B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 159
Situational Awareness
Aircraft Equipment Problem Critical; Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Aircraft Equipment Problem Dissipated; Flight Crew Returned To Clearance; Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft; Procedure
On base to a visual approach to Runway into airport; we were configuring for landing. As the PF commanded flaps 15; we noticed the left flap was indicating 3 and the right 5. We requested a delay vector with Tower and were directed to contact Approach and started the Trailing Flap Asymmetry Checklist. After the completion of the checklist; prior to the deferred items; we positioned the flap lever to the closest setting to the less extended flap; flaps 2. At some point after positioning the flap lever to 2 the flaps deployed symmetrically to 5. The Captain and I had a discussion about whether to run the Trailing Edge Flap Disagree Checklist and decided against it since we had adequate landing performance; a symmetric flap condition; and didn't want to risk another asymmetry. The Captain gave me control of the aircraft and we started turning back for the approach while he made a couple PAs to the Passengers and informed the Flight Attendants. We also [advised ATC] to have equipment standing by in case of hot brakes or any unforeseen problems. The landing was uneventful but the target speed was 161 knots. We cleared the runway; talked to the Passengers; and taxied to the gate leaving the flap lever at the 2 position. As we exited the runway; we noticed the flaps had retracted to the 2 position symmetrically. We also noticed we now had a PSEU light. Once at the gate we wrote the defect up and waited for Maintenance to arrive.
[Report narrative contained no additional information.]
With flaps commanded at 15; the flap indicator showed left flap at 3 and right flap at 5. There was no control issue so during approach; positioned flap lever to 2; the flaps deployed to 5. After landing; the flap lever was left at 2 and the flaps retracted to 2 symmetrically.