Accession Number : AD1009444


Title :   ACES II Seat Roller Study: Findings of Detrimental Friction under High Windblast or Adverse Flight Conditions


Descriptive Note : Technical Report,28 Jan 2013,12 Aug 2015


Corporate Author : SPACE WING (45TH) PATRICK AFB FL PATRICK AFB United States


Personal Author(s) : Stapf,Sean P


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/1009444.pdf


Report Date : 12 Aug 2015


Pagination or Media Count : 45


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.


Descriptors :   ejection seats , loads(forces) , friction , rollers , bearings , catapults , thrust , yaw , acceleration , retrofitting , fighter aircraft


Distribution Statement : APPROVED FOR PUBLIC RELEASE