Boulton Paul Overstrand gun turret
The Boulton Paul Overstrand was the first aircraft to be equipped with a fully-enclosed power-operated gun turret. It was also the last biplane bomber to enter RAF service, and remained in front line service until 1938.
How to cite this article:
Rickard, J (14 December 2009), Boulton Paul Overstrand gun turret , http://www.historyofwar.org/Pictures/pictures_boulton_paul_overstrand.html