Greenwood Military Aviation Museum
Aircraft Pelorus Drift Sight
This object is an Aircraft Pelorus Drift Sight. The item is early WWII era, produced by the US Navy but bought and used by the royal Canadian Air Force. A Pelorus Drift Sight is designed to function either as a Pelorus, for taking bearings on objects, or for improving dead reckoning aircraft navigation by measuring the angle between the heading and the track of an airplane. It consists of a small 'telescope' viewing vertically towards the ground, angled toward the direction of the aircraft. When viewing the ground through the scope while in flight, the navigator observes the travel of fixed objects across the lens. By rotating the scope on its location of the pointer on the base's scale. Once done, the course correction is calculated and communicated to the pilot. The Mark II-C consists of an Optical Head, an upright post. and a Measuring Base. The Optical Head features 3 interchangeable lenses to mitigate the view amid bright sun or could and smoke cover.