Technical Order No. 01-20EF-51, Air Publication No. 2099C. Handbook of Cold Weather Operations And Maintenance for the Army Model B-17F and G Airplanes, British Model Fortress II. October 1943, 16p. Looseleaf format stapled in top left corner. Restricted document which is a supplement to the Handbooks of Operation And Maintenance Instructions applicable to the B-17F. Issued to ensure its successful operation under extremely cold weather condition. Illustrated with photographs and diagrams. Good condition. Stock code P24215A-5.