RAF issue Aircraft Clock, 6A/2089
Description
1. The Smiths Type 5 A.C.A. (Ref. No. 6A/2089) clock has a conventional 8-day movement and is designed for general use in Service aircraft as an alternative to the Mk. 4 clock. It incorporates a centre-seconds hand and has hour numerals at 3, 6, 9 and 12 o'clock.
2. The spring is wound by rotating a knurled knob positioned at the base of the mounting. The same knob, when pulled out slightly, is used for setting the hands. Fitted between the bezel and the glass is a red lubber mark which can be used as a reference against any point on the dial. Four 4 B.A. lock-nuts, integral with the bezel, are provided for securing the instrument to the panel.
3. A lever for regulating the escapement is situated at the rear of the clock and is accessible through a protected aperture in the case. The weight of the clock is 5 oz approximately.