FULL-SCALE DYNAMIC CRASH TEST OF A SMALL OBSERVATION TYPE HELICOPTER

Abstract : This report discusses the results of experimental crash tests of two fully instrumented OH-4A helicopters. The first of these tests, conducted as a crane drop, illustrated the energy absorption capability of the tapered-wall landing gear strut. It further showed that high accelerations may be induced in occupants under level impact conditions of the aircraft in which the design sinking speed for the gear is exceeded. The latter of these tests, conducted from droned flight, indicated that rotor blade impacts with obstacles induced loads into the mast-transmission system which were sufficient to fail the structure at the transmission supports. The crashworthiness of the OH-4A showed an improvement over previous aircraft tested; however, further improvements are definitely possible. This report recommends the means of such improvements and proposes their implementation through appropriate study and test programs.