B-17 Aircraft Inspection and Maintenance Guide USAAF 1944 C-119 The indicator marked for engines

The indicator marked for engines 3 & 4 has a 1944 manufacturing serial number prefix

A graduated rotatable ring (verge)

observers could determine the location of friendly aircraft using triangulation

The #4 pointer appears to be loose but might be able to be re-inserted firmly

B-17 Aircraft Inspection and Maintenance Guide USAAF 1944 C-119 The indicator marked for enginesThis is an original WWII era Boeing B 17 Flying Fortress Bomber Aircraft Inspection and Maintenance Guide USAAF published May 1944. This 75 page, 5. 5 x 8. 5 inch booklet contains a detailed inspection checklist and procedural description, including a reference for relevant technical orders and a list of necessary tools. The guide is in reasonable condition given its age. There is a slight tear across the top cover, see photo.