What happened
On 27 May 1999, a modified Piper PA-28-151, registration G-BCIE, was performing a private flight at Perth Aerodrome, Scotland. During the landing phase on Runway 10, the pilot touched down approximately three-quarters of the way along the available asphalt. Deciding to execute a go-around, the pilot retracted the flaps and applied power. Although the pilot noted a slight lag during power application, the engine initially reached takeoff power levels.
As the aircraft climbed to an altitude between 50 and 10 and 100 feet, the engine power unexpectedly dropped to idle. In an attempt to recover, the pilot cycled the throttle and applied carburettor heat while lowering the nose to preserve airspeed. Due to obstacles including roads, houses, and trees, the pilot performed a 90-degree turn to the left, transmitting a mayday during the manoeuvre. As airspeed decayed to 60 knots, the aircraft lost elevator authority and struck the ground in a nose and left-wing down attitude. The impact caused the aircraft to come to rest inverted and resulted in the loss of the left wing. The one passenger sustained minor injuries, while the pilot was uninjured. Both occupants evacuated through the hatch without external help.
The investigation
Investigators examined the engine and fuel systems following the accident. Maintenance staff discovered that both fuel tanks and the carburettor bowl contained substantial amounts of fuel. The engine's mechanical components, including the gear train, crankshaft, and magnetos, were found to be functioning correctly with appropriate compression and spark production. No mechanical or electrical fault could be identified as a rational explanation for the power loss.
Meteorological analysis of the period showed that temperatures and dewpoints between the surface and 2,000 feet were highly conducive to carburettor icing. While these conditions were most likely to cause icing at higher altitudes, the investigators noted that the environment remained within the range known to cause serious icing in float carburettors at reduced power settings.
Findings
- The engine power loss likely resulted from carburettor ice formation within the induction system.
- It is possible that ice formed at a less critical location and was subsequently shed into the intake or moved to a position that obstructed airflow after the pilot applied climb power.
- The initial hesitation noted by the pilot during the application of power may have indicated the presence of significant ice in the intake.