Gyro gunsight

A particularly advanced model, the K-14 found in the North American P-51 Mustang, had separate projectors and displays for air and ground attacks.

[1][2] This arrangement meant the information presented to the pilot was of his own aircraft, that is the deflection/lead calculated was based on his own bank-level, rate of turn, airspeed etc.

[3] Prototypes were tested in a Supermarine Spitfire and the turret of a Boulton Paul Defiant in the early part of that year.

The Mark I sight had a number of drawbacks, however, including a limited field of view, erratic behaviour of the reticle, and requiring the pilot/gunner to put their eye up against an eyepiece during violent manoeuvres.

[4] Reflector sights consisting of a 45-degree angle glass beam splitter that sat in front of the pilot and projected an illuminated image of an aiming reticle that appeared to sit out in front of the pilot's field of view at infinity and was perfectly aligned with the plane's guns ("boresighted" with the guns).

Ferranti built a new factory in the Crewe Toll area of Edinburgh, Scotland to build the sights.

It was otherwise similar to the British models, although the dial for adjusting the target size was moved to the left side of the sight instead of the front.

The area where the Mark II had the dial was replaced by a moving scale that indicated the current range to the target, along with a large pad that prevented pilot head injuries in the case of rapid deceleration.

The development of the EZ 40 gyro sight began in 1935 at the Carl Zeiss and Askania companies, but was of low priority.

Tested in a Bf 109 F, Askania's EZ 40 produced 50 to 100% higher hit probability compared to the then standard sight, the REVI C12c.

Compared to the EZ 42, the Allied sight's prediction angle was found on average to be 20% less accurate, and vary by 1% per degree.

[11] Major Rudolf Sinner of JG 7 opposed their installation in his fighters after a demonstration in February/March 1945, finding the need to constantly adjust range to be unsuited to jet combat tactics.