Modifications and results of flight tests of a practice bomb adapter

Abstract

The Royal Netherlands Air Force was searching for a small, light and easy to handle practice bomb rack. Initial exploratory delivery flight tests with the tandem two place Multiple Practice Bomb Adapter (MPBA), carried at the outboard wing pylons of the F-16 aircraft, did not show adverse characteristics. A report on comparable flight tests with the A-7 Corsair II was also positive. In a delivery flight test program to collect scoring data, high-speed 16 mm movie recordings revealed bomb-to-pylon or bomb-to-adapter contact of both Mk-106 (at moderate airspeed) and BDU-33D/B (at higher speed) within the required release envelope. Subsequently the aerodjmamic shape of the practice adapter was modified. The internal, mechanical properties and the rack-to-aircraft interface remained unchanged. Flight tests with the modified rack showed still unacceptable separation behaviour. After providing spring type "tail-up restrictors" to the original and to the aerodynamically modified bomb rack, satisfactory separation characteristics were demonstrated by the BDU-33D/B practice bomb throughout the required release envelope. A more rigid construction of the tail-up restrictor will probably produce satisfactory separation characteristics for the Mk-106 practice bomb as well. The paper presents a comparison of the bomb adapter before and after modification and presents the results of the flight test programs.