FLIGHT TEST WEEK 'OPEN CONFERENCE' - hosted by Society of Flight Test Engineers (SFTE)

Running in Auditorium 3 on the Exhibits floor) on 18, 19, 20 Nov 2008


Sailplane Aerotow Takeoff Performance Evaluation Through Model Validation
Thursday 20th November 2008
13.30 - 14.00
Auditorium 3

USAF Test Pilot School (TPS) staff members conducted a flight test program to determine the takeoff and climb performance of the TG-15A Duo Discus at maximum gross weight, high density altitudes, and calm wind with the USAF Academy CC18-180 Top Cub tow plane. In the paradigm of Predict-Test-Validate, a mathematical model was constructed to predict takeoff performance during the buildup in glider gross weight. After flight test, the model was adjusted to match the test results at the test conditions. Flight test data were standardized using the model to support conclusions about the feasibility of operations.

This paper discusses the simple instrumentation used, including a Wide Area Augmentation System (WAAS)-enabled GPS for Time-Space-Position Information. The approach to takeoff testing is detailed. The process for estimating performance models from published data is discussed, along with the methods used to model the takeoff and initial climb and factors for adjusting that model. The final results of the model matching are shown, and a t-distribution is fitted to the standardized data. Details for calculating the Student’s t probability distribution function are also included.