HANDBOOK OF MAINTENANCE INSTRUCTIONS FOR MDHI 369D/E/FF-500/600N HELICOPTERS (ISSUED: 1990)

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

5.98 INCH

3.92 INCH

369D26012-5 SLEEVE

(15.189 CM)

(9.957 CM)

0.40 INCH

(REF)

(10.16 MM)

NOTE 1

SUPPORT ASSEMBLY

(NOTES 3 & 4)

2.90 INCH

BOLT

(7.37 CM)

(NOTE 2)

RIVNUT

(NOTE 2)

COMPONENT OF 369D292808-17 AND -18

(FOR UTILITY FLOATS ONLY)

VISU-LOK

(8 PLS) (NOTE 2)

RIVET

(NOTE 2)

PLUG

(NOTES 3 & 4)

EXTENSION TUBE

(NOTES 3 & 5)

369D26012-5

ADAPTER SLEEVE

ABRASION STRIP

(NOTES 3 & 4)

VISU-LOK

(8 PLS) (NOTE 2)

BOLT

(NOTE 2)

NOTES:

MATCH-DRILL 8 - 0.1945/0.1965 INCH (4.9403/4.9911 MM) DIAMETER HOLES THRU

BOTH TUBES AND CSK, 1005 X 0.378/0.385 INCH (9.6012/9.779 MM) DIAMETER.

APPLY PRIMER TO BARE METAL SURFACES.

COAT ATTACHING HARDWARE WITH PRIMER.

COAT MATING SURFACES WITH ZINC CHROMATE PUTTY.

SEAL MATING EDGES WITH SEALING COMPOUND.

G32-8010

Figure 903. Skid Tube Extension Installation

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MAINTENANCE MANUAL

(d). Reinstall skid tube extensions on to

E. Utility Float to Landing Gear Assembly

-5 adapter sleeve using a thin coat of

(Ref. Figure 904) The Utility Float Kit is shipped

sealing compound on mating sur

with as many parts assembled as practical;

faces. Seal with sealing compound.

however, certain items require assembly at

Secure with eight visu-lok fasteners

installation.

coated with primer.

(e). Install abrasion strip to each exten

Consumable Materials

sion tube with bolts and washers.

(Ref. Section 91−00−00)

Coat attaching hardware with

Item

Nomenclature

primer. Coat mating surfaces with

CM209

Zinc chromate putty

zinc chromate putty and seal mating

CM318

Primer

edges with approximately 0.060 inch

CM425

Sealing compound

(1.524 mm) bead of sealing compound

CM717

Tape, pressure sensitive

to insure watertight fit.

(3). Assembly of landing gear skid exten

NOTE: Prior to installation, apply primer

sion - On current configuration ex

(CM318) to all attaching hardware.

tended landing gear:

(1).

On early configuration extended

landing gear, coat abrasion strip with

(a). Insert float kit extension tube over

zinc chromate putty (CM209) and

adapter sleeve.

install with screws (view D).

(b). Align extension tube and sleeve

(2).

Install bolt cover pads using existing

holes, attach tube to skid with bolt

screws and wrap with two overlapping

spacer and nut.

layers of tape (CM717) (view B).

(3).

Coat mating surfaces of cap with

(4). Assembly of landing gear skid exten

sealing compound (CM425) and install

sion - On early configuration extended

using position light attaching screws.

landing gear:

(4).

Temporarily install tyrap bracket with

(a). Seal all edges of skid plug with

screw (view E).

sealing compound; install in tube by

(5).

Position utility floats over landing gear

using using rivets.

skids.

(b). Coat all surfaces of indexing plug and

(6).

Align bolt holes in floats with bolt holes

sleeve with sealing compound.

in skid assembly. Position gravel

guards, coat bolts and washers with

(c). Insert sleeve adapter in tube and

primer (CM318); attach floats, gravel

install using rivets.

guards and abrasion strip using bolts

and washers. Torque bolts to 25 - 35

(d). Install packing and indexing plug in

inch-pounds (2.82 - 3.95 Nm).

tube; align holes in sleeve, plug

(7).

Position cap assembly (view C) on skid

assembly and tube with skid assem

tube extension. Coat mating surfaces

bly. Install rivets and bolts with

with sealing compound and secure with

primer (4).

bolts and washers.

(e). Coat mating surfaces of abrasion

(8).

Assemble structure assembly and

strip with zinc chromate putty (71).

support assembly (view C). Coat mating

Install abrasion strips with screws

surfaces with sealing compound and

and primer (4). Seal all edges with

secure with bolts, washers, nuts and

approximately 0.06 in. bead of

plate. Secure assembled stabilizer

sealant (3).

assembly using bolts and washers.

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CSP-HMI-2

MAINTENANCE MANUAL

F. Utility Floats/Landing Gear Installation

If a preload condition prevents alignment,

disconnect one brace from strut assembly to

(Ref. Figure 902 and Figure 904)

eliminate preload (Ref. Sec. 32-10-00).

(4).

Secure new wire to forward foot using

Consumable Materials

tyrap bracket and screw (view E). Route

(Ref. Section 91−00−00)

wire to position light location through

Item

Nomenclature

tunnel provided in float. Use tie strap

CM318

Primer

as required. Attach wire to position

light.

CM425

Sealing compound

CM430

Sealant, solvent resistant

(5).

Install bracket using screws. Secure tab

CM717

Tape, pressure sensitive

and position light to bracket using

screws, washers and nuts. Install cover

using screws (view A).

(1).

At forward strut, install approximately

(6).

Install bolt cover pads using tape

3 feet (92 cm) of wire to position light

(CM717) (view B).

electrical harness using splice and

silicone tube. Apply sealant (CM430) to

(7).

Locate strobe light (Ref. Figure 901

ends of splice. Route wire through

view A). Remove attaching hardware

nutplate hole in forward foot (Ref.

and disconnect wire harness. Remove

Figure 902, view A) and seal gaps and

strobe light and doubler. Retain

holes with sealing compound (CM425).

attaching hardware and strobe light.

(2).

Connect wire harness to position light

(8).

Position shield and strobe light (Ref.

using bracket, screw, washer and nut

Figure 904). Connect wire harness to

(Ref. Figure 904, view A). Secure wire

strobe light and install shield and

harness to bracket with strap. Seal

strobe light using hardware retained

connection with sealant (CM430).

from removal.

(3).

Apply sealing compound (CM425) to

(9).

Install landing gear fairings (Ref. Sec.

mating surfaces of foot and strut

32-10-00).

assemblies. Insert forward and aft foot

assemblies into strut assemblies. Align

G. Weight and Balance

bolt holes, apply thin coat of primer

Weight and balance changes that result from in

(CM318) to ABC bolts and install bolts

stallation of utility floats are listed in Table 901.

while primer is still wet. Torque bolts to

After installation of utility floats, incorporate

40 - 60 inch-pounds (4.52 - 6.78

changes to helicopter weight and balance record

Nm).

as instructed in Section 08-10-00.

Table 901. Weight and Balance Data

Weight

Arm

Moment

Configuration

lbs (kg)

in.

(cm)

in.−lb/100 (kg mm/100)

369D290086−Basic

Added

+131.8

(59.783)

122.2

(310.39)

+161.06

(1855.60)

Removed

−9.5

(4.309)

103.9

(263.91)

−9.87

(113.71)

Change

+122.3

(55.474)

123.6

(313.94)

+151.19

(1741.89)

369D290086−501

Added

+143.1

(64.909)

125.5

(318.77)

+179.59

(2069.09)

Removed

−8.1

(3.674)

99.8

253.49)

−8.08

(93.09)

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CSP-HMI-2

MAINTENANCE MANUAL

EMERGENCY FLOAT SYSTEM

MAINTENANCE PRACTICES

1. Emergency Float System Description and

(2).

Flotation Equipment Emergency

Operation

flotation equipment consist of two

inflatable emergency floats, electroni

A collapsed emergency float with an emergen

cally controlled inflation equipment,

cy inflation system (stowed condition) is

four landing gear fairings and landing

attached to each landing gear skid. The floats

gear skid tube extensions. Nutplates on

may be fully inflated during flight in approxi

each skid tube and extension provide

mately five seconds. The electrically controlled

for float attachment. A cabin entry step

inflation system includes a self-test capability

may be used with the landing gear

to provide the pilot with a visual indication of

without interference with the floats.

the electrical circuit reliability. Landing on

water or land is permitted when emergency

(3).

Inflatable Emergency Floats Each of

floats are inflated.

the two inflatable neoprene emergency

floats consists of sealed airtight

Emergency flotation equipment in the stowed

chambers separated by internal walls

condition does not restrict normal land

that provide five individual watertight

operation of the helicopter. When inflated, the

compartments. Skid attachment strips

floats will support the helicopter on water at

(girts), bonded to the underside of the

maximum gross weight. After emergency

floats, are bolted to the landing gear

inflation, the inflation system may be serviced

skids. In addition, fore and aft web

with fully charged dry air or nitrogen pressure

support straps secure the floats to the

vessels, and the floats repackaged to a

skids. The floats are inflated to a

streamlined stowed condition.

nominal operating pressure of 4.0 psig

(28 kPa) by the emergency inflation

A. Emergency Float Description

system upon pilot activation of the

inflation system electrical control

(1).

Electrical System The emergency float

equipment. Relief valves provide for air

electrical installation assumes prior

pressure release at a compartment

incorporation of the 369H90129-31,

pressure of 4.5 psi (31 kPa) or above.

369H90129-505 or 369H90129-511

pilot's cyclic stick grip kit. The emer

A snap-on containment cover with

gency float electrical system includes a

lacing restrains the float in the stowed

circuit breaker, visual indicator switch

configuration until the emergency

for testing circuit operation reliability,

inflation system inflates the float. The

and a relay. The pilot's cyclic stick grip

containment cover inboard side auto

is equipped with an EMERG/FLOAT

matically unsnaps and is pushed

push-button switch. When the pilot's

outboard as the float inflates. After

grip switch is actuated, the electrical

emergency float use, deflation, pressure

system energizes and provides electrical

vessel recharging and folding, the cover

power for simultaneous operation of the

is again snapped in place over the float

left and right emergency float inflation

and replaced for subsequent reuse.

system. The float inflation system

consists of an electrically operated

A mooring ring atop each end of the

solenoid valve, or squib valve, attached

float is furnished for towing and

to a compressed dry air or dry nitrogen

mooring. An extended landing gear skid

pressure vessel. When the solenoid is

tube extension supports the float aft

energized or the squib is actuated, the

section on the landing gear. Forward

pressure vessel valve opens and

and aft restraining straps are provided

releases compressed dry air or dry

at landing gear strut and fairing

nitrogen into compartments of each

locations. Gap covers close off the

float.

inboard cutouts for the strut fairings.

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MAINTENANCE MANUAL

(4).

Emergency Inflation System The

(2). Check girt to skid attaching hardware

emergency inflation system consists of

for condition and corrosion.

a charged compressed pressure vessel,

air hoses, valves and associated

(3). Check float cover fasteners and lacing

components for inflation of the emer

for security.

gence floats. A complete emergency

(4). Examine float stowage cover for

inflation system is installed on and is

abrasive damage that may have

part of each float.

disturbed package float.

When actuated by inflation system

(5). Perform an operational check of float

electrical control equipment, a solenoid

inflation system electrical control

valve or squib valve attached to the

equipment.

pressure vessel releases compressed dry

air or dry nitrogen for distribution

4. Emergency Float Inspection

through the air hoses and inlet check

valves for the five float compartments.

NOTE: To be performed every six months or as

A relief valve on each float compart

necessary.

ment opens if compartment pressure

exceeds 5 ±0.5 psi (34.5 ±3.5 kPa).

(1). Check for proper air pressure indication

on pressure gage.

The pressure vessel operating pressure

is 3000 - 3575 psig (20684 - 24649 kPa)

(2). If float is stowed, unsnap containment

at 65 - 85°F (18 - 30°C); 3500 ±75 psig

cover and loosen restraining lacing for

(24132 ±517 kPa) at 65 - 85°F (18 -

access to emergency inflation system

30°C) is preferred. The manifold is

components.

attached to the pressure vessel along

with an indicating pressure gage, filler

(3). Remove pressure vessel, inspect for

valve and a pressure relief valve. The

damage and scratched, nicked or

pressure vessel relief valve operates at

otherwise damaged paint coating.

and above 4250 ±250 psig (29303 ±1724

NOTE: Superficial paint coating damage

kPa). Detachable rubber boots cover the

should be repaired by paint touchup.

filler and pressure relief valves for

protection against chafing. The pres

(4). Inspect valves, air hoses and other air

sure vessel may be detached from the

distribution components for damage,

float for servicing.

deformity, strain, chafing or corrosion.

Certification and Shelf/Service Life

NOTE: Corrosion of the electrically operated

solenoid/squib valve may occur as a result of

The Federal Aviation Administration (FAA)

improper charging of the pressure vessel.

has granted Squib PN 5003527-1 of the

Ensure that only dry air or dry nitrogen is

squib-actuated emergency float valve a

used to charge the pressure vessel.

provisional five-year life limit. This life limit

(5). Perform an inflation system electrical

is established by date of manufacture, which is

control equipment operational check to

ink-stamped on the body of the squib (Ref.

ensure electrical continuity and

Sec. 04-00-00).

connection of solenoid/squib valve.

3. Emergency Float Inspection (Stowed

Ensure that pressure vessel

Configuration)

CAUTION

gage is visible through inspec

tion window.

NOTE: The following inspections must be per

formed daily and before each flight.

(6). Tighten and re-tie the lacing and snap

the containment cover in place if not

(1). Observe vessel pressure through

continuing to Float Compartment

inspection window.

Pressure Test.

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CSP-HMI-2

MAINTENANCE MANUAL

Table 201. Troubleshooting Emergency Flotation Equipment

Symptom

Probable Trouble

Corrective Action

A charged float pressure vessel must be discharged before the associated float valve is removed

CAUTION

from the pressure vessel. Use care to prevent accidental float inflation.

No reliability light indication,

Burned−out lamp.

Replace lamp.

either left or right.

Defective connection or wiring.

Repair connection or wiring.

Open circuit to solenoid float valve.

Replace float valve.

No reliability light indication,

Defective connection or wiring.

Repair connection or wiring.

both left and right.

Reliability light indication for

Defective actuating switch.

Replace actuating switch.

both floats; neither float

Defective actuating switch wiring.

Repair wiring.

inflates.

Float leaks air.

Damaged float.

Repair float.

5. Emergency Float Compartment Pressure

6. Emergency Float Inspection (After

Test

Inflation)

To be performed every 6 months or after 5

Consumable Materials

inflations (Ref. Sec. 04-00-00).

(Ref. Section 91−00−00)

Item

Nomenclature

(1). Inflate all float compartments at the fill

valves to 4.5 psi (31 kPa) for one hour.

CM220

Naphtha aliphatic

Check for leaks and condition.

(1). Clean float as follows:

(2). Continue inflation to 5.5 psi (38 kPa)

and check that chamber pressure relief

(a). Clean away any oil or grease with

valves operate.

naptha (CM220).

(3). Lower pressure in all five float com

(b). Wash down with soapy water; flush

partments to 2.0 psi (14 kPa) and let

with clear fresh water and allow to

stand for 24 hours.

air dry.

(c). Clean air pressure gage inspection

NOTE: Changes in atmospheric pressure and

window with a clean cloth and fresh

temperature during pressure test of float

water.

compartments will affect pressure gage

readings. A temperature change of 1 degree

(d). After inspection is complete, dust

equals 0.032 psig (0.2206 kPa).

with talc.

(4). Check the pressure drop with a pres

(2). Recharge pressure vessel to 3500 psig

sure gage that indicates 0 - 15 psi (0 -

(24132 kPa) at 75°F (24°C).

103 kPa), graduated in 0.5 psi (5 kPa)

increments. The maximum allowable

(3). Inspect float bags for abrasion and

pressure drop in 24 hours is limited to

chafing.

0.5 psi (5 kPa) per compartment.

(4). Inspect pressure relief valves for

condition and closure.

(5). If a pressure drop occurs, check floats

for soundness.

(5). Inspect check valves for condition.

(6). Tighten and re-tie the lacing and snap

(6). Inspect all hoses and connectors for

the containment cover in place.

condition and security.

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MAINTENANCE MANUAL

(7). Check float girts, web support and

NOTE: Changes in atmospheric pressure and

restraining straps for condition and

temperature during pressure test of float

secure attachment to skid tube.

compartments will affect pressure gage

readings. A temperature change of 1 degree

(8). Check all release snaps and fasteners

equals 0.032 psig (0.2206 kPa).

for condition and serviceability.

(2). Check the pressure drop with a pres

(9). Check that pressure vessel relief valve

sure gage that indicates 0 - 15 psi (0 -

and filler valve boots are installed.

103 kPa), graduated in 0.5 psi (5 kPa)

increments. The maximum allowable

(10). Repack floats.

pressure drop in 24 hours is limited to

0.5 psi (5 kPa) per compartment.

7. Emergency Float Test

(3). If a pressure drop occurs, check floats

The squib is an electrically

for soundness.

WARNING

fired explosive device. Keep

9. Emergency Float Repair

squibs away from all sources of heat,

open flame, sparks and electrical con

Contact MDHS Field Service Department for

tacts. Squib plugs are to be in place un

repair information.

til squibs are installed in aircraft.

10. Solenoid−to−Squib Rework Procedure

(1). Perform inflation operational reliability

The following is a procedure to replace the

test of float inflation electrical system

solenoid, which is no longer manufactured, to

as follows:

the squib valve.

(a). Press LH/FLT and RH/FLT combi

(1). Turn off electrical power.

nation press-to-test switch located

(2). Unpack emergency floats.

below the lower switch and circuit

breaker panel on the sllmline instru

(3). Remove valve protector and unlace

ment panel and at the top-center of

cylinder sling lacing cords (Ref.

the ”T” panel, to test float inflation

Figure 402).

electrical circuit reliability.

(4). Disconnect solenoid valve electrical

wiring knife splice at (SP4, SP5, SP9

NOTE: Pressing the press-to-test switch ap

and SP10) solenoid.

plies low voltage (insufficient to energize/

actuate the pressure vessel valve solenoid/

(5). Loosen nut at outlet port of solenoid

squib) to the emergency float circuit.

valve. Disconnect valve assembly from

Internal light bulbs in the switch will illu

union by unscrewing cylinder and valve

minate if the circuit is operational.

assembly in counterclockwise direction.

Remove cylinder and valve assembly.

(b). Observe that each switch faceplate is

(6). If cylinder is not empty, discharge as

illuminated when pressed and goes

follows:

out when switch is released.

Exercise care when dis

NOTE: Failure to illuminate indicates a bur

WARNING

charging cylinder. Person

ned-out light bulb in the switch or a defec

nel can be injured by high pressure air

tive circuit. Extreme brightness indicates a

or flying debris.

defective circuit.

(a). Secure cylinder in chain vise or

(2). Check each pressure vessel for proper

equivalent. Point filler valve outlet in

(normal) air pressure, 3500 psig (24132

safe direction.

kPa) at 70°F (24°C).

(b). Use two open end wrenches, one on

filler valve body and one on nut. Turn

8. Float Compartments Pressure Test

nut slowly counterclockwise 2-1/4

(1). Inflate all five float compartments to

turns and allow all pressure to

2.0 psi (14 kPa) and let stand for 24

escape. Check gage to verify that no

hours.

pressure remains in cylinder.

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CSP-HMI-2

MAINTENANCE MANUAL

(7). Remove solenoid valve from cylinder.

3).

Install one lead of 0.5 ohm ±5%,

Discard solenoid valve and packing.

10W resistor in pin A of left-hand

connector (P101). Connect one test

(8). Install new squib valve (PN 23111380-3

lead of ammeter (VOM) to other

LH float, PN 23111380-4 RH float) with

lead of resistor. Connect other test

PN MS28778-12 packing on cylinder.

lead of ammeter (VOM) to pin D of

Torque to 360 - 504 inch pounds

connector (P101).

(40.67 - 56.95 Nm) (Ref. Figure 403).

4).

Close emergency float circuit

(9). Install fitting with PN MS28778-6

breaker (CB121).

packing on existing union.

5).

Press PRESS-TO-TEST switch

and observe current reading on

(10). Recharge cylinder and test for air leaks.

ammeter and brilliance of lamps.

(11). Install charge cylinder and squib valve

Current should be 75 MA mini

assembly with PN MS28778-6 packing

mum and brilliancy of lamps

on fitting.

should be fairly bright.

6).

Open emergency float circuit

(12). Revise emergency float electrical

breaker (CB121).

system as follows:

7).

Remove meter and resistor from

(a). Remove access panels and/or covers

connector (P101).

as necessary to expose emergency

float wiring.

8).

Repeat steps 3). through 7). for

right-hand connector (P102).

(b). Remove all emergency float wiring

except as noted in Figure 903.

(b). System check;

1).

Ensure that circuit breaker

(c). Remove and discard relay installa

(CB121) is open and connectors

tion, doubler and attaching hardware

(P101 and P102) are disconnected.

located on pilot's floor support, left

bulkhead.

2).

Install one lead of 40 ohm ±1%,

20W resistor in pin A of left-hand

(d). Remove emergency float switch light

connector (P101) and install other

assembly and install new switch light

lead of resistor in pin D of connec

assembly.

tor (P101).

(e). Install wiring as shown in

3).

Connect test leads of voltmeter

Figure 902. Do not plug in electrical

(VOM) across resistor.

connectors (P101 and P102) until

after electrical system check.

4).

Close emergency float circuit

breaker (CB121).

(f). Reinstall access panels and/or covers.

5).

Press firing switch on pilot's grip

(13). Turn on electrical power.

and observe voltage on meter.

Voltage should be 25.5 Vdc mini

(14). Perform inflation system electrical

mum.

control equipment operational check as

6).

Open circuit breaker (CB121).

follows:

7).

Remove meter and resistor from

(a). Test light check;

connector (P101).

1). Check ship voltage with VOM.

8).

Repeat steps 2). through 7). for

Voltage should be 27.5 Vdc.

right-hand connector (P102).

2). Open emergency float circuit

(c). Connect connectors (P101 and P102)

breaker (CB121).

to squib valves.

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MAINTENANCE MANUAL

EMERGENCY FLOAT SYSTEM

REMOVAL/INSTALLATION

1. Emergency Float Replacement

NOTE: If extension tubes are not installed on

helicopter, refer to Skid Tube Extension Re

A. Emergency Float Removal

placement.

(Ref. Figure 401)

(2).

Position float girts over skid tube

attach points.

(1). If float is in stowed configuration,

release fasteners to gain access to float

(3).

Temporarily attach float web support

package.

strap fittings at forward location;

Secure strap fitting at aft attach

(2). Detach lower restraining strap and gap

location with bolts and washers.

cover at forward and aft struts.

(4).

Place gravel guards over float girts and

(3). Disconnect solenoid valve electrical

secure with bolts and washers. Torque

wiring at knife splice at solenoid valve

all bolts securing float girts to skid

or disconnect squib valve electrical

tubes to 25 - 35 inch-pounds (2.82 -

connector at squib and install shunt.

3.95 Nm).

(4). Remove strut fairing, insulate strut

(5).

Apply zinc chromate putty (CM209) to

wire end knife splices, attach wiring to

contact surfaces of previously removed

strut in a stowed position and reinstall

abrasion strips, and skid extension

fairing.

abrasion strips to ensure watertight fit

on landing gear skids.

(5). Remove bolts and washers attaching for

and aft web support strap fittings to

(6).

Loosen float forward web strap fitting

skid tube.

and position abrasion strip on skid

below strut; position web strap fitting

(6). Remove bolts and washers attaching

over forward attach hole on abrasion

float girts to skid tube extension;

strip and secure strip to skid with bolts

remove float assembly.

and washers. Install remaining abra

sion strips; remove excess zinc chro

B. Emergency Float Installation

mate putty.

(Ref. Figure 401)

(7).

Install remainder of bolts and washers

securing float girts to skid tube exten

Consumable Materials

sion.

(Ref. Section 91−00−00)

(8).

Adjust and secure float landing gear

Item

Nomenclature

strut cutout restraining straps.

CM209

Zinc chromate putty

(9).

Unsnap float containment cover and

loosen restraining lacing to gain access

NOTE: The float assembly must be removed

to emergency inflation system compo

from the stowage envelope for installation.

nents.

(1). Open float package and release re

(10).

Connect squib valve electrical connector

straining straps.

at squib.

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MAINTENANCE MANUAL

FLOAT GIRTS

FLOAT ATTACHMENT

CONTROL

SWITCHES

STOWED FLOAT

GRAVEL GUARDS

CIRCUIT

BREAKERS

AFT LANDING GEAR STRUT

SKID TUBE

NARROW FAIRING

EXTENSION

WEB

ATTACHMENT

WEB SUPPORT

GIRT

STRAP

COVER

PRESSURE GAGE

INSPECTION WINDOW

ABRASION STRIP

SKID

COVER

ABRASION STRIP

INFLATED FLOAT

FITTING

GRAVEL GUARD

(NOTE)

FORWARD LANDING GEAR

CONTAINMENT

STRUT NARROW FAIRING

COVER

ABRASION STRIP

SUPPORT TUBE

AIR HOSE (TYP)

GRAVEL GUARD

RETAINING STRAP

ABRASION STRIP

(TYP)

SOLENOID

STRUT-TO-SKID

PRESSURE RELIEF VALVE

COVER

AND FILLER VALVE

PRESSURE VESSEL

FOOT

FILL VALVE

GAP COVER

(TYP)

MOORING

RING

MANIFOLD

PRESSURE

GAGE

ABRASION

SKID TUBE

STRIP

FORWARD FOOT - OUTBOARD SIDE

INLET CHECK VALVE

(TYP)

NOTE:

FORWARD FITTINGS ATTACHED AT FIRST NUTPLATE

PRESSURE RELIEF

FORWARD OF STRUT FOOT. REAR FITTINGS ATTACHED

VALVE (TYP)

AT FIRST NUTPLATE AFT OF STRUT FOOT.

G32-8002

Figure 401. Emergency Float Installation

Page 402

Revision 19

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

2. Emergency Float Pressure Vessel

D Squib valve: If actuated, replace with a

Servicing and Replacement

serviceable valve. Install valve on pres

420

sure vessel and torque to 380 -

(Ref. Figure 401) Maximum allowable temper

inch-pounds (42.93 - 47.45 Nm).

ature during charging is 165°F (75°C).

Detaching the pressure vessel from the float

during charging is the preferred procedure.

(5). Detach restraining lacing and remove

Maximum pressure vessel pressure is 3500

pressure vessel from float.

psig (24132 kPa) at room temperature, 70°F

(21°C). As outside air temperature will affect

(6). Recharge pressure vessel with dry

the day-to-day gage reading, temperature

nitrogen or compressed dry air to 3000

versus pressure readings are important during

- 3500 psi (20684 - 24132 kPa) at 75°F

servicing or inspection of the pressure vessel

(24°C); 3500 psig (24132 kPa) at 75°F

air pressure. The indicated pressure on the

(24°C) is preferred. Cool cylinder with

gage will increase or decrease 6.6 psig (45.5

water and charge slowly to maintain

kPa) per 1°F (0.4°C) increase or decrease,

vessel surface temperature below 250°F

respectively, in vessel air temperature. Slow

(122°C).

variations in ambient air temperature will be

reflected in the vessel air temperature;

however, it must be considered that direct or

NOTE: The pressure vessel may also be serv

reflected solar radiation will result in higher

iced by weight. When servicing by weight,

pressure than would be anticipated for the

use a scale and weigh the empty vessel with

existing ambient air temperature.

attaching hardware installed. Charge the

empty vessel until a weight increase of 3.7 -

4.4 pounds (1.68 - 2.0 kg) is obtained; 4.4

Consumable Materials

±0.1 pounds (2.0 ±0.05 kg) is preferred.

(Ref. Section 91−00−00)

When charging by weight, air temperature

Item

Nomenclature

variation will have no affect. Observe vessel

CM810

Leak detector, liquid

cooling precaution.

(1). If float is stowed, unsnap containment

(7).

Test for air leaks by applying liquid

cover to extent required for access to

leak detector (CM810) to the valve-

pressure vessel.

pressure vessel interface. No air

bubbles are permitted.

(2). Open manifold change valve to verify

that there is no pressure remaining in

pressure vessel.

(8).

Dry with clean lint-free cloth and then

allow to air-dry completely.

(3). Remove the three air hoses at air

manifold. Do not allow the manifold to

turn when disconnecting the hoses.

(9).

Inspect the emergency inflation system.

(4). Disconnect solenoid valve electrical

wiring knife splice at solenoid or

(10).

Cover vessel with bag and tie closure

disconnect squib valve electrical

lacing.

connector at squib and install plug.

Use a wide-strap wrench, 2 inch

(11).

Reinstall vessel and bag on float;

CAUTION

(5 cm) minimum width, to apply

re-connect air hose fittings and

torque on the pressure vessel, taking care

solenoid/squib valve electrical wiring

not to damage it. Use crowfoot adapter on

knife splice/squib valve electrical

the torque wrench at the valve body.

connectors. The pressure vessel must be

positioned so that air hose connections

NOTE:

place no strain on the solenoid/squib

D Solenoid valve: Do not remove solenoid

and the pressure gage is visible through

and relief valve assembly from pressure

the pressure gage inspection window

vessel.

when the floats are stowed.

Page 403

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Revision 19

CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

VALVE PROTECTOR

SOLENOID VALVE PROTECTOR

NUT

UNION

CROSS

PRESSURE VESSEL

G32-8003

Figure 402. Solenoid Valve Assembly

(12). Reinstall manifold cover.

(4). Spread plastic cover at it's parting line

until small round end of white plastic

(13). Perform an inflation system electrical

buttons pull through the black plastic

control equipment reliability test.

and over the squib connector, allowing

access to four screws that retain the

actuating valve body.

3. Squib and Squib Actuated Valve

Replacement

(5). Using Allen wrench, remove four

(Ref. Figure 402 and Figure 403) Each time

screws near the outlet port retaining

the emergency floats are inflated using the

the actuated valve body. Retain screws

emergency float inflation system, the squib

for installation of new valve.

and squib actuating valve must be replaced.

(6). Pull spent valve and squib off vessel.

NOTE: Solenoid valves used in the emergency

Discard activated valve and squib.

float system are no longer available from the

manufacturer. Emergency float systems

(7). Lightly lubricate O-ring on new valve

equipped with the solenoid valve must be

with MIL-G-4343 or equivalent

converted to the squib valve system when

pneumatic grease.

the service life of the solenoid valve is ex

ceeded.

The squib is an electrically

WARNING

fired explosive. Ensure con

(1). Open manifold change valve to verify

nector plug is installed in connector

that there is no pressure remaining in

pressure vessel.

prior to installation.

(2). Remove pressure vessel with squib

(8). Maintain squib orientation noted in

valve assembly attached.

step (3).. Install squib actuated valve,

with squib installed, into manifold.

(3). Note orientation of squib with respect

Squib actuated valve must bottom

to pressure gage.

metal-to-metal on face of manifold.

Page 404

Revision 19

32-82-00

CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

(9). Install four screws removed in step e.

cover, all snaps must be closed and the

hand tight until locking thread of

pressure vessel pressure gage must be

helicoil insert in manifold is engaged.

visible in the inspection window.

Special attention should be paid to the

(10). Using Allen wrench, tighten the four

following information which is pres

screws evenly until bottomed. Torque

ented as an aid in establishing a final

screws to 38 - 43 inch-pounds (4.29 -

float folding technique.

4.86 Nm).

(a). Accomplish float folding in two

(11). Remove plug from squib connector.

stages, first performing float arrange

Note that plug only fits one way.

ment (pre-folding) to the extent

Realign black plastic cover and pull it

necessary to position the float and

back over the squib connector. Replace

float components in approximate

squib connector plug.

required positions and then proceed

ing with the final folding.

(12). Snap white plastic buttons back

through holes in black plastic cover.

NOTE: Partial inflation of float compartments

Check plug in squib connector to ensure

is required to enable float arrangement dur

it is bottomed.

ing initial pre-folding.

(13). Charge pressure vessel and reinstall on

(b).

During pre-folding and before air

emergency float assembly.

evacuation of the forward compart

4. Emergency Float Folding

ments (cells) as outlined in step 4, do

the following. Gather and compress

(Ref. Figure 404) Folding instructions con

the float fabric tightly against the

tained in this procedure are provided as a

vessel and pull the cover over the

general guide for float packing. Float folding

inboard-facing pressure gage to

will require the aid of an assistant and

estimate final cover window-to-gage

considerable care in preparing the smallest

relationship. This fabric bunching/

float package possible during the initial folding

cover pulling action may be required

steps. A minimum amount of wrinkles and

several times before an approxima

complete air evacuation is essential to final

tion (best guess) of final window

closure of cover snap fasteners.

position is established. When cover

position appears good, evacuate all

(1). Position deflated float (five fill valves

air from the forward cells and

OPEN).

recheck the window-to-gage rela

NOTE: The float assembly must be removed

tionship.

from the stowage envelope for installation.

(c).

As soon as a float chamber is ar

Do not attempt to position the float for pack

ranged in the desired position, hold

aging with the float chambers fully col

the components in place, flatten as

lapsed.

many wrinkles as possible and

(2). Fold the float as outlined in the figure.

evacuate air from the float chamber.

On completion, the folded float must be

While the vacuum is still being

contained within the float stowage

applied, close the fill valves.

Page 406

Revision 19

32-82-00

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

STEP 7

FOLD HERE

STEP 2

LANDING GEAR AFT

STRUT (REF)

LANDING GEAR

FORWARD STRUT

STEP 3

(REF)

STEP 5

SKID TUBE

EXTENSION

(REF)

STEP 8

STEP 10 AND 11

STEP 4

STEP 6

STEP 1

STEP 9

STEP 1

OPEN ALL FILL VALVES OF INFLATED FLOAT AND COMPRESS CELLS LIGHTLY BY HAND SO THAT FLOAT IS FLAT

AND AS SMOOTH AS POSSIBLE.

STEP 2

PLACE FOLD AT AFT END OF SKID EXTENSION THEN EVACUATE AFT OUTBOARD AIR COMPARTMENT (CELL)

UNTIL FOLD IS FIRM AND SHARP. CLOSE FILL VALVE.

STEP 3

WHILE COMPRESSING SUPPORT TUBE AND HOLDING FLOAT CENTER FORWARD AND DOWN, PLACE A FOLD IN

INBOARD CENTER CELL BETWEEN INLET CHECK VALVE AND FILL VALVE. REARRANGE AIR HOSE AS REQUIRED.

CONTINUE HOLDING PRESSURE ON SUPPORT TUBE. EVACUATE CENTER CELL THEN AFT INBOARD CELL UNTIL

FOLDS ARE SHARP AND SUPPORT TUBE IS FIRMLY HELD FROM MOVING AFT. CLOSE FILL VALVE.

STEP 4

POSITION PRESSURE VESSEL SNUG AGAINST OUTBOARD SIDE OF FORWARD STRUT. WHILE HOLDING VESSEL IN

POSITION, EVACUATE FORWARD OUTBOARD CELL THEN FORWARD INBOARD CELL UNTIL CREASES ARE FIRM

AND SHARP. CLOSE FILL VALVE.

STEP 5

RECHECK FLOAT. CHECK THAT FLOAT IS AS FLAT AS POSSIBLE AND FREE OF ALL AIR POCKETS. DOUBLE CHECK

FIRMNESS OF ALL CREASES AND RE−EVACUATE CELLS AS NECESSARY.

NOTE: ANY REMAINING AIR MIGHT CAUSE FLOAT OPENING AT ALTITUDE AND DIFFICULTY IN PACKING.

STEP 6

FOLD FLOAT AFT AT FORWARD END. REPOSITION HOSES AS REQUIRED. STOWAGE COVER MUST BE OUTSIDE

OF FOLD LINE.

STEP 7

FOLD FLOAT FORWARD AT AFT END. REPOSITION AIR HOSES AS REQUIRED. STOWAGE COVER MUST BE

OUTSIDE OF FOLD LINE.

STEP 8

ROLL AND FOLD LENGTH OF FLOAT TOWARDS CENTER. DO NOT COVER PRESSURE GAGE.

STEP 9

ROLL AND FOLD LENGTH OF FLOAT TOWARDS CENTER. FASTEN SNAPS STARTING AT FORWARD END. ENSURE

THAT PRESSURE GAGE IS VISIBLE IN INSPECTION WINDOW. DO NOT FASTEN END COVER SNAPS.

STEP 10

TIGHTEN LACING. ENSURE THAT SNAP FASTENERS REMAIN CLOSED.

STEP 11

SECURE END COVER SNAPS. ALL SNAP FASTENERS MUST BE USED.

Figure 404. Emergency Float Folding

Page 407

32-82-00

Revision 19

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

EMERGENCY FLOAT SYSTEM

INITIAL INSTALLATION

1. Emergency Float System Initial

(a). Ensure that all flight compartment

Installation

switches are in OFF position.

Make certain BATT-OFF-EXT

A. General

CAUTION

switch is in OFF position.

Procedures in this section may be performed at

(2). Remove landing gear strut fillets and

the operator's discretion. Instructions are

fairings (Ref. Sec. 32-10-00). Retain all

provided for installation of emergency float kit

doublers, guides, pins and springs for

on either the current or early configurations of

reinstallation.

the extended landing gear. Subsequent

installation instructions for the emergency

(3). On current configuration landing gear,

floats and the float electrical control system

remove forward nut, bolt and spacer

are identical for the current and early ex

attaching existing extension to aft end

tended landing gear configurations. Equip

of skid tube; retain nut for reinstalla

ment removal and modification differences

tion.

between the current and early configurations

are noted in the subsequent instructions.

(4). On early configuration landing gear,

remove abrasion strip attached to

The emergency float kits are provided with as

existing skid tube extension (Ref. Sec.

many assembled parts as practicable to

32-10-00).

facilitate initial installation on the helicopter.

Installation of electrical equipment assumes

(5). Remove screws and bolts securing skid

prior incorporation of pilot's cyclic stick grip

tube extension; retain early configura

kit (369D90129-507 or 369D90129-511).

tion indexing plugs for reinstallation.

(6). Remove skid abrasion strips below for

B. Initial Preparation

and aft fairings; retain abrasion strips

for reinstallation.

Instructions in the following paragraphs are

applicable to both left and right landing gear

D. Landing Gear Skid Extension Assembly

assemblies. Prepare the aircraft for installa

tion of emergency floats as follows:

(Ref. Sec. 32-81-00)

NOTE: When installing emergency floats, the

E. Emergency Float System Electrical

V_NE cards must be replaced with the cards

Equipment Installation

that come with the floats (Ref. appropriate

PFM).

(Ref. Figure 901)

(1). Remove attaching hardware and

(1). Identify all components, including

separate lower switch and circuit

attaching hardware, and components

breaker panel from instrument panel

removed for access to work areas.

structure.

Protect components from damage and

contamination until installed.

(2). Remove covers from emergency float

press-to-test switch and circuit

(2). Raise aircraft clear of ground; Use

breaker cutouts from lower switch and

authorized hoisting or jacking methods

circuit breaker panel.

(Ref. Sec. 07-00-00). Place support

beneath skid tubes at strut locations.

(3). Install emergency float circuit breaker

in panel.

C. Existing Equipment Removal

NOTE: Press-to-test switch is installed during

(1). Remove Battery (Ref. Sec. 96-05-00).

subsequent wiring installation procedure.

Page 901

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Revision 19

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

F. Emergency Float System Electrical

(6). Install wiring through landing gear

Wiring Installation

struts as follows:

(Ref. Figure 902 thru Figure 905)

(a).

Drill 0.442 inch (11.2268 mm) hole

centered on outboard side of forward

struts located five inches (12.7 cm)

Consumable Materials

above centerline of skid tube; deburr

(Ref. Section 91−00−00)

holes internally and externally.

Item

Nomenclature

(b).

Coat bare metal in holes with primer

CM318

Primer

(CM318); allow primer to dry.

CM601

Insulation sleeving, electrical

(c).

Remove left and right foot support

fairing in passenger compartment for

(1).

Identify wires as required and form

access to landing gear forward struts.

wire bundle of applicable wires to

emergency float circuit breaker and

(d).

Install insulation sleeving on float

press-to-test switch on lower switch

valve squib wires.

and circuit breaker panel.

(e).

Locate position light wire bundle exit

(2).

From battery compartment area, route

holes on top inboard portion of left

and right landing gear struts; Insert

wire bundle forward and up through

respective float squib wire bundles

instrument panel support structure;

through position light wire bundle

route wire bundle with existing bundles

exit holes. Locate wires through

where possible.

previously drilled wire exit hole at

(3).

Install insulation sleeving (CM601) and

bottom of each strut. Carefully pull

connect applicable wires to contacts on

wires through holes allowing suffi

press-to-test switch and circuit

cient length for connections at either

breaker; assemble and secure press-to-

end.

test switch to panel.

(f).

Slide grommet over wire bundle on

(4).

Adjust wire bundle and allow sufficient

both struts; Install grommet in

slack for maintenance; strap and string

previously drilled wire exit holes.

tie bundle to form smooth flow of wires

(g).

Attach clip (Ref. Figure 901, view G).

to battery compartment area.

(h).

Coil and stow wires to avoid damage

(5).

Ensure all switch and circuit breaker

during float equipment installation.

contacts are secure and that sleeving is

properly installed; remove paint from

(7). Complete balance of all wiring. Install

panel and console in upper screw area

insulation sleeving as required to

to ensure good ground contact. Install

prevent shorting and chafing through

panel on console.

out circuit wiring.

Page 903

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Revision 19

CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

G. Emergency Float Electrical System

Ensure that the BATT-OFF-

CAUTION

Inspection

EXT switch is in the OFF posi

tion.

Before connecting battery plug, the following

H. Emergency Float System Strut Fairing

wiring installation inspection must be per

Installation

formed.

(Ref. Figure 906)

(1).

Inspect all wiring connections for

security and insulation.

Consumable Materials

(Ref. Section 91−00−00)

(2).

Inspect all wiring for interference with

Item

Nomenclature

moving parts and for areas where

chafing could occur.

CM209

Zinc chromate putty

(3).

Inspect all wiring for conformance with

The following installation instructions are

wiring diagrams.

typical for all four strut fairing assemblies.

Where riveting is required, Refer to referenced

(4).

Install all access panels, doors and

instructions for proper rivet types.

access covers previously removed.

(1).

Install center fairing, fillet and lower

(5).

Remove insulation and temporarily

fairing in respective order, and general

connect each set of float squib wires.

ly in accordance with instructions (Ref.

Sec. 32-10-00).

(6).

Install battery, connect battery plug

and place BATT-OFF-EXT switch in

(2).

During installation of fairings, ensure

BATT position.

that doublers, removed during disas

sembly, are installed between fairings

(7).

Momentarily press emergency float

and fillers at screw attach points.

press-to-test switch to verify proper

(3).

Ensure blocks are installed at lower

wiring continuity; all four switch lamps

trailing edge of fillets to ensure free

should illuminate.

action of fillet with strut movement.

(8).

Separate float squib wires at base of

(4).

Ensure that float solenoid/squib wire

struts.

bundles are free at bottom of lower

fairings on forward struts.

(9).

Actuate EMERG/FLOAT switch on

pilot's cyclic stick grip; use voltmeter to

(5).

Install bolt covers over inboard bolt

check for proper voltage and continuity

heads on strut foot/skid attach point.

through float squib valve circuits.

Apply sufficient zinc chromate putty

(CM209) to fill all voids between cover

(10).

Pull out emergency float circuit breaker

and bolt head area; secure forward

to remove power and release relay;

strut bolt covers with existing nylon

push circuit breaker in again to prepare

hardware. Torque screws to 25 - 35

circuit for emergency use.

inch-pounds (2.82 - 3.95 Nm).

Page 910

Revision 19

32-82-00

CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

I. Emergency Float Installation

(6).

Loosen float forward web strap fittings

and position abrasion strip on skid

below strut; position web strap fitting

Consumable Materials

over forward attach hole on abrasion

(Ref. Section 91−00−00)

strip and secure strip to skid with bolts

Item

Nomenclature

and washers. Install remaining abra

CM209

Zinc chromate putty

sion strips; remove excess zinc chro

mate putty.

Installation of the left and right emergency

(7).

Install balance of bolts and washers

floats is identical except for opposite positions.

securing float girts to skid tube exten

(1). Open float package and release re

sions. Torque all bolts to 25 - 35

straining straps.

inch-pounds (2.82 - 3.95 Nm).

(2). Position float girts over skid tube

(8).

Adjust and secure float landing gear

attach points.

strut cutout restraining straps.

(3). Temporarily attach float web support

strap fittings at forward location;

(9).

Unsnap float containment cover and

secure strap fitting at aft attach

loosen restraining lacing to gain access

location with bolts and washers.

to emergency inflation system compo

nents.

(4). Place gravel guards over float girts and

secure with bolts and washers.

(10).

Connect squib valve electrical connector

(5). Apply zinc chromate putty (CM209) to

at squib.

contact surfaces of previously removed

abrasion strips, and skid extension

(11).

Perform inspection of emergency float

abrasion strips, to ensure watertight fit

inflation system (Ref. Emergency Float

on landing gear skids.

Inspection - Stowed Configuration).

Table 901. Weight and Balance Data

Configuration

Weight

Arm

Moment

lbs (kg)

in.

(cm)

in.−lb/100 (kgmm/100)

−501

+151.7

(+68.872)

95.9

(243.59)

+145

(+1670.57)

−505

+150.8

(+68.463)

96.0

(243.84)

+145

(+1670.57)

−515

+129.1

(+58.611)

99.1

(251.71)

+128

(+1474.71)

−517

+127.7

(+57.976)

98.9

(251.21)

+126

(+1451.67)

−519

+152.7

(+69.326)

96.4

(244.86)

+147

(+1693.62)

−521

+152.6

(+69.280)

96.5

(245.11)

+147

(+1693.62)

−523

+152.5

(+69.235)

96.5

(245.11)

+147

(+1693.62)

−525

+127.5

(+57.885)

99.0

(251.46)

+126

(+1451.67)

−527

+152.5

(+69.235)

96.5

(245.11)

+147

(+1693.62)

−529

+152.5

(+69.235)

96.5

(245.11)

+147

(+1693.62)

−531

+152.5

(+69.235)

96.5

(245.11)

+147

(+1693.62)

Page 912

Revision 19

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CSP-HMI-2

MAINTENANCE MANUAL

TABLE OF CONTENTS

Para/Figure/Table

Title

Page

52-10-00 Crew, Passenger, Cargo Doors and Windows

Maintenance Practices

201

Crew and Passenger/Cargo Door Description and Operation

201

A. Early Door-Latching System

201

B. Current Door Latching System (Hook-Latch)

201

Hook-Latch Automatic Door Latching System Troubleshooting

202

Table 201. Hook-Latch Automatic Door Latching System Troubleshooting

202

Crew Compartment Door Replacement (369D/E/FF - 500/600N)

203

A. Crew Compartment Door Removal (369D/E/FF - 500/600N)

203

B. Crew Compartment Door Installation (369D/E/FF - 500/600N)

203

Passenger/Cargo Compartment Door Replacement (369D/E/FF - 500N)

203

A. Passenger/Cargo Compartment Door Removal (369D/E/FF - 500N)

203

B. Passenger/Cargo Compartment Door Installation (369D/E/FF - 500N)

203

Mid and Aft Door Replacement (600N)

203

A. Mid and Aft Door Removal (600N)

203

B. Mid and Aft Door Installation (600N)

203

Door Seal Compression Check

203

Figure 201. Crew and Passenger/Cargo Door Installation (Sheet 1 of 2)

204

Mid and Aft Door Strut Replacement (600N)

206

A. Mid and Aft Door Strut Removal (600N)

206

B. Mid and Aft Door Strut Installation (600N)

206

Snapvent Replacement

206

A. Snapvent Removal

206

B. Snapvent Installation

206

Outside Handle or Spindle Replacement

206

A. Outside Handle or Spindle Removal

206

B. Outside Handle or Spindle Installation

206

10. Automatic Latch Block Assembly Replacement

206

A. Automatic Latch Block Removal

206

B. Automatic Latch Block Installation

207

11. Cam Lock Replacement

207

A. Cam Lock Removal

207

B. Cam Lock Installation

207

12. Latch Assembly or Striker Adjustment

207

A. Door Seal Compression Adjustment

207

Figure 202. Door Latching System Installation (Sheet 1 of 2)

208

Page i

52 Contents

Revision 36

CSP-HMI-2

MD Helicopters, Inc.

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

B. Engagement Depth of Latch Bolts with Striker Adjustment

210

C. Connector Rod Adjustment

210

D. Latch Compression Adjustment (Early System)

210

13. Latching Mechanism Operational Check (Early System)

210

14. Hook-Latch Door Latching System Operational Check

210

Figure 203. Door Handle Positions and Latch Engagement (Sheet 1 of 3)

211

15. Autolatching Pilot and Cargo Doors Operational Check

213

16. Door-Latching Mechanism Inspection (All Systems)

214

17. Anti-Chafing Tape on Door Frame Repair

214

18. Window Replacement

214

A. Early Style Window Replacement

214

B. Current Style Window Replacement

215

19. Hinge Replacement

215

A. Preload Spring Replacement

216

Figure 204. Door Hinge Replacement

216

Figure 205. Window and Hinge Repair

217

Figure 206. Current Style Window Installation

218

B. Rubber Stop Replacement

218

20. Automatic Latch Block Assembly Repair

219

21. Strike Pin Repair

219

22. Litter Door Inspection (50 Hour)

219

Figure 207. Automatic Latch Block and Striker Repairs (Sheet 1 of 2)

220

Figure 208. Door Seal Repair

222

23. Pilot and Cargo Door Repair

223

A. Seal Repair

223

B. Partially-Separated Seal Repair

223

24. Improved Door Seal Installation

223

Figure 209. Improved Door Seal Installation

224

52-40-00 Engine Access Doors

Maintenance Practices

201

1. Engine Access Door - General

201

2. Engine Access Door Replacement

201

A. Engine Access Door Removal

201

B. Engine Access Door Installation

201

3. Engine Access Door Inspection

201

4. Engine Access Door Repair

201

A. Sheet Metal Repair

201

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CSP-HMI-2

MAINTENANCE MANUAL

TABLE OF CONTENTS (Cont.)

Para/Figure/Table

Title

Page

B. Abrasion Strip Replacement

201

C. Hinge Replacement

202

D. Catch/Latch Hook Replacement

202

5. Engine Access Door Adjustment

202

Figure 201. Engine Access Doors (Sheet 1 of 3)

203

52-50-00 Miscellaneous Access Doors

Maintenance Practices

201

1. Access and Inspection Provisions

201

2. General Access Doors Inspection

201

3. Pilot Compartment Floor Access Doors

201

4. Pilot Compartment Floor Access Door Replacement

201

A. Pilot Compartment Floor Access Door Removal

201

B. Pilot Compartment Floor Access Door Installation

201

Table 201. Access and Inspection Provisions Information

202

Figure 201. Access and Inspection Provisions and Locations (369D/E/FF)

(Sheet 1 of 3)

204

Figure 202. Access and Inspection Provisions and Locations (500N)

(Sheet 1 of 2)

207

Figure 203. Access and Inspection Provisions and Locations (600N)

209

Figure 204. Floor Access Covers and Engine Bypass Door (600N)

210

Page iii

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Revision 36

MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

CREW, PASSENGER, CARGO DOORS AND WINDOWS

MAINTENANCE PRACTICES

1. Crew and Passenger/Cargo Door

The latch sliders are interconnected to rods

Description and Operation

and clevis devices and are moved by turning

inside or outside door handle.

The pilot and passenger/cargo doors are

bonded aluminum alloy frames containing

Movement of either handle into safelock

large smoke-grey-tinted cast acrylic windows.

position is prevented until door is closed and

safelock position is prevented until door is

Plastic snapvents are installed in each door

closed and safelock triggers are actuated by

window. An acrylic stop, bonded to the doubler,

the strikes. This actuation causes the safelock

prevents normal airflow from pulling the

triggers to clear notches on latch sliders,

snapvent from the window during flight. These

allowing the latch sliders and linkage to move

units may be rotated for intake or exhaust of

into safelock position.

ventilating air and may be pulled inward for

complete closure. Damaged snapvents should

B. Current Door Latching System

be replaced, (Ref. Snapvent Replacement);

(Hook−Latch)

repair is not practical.

Pilot and passenger/cargo doors are equipped

Current door latching mechanisms used on

with an automatic latching mechanism. Two

pilot and passenger/cargo compartment doors

door hinges on each door are provided with

consist of four hook type latches mounted on

quick-removal type ball-lock hinge pins.

the door frame. The four latches are actuated

by latch sliders which are synchronized and

Pilot and passenger/cargo doors are equipped

connected by steel connector rods to the door

with automatic latching mechanisms. The

handle.

latching mechanisms permit the door to be

closed and safelocked from inside or outside.

With the door handle at the rest position, the

Each installation contains a key-operated cam

door may be firmly shut and the hooks will

lock, actuated from outside. Opening door from

ride up over and engage their striker pins.

inside overrides key-operated cam lock. Pilot

Safelocking is accomplished by moving the

and cargo door latching mechanisms are

door handle to the lock position, which causes

essentially the same except for length of

the latch slider that operates each hook latch

interconnecting rods.

to engage a pin within the latch block,

preventing further movement until the handle

A. Early Door−Latching System

is moved to the open position. When the

Early mechanisms, installed within the door

handle is moved to the open position, the latch

panel, consist of four latch blocks that house

sliders fully extend the latch hooks from their

spring-loaded latch bolts and safelock triggers

latch blocks, disengaging them from their

together with latch sliders.

striker pins and allowing the door to open.

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MAINTENANCE MANUAL

2. Hook−Latch Automatic Door Latching

System Troubleshooting

Table 201. Hook−Latch Automatic Door Latching System Troubleshooting

Problem

Probable Cause

Repair

Hooks fail to engage striker

Door seal swollen or bonding

Repair seal (Ref. Door Seal Repair).

pin, or more than 0.050 inch

to door frame failed.

(1.27 mm) gap between latch

Striker assembly mounted too

Loosen striker assembly mounting screws and

hook and striker pin (Latch

far inboard or outboard on

adjust striker assembly position.

hooks extend normally).

door frame.

Latch block assembly too far

Add or remove 0.063 inch (1.60 mm) and

from striker pin.

0.032 inch (0.81 mm) washers as shims under

latch block mounting screws, as required (1).

Remove or add shims under striker assembly,

as required.

Striker assembly hitting or

Route out waffle enough to clear.

rubbing on door waffle.

Striker assembly hitting latch

Check latch covers for dents or chipped paint

cover (2).

that indicates contact between latch cover and

striker assembly. Remove material from latch

cover to allow striker assembly clearance.

Latches fail to extend from

Latch hooks or latch sliders

Lubricate latch block moving parts.

latch block when handle

sticking in latch block.

moved to open position.

Connector rod(s) improperly

Adjust connector rod(s) by removing clevis

adjusted.

from sliding cam and raising or lowering

threaded connector as required on threaded

portion of rod. Threads of rod and connector

must be engaged through solid portion of

connector. Rod end may be flush with or

extend beyond bottom, of solid part of

connector.

Connector rod bent or

Check connector rods and clevis. Replace

damaged.

damaged part.

Door does not safelock when

Connector rod(s) improperly

Check witness hole in latch blocks.

door handle is moved to lock

adjusted.

Semi−circle cutout in each latch slider must be

position.

fully seated around pin when safe locking is

engaged. Adjust connector rods until correct

pin engagement is achieved for each latch

slider.

NOTES:

(1) If latch block protrudes beyond middle line or door after shimming, slot mounting holes in latch block

cover 0.20 inch (5.08 mm) downward from center of existing hole to allow cover to shift up above middle

line of door waffle.

(2) Door should be closed from inside helicopter to determine if striker pin assembly is hitting or rubbing latch

cover. Enough force can be applied when closing door from outside to prevent detection of contact

between striker pin assembly and latch cover.

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MAINTENANCE MANUAL

3. Crew Compartment Door Replacement

(4). Re-safety from top hinge pin.

(369D/E/FF − 500/600N)

(5). Install interior trim covers.

(Ref. Figure 201)

5. Mid and Aft Door Replacement (600N)

A. Crew Compartment Door Removal

A. Mid and Aft Door Removal (600N)

(369D/E/FF − 500/600N)

(1). Remove nuts and washers from door

(1). Remove cover plates from interior trim

hinge bolts.

forward of crew doors.

(2). While supporting door, slide bottom

(2). While supporting door, turn hinge pins

bolt, and then top bolt from hinges.

to unlock the tabs.

(3). Remove door from helicopter.

(3). Remove lower pin, then remove top pin.

B. Mid and Aft Door Installation (600N)

(4). Remove door from helicopter.

(1). Position door so door-mounted hinge

B. Crew Compartment Door Installation

aligns with airframe-mounted hinge.

(369D/E/FF − 500/600N)

(2). Insert bolt, with washer, into each

hinge.

(1). Slide door hinges into slots on side of

airframe.

(3). Install washer and nut on bolt and

torque to 50 - 70 inch-pounds (5.65 -

(2). Insert pins, from inside the aircraft,

7.91 Nm).

into airframe holes and though hinges.

6. Door Seal Compression Check

(3). Turn hinge pins to lock tabs into slots

in airframe.

(Ref. Figure 208) Inspect rubber weatherstrip

compression seal for tight compression

(4). Install interior trim covers.

between the door and frame as follows:

4. Passenger/Cargo Compartment Door

(1). Open door.

Replacement (369D/E/FF − 500N)

(2). Hold a strip of heavy paper against

A. Passenger/Cargo Compartment Door

door seal so that strip extends approxi

Removal (369D/E/FF − 500N)

mately 1/4 inch (6.35 mm) beyond seal

toward outside of doorway.

(1). Remove cover plates from interior trim

aft of crew doors.

(3). While holding paper strip in place, close

door.

(2). Remove safety from top hinge pin.

(4). Attempt to pull paper strip from

(3). While supporting door, turn hinge pins

between door frame and seal. Strip

to unlock the tabs.

should not pull out unless a moderately

heavy pull is exerted.

(4). Remove lower pin, then remove top pin.

NOTE: Correct fit is indicated by an approxi

(5). Remove door from helicopter.

mate 0.060 inch (1.524 mm) interference fit

between door seal and bumper. Where strip

B. Passenger/Cargo Compartment Door

can be withdrawn with a light pull, fit of

Installation (369D/E/FF − 500N)

door against frame is not sufficiently tight

(1). Slide door hinges into slots on side of

to provide an adequate seal. This condition

airframe.

may be due to deterioration of weatherstrip

compression seal, deformation of door

(2). Insert pins, from inside the aircraft,

frame, worn hinges or improper latching.

into airframe holes and though hinges.

(5). Repeat this procedure at approximately

(3). Turn hinge pins to lock tabs into slots

1 foot (30 cm) increments along length

in airframe.

of door seal.

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MAINTENANCE MANUAL

7. Mid and Aft Door Strut Replacement

(2). Slip snapvent flange into window hole

(600N)

at an angle of about 30° degrees to

window surface.

(Ref. Figure 201)

(3). Be sure that ends of wire stiffener are

A. Mid and Aft Door Strut Removal (600N)

inside window hole.

(1). Remove nut and washer that secures

9. Outside Handle or Spindle Replacement

gas strut pivot post ball to door fitting.

(Ref. Figure 202)

(2). Remove nut and washer that secures

A. Outside Handle or Spindle Removal

gas strut pivot post ball to airframe

fitting.

(1). Remove three screws and washers

securing escutcheon to door exterior.

(3). With door in open position, pull gas

strut up away from fittings to remove.

(2). Drive spring pin from handle and slide

handle from spindle.

B. Mid and Aft Door Strut Installation (600N)

B. Outside Handle or Spindle Installation

(1). Insert pivot post ball fitting, at shaft

(1). Attach replacement handle to escutch

end of strut, into outboard hole in

eon with handle washers. Use maxi

airframe fitting and install washer and

mum number of handle washers

nut.

possible without impeding free move

ment between handle and escutcheon.

(2). Insert pivot post ball fitting, at tube

end of strut, into hole in door fitting

(2). Slide handle on spindle and secure

and install washer and nut.

escutcheon to door with washers and

screws.

(3). While holding pivot post ball fitting to

prevent rotation, torque nuts to 60 - 85

10. Automatic Latch Block Assembly

inch-pounds (6.78 - 9.60 Nm).

Replacement

(4). Adjust strut pressure after installation

(Ref. Figure 202)

by carefully loosening screw at end of

strut and releasing pressure until door

A. Automatic Latch Block Removal

opens fully and operates smoothly

(1). Perform this procedure with door in

through full range of travel.

open position and handles at latched

rest position.

8. Snapvent Replacement

(2). Remove screws securing latch cover.

(Ref. Figure 201)

(3). Mark lockplate/nutplate so that

A. Snapvent Removal

replacement latch block can be installed

at approximately same position as latch

(1). Push snapvent outward in window

that is to be removed.

(open position).

(4). Remove four screws and washers

(2). Grasp open side of snapvent and gently

securing latch block to lockplate/nut

squeeze it into an elliptical shape.

plate. Note any washers found between

latch block and lockplate/nutplate.

(3). Slip snapvent out of window hole at

These are adjustment shims and should

about a 30° degree angle to surface of

be reinstalled at same location and

window.

position at reinstallation of latch block.

B. Snapvent Installation

(5). Remove cotter pin, washer and pin

securing rod end clevis to latch block.

(1). Grasp open end of snapvent and gently

squeeze it into an elliptical shape.

(6). Remove latch block from door.

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MAINTENANCE MANUAL

(7). Lubricate moving parts of latch block

B. Cam Lock Installation

(Ref. Automatic Latch Block Assembly

Repair).

NOTE: Currently available cam lock is longer

than early cam lock and requires a spacer

B. Automatic Latch Block Installation

between lock flange and outside surface of

door skin.

(1). Reconnect link and connector rod end to

(1). Position lock boss, torsion spring,

handle arm with cotter pin and washer.

washer and replacement handle into

position and insert spindle.

NOTE: Cotter pin and washer are to be in

stalled on outboard side of connector rod end

(2). Install spindle washers and screw to

to eliminate possibility of interference. To

secure spindle in lock plate.

eliminate excess play, use extra washers for

shimming.

(3). Attach one spring hook in hole of lock

boss and attach other spring hook at

(2). Secure latch block to lock plate with

notch in lock plate. Use wire to pull

four screws and washers.

spring hook into place.

(3). Check door latching and safelocking

(4). Install outside handle.

operation and make any necessary

adjustment.

(5). Check door latching and safelocking

operation and make any necessary

11. Cam Lock Replacement

adjustment.

(Ref. Figure 202)

12. Latch Assembly or Striker Adjustment

A. Cam Lock Removal

(Ref. Figure 203)

(1). Remove outside handle.

Consumable Materials

(Ref. Section 91−00−00)

(2). Remove latch block.

Item

Nomenclature

CM425

Sealing compound

(3). Note position of lock boss and handle

torsion spring to aid at reinstallation.

(1). Adjust latch assemblies and strike as

(4). Hold handle, lock boss and torsion

necessary to ensure proper door

spring in position and withdraw

latching, safelocking and keylocking

spindle. Then slide handle lock boss

functions.

and torsion spring out of lock plate.

(2). After adjustments are made, perform a

(5). Remove handle grip from handle arm

final inspection of all latching and

by loosening setscrew and sliding grip

locking functions, then install latch

from arm.

covers.

NOTE: When lock is set to locked position, be

(3). Fill in gaps and fair-in area between

sure that cam actuates hinged lock bar.

strikes and bumper stripes at each

When lock is in correct position, secure it in

position with sealant (CM425).

place by center-punching surface of lock

plate assembly close to flat on hexagonal

A. Door Seal Compression Adjustment

locking nut.

To adjust door seal compression, remove latch

(6). Replace key-operated cam lock by

covers. Move strikes as necessary in their

unscrewing hexagonal nut.

slotted mounting holes.

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MAINTENANCE MANUAL

SNAPVENT

LATCH COVER

DOUBLER

(TYP)

DOUBLER

STOP

AUTOMATIC

DOOR LATCH

WINDOW

MECHANISM

STOP

DOOR SEAL

LATCH COVER

(TYP) (4 PLCS)

AUTOMATIC

DOOR SEAL

PASSENGER/CARGO DOOR

DOOR LATCH

(369D/E/FF - 500N)

MECHANISM

CONNECTOR

CLEVIS

ROD

DOOR PANEL

PILOT'S DOOR

LATCH SLIDER

(369D/E/FF - 500/600N)

LATCH BLOCK

ROD MOUNTING

BRACKET

STRIKER

ASSEMBLY

LATCH BLOCK

SPACER

NOTE 2

MOUNTING

BRACKET

SPRING

SHIM WASHER

(NOTE 3)

CLEVIS

DOOR PANEL

(NOTE 1)

(NOTE 2)

DOOR

LATCH SLIDER

FRAME

LOCKPLATE ASSEMBLY

LATCH BLOCK ASSEMBLY

(NOTE 4)

SPRING HOOK NOTCH

SPRING

CONNECTOR ROD

CLEVIS

SPINDLE

LINK PIN

SHIM

LINK

ARM

LATCH BLOCK ASSEMBLY

GRIP

NOTES:

ESCUTCHEON

SET SCREW

FOR ADJUSTMENT INFORMATION, REFER TO

SPRING PIN

LOCK BOSS

ADJUSTING LATCH COMPRESSION.

INSTALL OUTBOARD TO ELIMINATE POSSIBILITY

OF INTERFERENCE.

SPACER

CONNECTOR

AS REQUIRED, FOR LATCH ADJUSTMENT, NOT

CAM LOCK

(NOTE 5)

ROD END

ON ALL WINDOWS.

(KEY OPERATED)

IDENTIFIED AS NUTPLATE AT OTHER LOCATIONS.

LATCH ASSEMBLY - EXPLODED VIEW

SPACER REQUIRED ON NEW LOCKS WHICH ARE

EARLY SYSTEM

LONGER THAN EARLY MODEL CAM LOCKS.

G52-1002-1

Figure 202. Door Latching System Installation (Sheet 1 of 2)

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MAINTENANCE MANUAL

B. Engagement Depth of Latch Bolts with

modifying as required to compress

Striker Adjustment

spring 0.060 - 0.080 inch (1.524 - 2.032

mm) when mechanism is at safelocked

Adjust engagement depth of latch bolts with

position.

strikes by removing latch covers and moving

latch assemblies as necessary in their slotted

(2). Fill gaps and fair-in area between latch

mounting holes or by adding shims under

strikes and bumper strips at each

strikes.

position, using sealant (CM425).

NOTE: Complete safelocking exists when latch

13. Latching Mechanism Operational Check

bolt extension is at maximum and roller on

(Early System)

safelock trigger is engaged in safelock slot in

latch slider. At this condition, safelock trig

(1). Check inside and outside door handle at

ger retracts when latch slider is moved

all positions for function.

slightly in unlatch direction.

(2). Close door from inside. Entire beveled

C. Connector Rod Adjustment

face of each bolt must make contact

with strike and must hold door firmly

(1). Open door or remove from helicopter.

against door seals. Bolts must be

(2). Remove latch cover.

positioned on strike such that there is

sufficient space for bolt to extend an

(3). Press all safelock triggers and rotate

additional minimum 0.125 inch (3.175

handle to safelock position. Remove

mm) into strike for safelocking latches

clevis pin from connector rod or latch

(Ref. Figure 203).

being adjusted.

(3). Check that each latch bolt makes

(4). Move latch slider manually to complete

contact with mating strike. Unequal

safelock position. Adjust connector rod

striking and latching indicates latch

length so that clevis pin can be in

assembly or strike require adjustment

stalled easily.

or shimming.

NOTE: Position of fourth and first latches can

(4). Safelock door and observe that door is

be individually adjusted without disturbing

forced inward for seal compression at

adjustment of other latches. If position of

each latch position. Unequal safelock

second or third latches is adjusted, then all

ing may indicate that connector rods

should be checked. When adjusting all four,

are not properly adjusted for complete

start with third latch, and proceed to sec

extension of latch bolts.

ond, first and then fourth.

D. Latch Compression Adjustment (Early

14. Hook−Latch Door Latching System

System)

Operational Check

Latch compression spring adjustment may be

(Ref. Figure 203)

necessary and should be checked if part

replacement, particularly in stack-up between

Perform following operational check of

upper clevis on third latch and first mounting

hook-latch door-latching system. If malfunc

bracket or change in position of clevis has been

tion is noted, refer to Table 201 for trouble

made.

shooting and repair information.

(1). Check inside and outside door handle at

Consumable Materials

all positions for function. From open

(Ref. Section 91−00−00)

and lock positions door handle should

Item

Nomenclature

spring back to rest position when

CM425

Sealing compound

released.

(2). Move handle to open position. Ensure

(1). Readjust spring load using shorter or

all four latch hooks are fully extended

longer spring compressor spacer and by

from their latch blocks.

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MAINTENANCE MANUAL

INSIDE HANDLE UNLATCH

ACTION POSITION

OUTSIDE HANDLE SAFELOCK

ACTION POSITION

INSIDE HANDLE

TUBING

OUTSIDE HANDLE SAFE

LOCKED POSITION

INSIDE HANDLE LATCHED

OUTSIDE HANDLE

REST POSITION (NOTE 2)

DOOR FRAME STRUCTURE

CHANNEL STRIP

LATCH COVER

OUTSIDE HANDLE LATCHED

REST POSITION (NOTE 2)

INSIDE HANDLE

SAFELOCKED POSITION

DOOR PANEL

OUTSIDE HANDLE UNLATCH AC

TION POSITION

HANDLE POSITIONS

SAFELOCK ACTION

(RIGHT DOOR INSIDE VIEW)

LATCH SLIDER

DOOR FRAME

CLEVIS

BUMPER

SAFELOCK SLOT

SHIM

SAFELOCK TRIGGER

LATCH BOLT

ROLLER

STRIKER PLATE

INSIDE

HANDLE

0.88 INCH (22.35 MM)

UNLATCH ACTION

NOTE 1

NOTES:

WHEN LATCH IS COMPLETELY SAFELOCKED,

MINIMUM OF 0.125 INCH (3.175 MM) OF FLAT

SURFACE (BEYOND ANGLED LEADING EDGE )

OF LATCH BOLT MUST BE ENGAGED WITH

LATCH ENGAGEMENT

STRIKER PLATE.

(THIRD LATCH INTERIOR

LATCHED REST POSITION APPLIES WITH DOOR

SHOWN FOR CLARITY)

OPEN OR CLOSED.

G52-1003-1

Figure 203. Door Handle Positions and Latch Engagement (Sheet 1 of 3)

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MAINTENANCE MANUAL

WITNESS HOLE

LATCH

SLIDER

LATCH BLOCK

HOUSING

ASSEMBLY

0.050 INCH (1.27 MM) MAX

GAP BETWEEN DOOR

STRIKER PIN AND HOOK

LATCH WHEN DOOR

LATCH

CLOSED AND LATCH IN

SLIDER

REST POSITION.

G52-1003-3A

Figure 203. Door Handle Positions and Latch Engagement (Sheet 3 of 3)

(3). Check latch blocks, latch sliders, door

that semi-circle cutout on latch slider is

waffle and striker pin assemblies for

fully seated around pin on latch block.

any nicks, dents, scratches, chipped

(7). Move handle to open. Note that all four

paint or other evidence of contact

latch hooks extend fully from their

caused by misalignment of door latches

latch blocks and fully disengage their

or striker pin assemblies.

striker pins, allowing the door to open.

Handle should spring back to rest

NOTE: Extreme temperatures may cause door

position when released.

seal to swell or door seal-to-door frame

bonding failure. Door seal protrusions

15. Autolatching Pilot and Cargo Doors

caused by swelling or bonding failure may

Operational Check

interfere with latching function.

NOTE: When opening door, apply light inward

(4). Check door seal and repair as required.

force on door. This reduces wear of latching

mechanism by overcoming door seal pres

sure.

(5). Close door firmly from inside helicopter.

Check that all four latch hooks engage

(1). Open and close door to check for smooth

their striker pins and that there is not

operation of handles and latch mecha

more than 0.050 inch (1.27 mm)

nism. Check operation of door stop.

between each hook and striker pin.

(2). Close door from inside. Check all inside

(6). Move handle to lock (full down). With

latches for correct engagement at latch

door locked, use flashlight to check

and safelock positions of interior and

witness hole on each latch block. Note

exterior handle. (Ref. Figure 203).

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MAINTENANCE MANUAL

(3). Check that setting interior and exterior

handles to safelock position pulls door

Consumable Materials

inward for proper closure and sealing.

(Ref. Section 91−00−00)

Item

Nomenclature

(4). Check that key locks and unlocks door

CM219

Methyl-ethyl-ketone

handle.

CM717

Tape, pressure sensitive

16. Door−Latching Mechanism Inspection (All

Systems)

18. Window Replacement

(Ref. Figure 202 and Figure 203)

A. Early Style Window Replacement

Make following checks with magnification

(Ref. Figure 205) For repair of plastics refer to

glass and strong light:

FAA AC 43.13-1B. Replace window as follows:

(1).

All parts for excessive wear, nicks,

cracks and corrosion.

Consumable Materials

(Ref. Section 91−00−00)

(2).

Threaded parts for worn, crossed or

Item

Nomenclature

otherwise damaged threads.

CM415

Cement

(3).

Early latch block assemblies for broken

CM418

Cement, epoxy

springs and wear on strike contact

CM425

Sealing compound

surfaces of latching bolts; and for undue

CM432

Dichloromethane

wear of latch sliders, bolts and bolt

CM433

Ethylene chloride

rollers. Current latch block assemblies

CM717

Tape, pressure sensitive

for wear, damage or distortion of latch

sliders and latch hook.

(1).

Remove snapvent from window (Ref.

(4).

Cam lock for jamming when key is

Snapvent Replacement).

operated.

(2).

Drill out rivets attaching window

(5).

Link for wear or distortion.

retainers to door structure and remove

window. Remove two screws, washers

(6).

Handles for distortion, worn pivot holes

and nuts from door hinge doubler.

and worn finish.

(3).

If door frame or window is to be reused,

(7).

Escutcheon and handle for looseness,

carefully scrape off sealant around edge

distortion, thread damage and break

of door or window frame using a

age.

wooden, plastic or other suitable

nonmetallic scraper.

(8).

Lockplate assembly for wear, distortion,

thread damage and breakage.

(4).

Repair retainer-to-window bond, if

applicable, with dichloromethane

(9).

Latch block nutplates for thread

(CM432) or ethylene chloride (CM433);

damage and loose rivets.

or use PS-18 or S147 cement (CM415).

(10).

Rods and clevis for wear in clevis pin

(5).

Trim retainer as required to provide

holes, thread damage, and distortion.

clearance for door handle and end butt

joint.

17. Anti−Chafing Tape on Door Frame Repair

(6).

Place window in position and check for

(Ref. Figure 208) Inspect condition of anti-

0.380 inch (9.652 mm) minimum

chafing tape installed on pilot's and cargo

engagement and flush fit with window

compartment door frames. For minor repair,

frame. Trim excess if required.

remove defective tape where necessary. Clean

frame surface with MEK (CM219). Replace

(7).

Use 1/2 inch (12.70 mm) pressure-sen

with polyurethane pressure-sensitive tape

sitive tape (CM717) on edge of window.

(CM717).

Bond seals to retainer and to door

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MD Helicopters, Inc.

CSP-HMI-2

MAINTENANCE MANUAL

frame using cement, epoxy (CM418);

(6). Apply 0.250 inch (6.35 mm) tape

bond inside of seals to window using

around outside of drawn line.

sealant (CM425). Do not stretch seals

(7). Trim glass to the outside of applied

when bonding.

0.250 inch (6.35 mm) tape.

(8).

With retainer and window in position

(8). Remove tape and gently smooth the

on door frame, press down firmly and

edges.

evenly on retainer so that seals are

compressed tightly against window

NOTE:

around full circumference of door

D It is best to have ends of seal on aft side of

frame.

window to help keep moisture out while

in flight.

(9).

Locate existing holes in door-reinforc

ing frame. Mark and drill holes in

D Ensure seal is firmly worked onto door to

retainer. It is permissible to install new

prevent seal from being cut too short.

rivets between existing holes in rivet

(9). Install window seal around periphery of

pattern.

window opening with groove for glass to

(10).

Rivet window to door using rivets of

the inside. Cut seal to size if new.

correct length. Blind rivets are used for

(10). Gently trim seal, where needed, around

retainers riveted to door reinforcing

top door hinges.

frame.

Do not use any tools with sharp

(11).

Install doubler over retainer at hinge

CAUTION

edges to aid in installing glass

area with two screws, washers and

into seal, glass is easily damaged.

nuts. Drill (No. 21 drill) and ream to

0.166 inch (4.216 mm) diameter window

NOTE: To aid in installation of glass into seal,

panel for screws, using slow speed drill

use a mild mixture of soapy water liberally

(700-800 rpm).

applied to the edge of the glass and into

groove in seal. Do not use any lubricants.

(12).

Install snapvent (Ref. Snapvent

Replacement).

(11). Install glass from inside by sliding up

into the seal.

(13).

Remove protective covering and clean

window (Ref. Sec. 20-20-00).

(12). With hands on either side of glass, work

glass firmly into seal.

B. Current Style Window Replacement

(13). Using a blunt plastic spatula or probe,

(Ref. Figure 206)

gradually work edge of window into

groove of window seal.

(1). Using a blunt plastic spatula or probe,

pull back edge of window seal and

(14). If there is a gap at the seal ends, use

gradually work window out from groove

commercially available clear silicone

in seal.

seal to fill gap.

(2). Remove seal and clean for re-installa

19. Hinge Replacement

tion of window, discard if not pliable.

(Ref. Figure 204)

(3). Mask around new glass for marking.

(1). Remove door and drill out hinge-at

(4). Place new glass against door and center

taching rivets.

over the window opening.

(2). Install replacement hinges at body

(5). Trace line on glass from window

attach points with door hinge pins.

opening in door.

(3). With damaged hinges removed, install

NOTE: The following step is to ensure the glass

doors in closed position. Have an

is larger than the door opening so glass will

assistant retain door in place by

not blow out in flight.

actuating door handle locking levers.

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MAINTENANCE MANUAL

(4).

If required for door fit, use one-piece

(3). Replace preload spring; with longest

solid aluminum alloy shim, up to 0.040

flat area outboard and aft in hinge body

inch (1.016 mm) maximum thickness

recess.

trimmed flush with hinge outer edges,

under upper or lower hinge (between

(4). Replace door spring; with longest flat

hinge and door exterior).

area also outboard and aft in body

hinge recess.

(5).

Mark hinge rivet attach locations

through existing holes in door. Locate

NOTE: Forward curved area of door hinge pres

and mark blind rivet attach points

ses against preload spring inboard curved

(cargo door only).

area, at installed position.

(6).

Remove door hinges and check for

(5). Install hinge pins and cotter pins. Pins

proper edge distance.

may be installed upward if interference

does not permit installation with cotter

(7).

Drill holes with a No. 28 drill at pilot's

pin hole down.

door upper and lower hinge aft attach

points. Use a No. 21 drill at all other

(6). Cover exposed sharp edges of cotter

pilot and cargo door attach points.

pins and pins with sealer (CM424).

(8).

On pilot's door upper hinge, install

rivets with washers under bucked

(7). Install doors and perform operational

heads.

check (Ref. Automatic Latching Mecha

nism (Early System) Operational

(9).

Install rivets at remaining pilot's door

Check.

attach points.

SHIM AS REQUIRED

(10).

Install two mechanically-expanding

(NOTE)

rivets at aft cargo door hinge attach

points.

(11).

Install four rivets at remaining attach

points.

(12).

Paint as required.

(13).

Install doors and perform an operation

al check (Ref. Automatic Latching

Mechanism (Early System) Operational

DOOR STRUCTURE

Check).

DOOR HINGE HALF

SHIM AS REQUIRED

A. Preload Spring Replacement

(NOTE)

(Ref. Figure 205)

Consumable Materials

(Ref. Section 91−00−00)

Item

Nomenclature

CM424

Sealing compound

NOTE: The following procedures apply to both

upper and lower hinges.

NOTE: SHIM AS REQUIRED UNDER HINGE WITH ONE PIECE

OF 2024-T3 ALUMINUM, 0.050 IN. (1.270 MM) MAXIMUM. TRIM

(1). Remove two cotter pins and clevis pins.

TO OUTER PERIPHERY OF HINGE.

G52-1004

(2). Remove door spring first; then remove

preload spring.

Figure 204. Door Hinge Replacement

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MAINTENANCE MANUAL

20. Automatic Latch Block Assembly Repair

(2). Replace anti-chafing tape if damaged.

(Ref. Figure 201 and Figure 207, Sheet 1 of 2)

(3). Install washer (if applicable), shims,

Replace worn or damaged parts as necessary.

dam (if applicable), strike pin and

Disassemble only to extent required for

secure with screws.

replacement of parts. Perform following steps

as required:

22. Litter Door Inspection (50 Hour)

The following is a procedure for inspecting the

Consumable Materials

litter door installation for proper condition and

(Ref. Section 91−00−00)

security of the quick-release fastener assem

Item

Nomenclature

blies and the rubber seal (gasket) installed

between the window glass and door frame. The

CM108

Graphite, powdered

visual inspection is applicable to the PN

CM118

Grease

369H92733-1 / -2 bubble window assemblies

CM234

Solvent, dry-cleaning

(or PN 369H92731-1 / -2 flat window assem

CM307

Lacquer, acrylic semi-gloss

blies, if installed) in the PN 369H90085 litter

door installation.

(1). Lubricate all moving parts except lock,

(1). Remove quick-release fasteners

with grease (CM118) to prevent

securing bubble (or flat) windows to

binding.

litter doors.

(2). Lubricate lock with powdered graphite

(2). Visually inspect each fastener for

(CM108).

condition, and each anchor receptacle in

door structure for condition and

(3). At time of disassembly clean reusable

security of attachment.

parts except locks, using soft bristle

brush dipped in solvent (CM234).

(a). Replace each fastener if stud is loose

or worn.

(4). Dry parts using clean, lint-free cloth or

dry compressed air at 20 psi maximum.

(b). Replace anchor receptacle and/or

rivets as required.

(5). Clean key-operated cam locks, using

dry compressed air at 20 psi maximum.

(3). Visually inspect rubber seal (gasket) on

window assemblies for condition. Seal

(6). Touchup handles with semigloss black

must be fully intact; rebond seal to door

acrylic lacquer (CM307).

structure as required.

(7). Eliminate binding by lubricating

(a). Replace seal if worn, cracked or hard.

moving parts.

(4). Reinstall window assemblies to litter

21. Strike Pin Repair

doors using quick-release fasteners.

(Ref. Figure 207)

(5). Check for gaps between window glass,

rubber seal and door structure.

NOTE: The 369 model has three different con

figurations. Select the configuration that

(6). Replace seal and/or use shorter length

pertains to your specific application.

studs if any gap is noted.

(1). Remove screws, strike pin, dam (if

(7). If seal is extruded, use longer length

applicable), shim and washers (if

studs; replace seal if extrusion still

applicable) from door frame.

exists.

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MAINTENANCE MANUAL

UPPER LATCHES

3.50 INCH

3.50 INCH (8.89 CM)

(8.89 CM)

8.00 INCH (20.32 CM) BLENDED FROM 0.12 INCH (3.05 MM)

DIMENSION TO EDGE OF DOOR (2 PLACES)

8.00 INCH

0.12 INCH (3.05 MM)

(20.32 CM)

SEAL

0.12 INCH (3.05 MM)

0.25 INCH (6.35 MM)

8.00 INCH (20.32 CM)

SEAL

0.12 INCH (3.05 MM)

(FLUSH WITH

EDGE OF DOOR

AT BOTTOM)

0.35 INCH

0.12 INCH

(8.89 MM)

(3.05 MM)

PILOT'S DOOR

(LEFT DOOR SHOWN)

(NOTE 1)

FINGER TYPE SEAL

(NOTE 2, 3)

SEAL

SECTION

A - A

DOOR REINFORCING

0.12 INCH

FRAME

(3.05 MM)

0.025 INCH

(NOTE 1)

CARGO DOOR

SEAL (FLUSH WITH

(6.35 MM)

EDGE OF DOOR AT

(LEFT DOOR SHOWN)

BOTTOM)

(NOTE 2, 3)

SECTION

B - B

(BOTTOM SEAL FINGERS DOWNWARD;

PILOT'S DOOR ONLY)

NOTES:

SEAL NOT TO BE LOCATED ON RADIUS OF

REINFORCED FRAME.

SEAL INSTALLED USING ADHESIVE ACCORDING

TO CONTAINER INSTRUCTIONS.

SHIM AS REQUIRED UNDER SEAL USING TAPE

BONDED WITH ADHESIVE.

G52-1000A

Figure 208. Door Seal Repair

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CSP-HMI-2

MAINTENANCE MANUAL

23. Pilot and Cargo Door Repair

24. Improved Door Seal Installation

(Ref. Figure 209) The following procedure is for

A. Seal Repair

installation of QGR2178 door seals on the

cargo/passenger doors.

(Ref. Figure 208)

Consumable Materials

(Ref. Section 91−00−00)

Item

Nomenclature

Item

Nomenclature

CM220

Naphtha aliphatic

CM418

Cement, epoxy

CM235

Cleaner

CM322

Primer, Silicone, Red

CM414

Adhesive, cyanoacrylic / Accelerator

(1). Carefully pull or scrape away damaged

CM439

Adhesive

seal.

(2). Restore chemical film protection to any

(1). Remove existing door seals using

base metal exposed during cleaning

Desoclean 45 (CM235) or naphtha

process (Ref. Sec. 20-20-00).

aliphatic (CM220). Ensure that all

surfaces are clean to allow proper

(3). Clean seal contact area on metal and

adhesion of new seal material. Allow

rubber seal.

surface to air-dry a minimum of 15

minutes.

(4). Carefully align and bond seal to

NOTE:

mounting surface with cement, epoxy

(CM418) according to container instruc

D On the 369D/E/FF - 500N helicopters,

tions.

seals are to be installed around the entire

circumference of the aft doors.

NOTE: Correct seal mounting position results

D On the 600N helicopters, seals are to be

in an approximately 0.060 inch (1.52 mm)

installed around the entire circumference

interference fit between door seal and bum

of the mid doors. Seals are to the applied

per.

to the top, bottom and aft edges of the

aft-cabin doors.

B. Partially−Separated Seal Repair

(2). Prime seal faying surface with red

silicone primer (CM321) and allow to

(Ref. Figure 208)

air-dry a minimum of 15 minutes.

(3). Apply a thin uniform coat of adhesive

Consumable Materials

(CM439) to faying surface of door and

(Ref. Section 91−00−00)

seal. Allow to air-dry a minimum of

Item

Nomenclature

five minutes.

CM220

Naphtha aliphatic

(4). Apply a second thin uniform coat of

CM418

Cement, epoxy

adhesive to faying surface of door and

seal. Allow to air-dry a minimum of

five minutes.

(1). Clean separated area with naphtha

(CM220) and allow to dry for minimum

(5). Test glue with clean knuckle. If adhe

of 20 minutes.

sive does not transfer to knuckle, press

the seal into place.

(2). Apply one uniform brush coat of

(6). Butt joints at forward and aft lower

cement, epoxy (CM418) to rubber seal

locations.

and mating surface contact area. Allow

to dry for 5 minutes and press mating

(7). Maximum gap of 0.030 inch (0.762 mm)

surfaces together.

at butt joints.

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MAINTENANCE MANUAL

ENGINE ACCESS DOORS

MAINTENANCE PRACTICES

1. Engine Access Door − General

3. Engine Access Door Inspection

(Ref. Figure 201) Engine access doors have

(1). Check door hinges, door-attaching

upper and lower door hinges that allow door fit

hardware and latches for looseness,

adjustment. Fore and aft adjustment and fit of

cracks and damage.

doors is made possible by slotted holes in

(2). Check outside edge of door for security

hinges and serrated mating surfaces between

of bonding between outer and inner

hinges and doors. Lateral adjustment is

skin. Any separation requires repair.

obtained with laminated shims under door

hinges. Closed-door alignment is provided by

(3). Inspect doors for corrosion, distortion,

spring-type retainers on door frames at the

breaks or cracks and condition of

lower latch, and two locating pins that engage

abrasion strip tape along upper inside

holes in lower fuselage structure.

door edge and under retainers.

2. Engine Access Door Replacement

(4). For repairs (Ref. Engine Access Doors

Repairs).

A. Engine Access Door Removal

4. Engine Access Door Repair

(1). Release three latches to open access

doors. Index mark hinge, shim and

A. Sheet Metal Repair

serrated plate to door structure.

(Ref. CSP-SRM-6, Structural Repair Manual)

Remove three engine access door hinge

Abrasion strip tape along upper inside door edge

attachment screws with washers.

and on area that mates with retainers must be

Forward screws are attached with nuts

replaced when worn.

and aft screws attach to rivnuts.

B. Abrasion Strip Replacement

(2). For inspection (Ref. Engine Access Door

Inspection).

Consumable Materials

B. Engine Access Door Installation

(Ref. Section 91-00-00)

Item

Nomenclature

Consumable Materials

CM220

Naphtha aliphatic

(Ref. Section 91-00-00)

CM710

Tape, high temperature

Item

Nomenclature

CM717

Tape, pressure sensitive

CM425

Sealing compound

(1).

Replace worn abrasion strip tape along

upper inside door edge by cleaning

(1). Position door and temporarily install

contact area with naphtha (CM220);

shim, serrated plate and attachment

allow to air-dry a minimum of 30

hardware.

minutes. Install 0.50 x 40.0 inch (1.27 x

101.60 cm) strip of polyurethane tape

(2). Align indexing marks on shim, serrated

(CM717) to clean, dry surface. Apply

plate and hinge with those on door and

hand pressure to ensure firm contact

then tighten screws.

and trim as required.

(3). Close and latch doors and check for

(2).

Replace worn abrasion strip on area

firm fit with no deflections.

that mates with retainers by cleaning

retainers with naphtha (CM220).

(4). Apply sealing compound (CM425) to all

Install high temperature tape (CM710)

cotter pins.

to clean, dry surface. Apply hand

(5). For adjustment (Ref. Engine Access

pressure to ensure firm contact. Trim as

Door Adjustment).

required.

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MAINTENANCE MANUAL

C. Hinge Replacement

(1). Carefully drill out rivets and remove

defective latch hook or catch from

Replace door hinges as follows:

engine access door or fuselage structure

Replace defective stops or serrated

adjustment plates, if required, by

Consumable Materials

drilling out attaching rivets.

(Ref. Section 91-00-00)

Item

Nomenclature

(2). Locate existing rivet holes and install

CM318

Primer

replacement latch, catch, door stop or

adjustment plate. Secure with replace

(1).

Remove door from fuselage structure

ment rivets.

(Ref. Engine Access Door Removal).

(3). Adjust latches as required for proper

(2).

Remove nut, washers and hinge pivot

tension of latch lever to catch without

screw.

deflecting door (Ref. Engine Access

Door Adjustment).

(3).

Carefully press out hinge pivot point

spacer and separate hinge halves.

(4). Refinish area (except latch lever

Retain two nylon washers.

assembly) as required (Ref. Sec.

20-30-00).

(4).

Carefully drill out rivets that secure

defective hinge half to fuselage struc

5. Engine Access Door Adjustment

ture.

Door alignment is provided by means of

(5).

Transfer existing hole pattern in

spring-type retainers riveted in door frames

fuselage structure to replacement

adjacent to lower latch.

fuselage hinge half and drill out holes.

Install hinge and shim on fuselage

structure and secure with replacement

Consumable Materials

rivets.

(Ref. Section 91-00-00)

Item

Nomenclature

(6).

Assemble hinge halves with nylon

washers as shown. Press steel pivot

CM702

Lockwire CRES

spacer coated with primer (CM318)

through mating holes. Install pivot

(1). Remove lockwire from threaded

screw with washer and nut.

(adjustment) end of hooks.

NOTE: Install shims under door hinge to obtain

(2). Loosen all hooks until spring type

firm fit without binding at door-to-fuselage

retainers engage in light contact with

contact surfaces when door is closed. Use

no door deflection when hooks are

slotted holes in hinge and serrated surfaces

latched.

to obtain forward and aft adjustment. When

adjustments are complete, tighten screws

(3). Unlatch doors and tighten all hooks

that secure hinge to access door.

four to five turns. Check door latching

and make additional minor adjust

(7). Refinish repaired area (Ref. Sec.

ments as required.

20-30-00).

(4). Install lockwire (CM702) in hook

D. Catch/Latch Hook Replacement

threaded end in a manner to allow

Replace defective catches or latch hooks as

latching and unlatching without

follows:

interference.

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HANDBOOK OF MAINTENANCE INSTRUCTIONS FOR MDHI 369D/E/FF-500/600N HELICOPTERS (ISSUED: 1990) - page 14