Fall Testing of the Personal Airborne Equipment Backpack: Ground and Flight Testing

Abstract

This article evaluated the functionality and reliability of the personal airborne equipment backpack TL-98 before its launch in military parachute operations. An objective of this project was the verification of the TL-98’s characteristics which could be important in terms of the safety of the operation of the parachute, i.e., its functionality and reliability during flight and fall tests. A major effort within this research was focused on the fall tests of the TL-98 in standard parachute operational conditions. The strength of the backpack’s anchorage points (by which the backpack is attached to the parachute harness) was verified by flight test, where it was dropped from the aircraft at the maximum operating speed and at the maximum operating weight of the backpack; the backpack’s maximum operating weight had been increased by multiplying the standard maximum operating weight by a safety factor of 1.2. During the fall tests of the backpack, after its disconnection from the parachute harness (during ground tests and the test during the test jump), the strength of the backpack’s anchoring eye and the strength of the rope with which the backpack is connected to the parachute harness were verified. Another objective of this research was the collection of information to define the TL-98’s rope lifetime, which serves for the dropping of the TL-98. To fulfill this goal, the impact forces on the rope during the backpack’s fall were measured using a force sensor. The values of the impact forces were then calculated and compared with the values from the experiment. Using experimentally obtained results and their comparison with the calculated results, the lifetime of the TL-98 rope for parachuting operations was determined on the basis of predetermined criteria.