ACES II Pre-Planned Product Improvement (P3I) Program Update

摘要

Ejection seats are inherently unstable during high and low speed ejections unless positive stabilization devices are incorporated. Today's expanded 103 to 245 pound aircrew size range further challenges seat stability. The USAF ACES II seat is by far the most stable ejection seat in the world under low speed conditions. The ACES II is stabilized at zero to low airspeed with the STAPAC rocket assembly, and is aerodynamically stabilized at high speed by the STAPAC and a 5.0 ft. hemisflo ribbon drogue parachute. The USAF developed the Enhanced Drogue System, as part of the US/Japan Cooperative Modification Project, which improves high-speed seat stability and reduces the aircrew injury risk. Goodrich, the seat OEM, and the USAF analyzed the Enhanced Drogue design under the ACES P3I Program and identified minor modifications that sled testing has shown further reduces the risk of injury without negatively impacting stability or terrain clearance.Concurrent with the drogue modification, the USAF and Goodrich have developed and sled tested an inertia reel access door retrofit kit for use on ACES II seats. This access door kit allows for inertia reel replacement while the seat is in the aircraft. A USAF decision on a separate inertia reel access door retrofit, versus combining it with the Enhanced Drogue retrofit, is pending. This update describes the process used to investigate drogue optimization and describes drogue reefing time and ratio changes allowing further improvement in MDRC performance for all occupants. In addition, the requirements and installation details of the inertia reel access door retrofit kit will be reviewed. Expanding the accommodation characteristics for legacy aircraft has challenged the crew escape and cockpit design community. In particular, the small occupant offers challenges in achieving the proper sitting eye height, reaching aircraft controls, and providing safe ejections. As part of the ACES P3I Program, Goodrich was tasked to integrate the accommodation enhancements from the CMP program with the comfort improvement program enhancements resulting in a comfortable accommodation package for today’s ACES II. In addition, Goodrich/UPCO has been tasked to incorporate accommodation kit maintenance improvements. Existing accommodation designs, design requirements for the updated accommodations kit, development status, safety impact, and performance data are reviewed.Limb flail is recognized as a major injury concern during high-speed ejections. The ACES P3I Program includes research and development of passive restraint systems to reduce limb flail injuries. The program is qualifying a retrofittable variant of the F/A-22 passive leg well restraint system for use on the F-15 and F-16 aircraft platforms. In addition, inflatable and net arm restraint technologies are being investigated. Special emphasis is being given to minimizing the aircraft modifications required to install the limb restraint systems into the aircraft. The requirements, design/qualification status, test schedule, and projected fielding timeframe for these systems will be reviewed as part of this update.