What happened
On 19 June 2001, a Commander 114TC, registration N294TC, departed Southampton Airport for a flight to Guernsey. Shortly after takeoff, the pilot transmitted an emergency message to the air traffic controller, stating that the aircraft was failing to climb and requesting to return to the airfield. Witnesses observed the aircraft performing an unusually long ground roll, using significantly more runway than predicted for its type.
As the aircraft climbed, observers noted various signs of engine distress, including blue and brown smoke trailing from the engine area and an irregular engine sound. During a steep right-hand turn back toward the airport, the aircraft appeared to sideslip and lose altitude. While the pilot appeared to regain control at a low altitude, the aircraft's performance remained compromised. As the aircraft approached a line of trees, a final attempt to climb resulted in a sudden pitch-up, a roll to the right, and a vertical dive into the ground. The impact caused a large fire, and both crew members were killed.
The investigation
The investigation examined the aircraft's weight, engine condition, and the sequence of events leading to the loss of control. Technical analysis of the Lycoming engine revealed that the number 2 cylinder had experienced recent running in a fuel-rich condition, evidenced by black deposits. Investigators found that the number 2 fuel injector nozzle was producing an uneven and poorly atomized spray pattern. Additionally, evidence suggested the inlet valve in the same cylinder might have been prone to sticking, which could have caused intermittent loss of compression.
Regarding the aircraft's weight, the investigation established that the aircraft was approximately 230 lb overweight for takeoff. This was due to the combination of the two pilots, full fuel tanks, and additional onboard equipment. The investigation also noted that the air conditioning system was in use, which would have further reduced the climb performance.
Findings
- The aircraft was operating above its maximum takeoff weight, which increased the required takeoff distance by approximately 13.6%.
- A malfunctioning fuel injector nozzle in the number 2 cylinder caused uneven fuel distribution and a fuel-rich running condition.
- The use of the air conditioning system during takeoff further degraded the aircraft's climb capability.
- The pilot's decision to continue the takeoff despite an unusually long ground roll prevented the opportunity to abort the flight before the aircraft became airborne.
- The combination of high weight, engine power loss, and a high-bank turn likely led to an aerodynamic stall and subsequent loss of control.