ACES II Seat Roller Study: Findings of Detrimental Friction under High Windblast or Adverse Flight Conditions
Abstract
Analytical findings of an intrinsic, detrimental high-friction response of the ACES-II Ejection Seat's 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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 12, 2015
- Accession Number
- AD1009444
Entities
People
- Sean P. Stapf