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MAINTENANCE MANUAL
CSP-HMI-2
SEAT BELTS/INERTIA REEL
MAINTENANCE PRACTICES
1. Seat Belts/Inertia Reel Description and
Operation (369D/E/FF − 500N)
Inertia reel-type seat belt/harness equipment
consists of a shoulder harness, an inertia reel,
and a two-piece adjustable seat belt for both
the pilot and copilot.
The shoulder harnesses and seat belts are of
nylon web material with sewn-in length
adjusters and end adapters for attachment of
the harnesses to the seat belts. Inertia reels,
furnished as part of the harnesses, are
mounted on the Sta. 78.50 canted frame. The
reels permit the pilot and copilot freedom for
slow, deliberate shoulder movement, but lock
with any sudden forward movement. Full
extension or retraction of the straps on the
spring-loaded reels is approximately 25 inches
(63.5 cm).
Some installations have a handle: with the
handle up, the inertia reel operates normally;
with the handle down, the inertia reel is locked
up to restrain movement.
2. Seat Belts/Inertia Reel Description and
Operation (600N)
The crew seats utilize a four-point restraint
harness. This harness combines the lap seat
belts with double shoulder straps attached to
an inertia reel mechanism. Both mid and aft
passenger seats are equipped with a threepoint restraint system. The lap seat belt and
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
shoulder strap are joined at the end into a
single unit for ease of attachment and conve­
nience. In one motion, the lap and shoulder
belts together can be attached to the seat
buckle.
3. Crew Seat Belt/Harness Cleaning
The harness and seat belt may be cleaned
using a soft-bristle brush and a mild solution
of warm water and laundry detergent.
4. Seat Belt/Inertia Reel Replacement
(369D/E/FF − 500N)
(Ref. Figure 201, Figure 202 and Figure 203)
(1). For access to seat belt attach fittings,
remove crew compartment seats.
(2). Remove inertia reel, with harness, from
canted bulkhead lateral beam by
removing four bolts.
(3). Install replacement harness by securing
inertia reel, with harness, to canted
bulkhead lateral beam.
(4). Install replacement seat belts and
shoulder straps as shown. Place snap
end fittings up or down to eliminate any
twist in seat belt.
(5). Tongue portion of center passenger lap
belt must be installed on right side and
buckle portion on left side as shown.
25-20-00
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MD Helicopters, Inc.
MAINTENANCE MANUAL
FITTING
INERTIA REEL
SNAP END
FITTING
SEAT BACK
SEAT BELT FITTING
ATTACHMENT
NOTE 1
PASSENGER COMPARTMENT
INERTIA REEL
INERTIA REEL
FLOOR STRUCTURE
NOTE 2
HARNESS MUST UNREEL
IN DIRECTION SHOWN
41° ±3°
90° LIMITS OF CUTOUT
IN ALUM. HOUSING
INERTIA REEL
NOTE 1
NOTES:
1. SHOWN WITHOUT CUSHION
FOR CLARITY.
2. CENTER CUSHIONS AND SEAT
BELTS ONLY FOR 3-PLACE
SEATING.
CREW COMPARTMENT
INERTIA REEL
SEAT STRUCTURE
G25-2002
Figure 201. Seat Belt/Inertia Reel Installation (Sam Browne Style) (369D)
Page 202
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The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
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MD Helicopters, Inc.
MAINTENANCE MANUAL
CSP-HMI-2
PASSENGER / CARGO
COMPARTMENT AFT
BULKHEAD
SNAP END FITTING
(HOOK UP)
SEAT BELTS AND SHOULDER HARNESSES
SNAP END FITTING
(HOOK DOWN)
SNAP END FITTING
(HOOK UP)
NYLON WEBBING
SHOULDER STRAP
NOTE:
SLIDE BAR
HARNESS LENGTH ADJUSTER.
ADAPTER
(NOTE)
SNAP END FITTING
(HOOK UP)
SNAP END FITTING
(HOOK DOWN)
NYLON WEBBING
SEAT BELT
INERTIA REEL
BUCKLE
LATCH
ADAPTER
ADAPTER
(NOTE)
NYLON WEBBING
SHOULDER STRAP
SNAP END
FITTING
SNAP END FITTING
(HOOK DOWN)
ADAPTER
(NOTE)
HARNESS MUST UNREEL
IN DIRECTION SHOWN
41° ±3°
90° LIMITS OF CUTOUT
IN ALUM. HOUSING
BUCKLE
ADAPTER
LATCH
FITTING
ADAPTER
(NOTE)
NYLON WEBBING
SEAT BELT
SNAP END FITTING
INERTIA REEL
PILOT AND COPILOT SEAT BELT AND SHOULDER HARNESS ASSEMBLY
G25-2003
Figure 202. Seat Belt/Inertia Reel Installation (Yoke Style) (369D)
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
25-20-00
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MD Helicopters, Inc.
MAINTENANCE MANUAL
INERTIA REEL (2)
SEAT BACK CUSHION
VELCRO STRIP
FASTENER (TYP)
SUPPORT CUSHION
AFT SUPPORT
FITTING AND HEIGHT
ADJUSTMENT
SEAT BOTTOM CUSHION
PASSENGER COMPARTMENT
INERTIA REEL (2)
LOCK PIN
SEAT BACK
CUSHION
LOWER FRAME
RELEASE PIN
SUPPORT LEG AND
HEIGHT ADJUSTMENT
SEAT BOTTOM
CUSHION
FLOOR STRUCTURE
INERTIA REEL (2)
CREW COMPARTMENT
VELCRO STRIP
FASTENER (TYP)
SEAT STRUCTURE
G25-2004
Figure 203. Seat Belt/Inertia Reel Installation (Yoke Style) (369E/FF − 500N)
Page 204
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The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
MD Helicopters, Inc.
CSP-HMI-2
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MAINTENANCE
MANUAL
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5. Crew Seat Belt/Harness Replacement With
(2). Remove inertia reel, with harness, from
fiberglass mount by loosening four bolts
Manual Lock Option (369D/E/FF − 500N)
and upper ferrule nut.
(3). Install seatbelts by fastening snap type
end fittings to bulkhead structure
fittings.
(Ref. Figure 204 and Figure 205)
(1). Remove seatbelts by unfastening snap
type end fittings from bulkhead
structure fittings.
(4). Install inertia reel, with harness, to
fiberglass mount with ferrule nut and
four bolts, nuts and washers.
CONTROL HEAD ROTATED
90° CW FOR CLARITY
UPPER FERRULE NUT
AUTOMATIC
INERTIA
REEL ASSY
CABLE
MANUAL LOCK
LOWER
FERULE
NUT
ADJUSTER
(TYP)
TAB RELEASE
(TYP)
CONTROL ASSY
0101935-1 SHOULDER
HARNESS ASSY
1.88-2.12 IN. (4.776-5.385 CM)
WIDE WEBBING
ADJUSTER
2.88-3.12 IN. (7.315-7.925 CM)
WIDE WEBBING LAP BELT ASSY
(0101936-1 ASSY)
END FITTING
LINK
LATCH
ADJUSTER
G25-2006A
Figure 204. Webbed Shoulder Harness and Seat Belt Installation with Manual
Inertia Reel Lock (369D)
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
25-20-00
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MAINTENANCE MANUAL
LOW SHOULDER BEAM INSTALLATION
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HIGH SHOULDER BEAM INSTALLATION
G25-2005
Figure 205. Crew Inertia Reel Installation with Manual Inertia Reel Lock
(369D/E/FF − 500N)
6. Seat Belt/Inertia Reel Testing
(Ref. Pull tests of seat belts and shoulder strap
harnesses shall be accomplished in accordance
with FAA AC 43.13-1B, Aircraft Inspection
and Repair for Standard Sheet Metal Repair
and TSO C22.
7. Seat Belt/Inertia Reel Inspection
Ensure center passenger lap
WARNING belt is installed with tongue
portion to the right of the seat and
buckle portion to the left. (Quick re­
lease of the lap belt and shoulder strap
may be impaired if the assembly is im­
properly installed.) If tongue and
buckle portions are reversed, remove
and reinstall in correct positions and
document reinstallation in Compliance
Record of Helicopter Log Book.
(1). Pull seat belt or shoulder strap out of
inertia reel to full extended length.
Ensure harness strap cannot be pulled
out of inertia reel. With tension re­
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leased, harness strap should automati­
cally reel back into reel. Exert a sudden
forward pull on seat belt or shoulder
strap to ensure inertia reel locks.
(2). Inspect inertia reels, snap end fittings,
adjusters, links, buckles, latches and
belt attachment fittings for cracks,
wear, corrosion and deformation. Check
for freedom from binding, ease of
adjustment and operation as applicable.
If doubt exists as to strength, perform
pull test (Ref. Seat Belts/Inertia Reel
Testing).
(3). Inspect shoulder harnesses and seat
belts for worn, frayed or deteriorated
condition, and loose stitching.
(4). (Manual Lock Option) Check mechani­
cal inertia lock mechanism for proper
operation, with handle up and with
handle down. Inspect fiberglass mounts
for cracking and separation. Inspect
laminates for debonding.
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
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8. Seat Belt/Inertia Reel Repair
MD Helicopters, Inc.
MAINTENANCE MANUAL
(1). Replace seat belts and shoulder straps
if fabric is frayed, worn, deteriorated,
stitching is loose, or if enertia reels are
destroyed or do not function properly.
(2). Polish minor nicks and scratches.
Restore protective finish to aluminum
parts as required.
(3). Repair fiberglass mounts (Ref. Sec.
25-30-00, Boltaron Trim Panels
Repair).
9. Seat Belt/Restraint Harness, Crew Seat,
Replacement (600N)
(Ref. Figure 206)
A. Seat Belt/Restraint Harness Removal
(1). Release end fittings to remove lap seat
belts.
CSP-HMI-2
(2). Remove hardware that attaches inertia
reel to mounting surface.
(3). Remove complete seat belt restraint
harness from seat.
B. Seat Belt/Restraint Harness Installation
(1). Position lap seat belt and shoulder
harness into seat assembly.
(2). Engage end fittings attaching lap seat
belts.
(3). Install hardware attaching inertia reel
to mounting surface.
(4). Ensure proper engagement and release
of seat buckle and inertia reel mecha­
nism.
ADJUSTOR
ADJUSTOR
SHOULDER
HARNESS
END FITTING
LAP
SEAT BELT
SHOULDER
HARNESS
ADJUSTOR
ADJUSTOR
LAP
SEAT BELT
END FITTING
BUCKLE
6G25-070
Figure 206. Seat Belt/Restraint Harness Installation, Crew Seat (600N)
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
25-20-00
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11. Seat Belt/Restraint Harness, Aft
Passenger Seat, Replacement (600N)
MD Helicopters, Inc.
MAINTENANCE MANUAL
10. Seat Belt/Restraint Harness, Mid
Passenger Seat, Replacement (600N)
(Ref. Figure 207) These three individual seat
belt harnesses are completely contained in the
seat assembly and attach to the seat frame.
This feature aids in the quick removal and
installation of the mid bench seat assembly.
A. Seat Belt/Restraint Harness Removal
(1). Remove hardware that attaches inertia
reel end of harness to seat back.
(2). Release end fitting that attaches lap
seat belt to seat frame.
(3). Release end fitting that attaches buckle
end of harness to seat frame.
(4). Remove seat belt/restraint harness.
B. Seat Belt/Restraint Harness Installation
(1). Position seat belt/restraint harness into
seat assembly.
(2). Engage end fitting attaching buckle end
of harness to seat frame.
(3). Engage end fitting attaching lap belt to
seat frame.
(Ref. Figure 207)
A. Seat Belt/Restraint Harness Removal
(1). Remove hardware that attaches inertia
reel end of harness to mounting
surface.
(2). Release end fitting that attaches lap
belt to mounting surface.
(3). Release end fitting that attaches buckle
end of harness to mounting surface.
(4). Remove seat belt/restraint harness.
B. Seat Belt/Restraint Harness Installation
(1). Position seat belt/restraint harness into
seat assembly.
(2). Engage end fitting attaching buckle end
of harness to mounting surface.
(3). Engage end fitting attaching lap belt to
mounting surface.
(4). Install hardware attaching inertia reel
end of harness to seat back.
(4). Install hardware attaching inertia reel
end of harness to mounting surface.
(5). Ensure proper engagement and release
of seat buckle and inertia reel mecha­
nism.
(5). Ensure proper engagement and release
of seat buckle and inertia reel mecha­
nism.
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The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
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MD Helicopters, Inc.
MAINTENANCE MANUAL
MID SEAT
CSP-HMI-2
AFT SEAT
END FITTING
INERTIA REEL
MOUNT
INERTIA REEL
ADJUSTOR
END FITTING
BUCKLE
6G25-086
Figure 207. Seat Belt/Restraint Harness Installation, Passenger
Seats (600N)
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
25-20-00
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position as close as possible next to
inertia reel.
MD Helicopters, Inc.
MAINTENANCE MANUAL
12. Comfort Clip Installation and Decal
Application (369D/E/FF − 500N)
(Ref. Figure 208 and Figure 209) The comfort
clip is designed to maintain proper strap
tension and relieve excessive pressure of the
inertia reel shoulder harness on the pilot or
passenger during flight. It is available for
installation on helicopters equipped with Sam
Browne style seat belt assemblies.
(1). Pry open slot on underside of clip.
(4). After each flight, reposition comfort clip
on harness strap at original position
next to buckle.
(5). Clean panel or door frame where decal
is to be applied. Decals will not adhere
to a greasy or soapy film.
(2). Insert harness strap in slot.
(6). Mark location(s) of decal per the
illustrations.
(3). After seat belt and shoulder harness
assembly is fastened and adjusted for
individual comfort and safety, slide
comfort clip up on harness strap and
(7). Peel backing off decal and position. Use
a cloth to squeeze all bubbles from
under the decal, working from the
center outward.
DECAL
CENTER DECAL BETWEEN END OF
DOOR FRAME AND FIRST SCREW
VIEW LOOKING OUTBOARD FROM
CL OF SHIP TO LH SIDE
COMFORT CLIP INSTALLATION
G25-2001
Figure 208. Comfort Clip Installation and Crew Compartment Decal
Application (369D/E/FF − 500N)
Page 210
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The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
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MAINTENANCE MANUAL
CSP-HMI-2
TO APPLY DECAL:
1. CLEAN PANEL AREA WHERE DECAL IS TO BE APPLIED.
DECAL WILL NOT ADHERE TO A GREASY OR SOAPY FILM.
2. MARK LOCATION OF DECAL PER THE ILLUSTRATION.
3. PEEL BACKING OFF DECAL AND POSITION. USE A CLOTH
TO SQUEEZE ALL BUBBLES FROM UNDER THE DECAL,
WORKING FROM THE CENTER OUTWARD.
CL SHIP
DECAL
PANEL ASSEMBLY
5.00 ±0.25 IN.
(12.70 ±0.635 CM)
G25-2000A
Figure 209. Comfort Clip Decal Application − Passenger Compartment
(369D/E/FF − 500N)
The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc
25-20-00
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The information disclosed herein is proprietary to MD Helicopters, Inc.
Neither this document nor any part hereof may be reproduced or transferred to
other documents or used or disclosed to others for manufacturing or any other
purpose except as specifically authorized in writing by MD Helicopters, Inc.
Copyright © 1999−2014 by MD Helicopters, Inc