Astrodome (aviation)

An astrodome is a hemispherical transparent dome fitted in the cabin roof of an aircraft for the purpose of allowing the use of a sextant during astro-navigation.

Prior to the introduction of electronic means of navigation the only way to fix an aircraft's position at night was by taking star sights using a sextant in the same manner as that used by marine navigators on board ships. To do this requires a 360-degree view of the horizon and the astrodome was devised to allow an uninterrupted view of the sky from horizon to horizon.

Astrodomes were prominent on Royal Air Force multi-engined aircraft of the Second World War, and on such aircraft ordered by them, as a considerable part of their operations were carried out at night.