History of the Flight
On 19 May 2010, at approximately 0944 hrs, a Jabiru J400, registration G-CDLS, was damaged during a forced landing near Hinderwell, Yorkshire. The aircraft had departed from Fishburn Airfield at about 0725 hrs with a pilot and one passenger, carrying approximately 60 litres of Avgas for a flight to Scarborough and back. On the return leg, while flying at about 1,000 ft north-west of Whitby, the engine began misfiring severely. At 0812 hrs, the pilot transmitted a MAYDAY and selected a field to the east for a forced landing.
During the downwind leg, the pilot judged the aircraft too low to continue the approach as intended and turned sharply left into wind. Before completing the turn, the aircraft impacted the ground, coming to rest on its front left fuselage after the nose and left landing gear legs failed. During the short ground travel, the engine started to rev up, so the pilot switched it off before vacating the aircraft with the passenger using the right cabin door. There was no fire, and the uninjured occupants signaled to a Coast Guard helicopter that attended shortly afterward. Police and ambulance services later arrived.
Aircraft Information
The aircraft was constructed by the pilot from a kit. The kit manufacturer states that the engine type (Jabiru Aircraft PTY 3300A piston engine) has a fuel consumption of approximately 26 litres per hour at 75% cruise power, noting that the actual figure varies depending on installation, propeller, and power settings. The engine is equipped with a means of heating the carburettor to reduce ice accretion.
Two days after the accident, an engineer familiar with the type recovered the aircraft. While dismantling it, he drained approximately 27 litres of fuel from its wing tanks. During an informal examination, he determined that the engine could be turned freely and exhibited compression in each cylinder.
Meteorological Information
A meteorological report valid at 0820 hrs for Durham Tees Valley Airport, 24 nm west of the accident site, indicated a surface wind from 200° at 5 kt, visibility in excess of 10 km, no cloud below 4,000 ft, a temperature of 14°C, and dew point 8°C. This combination is conducive to moderate carburettor icing at cruise power and close to combinations that might give rise to severe icing at any power.
Discussion
The quantity of fuel recovered (27 litres) suggests the loss of power was not due to lack of fuel. The informal engine inspection and the pilot's report that the engine "started to rev up" on the ground indicate that the engine had not suffered a serious mechanical failure prior to impact. In his report, the pilot observed that the loss of power in flight may have been caused by carburettor icing. Safety Sense Leaflet 14 – 'Piston Engine Icing', published by the CAA, discusses the phenomenon and suggests procedures for minimizing its effects.