What happened
On 19 June 2005, a student pilot was conducting solo training circuits at Barton Airfield, Manchester, in a Grob G115, registration G-BOPT. After completing several successful circuits, the engine began running roughly during the third downwind leg. The pilot attempted to address the issue by manipulating the carburettor heat and various power settings, but the engine performance remained poor.
As the aircraft transitioned to the final approach, the pilot noted an airspeed significantly higher than required. In an attempt to reduce speed, the pilot pitched the aircraft up, but this action, combined with the late deployment of flaps and continued attempts to troubleshoot the engine, resulted in the aircraft being too high and fast on the approach. With no suitable alternative landing sites available due to nearby buildings, hedges, and a dual carriageway, the pilot continued the landing attempt on the grass runway.
The aircraft touched down at the far end of the runway, bounced, and subsequently landed again on rough ground beyond the runway end. The aircraft sustained significant damage to the landing gear and propeller, but the pilot escaped without injury.
The investigation
The investigation examined the pilot's actions and the environmental conditions at the time of the accident. Investigators noted that the pilot became distracted by troubleshooting the engine, which compromised the primary task of managing the aircraft's flight path. The investigation also reviewed the engine's behavior, specifically noting that the rough running worsened when the carburettor heat was set to the hot position.
Findings
- The pilot's focus on resolving the engine issue led to a loss of situational awareness regarding the aircraft's approach speed and height.
- The aircraft was high and fast on the approach due to the combination of engine troubleshooting, late flap selection, and an upward pitch maneuver to reduce speed.
- Atmospheric conditions, characterized by a temperature of 26°C and a dew point of 20°C, were conducive to carburettor icing.
- The worsening of the engine's condition when selecting carburettor heat to hot suggests the potential presence of induction system ice, though no specific mechanical fault was identified.