Recording the braking process of a catastrophic flight data recorder protection cassette during a crash test

Abstract

The article describes methods for recording the course of a test probe crashing into an obstacle in the form of a sand bed and the consequent rapid deceleration process by the braking object. The tested probe is adapted for placing a catastrophic flight data recorder protection cassette inside of it. The tests were conducted in order to confirm the resistance of the protection cassette to a g-load of 3400g acting on the cassette for ca. 6.5 ms, as per the guidelines of the standards: European EuroCAE ED-112 and Polish NO-16-A200. The probe was accelerated to a required velocity using a DPZ-250 pneumatic can-non, owned by the Institute of Aviation. The controlled braking pro-cess was obtained thanks to a sand bed located within the braking station, which was designed and constructed at Air Force Institute of Technology (AFIT). The course of each crash test, that is, the flight and the process of a test probe crashing into the sand was recorded by a camera for recording fast transient phenomena. Conducting the crucial tests involved installing an overload recording system inside the test probe, which directly records and saves the overloads associated with collisions. The objective of the first test stage was to confirm the correctness of the adopted methodology and to develop test procedures used in further experiments. The essential tests involved in-stalling a catastrophic flight data recorder electronics package inside the test probe in order to confirm satisfying the requirement in terms of overload. The executed tests confirmed reaching the parameters of the experiment, which satisfy the normative requirements of the test conditions. The checks of the tested catastrophic flight data recorder elements proved its resistance to a g-load of 3400 g. The applied g-load re-cording methods enabled the inspectors to confirm reaching the required value and the nature of changes of the hazards, the test probe was subjected to during the impact tests.