4-17. ASPSU - Test (Cont)
1. General information (Cont).
b. Test modes. Two testing modes exist. The two modes are:
Destruction test (actual firing of the ASPSU)
(1) Operational Test. In this test mode, the Altitude Sensor and Cutter Module are mated together in the airdrop
configuration and installed in the test chamber of the ASPSU test set. A test cable, from the test set, is employed to
provide an electrical interface. With the ASPSU installed in the test chamber, a vacuum pump and associated chamber
controls on the test set are used to raise the chamber to a simulated altitude (reduced pressure). Simulated altitude is
displayed on the test sets altimeter. The simulated altitude represents an environment identical to that encountered on
board an aircraft. Activation of the sensor module as it passes through the set altitude is indicated by illumination of the
(2) Destructive Testing. In this test mode, the ASPSU is armed with a vacuum cylinder/pull mechanism
controlled by the test sets front panel switch, ASPSU ARM, which pulls the ASPSU firing pin. Chamber control is
identical to that employed for operational testing. Additional chamber controls on the test set permit a decrease in
chamber altitude at a fixed rate. As the altitude passes through that selected is the activation altitude on ASPSU, the
ASPSU fires, thus severing a section of test nylon webbing. This event is correlated to the altimeter reading to verify the
accuracy of the ASPSU.
END OF GENERAL INFORMATION
2. Operational test procedure. This test is conducted before the ASPSU is rigged to the HAARS.
a. Test set preparation.
(1) Electrical hookup. Remove and connect the 115 VAC power cable in the ASPSU test set in accordance with
Insure that all test set switches are in the OFF or DOWN position.
(2) Raise the pressure chamber door.
(3) Check fuses and lights in accordance with TM 10-1670-266-13&P.
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