Drift Sight, Tail, RAF Mk IV Kit Ref No 6B/110, 1939 Viscount This instrument seems to have

This instrument seems to have had a very interesting history

and ~4 inches and 5 inches wide

and displays fuel quantity on the refueling panel at the flight engineers station (see photo of the panel and location of the indicator from the KB-29P Flight Manual dated 1951)

There were two complete M6 periscopes in brackets on the turret walls

75 inches diameter

Drift Sight, Tail, RAF Mk IV Kit Ref No 6B/110, 1939 Viscount This instrument seems to haveHere is a WWII era Tail Drift Sight, Mark IV Kit, as used in bomber and transport aircraft of the British Royal Air Force with navigator aircrew, such as the Avro Lancaster, and likely used in other bombers such as the Vickers Wellington and Short Stirling. This kit includes the optical periscope, a base plate, and the aluminum drift plate that screws onto the base plate, and wooden carry case with leather strap. Stamped on the label on the case of