4-17. ASPSU - Test
This task covers: Testing
General Safety Instructions:
ASPSU test set FLT4240
Always insure that the ASPSU test set is
depressurized before attempting to open chamber
door as personnel injury may result.
Rigger's knife NSN 5110-00-162-2205
Screwdriver, cross tip NSN 5120-00-234-8912
Screwdriver, plane tip NSN 5120-00-979-4557
The altitude sensor parachute staging unit (ASPSU)
contains a class C explosive in the cutter
mechanism of the cutter module. Procedure steps
shall be followed to prevent early activation and
destructive test only.)
possible personnel injury.
When connecting the ASPSU arming cable, do not
43E (10) parachute rigger
pull on cable as force in excess of 18 lbs. may
cause the ASPSU to activate resulting in personnel
The instructions pertain to the functional group
number sequence 02 in the MAC and RPSTL.
External power of ASPSU test set must be connected to
115 VAC @ 60 5 Hz
Special Environmental Conditions:
Temperature: Room Ambient, 70 10
(22 4 )
Humidity: Room Ambient, 55% normal
1. General information.
a. Functional description of ASPSU
(1) ASPSU Overall Function Description. The mechanically joined modules constitute the ASPSU. Electrical
interface between the modules is effected by a mated connector pair when the two modules are joined. The interface
supplies d.c. voltage from the thermal battery to operate the sensor electronics which in turn furnishes the command
signal to activate (fire) the webbing cutter.
(2) Electronic Circuit Function. The altitude sensor electronics is a single printed circuit card assembly mounted
in the altitude sensor module. The electronics perform the primary function of sensing altitude, or atmospheric pressure,
and converts this pressure to a calibrated d.c. voltage which is further conditioned to provide a signal to activate the
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