USAAF Instrument Letdown Procedures TO 08-15-3 July 1944 C-46 The cover page is missing

The cover page is missing but the rest of the pages are present and intact

It consists of a simple type of collimator rotatable in a housing mounted in gimbals for leveling

and engines

This unit has the filter for cleaning vacuum air as it is pulled across the gyro to power it

Technical Order No 00-40-1

USAAF Instrument Letdown Procedures TO 08-15-3 July 1944 C-46 The cover page is missingThis is an original WWII era US Army Air Force technical order for Instrument Letdown Procedures. The 118 page document provides letdown procedures for airports across the US. A letdown procedure consists of maneuvers executed in a standard sequence designed to bring the pilot, flying on instruments or on top, down through a low overcast into conditions of ceiling and visibility which will permit the landing to be completed under visual contact