B737 Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Total 12065
Deviation / Discrepancy - Procedural Maintenance; Deviation / Discrepancy - Procedural Published Material / Policy
General Maintenance Action
Human Factors; Weather; Procedure
I was doing the walk-around. I found that there was a red rag jammed into the drain holes of the left inboard flap track fairing. I called Operations from my phone while on the ramp and asked if they could send maintenance out to the aircraft as I had found a rag stuck into the flap track fairing. To me it looked like someone might had placed it there to see if it would stay on during flight; either the inbound or outbound. A mechanic came to the aircraft and removed the rag stating that they changed the #1 tire that night and to prevent water from dripping on them while changing the tire; they plugged the flap fairing drain holes with the rag. I would bet it's safe to say that this is NOT the correct procedure in the Aircraft maintenance manual. This rag most likely could have interfered with the flaps during retraction if the rag was to come loose during takeoff.
B737 Captain reported that a rag was observed in a wing flap fairing during preflight.