What happened
On September 9, 2007, at approximately 11:00 local time, a Piper PA30 departed from runway 32L at Cologne-Bonn Airport for a private pleasure flight. The aircraft was carrying five occupants. Shortly after liftoff, eyewitnesses observed the aircraft's pitch angle increasing sharply. The pilot reported attempting to push the control column forward to correct the nose-up attitude, but the controls were unresponsive. In an attempt to manage the situation, the pilot reduced engine power and turned the aircraft north toward taxiway B. During the maneuver, the aircraft tipped to the right and struck a grassy area.
The investigation
The BFU investigation focused on the aircraft's weight and balance configuration at the time of departure. The aircraft, which was registered in the United States, was equipped with additional nacelle fuel tanks. Investigators analyzed the fuel load, noting that while the pilot estimated having under 60 gallons on board, emergency responders pumped between 77 and 88 gallons from the wreckage. The investigation also reviewed the weights of the five occupants and the distribution of the fuel load.
Findings
- The aircraft was significantly overweight; the actual takeoff weight was calculated to be between 3,875 and 4,049 pounds, exceeding the maximum takeoff weight of 1,693 kg (approximately 3,730 lbs).
- The aircraft was in an extreme aft center of gravity condition. The center of gravity was calculated at 93.7 inches, which was 96% of the way toward the rear limit, far exceeding the allowable range of 88.2 to 91 inches.
- The combination of high fuel volume in the nacelle tanks and the weight of the passengers caused the longitudinal stability to be compromised, leading to the uncommanded pitch-up during the takeoff roll.