MD Helicopters 369-500, Maintenance Instructions Manual

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CSP-HMI-3
MD Helicopters, Inc
.
MAINTENANCE MANUAL
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Page 202
Revision 7
95-10-20
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 − 2016 by MD Helicopters, Inc.
wheels, not casters. If a truck is used,
the truck must have pneumatic tires,
and the container must be positioned
where it will not be bounced or jarred
during movement of the truck.
(5). Do not drop, kick, toss, bump, or
tumble a container housing a gyro.
(6). When it is necessary to ship a gyro, use
air shipment.
(7). Retain all gyro shipping containers and
dunnage for reuse.
B. Gyro Handling
(1). When installing a gyro, place the
container housing the gyro as near as
possible to the point of installation. If
applicable, remove the gyro to be
replaced and gently place it next to the
shipping container. Remove the new
gyro from the shipping container and
install it in the helicopter. If applicable,
properly pack the removed gyro in the
shipping container for transport to the
shop, etc.
(2). Where practical, do not ground-handle
a helicopter in which an installed gyro
has been energized for 20 minutes after
power has been removed from the gyro.
(3). Do not move a gyro if the gyro rotor is
running. Allow a 20 minute run down
after power is removed.
(4). Do not rotate or tumble the gyro during
handling.
(5). When removing or installing a gyro,
remember that it is to be treated like
an egg. Do not bump it, drop it, strike
it, tumble it or jolt it.
(6). Be extremely careful when setting a
gyro on a fixture, bench, table or any
surface. Dropping one end of a gyro 3/4
inch is equivalent to a 20g impact for
the gyro. A 2-1/2 inch drop can ruin the
gimbal bearings.
(7). Always keep strong magnetic fields
away from gyro (to prevent possible
internal component damage).
C. Attitude Gyro Indicator Troubleshooting
(Ref. Figure 202)
NOTE:
Use an external power source for all
troubleshooting that involves electrical
power (Ref. Chap. 96).
D. Circuit Breaker and Switch
Ensure that GYROS circuit breaker and
switch are mechanically sound and function
electrically. Both the circuit breaker and
switch are spring-loaded and should positively
snap into either the ON or OFF position. If
either circuit breaker or switch fails to
function properly, replace.
E. Electrical Overload
If an overload has tripped circuit breaker,
allow system to cool for approximately 2
minutes and press circuit breaker to ON
position. If circuit breaker trips again, leave
system OFF, troubleshoot circuitry, and repair
as required.
F. Wiring Harness
Ensure that pins and sockets of all connectors
of wiring harness and all other components are
undamaged, clean, and correctly connected
and secured.
(1). Wiring Harness After Repair:
Wiring harness problems can result
because of incorrect connections at
terminal blocks. Carefully inspect
connections to ensure that all wires are
correctly and securely attached to the
appropriate terminals.
(2). Damaged or Worn Wiring Harness:
If wiring harness is correctly connected
to all terminals, inspect harness for
physical condition. Ensure that insula­
tion is intact, and not chafed or
pinched. If there is any question about
continuity or condition of wires, use
volt-ohm meter (VOM) to check for
open or short circuit. If wiring harness
is in satisfactory operating condition,
proceed with next analytical trouble­
shooting step and take appropriate
corrective action.