History of the Flight
On 19 May 2019 at 1006 hrs, the pilot of G-BZOR, a Team Minimax 91, was cruising at 2,000 ft and 80 kt when the engine began misfiring and lost power. Increased vibration and reduced throttle response suggested to the pilot that one cylinder had failed. Unable to maintain height, he positioned the aircraft for a forced landing. Not receiving an air traffic control service, he chose to focus on flying rather than transmitting a MAYDAY call.
Initially over a copse of trees, the pilot selected a landing site on an uphill slope in open heathland south of the woods. Aware of the need for a tight turn into wind on finals, he increased airspeed from 55 to 75 mph to improve stall margin.
The Landing
After rolling out into a light north-north-easterly breeze, the pilot reduced speed and achieved a gentle touchdown. As G-BZOR came to a halt, its front axle fouled in heather, causing the aircraft to tip forward. This resulted in minor damage to the airframe and a broken brake cable.
Aircraft Information
The pilot described the aircraft as carefully maintained. Within the previous 30 flying hours, the engine had been rebored, rebuilt with new bearings, and fitted with a new main ignition module. The crankshaft had been clearance checked, spark plugs were less than five hours old, and the propeller was brand new. The fuel (MOGAS) was drawn that day from a busy source, correctly diluted with oil, and filtered into the tank.
The Rotax 447 engine is not a certificated aircraft engine but is recommended in the Pilot's Operating Handbook and accepted by the Light Aircraft Association for the Team Minimax 91. The engine's POH includes warnings that it is subject to sudden stoppage and that the user assumes all risks. Carburettor heating is not pilot-selectable; fixed ducts circulate warm air from the engine bay.
Examination
Post-accident inspection revealed that the carburettor float bowl contained a suitable amount of uncontaminated fuel. Spark plugs were clean, correct colour, and sparked normally. Diagnostic testing found that the ignition stator was breaking down under load, causing the engine to misfire. After fitting a new stator, the engine ran normally.
Personnel
The pilot, aged 61, held a Private Pilot's Licence with 182 hours total experience, including 22 hours on type. His last 90 days included 2 hours flying, and the last 28 days 1 hour. He credited good training and regular practice of abnormal situations as significant contributors to the successful outcome.