ACES II Seat Roller Study: Findings of Detrimental Friction under High Windblast or Adverse Flight Conditions
Technical Report,28 Jan 2013,12 Aug 2015
SPACE WING (45TH) PATRICK AFB FL PATRICK AFB United States
Pagination or Media Count:
Analytical findings of an intrinsic, detrimental high-friction response of the ACES-II Ejection Seats legacy seat roller six metal wheels on six dry metal shafts when subject to high loads such as windblast from a 600 KEAS ejection, or adverse aircraft conditions of yaw or roll rate. Verification and validation is provided through 6-DOF mechanical-dynamics simulations, classical hand calculations, comparison against the F-16 Aviano Mishap data, comparison against sled tests 110E-A1 of 2012 F-16 at 600 KEAS, with forward 5th percentile and aft 95th percentile manikins, and theoretical discussion of the dynamic mechanical relations. Two recommendations are made, 1 Replace the current ACES-II seat rollers with modern industrial cam rollers or similar load-rated roll-and-thrust bearing wheel system, and 2 insure that no future ejection seat system such as an ACES 5, Mk 16, or other with limited-energy propulsion such as a propellant charge is fielded to the fleet without a seat-to-aircraft release system that maintains a friction coefficient below 0.01 under normal X-axis loads of 10000 lbf and lateral Y-axis loads of 1500 lbf.