B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 156; Flight Crew Total 8000; Flight Crew Type 5000
Communication Breakdown; Situational Awareness; Distraction
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types
Air Traffic Control Issued New Clearance; Flight Crew Returned To Departure Airport; General Maintenance Action
Airspace Structure; Human Factors; Aircraft
During takeoff; just at rotate; I noticed the number 1 engine oil quantity rapidly decreasing towards zero. At gear retraction oil quantity read zero. We requested vectors with tower for a return to the field. We climbed to approximately 4;000 feet and at level off the quantity fluctuated between 0 and 30 percent. Oil pressure was normal during climb out and at level off. The oil quantity eventually stabilized at 30% and all other engine readings were normal. We elected to [advised ATC] and leave the engine running for the return. After clearing the runway we shut down the No. 1 engine for the taxi back to the gate. After takeoff we climbed to the assigned heading and leveled off to assess the situation with the engine. The heading initially pointed us towards a TFR. ATC directed us to turn towards the north to avoid the area. While assessing the situation we missed the call for a turn. I don't think we penetrated the TFR but we perhaps could have turned a bit sooner. We were a little task saturated trying to assess the malfunction.
During rotation on takeoff the left (1) engine oil quantity decreased to zero. Continued climb to a safe altitude and requested a return expecting an engine failure. The engine did not fail and the oil quantity bounced between 0 and 30 percent. While receiving vectors after takeoff we were required to turn north to avoid a TFR for a local air show. With a running engine we received vectors for time to run checklist and plan for an overweight landing. That completed we [advised ATC] with both engines running landed safely. After landing we shut down the left engine and taxied to the gate.
The flight crew of a B737 experienced a loss of oil quantity indication during takeoff. While preparing for a return to the field; they received a turn away from a TFR that may have been delayed due to their running of the checklist.