Measurement of UV radiation in commercial aircraft.

Ultraviolet radiation (UVR) is significantly higher at aviation altitudes with respect to sea level. Cockpit windshields protect pilots from UV-B radiation but studies have shown that this is not necessarily the case for UV-A radiation. This work investigates the spectral properties of several windshields under flight conditions. Only one of the investigated windshields showed good UV-A attenuation. Furthermore, the altitude dependence of UV-A irradiance behind a windshield was measured with high spatial resolution. Measurements of the maximal UV irradiance behind the windshield surfaces and at the pilot's position are compared to the recommendations by the International Commission on Non-Ionising Radiation Protection. Some recommended limits were exceeded at the surface of the windshields with direct sunlight and a large field of view. At the pilot's position, with a more realistic field of view, the unweighted recommended level could have been exceeded within tens of minutes by looking in the direction of the Sun without visor or other protective measures. The weighted recommended maximal UVR exposure was not exceeded, neither with the use of the visor at the pilot's position nor without it. The use of the visor for filtering direct sunlight was very effective in terms of UV-A reduction.

Impact of the South Atlantic Anomaly on radiation exposure at flight altitudes during solar minimum.

The South Atlantic Anomaly (SAA) is a geographical region over the South Atlantic Ocean where the inner Van Allen radiation belt extends down particularly close to Earth. This leads to highly increased levels of ionizing radiation and related impacts on spacecraft in Low Earth Orbits, e.g., correspondingly increased radiation exposure of astronauts and electronic components on the International Space Station. According to an urban legend, the SAA is also supposed to affect the radiation field in the atmosphere even down to the altitudes of civil aviation. In order to identify and quantify any additional contributions to the omnipresent radiation exposure due to the Galactic Cosmic Radiation at flight altitudes, comprehensive measurements were performed crossing the geographical region of the SAA at an altitude of 13 km in a unique flight mission-Atlantic Kiss. No indication of increased radiation exposure was found.