Effect of Modified Seat Angle on Air to Air Weapon System Performance Under High Acceleration

Abstract

In air to air combat, the weapnos system that has the highest agility and G maneuvering capability has a decided advantage over a less capable system. A method of increasing the G tolerance of the human portion of the system is the use of reclining seats. However, a question beyond homeostasis is that of performance capability. The modified closed loop Dynamic Environment Simulator system was employed as the experimental test bed for investigation of centrifuge pilots in the reclined position. 'The centrifuge pilots were required to fly through a series of G on G combat maneuvers and to perform target lock-on and boresight cannon firing through a predictive gunsight. reticle at a projected enemy aircraft. The performance scoring was measured as number of ballistic rounds delivered on the target. Pie seat was constructed with high heel line seat pan angle of 230 and back angles of 30,45, 5,Kii6f5* measured from G vector vertical. G suit pressures were modified to allow for comfort at more horizontal angles. Results indicate that the greter tilt angles provide for a significant degree of performance enhancement at higher G levels. The data has been developed in the form of a process model of best fit polynomial curves. Correlation of model to scores is .95 or better at each cass For a given performance level; Le., 50%, there is a 2 G increase in maneuvering capability with a change in seat back angle from 30 to 650. Also, for a given G level (8 G), there is a performance increase of 30% for the change of seat angle from 30) to 65". D D N"OV 4.14 73Io'ae The research in this report was conducted on the Dynamic Environment Simulator (DES) located in the Environmental Medicine Division, Aerospace Medical Research Laboratory. The program ran over a period of 8 months and involved actual G time exposures that totaled over 50 hours.Significant contributions to the program were made by Ihe entire DES operating team: J. W.

A Predictive Model of Cognitive Performance Under Acceleration Stress

“…The results seem to indicate a general slowing of the perceived time for the target to reach its destination. Furthermore, although the ability to find and track targets is important to any aircraft hostile environment, only one study has attempted to truly investigate how acceleration might affect this ability (Rogers, et al, 1973). This study required subjects to fire on a target once it was in the crosshairs following a Gz profile ranging between 1 and 8 Gz.…”

High-g Environments and the Pilot

“…Task performance is degraded as a function of +gz (Chambers, 1963;Rogers et al, 1973;Whinnery & Shaffstall, 1979). For tracking performance, increased +gz results in decreased pilot gain and decreased open-loop system crossover frequency (Sadoff & Dolkas, 1967).…”

The Development of Perceptual/Motor and Cognitive Performance Measures under a High-G Environment: A Preliminary Study

“…There is currently a lack of data on the operator's ability to perform flight and weapon system management functions under a high G environment. A few studies have, however, investigated tracking performance during acceleration (Rogers, 1973 ;3 Glaister & Lisher, 1976)1, while Usher & Glaister (1987)2 examined the effect of acceleration on performance of a reaction time task. The ability to correctly track enemy targets and respond with appropriate countermeasures is dependent upon the operator's ability to perform both perceptual/motor and cognitive functions.…”