B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 218
Communication Breakdown; Situational Awareness
Aircraft Equipment Problem Critical
General Maintenance Action
Procedure; Aircraft; Human Factors
Informed by Chief Pilot on Call that the Oxygen psi on Aircraft X dropped approximately 200 psi during a preflight check. Maintenance was notified and discovered the wheel well oxygen valve opened only 1/4 turn. I flew this aircraft two legs and do not recall any drop in oxygen psi during our preflight checks in ZZZ or ZZZ1. Maintenance discovered oxygen valve in wheel well only 1/4 turn open; 3-days after flight.
Captain was informed by his Chief Pilot that the crew oxygen on a B737 he had flown two legs on; had a 200 psi drop in oxygen mask pressure during a subsequent preflight check. Maintenance found the oxygen valve handle only 1/4 turn 'Open'.