B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 182; Flight Crew Type 14000
Aircraft Equipment Problem Critical
Flight Crew Diverted; Flight Crew Landed As Precaution; General Maintenance Action
Aircraft
On climbout we were given a climb from 5;000 FT to FL190. Autothrottles armed; we commanded a climb to assigned altitude. At about 7;000 FT MSL; we both noticed a #2 engine N1 overspeed; flashing red dial and associated left yaw. First Officer (pilot flying) immediately retarded thrust levers to mid range level and maintained control of the aircraft. It appeared the number 2 engine rolled back due to the overspeed; but when the thrust levers were retarded; the #2 engine appeared to have auto relit. Both engines were now operating normally in the mid power ranges. We coordinated with Dispatch and Maintenance about the occurrence and elected to divert. We did not declare an emergency. Approach and landing were uneventful. I had contacted the flight attendants as we were turning to a divert airport to keep them informed. I asked them if they noticed anything unusual; and they did not feel the yawing moment; only felt the aircraft was flying a little slower than normal. Made a PA and told the passengers that everything was fine; but we were making a precautionary landing just to be safe. On a side note: The previous flight on descent; we got a Master Caution light and an OVHD warning for about five seconds. We never did see anything abnormal on the overhead panel. The light went out and the remainder of the approach/landing was uneventful. In hindsight; I suspect it was an EEC on the verge of failing and it materialized on the next flight. Dispatch/Maintenance/ATC all worked seamlessly for us.
Was climbing out of 5;000 FT to FL190; selected Level Change at 5;000 FT with autothrottles engaged and pushed throttles up slightly to reduce time for engines to reach climb thrust. Shortly after the aircraft yawed to the right and overspeed warning light on; engine instrument panel alerted. Pulled the throttles back; engine #2 recovered. [We] diverted as a precaution. No emergency declared.
B737-700 flight crew experienced an over speeding engine during climbout. The thrust levers are retarded and the engine returns to normal operation but the crew elects to divert to a suitable alternate.