6A/374 - A.S.I. Air Speed Indicator Mk.IVC (Cat No AVG173) 6A/374 - A.S.I. Air Speed Indicator Mk.IVC (Cat No AVG173)
Range 40 - 210 Knots, this is the large size ASI, as fitted to 1st WW aircraft, but allows for an increased speed range; it was designed to be fitted to 1920s military naval aircraft (being in knots) and was in use up to the late 1930s, in such aircraft as the Hawker Nimrod and Osprey, Fairey Fox and many other types. This has a capsule movement which are much more reliable that the rubber diaphragm type of the 1st WW era. This instrument has now been completely dismantled and fully reconditioned but will require check calibrating before use, which we can do. There is the AM and Crown stamp on the rear, plus the 1st WW ‘A’ over an arrow, meaning its history goes back a long way. It was a luminous instrument but this material has been professionally removed, though it may have some residual background radiation from affected nearby parts; at least the harmful dust has been all removed. The figures have been re-painted in a brown colour mimicking decayed luminous paint. On the dial is painted by hand in minute writing ‘19/9/36’ which will be a repair or overhaul date. The serial no. is 7424. Extremely rare. £1,950. Catalogue no. AVG 173