What aircraft was involved and where did it happen?

The accident on 1999-12-18 involved a CESSNA F150L, registration G-BFWL, at Manchester (Barton) Aerodrome, GB.

What was the probable cause of the accident?

The accident was caused by the aircraft's left wing dropping during takeoff, likely due to the presence of remaining hoar frost on the upper wing surfaces and the performance challenges presented by a soft, wet runway.

Cessna 150 Crash at Barton Aerodrome

A private flight in a Cessna F150L resulted in a significant accident at Barton Aerodrome when the aircraft's left wing dropped during takeoff, causing a cartwheel.

What happened

On 18 December 1999, a Cessna F150L, registration G-BFWL, was performing a private flight from Barton Aerodrome, Manchester. The aircraft was operating on a short, temporary grass runway. Due to overnight hoar frost and very wet, soft soil, the pilot opted for a short/soft field takeoff technique. During the takeoff roll, the pilot noted that acceleration was slower than usual. After rotating approximately two-thirds of the way down the runway, the aircraft became airborne. However, at an altitude of roughly 15 to 25 feet, the left wing dropped. Despite the pilot's attempts to correct the wing drop using the rudder, the aircraft struck the runway, cartwheeled, and crashed near the threshold of Runway 09 South. There were no fatalities and no injuries to the two occupants, who exited the aircraft through the doors without assistance. The aircraft sustained heavy damage, including an engine detachment, a bent left wing tip, and structural damage to the fuselage and tail, rendering it a total loss.

The investigation

The investigation examined the environmental conditions, the pilot's pre-flight preparations, and the mechanical state of the aircraft. Investigators noted that while the pilot had spent significant time defrosting and demisting the aircraft, a witness observed that the leading edges of the wings had only been cleared of frost for a few inches, leaving the rest of the upper wing surfaces covered in hoar frost. The pilot had used a scraper and cloth to remove much of the frost but acknowledged that the process might have been incomplete. Additionally, a ground worker reported hearing a popping sound coming from the engine during the takeoff roll. The investigation also considered the impact of the wet, waterlogged runway surface and the lack of a headwind on the aircraft's performance.

Findings

The aircraft's left wing dropped during the initial climb, leading to a loss of control and a subsequent cartwheel.
Incomplete removal of hoar frost from the upper wing surfaces likely contributed to the aerodynamic instability.
The soft, waterlogged condition of the grass runway contributed to sluggish acceleration during the takeoff roll.
The presence of frost on the wing surfaces and the potential for carburetor ice or impact ice from the wet ground were identified as contributing factors.