Stability and Limb Dislodgement Force Measurements with the F-105 and ACES-II Ejection Seats
Abstract
Forces on the arms and legs of test subjects seated in the F-105 and ACES-II ejection seats were measured over a range of speeds in a wind tunnel. It was found that the forces varied considerably between individuals. The variation was not identified with any outwardly visible physical features of the individuals. Averaged values for the group were compared over a range of pitch and yaw angles and between two different seats. Outward force at the knee was found to vary systematically with yaw angle up to 30 deg, and to be little affected by pitch, and to be practically the same on both seats. Forces at the feet and hands showed less systematic variation and were different between the two seats. Attempts to modify the forces by appurtenances attached to the limbs succeeded only in reducing them for some conditions at the expense of others. Both seats were shown to be statically unstable, with and without occupant, in free flight. Static stability was exhibited when equipped with an array of in- plane stabilizer plates on both the F-105 and ACES-II ejection seats. Pressures inside the helmet, and overall forces tending to remove it, were also measured. Powerful lift forces were derived from low pressures over the outside, quite sufficient to ensure helmet loss at high speed, unless the retention strap is designed to react large loads; in which case, some form of neck injury can be anticipated.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1975
- Accession Number
- ADA015726
Entities
People
- Anthony J. Euler
- Fred W. Hawker
- Peter R. Payne