A-11 Navigation (Hack) Watch Manual Below are scans from the original War Department publication AN 05-35A-8, Handbook of Instructions with Parts Catalog for Navigation (Hack) Watch, 10 April 1945, a joint publication of the USAAF, USN, and RAF.
It contains instruction for the care and maintenance of the Waltham A-11 wristwatch issued for air navigation and includes complete servicing and adjustment instructions.
It’s interesting to see that the accuracy tolerance was a mere +/- 30 seconds in two positions, which starts to make on realize exactly how accurate modern watches are.