NTSB Factual Report

On June 16, 2007, at 2020 central daylight time, an American Aviation Corp. (AAC) AA-1, N5651L, was substantially damaged when the airplane impacted terrain shortly after takeoff from Lansing Municipal Airport (IGQ), Lansing, Illinois. The pilot received serious injuries. The 14 Code of Federal Regulations Part 91 local flight was departing IGQ at the time of the accident. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed.

In a conversation with a Federal Aviation Administration investigator, the pilot stated that he was performing touch and go landings on runway 36 (4,002 feet by 75 feet, asphalt) and that on the third takeoff, at approximately 900 feet, the engine RPM started "dropping" and the stall warning horn came on. The pilot "held the throttle full in", but the engine RPM decreased to less than 1,000 RPM. The airplane started to lose altitude and was just above power lines when the pilot saw a golf course and a road. The pilot stated that the airplane "started to buffet" and he decided to land on the golf course fairway. The pilot reported that the "left wing stalled and [the airplane] rolled left". The pilot then "pushed the nose over and rolled right 20-30 feet above the trees". The pilot stated that the airplane righted itself just prior to hitting a tree with the right wing. The airplane subsequently impacted terrain on the golf course fairway.

The pilot held a commercial pilot certificate with rotorcraft - helicopter and instrument helicopter ratings. The pilot stated that he had accumulated approximately 1,000 hours in helicopters. According to the pilot's logbook, the pilot had logged approximately 34 hours in fixed wing airplanes, all in a Cessna 172. The pilot had a solo endorsement dated March 19, 2007, for solo flight in a Cessna 172, and the pilot had logged 4 solo hours in a Cessna 172. There were no records of instruction received or endorsements for solo flight in the accident airplane make and model.

According to the carburetor ice probability chart, the temperature and dew point at the time of the accident indicated that a serious risk of carburetor icing at descent power was possible.

Weather reported near the time of the accident was: Wind variable at 5 knots; visibility 10 statute miles; scattered clouds at 12,000 feet; temperature 24 degrees Celsius (C); dew point 22 degrees C; altimeter setting 29.99 inches of mercury.

A post accident inspection of the engine, which had 1,749 hours since new without an overhaul, revealed the following: 1) No visible impact damage to the cylinders and crankcase; 2) "Thumb" compression was established on all cylinders when the engine was rotated by hand; 3) engine drive train continuity was established; 4) the magnetos produced sparks at all leads when rotated by hand; 5) fuel was found in the carburetor; 6) the fuel inlet screen, electric fuel pump screen, oil pressure screen, and suction screen were found clear of debris; 7) the fuel pump produced pressure at the discharge port when operated by hand; 8) no anomalies were noted on the cylinders; 9) all valves except #3 exhaust valve were found free to operate and showed no indication of transfer; 10) the #3 exhaust valve was bent, the valve guide was found oval shaped, and when the valve was rotated it would bind; 11) the #1 and #3 top spark plugs appeared carbon fouled; 12) the #1 bottom plug was lead, carbon, and oil fouled with the electrode bridged; and 13) the #3 bottom plug was carbon fouled.

NTSB Probable Cause

The loss of engine power during takeoff-initial climb due to a bent exhaust valve and fouled spark plugs.