TB 1-1520-210-20-17
(4)
Close access to overhead console circuit breaker and wiring.
(5)
Install overhead cabin sound proofing blanket.
(6)
Close nose compartment door.
(7)
Connect the aircraft battery.
(8)
Turn power on to provide 28 volts to GPS circuit breaker on center post circuit breaker panel.
(9) Verify pin B of the GPS five pin audio connector is common with airframe ground and that pin D (see Figure 4)
has 28 VDC on it.
(10) (Optional) Install the Trimpack unit (See note in paragraph 1) and remote antenna in the aircraft. Move the
aircraft to outside ramp with good GPS satellite visibility. Power up the aircraft. Turn the Trimpack on and check to see that it
acquires the GPS satellites which are visible at the time of the test
12. Kit B Installation Procedure.
a. Remove GPS antenna blankoff panel (if installed) from the GPS antenna mount on upper wire strike cutter of aircraft
(see Figure 5).
b.
Install GPS antenna on its mount and secure with four MS35206-247 screws and four AN960C8L washers (see Figure
NOTE
To facilitate removal, do not seal the antenna to its mount.
NOTE
Only Trimble Trimpack GPS receiver part number 16768-10 and 16768-20 are allowed
for this installation. These receivers have software to compensate for rotor modulation
and have green lights. All other Trimble Trimpacks receivers can not be used. The part
number is on a nameplate located between the receiver and battery pack. The battery pack
must be removed to see the nameplate. An ANVIS night vision imaging filter kit, NSN
5895-01-340-5502 provides an acceptable display when used with either GPS receiver.
Instructions for ANVIS filter installation are contained in ILS 9L-ANV0002, dated March
1991, provided with ANVIS kit.
c. Remove caps from GPS Trimpack receiver power connector and external antenna cable connector. Tape caps to side of
receiver with pressure sensitive tape PPP-T-42 to prevent chafing.
d. Install receiver in its mount on copilots pedestal and secure with clamp assemblies. Connect power cable and antenna
cable to the receiver.
e. Move the aircraft to outside ramp with good satellite visibility. Power up aircraft Turn the Trimpack on and check to
see that it acquires the GPS satellites which are visible at the time of the test
7
