Accident Summary
On 13 April 2017 at 1550 UTC, a privately operated YAK-52 aircraft, registration G-SPUT, experienced a ground incident while taxiing after landing at Brown Shutters Airfield in Somerset. The aircraft sustained damage to the propeller, engine and wing. The sole occupant, a 49-year-old pilot holding a Private Pilot's Licence with 267 total flying hours (49 on type), was uninjured.
Flight History
The pilot had just completed an uneventful landing on Runway 33 and proceeded to taxi the aircraft off the end of the designated grass runway area. While attempting a left turn at an estimated ground speed of 20–25 mph, the aircraft slid sideways to the right down a grass slope. It struck a mound and tipped onto its nose and a wingtip, resulting in damage to the propeller, engine and wing.
At the time of the incident, weather conditions were dry with light and variable wind and visibility of 10 km. The airfield's webpage describes it as challenging due to the landing distance available (referencing CAA Safety Sense Leaflet 07). Although infrastructure works were taking place at that end of the airfield that day, the pilot did not mention them in his statement.
Aircraft Information
The YAK-52 is a two-seat trainer with a single Ivchenko Vedeneyev M-14P piston engine. Its nosewheel is not steerable; rudder input controls a valve distributing pneumatic brake pressure to the left and right brakes. The brake control is on the control stick. At taxiing speeds, directional control relies on differential braking, with rudder effectiveness dependent on propeller airflow.
Pilot Comments
The pilot reported that braking was totally ineffective due to the slippery nature of the grass. He also stated that he did not sufficiently account for the slope or the lateral forces acting on the aircraft on the grass surface. No technical problems with the braking system were reported.