B737-400
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Overcame Equipment Problem; General Maintenance Action
Aircraft
Configuring to land flaps 30. When flaps 25 was selected; both pilots heard a pop and the aircraft began to roll left. Opposite aileron by the First Officer (pilot flying) countered the roll. Captain stated flaps were being returned to 15 degrees and then selected flaps 15. Roll inclination improved; but was still present. V-speeds for flaps 15 landing were set and landing was made without incident and minimal braking. Passengers were never aware of any problems. Made write-up in logbook and called Maintenance Control as well as Local Maintenance. Waited for inbound crew and relayed experience to them. I have never experienced this in my career. I have no idea what happened and only associate it as a flap abnormality because the pop occurred while flaps were being selected.
A B737 Captain reported a 'pop' sound accompanied with a left roll as flaps 25 were selected for landing. The flaps were selected to 15; the V speed reset; and the landing completed with aileron input required.