, with plunger depressed, to line assembly fitting via

flexible tubing.

3. Slowly apply suction to system by withdrawing syringe plunger until manifold

pressure gage indicates 10 inches Hg (plunger will remain in place).

4. If manifold pressure gage indication rises more than one inch in one minute,

an unacceptable leak is indicated. Slowly release suction. Locate and repair

leak(s). Retest after any repairs.

5. Remove test equipment.

Page 13.10

Chapter 13 Instrument System

OCT 2018

13-26 Magnetic Compass

NOTE

United States operators may refer to FAA AC 43-215 for

additional information.

A. Description

An internally illuminated, wet-type compass is attached to the center bow between

the windshields above the instrument panel.

Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

1. Remove hardware securing compass mount to windshield bow.

2. Remove hardware securing compass assembly to mount.

3. Remove heat shrink as required and disconnect light bar wires from airframe

harness. Remove compass.

D. Installation

1. Install heat shrinks over wires and connect compass assembly’s light bar wires to

airframe harness. Verify security. Activate heat shrinks.

2. Install hardware securing compass to mount. Verify security.

3. Install hardware securing mount to windshield bow. Verify security.

4. At governed RPM, using the airport compass rose, align the helicopter skids on

the rose lines, and record the indicated compass headings at 30° increments.

Adjust compass compensator magnets as required until the maximum error at

any heading is 5° or less with all avionics operating, all exterior lights on, and

dimmer full bright. Record the final readings on the aircraft compass card. Re-

check 4 cardinal headings with lights off and all avionics off except COM radio 1

and transponder. Verify maximum error remains 5° or less.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. Perform compass deviation check per Part D step 4.

2. If compass cannot be adjusted to limits specified, remove compass per Part C,

and install airworthy compass per Part D.

OCT 2018

Chapter 13 Instrument System

Page 13.11

13-30 Engine Gages

13-31 Ammeter

A. Description

The ammeter indicates electrical system loads. System load is measured at the shunt

located on the lower-left side of the vertical firewall in the engine compartment.

Schematic

Refer to Figure 14-39A for electrical schematic.

C. Instrument Cluster Removal

1. Turn battery switch off and pull out applicable circuit breaker(s).

2. Remove Aspen PFD per § 13-61 if installed.

3. Remove screws securing upper console to lower console and tilt upper console aft.

4. Remove nuts securing console wiring to B144 instrument cluster and remove wiring.

5. Remove screws securing instrument cluster to shell assembly’s face plate and

remove instrument cluster.

D. Instrument Cluster Installation

1. Turn battery switch off and pull out applicable circuit breaker(s).

2. Position B144 instrument cluster on shell assembly’s face plate and install screws.

Verify security.

3. Install nuts securing console wiring to instrument cluster studs. Verify security.

4. Tilt console forward and install screws securing upper console to lower console.

Verify security.

5. Install Aspen PFD per § 13-61 if removed.

6. Perform appropriate function checks per § 2.200.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. Check continuity across two 3-amp fuses in B304-18 fuse assembly (at the

ammeter shunt) and replace fuse assembly as required.

2. Inspect wiring for loose, chafed, frayed, or broken wires. Verify no damaged

connectors. Verify wiring neatness, proper routing and installation, and security.

3. If ammeter is still inoperative, remove ammeter per Part C, and install airworthy

ammeter per Part D.

Page 13.12

Chapter 13 Instrument System

OCT 2018

13-32 Engine Oil Pressure Gage

A. Description

The engine oil pressure gage indicates engine oil pressure and receives its signal

from a variable-resistor-type sender located in left-hand forward corner of engine

compartment next to hourmeter pressure switch.

Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

Remove instrument cluster per § 13-31 Part C.

D. Installation

Install instrument cluster per § 13-31 Part D.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. Inspect wiring for loose, chafed, frayed, or broken wires. Verify no damaged

connectors. Verify wiring neatness, proper routing and installation, and security.

2. Perform appropriate function checks per § 2.200. If accuracy of engine gage is

suspected, remove instrument cluster per § 13-31 Part C, and return to RHC for

inspection.

3. Install airworthy instrument cluster per § 13-31 Part D.

OCT 2018

Chapter 13 Instrument System

Page 13.13

13-33 Engine Oil Temperature Gage

A. Description

The engine oil temperature gage indicates engine oil temperature and receives its signal

from a probe mounted in the engine oil pressure screen housing or oil filter adapter.

B. Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

Remove instrument cluster per § 13-31 Part C.

D. Installation

Install instrument cluster per § 13-31 Part D.

E. Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

F. Special Maintenance and Inspections

Perform special maintenance and inspections per § 13-32 Part F.

13-34 Cylinder Head Temperature Gage

A. Description

The cylinder head temperature gage indicates the temperature of the #4 cylinder and

receives its signal from a thermocouple installed in the #4 cylinder head.

B. Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

Remove instrument cluster per § 13-31 Part C.

D. Installation

Install instrument cluster per § 13-31 Part D.

E. Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

F. Special Maintenance and Inspections

Perform special maintenance and inspections per § 13-32 Part F.

Page 13.14

Chapter 13 Instrument System

OCT 2018

13-35 Fuel Quantity Gages

A. Description

The fuel quantity gages indicate the fuel level of main and aux (if installed) fuel tanks

and receive signals from variable resistance type senders mounted on the bottom of

each tank.

B. Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

Remove instrument cluster per § 13-31 Part C.

D. Installation

Install instrument cluster per § 13-31 Part D.

E. Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

F. Special Maintenance and Inspections

Perform special maintenance and inspections per § 13-32 Part F.

13-36 Carburetor Air Temperature Gage

A. Description

The carburetor air temperature gage is used to determine when carburetor heat is

required during possible carburetor icing conditions, such as high humidity. Apply

heat as required to keep needle out of yellow band. The carburetor air temperature

gage should read approximately the same as the OAT gage when engine is cold.

B. Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

Remove instrument cluster per § 13-31 Part C.

D. Installation

Install instrument cluster per § 13-31 Part D.

E. Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

F. Special Maintenance and Inspections

Perform special maintenance and inspections per § 13-32 Part F.

OCT 2018

Chapter 13 Instrument System

Page 13.15

13-40 Additional Standard Indicating Equipment

13-41 Clock

A. Description

A manually set electric analog clock is standard equipment; a digital clock is optional.

Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

1. Turn battery switch off.

2. a. Remove perimeter screws securing face to console and pull face aft, or

b. Remove Aspen PFD per § 13-61 if installed, and remove screws securing

upper console to lower console and tilt upper console aft.

3. Remove screws securing clock to face.

4. Disconnect console wiring from clock wiring at connectors, and remove clock.

D. Installation

1. Turn battery switch off.

2. Connect console wiring to clock wiring at connectors. Verify security.

3. Install screws securing clock to face. Verify security.

4. a. Install perimeter screws securing face to console and verify security, or

b. Tilt console forward and install screws securing upper console to lower console

and verify security; install Aspen PFD per § 13-61 if removed.

6. Perform appropriate function checks per § 2.200.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. Check AGC-3 (3 amp) fuse at firewall for evidence of melting and replace fuse as

required.

2. Inspect wiring for loose, chafed, frayed, or broken wires. Verify no damaged

connectors. Verify wiring neatness, proper routing and installation, and security.

3. If clock is still inoperative, remove clock per Part C, and install airworthy clock per

Part D.

Page 13.16

Chapter 13 Instrument System

OCT 2018

13-42 Outside Air Temperature (OAT) Gage/Voltmeter

A. Description

NOTE

No cutting or splicing of OAT probe wires is permitted.

The outside air temperature indicator has a stainless steel probe protruding from chin

of rotorcraft and is connected to gage by a calibrated length of cable.

Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

1. Turn battery switch off.

2. Remove Aspen PFD per § 13-61 if installed.

3. Remove screws securing upper console to lower console and tilt upper console aft.

4. Remove screws securing OAT gage to face.

5. Disconnect console wiring from OAT gage wiring at connectors, and remove

gage.

D. Installation

1. Turn battery switch off.

2. Connect console wiring to OAT gage wiring at connectors. Verify security.

3. Install screws securing OAT gage to face. Verify security.

4. Tilt console forward and install screws securing upper console to lower console.

Verify security.

5. Install Aspen PFD per § 13-61 if removed.

6. Perform appropriate function checks per § 2.200.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. Inspect wiring for loose, chafed, frayed, or broken wires. Verify no damaged

connectors. Verify wiring neatness, proper routing and installation, and security.

2. If OAT gage is still inoperative, remove OAT gage per Part C, and install airworthy

OAT gage per Part D.

OCT 2018

Chapter 13 Instrument System

Page 13.17

13-43 Hourmeter

A. Description

An hourmeter actuated by engine oil pressure is located on the ledge just forward of

the pilot’s seat.

Schematic

Refer to Figure 14-39A for electrical schematic.

C. Removal

1. Remove screws securing D830-1 hourmeter to ledge just forward of the pilot’s seat.

2. Disconnect airframe wiring from hourmeter and remove hourmeter.

D. Installation

1. Connect airframe wiring to hourmeter (A859-42 to positive terminal). Verify security.

2. Install screws securing D830-1 hourmeter to ledge just forward of the pilot’s

seat. Verify security.

Scheduled Maintenance and Inspections

Refer to § 2.400 100-Hour/Annual Inspection.

Special Maintenance and Inspections

1. Inspect wiring for loose, chafed, frayed, or broken wires. Verify no damaged

connectors. Verify wiring neatness, proper routing and installation, and security.

2. If hourmeter is still inoperative, remove hourmeter per Part C, and install airworthy

hourmeter per Part D. Make appropriate maintenance record entries.

13-50 Instrument Markings

See R22 Pilot’s Operating Handbook (POH) Section 2 for instrument markings.

Page 13.18

Chapter 13 Instrument System

OCT 2018

13-60 Electronic Flight Displays

13-61 Aspen PFD Installation

A. Description

The Aspen PFD (Primary Flight Display) is an LCD unit with displays for attitude,

altitude, airspeed, heading, and optional NAV (HSI/CDI). The Aspen PFD is a

situational awareness aid, to be used in conjunction with required VFR instruments

(altimeter, airspeed indicator, and magnetic compass).

The standard Aspen PFD installation configures the lower half of the display as a

directional gyro. An optional installation configures the lower half of the display to

a Horizontal Situation Indicator (HSI).

B. Schematic

Refer to Figure 14-42 for C800-1 Aspen PFD electrical schematic.

C. Removal

1. Turn battery switch off and pull-out EFIS circuit breaker (7.5 amp) at panel.

2. Gently depress blue tab at top of Aspen PFD to release display from mounting

bracket.

3. Disconnect pitot and static lines from display using quick-disconnect couplers.

Temporarily cap pitot and static line fittings at display and in aircraft to prevent

contamination.

4. Loosen screws securing airframe wiring harness connector to display, unplug

connector, and remove display.

D. Installation

1. Turn battery switch off and pull-out EFIS circuit breaker (7.5 amp) at panel.

2. Plug airframe wiring harness connector into Aspen PFD display and tighten

screws. Verify security.

3. Remove temporary fitting caps and connect pitot and static lines to display using

quick-disconnect couplers.

4. Insert display into mounting bracket until blue tab snaps into place. Verify

security.

5. Push-in EFIS circuit breaker (7.5 amp) at panel. Turn battery & avionics switches

on.

6. Perform appropriate functional checks per Aspen EFD1000H PFD Pilot's Guide.

Turn battery and avionics switches off.

7. Perform pitot-static leak check.

OCT 2018

Chapter 13 Instrument System

Page 13.21

13-61 Aspen PFD Installation (continued)

E. Antenna

Refer to § 16-80 for antenna locations & R22 Illustrated Parts Catalog (IPC) Chapter 6.

NOTE

Do not use magnetized tools.

Removal

1. Turn battery switch off and pull-out EFIS circuit breaker (7.5 amp) at panel.

2. Using plastic scraper, remove B270-1 sealant from around EFIS antenna at

corners where it attaches to tailcone.

3. Cut and discard ty-raps as required and disconnect antenna cable at connectors

(secured to frame). Remove screws securing antenna and antenna ground

wire to tailcone and remove antenna.

Installation

1. Turn battery switch off and pull-out EFIS circuit breaker (7.5 amp) at panel.

2. Remove paint and primer from antenna and antenna ground wire mating

surfaces to ensure electrical ground.

3. Install screws securing antenna and antenna ground wire to tailcone. Verify

security.

4. Apply small bead B270-1 sealant (0.1 inch max in height) around antenna at

corners where it attaches to tailcone and allow to dry.

5. Connect antenna cable to antenna at connectors; secure to frame using ty-

raps. Verify security.

6. Perform ground checks per Part D steps 5 and 6.

F. Scheduled Maintenance and Inspections

Maintenance is on condition. Contact Aspen Avionics at www.aspenavionics.com

for instructions for continued airworthiness.

NOTE

Refer to § 34-60 for avionics software information.

Page 13.22

Chapter 13 Instrument System

OCT 2018

13-61 Aspen PFD Installation (continued)

G. Special Maintenance and Inspections

1. Turn battery and avionics switches off. Open circuit breaker panel and upper

console.

2. Inspect condition of and verify no obvious damage to Aspen displays, pitot-static

lines, metal braiding, copper bus bars, circuit breaker, and wiring. Verify no

loose, chafed, or broken wires or terminals. Verify no evidence of arcing. Verify

equipment security.

3. Secure circuit breaker panel and upper console. Perform ground checks per Part

D steps 5 and 6.

OCT 2018

Chapter 13 Instrument System

Page 13.23

CHAPTER 14

ELECTRICAL AND AVIONICS SYSTEMS

Section

Title

Page

14.000 Electrical and Avionics Systems

14.1

14.600 Electrical Systems Schematics

14.12

14.800 Avionics Schematics

14.25

14.900 Upper Console Harness Plugs

14.41

14.1000

IFR Trainer

14.43

14.1010

IFR Trainer Component Loads

14.43

14.1020

IFR Trainer Console Access

14.45

14.1030

IFR Trainer Component Location

14.46

14.1040

IFR Trainer Avionics Schematics

14.47

14.1100

R22 Mariner Avionics Schematics

14.60

OCT 2018

Chapter 14 Electrical and Avionics Systems

Page 14.i

Robinson R22 Helicopter. MAINTENANCE MANUAL (2018) - page 4