'Supplement No.1 To Instructional Course Handbook. Notes for the Lancaster Aircraft', AVRO Type '683' MK.II. Published by A.V.Roe & Co. Ltd., Manchester, September 1942. Card covers, 15 x 23cm. Approximately 14p plus around 15 pullout diagram/charts at the back. Contains the diagrams of those services and installations which in the Mark II aircraft differ from those of the Mark I. Subjects covered include the fuel system, engine cooling system, electric propellers, cylinder head gauges, Merlin XXVIII Engine installation, CO2 Installation (Lanc Mod.575). The diagrams include engine control settings, air intake and slow running control systems. haydaulic feed system, diagram of oil system, rigging instructions, hydraulic system, diagram of fuel system, Rotol electric airscrews and Cowl Gill motors and indicators charts. Each copy was marked as 'Confidential', covered by the official secrets act and had an individual reference number, 640 in this case. The cover is a bit grubby, creased and dog-eared at the edges. The pages and diagrams are a little soiled with bent corners but are generally good. This is the first 'Supplement' to the Course Handbook we've had. Excellent reference material. Stock code P20105.