Special Report on Bell ACAP Full-Scale Aircraft Crash Test

A full-scale aircraft crash test of the Bell ACAP developed under the U.S. Army's Advanced Composite Airframe Program was conducted at NASA Langley Research Center's Impact Dynamics Facility on August 27, 1987. The test demonstrated that the Bell ACAP was capable of meeting the U.S. Army's stringent crash survivability requirements of 50-ft/s resultant ground impact velocity (42-ft/s sink speed, 27-ft/s forward velocity, with two-thirds DGW rotor lift) at an aircraft attitude of 10° roll and 10° nose-up pitch without any apparent serious injuries to the occupants. The impact velocity is comparable to a free fall from a four-story building. The ACAP crash test represents the first time any helicopter has ever been tested to this 50-ft/s impact level with the aircraft attitudes of 10° for both roll and pitch conditions. It is significant that this was accomplished with an all-composite airframe, for it demonstrates a state-of-the-art advancement in the application of composite materials to future generations of Army helicopters. This paper summarizes the results of the crash test and includes a comparison of the test motion sequence with the KRASH computer simulation.