What happened
On 30 August 2006, a Piper PA-28-161 Cherokee Warrior II, registration G-BYKR, was conducting a training flight at Oxford Airport. The aircraft was occupied by an instructor, a student, and a passenger. During the initial engine start, the instructor noted symptoms of carburettor icing and opted to run the engine at a higher RPM (between 1,300 and 1,400) to accelerate the warm-up process.
Following a relatively long taxi to the departure point, the crew performed standard checks. Although carburettor heat was applied at the holding point, the aircraft experienced a loss of power and an engine cough shortly after rotation. The instructor managed to land the aircraft back on the runway; however, there was insufficient distance to stop. The aircraft overran the paved surface, breached the airport boundary fence and hedge, and eventually came to rest inverted on Langford Lane, a public road. Despite the significant damage and fuel leaks, there were no injuries to the three occupants.
The investigation
The AAIB examined the wreckage at a hangar in Oxford. The impact had caused the left wing to separate from the fuselage and severely damaged the nose landing gear, empennage, and fuselage. The investigation focused on the engine, fuel system, and environmental conditions.
Testing of the engine and its components, including the carburettor, revealed no mechanical defects. The engine produced near-nominal rated power during subsequent tests. The fuel system, including the gascolator, fuel lines, and tank vents, was found to be clear of obstructions or debris. While the mixture control was found to be stiff due to impact-related distortion, the fuel itself was confirmed to be uncontaminated Avgas 100LL.
Findings
- The weather at the time of the accident featured a temperature of +9ºC and a high relative humidity of 88%, conditions highly susceptible to carburettor icing.
- Although carburettor heat was applied at the holding point, it may not have been sufficient to clear all ice, or ice may have reformed during the long taxi.
- The engine power loss occurred shortly after takeoff, and the subsequent investigation found no technical faults in the engine or fuel delivery systems to account for the event.