History of the Flight
The aircraft, a Beech 58 Baron registered N80HC, completed an uneventful transit from Guernsey to Wellcross Farm, West Sussex. The flight was private, with one pilot and one passenger on board. The commander, aged 63, held an FAA Private Pilot's Licence and had accumulated 1,607 total flying hours, 108 of which were on type.
Weather and Runway Conditions
Weather on arrival was good with isolated thunderstorms; one had recently passed over Wellcross Farm Airstrip. Surface wind was calm, visibility 10 km, and broken cumulo-nimbus cloud at 2,000 ft. The airstrip had a short grass runway oriented 04/22, 650 m long by 40 m wide, with an initial upslope on Runway 22.
Landing and Accident Sequence
The pilot configured the aircraft with landing flap and gear down, making a normal approach to Runway 22 at an indicated airspeed of 80 kt. The aircraft touched down approximately 35 to 40 m from the threshold. Due to the runway's upslope, braking was not initiated until about 200 m along the runway. Initially, as brakes were applied, the aircraft appeared to accelerate. Despite modulating the wheel brakes, braking action remained very poor. The pilot decided a go-around was too late and continued braking with little effect. Recognizing an overrun was inevitable, he attempted to steer right into an adjacent wheat field. During the turn, the aircraft skidded sideways through approximately 110°. The pilot selected the mixture levers to CUT OFF and turned the magnetos off. Shortly after, the aircraft departed the right side of the runway, where the nose landing gear entered a drainage ditch and collapsed. Both occupants vacated the aircraft through the normal exit.
Damage
The accident resulted in a collapsed nose landing gear and slight damage to the tips of two right propeller blades.
Pilot's Assessment
The pilot considered that the accident occurred due to poor runway friction and aquaplaning caused by short wet grass and pools of standing water from the recent thunderstorm.
Analysis
The AAIB noted that the landing roll distance for the type is quoted as 318 m (1,044 ft) on a hard, dry surface in still air. Applying performance factors from CAA Safety Sense Leaflet 7B indicated a practical required ground roll of about 591 m for level, wet grass on firm soil. The initial upslope on Runway 22 would slightly reduce the required distance only if wheel brakes were applied immediately after touchdown, which they were not. No factors are offered for a flooded runway surface or standing water, as the predicted increase in landing rollout is unquantifiable. The AAIB concluded that the partially flooded condition of the strip was probably the prime causal factor.