On February 6, 1998 the Eclipse project accomplished its sixth and final towed flight, bringing the project to a successful completion. Preliminary flight results determined that the handling qualities of the QF-106 on tow were very stable, actual flight measured values of tow rope tension were well within predictions by the simulation, aerodynamic characteristics and elastic properties of the tow rope are a signficant component of the towing system, and Dryden's high fidelity simulation provided a representative model of the performance of both the QF-106 and C-141A airplanes in tow configuration. All six flights were highly productive and all project objectives were achieved.
NASA Dryden Flight Research Center supported and hosted a Kelly Space and Technology, Inc., (KST)/USAF project, known as Eclipse, which demonstrated a reusable tow launch vehicle concept. The goal of the project was to successfully tow in flight a modified QF-106 delta-wing aircraft with an Air Force C-141A transport-type aircraft. Dryden was the Responsible Test Organization and had flight safety responsibility for the Eclipse project. Dryden also supplied engineering, instrumentation, simulation, modification, maintenance, range support, research pilots, and chase aircraft for the test series.Eclipse project QF-106 and C-141A takeoff on first tethered flight December 20, 1997
The Air Force Flight Test Center (AFFTC) supplied the C-141A transport aircraft and crew and configuring the aircraft as required for the tests. They also provided general engineering support and assumed flight safety responsibilities for the C-141A. KST provided concept and detail design and analysis as well as hardware for the tow system and QF-106 modifications. Dryden performed the modifications to convert the QF-106 drone into the piloted EXD-01 (Eclipse eXperimental Demonstrator -01) experimental airplane. KST planned to use the results gleaned from the tow tests in developing a series of low-cost, reusable launch vehicles.
These tests were to demonstrate the viability of towing a delta-wing aircraft having high wing loading, validate the tow simulation model, and demonstrate various operational procedures, such as ground processing, in-flight maneuvers, and emergency abort scenarios.