TRANSPORT AIRCRAFT VERTICAL ACCELERATION DETECTION.

Three commercially available accelerometer systems designed to measure vertical acceleration were evaluated for transport aircraft use by performing a series of laboratory and flight tests. The tests results indicated that the off-the-shelf systems failed to record the flight test accelerations satisfactorily. However, the essential physical characteristics required of a transport aircraft's vertical acceleration sensing and recording system were determined from the flight test data. It was concluded that a transport's accelerometer system should contain three accelerometer units. Two identical accelerometer units mounted on the left and right landing gear mounting structure to sense landing impacts, and one accelerometer unit installed at the aircraft's c.g. position to sense flight accelerations. Airworthiness inspection requirements, due to aircraft vertical accelerations, may be ascertained by performing an engineering analysis of the recorded accelerations and the aircraft limit load data. (Author)