Volume 1. Performance Flight Testing Phase. Chapter 4. High L/D.
Abstract
In 1967, the USAF Test Pilot School inaugurated an introductory soaring program which provided each student with about three hours of sailplane flying. The program was conceived to expose student test pilots and flight test engineers to an additional type of aircraft with flying characteristics unlike any other in the school curriculum. TPS students are regularly flying aircraft whose lift-to-drag ratios (L/D) vary respectively from 2.2:1 (T-38 Low L/D) to 11:1 (A-37). The soaring program completes the higher end of this spectrum with aircraft having an L/D of 36:1 (Grob 103). The soaring program lends itself effectively to the investigation of nonsteady state stability and control flight testing techniques. This type of testing is presently applied to the T-38 when it is configured to simulate a power limited or powerless aerospace vehicle. Since the motive power of a sailplane is derived solely from gravity, this nonsteady state test method is the only way of determining the stability and control characteristics. The lifting body and space shuttle concepts dictate a gliding, power-off approach and landing pattern. Consequently, NASA initiated a mandatory soaring program for their lifting body test pilots. Experience gained in the TPS soaring program is likewise expected to benefit and better prepare the school graduate for such a test program. It also is a valuable background for operations where flame-out patterns may be required. The meteorological state of the atmosphere plays a significant role in soaring flight. The conditions that exist to produce lift are of vital interest to the soaring pilot. Consequently, one of the benefits to be realized from a soaring program is an increased awareness and appreciation of the meteorology of flight.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA320222