RAF Air Diagram 2187 - Aircraft Torpedo Sighting - Gyro Angling (GA) Technique For Torpedo Release. Approximately 113 x 88cm, March 1942 (May 1942 print date). Prepared by the Ministry of Aircraft Production and printed by S.P.& Co. Ltd. The GA method of sighting allows a torpedo to be dropped by an aircraft on a direct attack towards the target. Once the torpedo has descended and 'plunged' an integral gyro allows it to change course through the 'Gyro Angle' to then run straight until it hits the target. The air diagram illustrates how this is done. It has fairly minor edge damage and some small tears on the folds but is in very good overall condition. Gyro Angling is mentioned in AP2495 which is offered for sale elsewhere on the website. Stock code P16291.