Infrared Radiation Transmittance and Pilot Vision Through Civilian Aircraft Windscreens
FEDERAL AVIATION ADMINISTRATION OKLAHOMA CITY OK CIVIL AEROSPACE MEDICAL INST
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In support of a Department of Homeland Security project, the Federal Aviation Administrations Civil Aerospace Medical Institute measured the optical transmittance properties of aircraft windscreens. This paper focuses on windscreen transmittance in the infrared IR spectral region 780 - 4000 nm of the electromagnetic spectrum. Transmission measurements were performed on eight aircraft windscreens. Three windscreens were from large commercial jets MD 88, Airbus A320, and Boeing 727737 two from commercial, propeller-driven passenger planes Fokker 27 and the ATR 42 one from a small private jet Raytheon Aircraft Corporation Hawker Horizon and two from small general aviation GA, single-engine, propeller-driven planes Beech Bonanza and Cessna 182. The two GA aircraft windscreens were plastic polycarbonate the others were multilayer laminated composite glass. The average transmittance for both glass laminate and plastic windscreens in the IR-A region 780 - 1400 nm varied considerably 47.5 11.7, with glass windscreens consistently attenuating more IR than plastic windscreens. The average difference in transmittance between the two materials fluctuated 27.3 15.9 throughout the first half of the IR-B spectrum 1400 - 3000 nm up to approximately 2200 nm when transmittance dropped below 7. The average transmittance for glass and plastic windscreens became negligible beyond 2800 nm. Aircraft windscreens provide a level of protection from potential ocular and skin hazards due to prolonged or intense exposure to IR radiation. The amount of protection is dependent on the type of windscreen material, the wavelength of the radiation, and angle of incidence. On average, laminated glass windscreens attenuate more IR than plastic.
- Commercial and General Aviation
- Anatomy and Physiology
- Surface Transportation and Equipment