Vans RV-8 Runway Overrun at Private Airstrip Near Stevenage (G-HILZ)

Overview and Aircraft Details On 21 April 2012 at 1600 UTC, a Vans RV-8 with registration G-HILZ was involved in an accident at a private airstrip near Stevenage, Hertfordshire. The aircraft was a 2007 model equipped with a single Superior XP-IO-360-B1AA2 piston engine. The flight was a private operation with one crew member on board and no passengers. The pilot held an Airline Transport Pilot’s Licence and was 48 years old, with 12,713 total hours of flying experience, including more than 750 hours on type. In the 90 days preceding the accident, the pilot had logged 112 hours, and in the 28 days before the event, 53 hours. ## Event Description The pilot was landing at the private airstrip, which was oriented 05/23, after a flight from Duxford Airfield. Weather conditions were generally favorable with calm winds, but a recent shower had left the grass runway wet. The pilot made a normal approach from the south-west, achieving the target approach speed and touching down at the intended point on the approximately 525 m (1,720 ft) strip. Upon landing, the pilot encountered unexpectedly poor braking effect. Although feedback from the brake pedals appeared normal, almost no retardation was felt. The pilot attempted to improve braking through aerodynamic means and varying brake application, but with little effect. As a runway overrun became likely, the pilot attempted to steer the aircraft away from a small hangar building at the end of the strip. This maneuver was only partially successful; while the aircraft’s heading altered about 80° to the right, its ground track changed only slightly. The aircraft encountered the concrete apron and grass reinforcement area before its left wing struck the side of the hangar. The aircraft came to a stop on the small apron, and the pilot, who was uninjured, made the aircraft safe and vacated it. ## Damage and Performance Analysis The accident resulted in damage to the left landing gear, fuselage, left wingtip, and left tailplane, along with minor damage to the hangar. The pilot had flown from the strip for a number of years in varying conditions and had not known this or similar aircraft to encounter problems with the available landing distance. The aircraft’s listed performance figures predicted a landing roll of between 300 and 500 ft, which the pilot felt was realistic in favorable conditions. However, taking into account conservative allowances for the wet grass, slight down slope of the field, conditions of the day, and applying the recommended safety factor of 1.431, the aircraft’s predicated landing roll would be 1,030 ft. In fact, the actual landing roll until contact with the building was about 1,350 ft. The pilot further observed that the recent rain had fallen after an extended dry period, and thought that this, together with the particular characteristics of the local clay sub-soil, could have played a part in the unusually poor braking effect. The pilot intended to highlight his experience in the conditions to other users of the strip in future.