Flutter testing in the 90´s (The GBU-24 saga)

Operation Desert Storm demonstrated the benefits of employing large guided penetrating weapons with long standoff ranges against hardened targets. The article concerns the GBU-24B/B laser-guided bomb (LGB). Before flight testing, a flutter analysis study indicated that certain CF-18/GBU-24 configurations exhibited 5.6 Hz antisymmetric flutter. It was therefore recommended that a flutter/limit cycle oscillation (LCO) flight test be conducted prior to fleet release of the GBU-24. Initial testing was completed using a production lot V CF-18B aircraft configured with symmetrical GBU-24s on the outboard wing stations, symmetrical external fuel tanks on the inboard wing stations, and symmetrical wing tip missiles. Flutter flight testing was temporarily suspended during the program after explosive flutter was encountered. The paper discusses the flight test approach, the buildup technique, the conduct of the tests up to and beyond this point as it evolved in the light of findings, the results and, most importantly, the lessons learned during the entire flutter flight test programs of the CF-18 in GBU-24 configurations