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 USAFand Goodrich have developed and sled tested aninertia reel access door retrofit kit for use on ACESII seats. This access door kit allows for inertia reelreplacement while the seat is in the aircraft. AUSAF decision on a separate inertia reel access doorretrofit, versus combining it with the EnhancedDrogue retrofit, is pending. This update describesthe process used to investigate drogue optimizationand describes drogue reefing time and ratio changesallowing further improvement in MDRCperformance for all occupants. In addition, the requirements and installation details of the inertiareel access door retrofit kit will be reviewed.Expanding the accommodation characteristics forlegacy aircraft has challenged the crew escape andcockpit design community. In particular, the smalloccupant offers challenges in achieving the propersitting eye height, reaching aircraft controls, andproviding safe ejections. As part of the ACES P3IProgram, Goodrich was tasked to integrate theaccommodation enhancements from the CMPprogram with the comfort improvement programenhancements resulting in a comfortableaccommodation package for today’s ACES II. Inaddition, Goodrich/UPCO has been tasked toincorporate accommodation kit maintenanceimprovements. Existing accommodation designs,design requirements for the updatedaccommodations kit, development status, safetyimpact, and performance data are reviewed.Limb flail is recognized as a major injury concernduring high-speed ejections. The ACES P3I Programincludes research and development of passiverestraint systems to reduce limb flail injuries. Theprogram is qualifying a retrofittable variant of theF/A-22 passive leg well restraint system for use onthe F-15 and F-16 aircraft platforms. In addition,inflatable and net arm restraint technologies arebeing investigated. Special emphasis is being givento minimizing the aircraft modifications required toinstall the limb restraint systems into the aircraft.The requirements, design/qualification status, testschedule, and projected fielding timeframe for thesesystems will be reviewed as part of this update.