Oxygen Regulator Type A-9A S2 Tracker

Oxygen Regulator Type A-9A S2 TrackerThis is a WWII era aircraft Oxygen Regulator Type A 9A as used across bomber and transport aircraft of the US Army Air Force and US Navy, such as the B 17 Flying Fortress (see image illustrating the location of the co pilot's regulator from the B 17F flight manual dated 1943). This example has a serial number prefix of AC41, evidence of a year of manufacture of 1941. The A 9A regulator was a low pressure continuous flow regulator (vs the on demand,

The pilot can select the mode of operation desired by use of the Reset/Stby switch located on the lower right corner of the instrument case

In the center of the bowl is a semi-float type card to which are attached the magnetized needles and the radial arms

in its original wooden case

operates in the same manner but has greater air volume capacity for larger aircraft with more air-driven instruments such as a heavy bomber or transport

so it could use repair

with a serial number prefix of AC-39

and subsequently maintain the aircraft

given the rubberized interface tool affixed to the spindle

This "Rebecca" Receiver/Indicator is identified as ID-169A/APN-12 AT-2/APN2

The booklet contains maps of Japan and its major home islands

The manual is 950 pages and ~2inches thick

Here is a 1960's Vietnam War era Autopilot Flight Controller