An A319 returned to the gate because of an IDG malfunction with the flaps in the takeoff configuration. While waiting to start an engine for an IDG leak check; a ground crewman found a hole in the outboard portion of a leading edge slat.

Narrative

While taxing out of BOS we had a failure of IDG number 1; we stopped the aircraft and performed the ECAM procedure; then returned to the gate. While taxing back I did not call for flaps up so we returned to the gate with the flaps at Config 1. Maintenance met the aircraft; inspected the IDG and placed it on MEL. We had to start the engine at the gate to check for disconnect of the IDG and leaks. One of the BOS ramp crew; whom I did not get to thank; with a real attention to detail; did an aircraft walk around to clear ground equipment for engine start and noticed a hole in the leading edge of the right wing leading edge flap about 6 inches from the outboard end. The hole was about the size of a golf ball in what appears to be a composite leading edge; in my opinion was caused by a bird strike. There was no additional visible damage on the bottom of the flap surface. There was; after close inspection; what appeared to me traces bird remains on the bottom of the flap. There's no telling how long this had been there; even in daylight it looked like a spot of peeling paint. I don't know the frequency of flaps down walk around inspection; but this would have be the only way to find this hole without reason to drop the flaps like they do after a reported bird strike to maintenance. Maybe a flaps down close inspection of the flap leading edges can be done on overnight and daily checks with all the attention on bird strikes lately.