Accident Overview
On 14 June 2018, at approximately 18:20 local time, an ultralight 3Xtrim aircraft (registration SP-SYPT) sustained a crash during an emergency landing at Katowice Muchowiec Airport (EPKM). The aircraft was destroyed by post-impact fire. The pilot, a 67-year-old male with a valid ultralight pilot license but an expired medical certificate, was uninjured. The passenger, a fellow pilot instructor, sustained minor facial burns.
Sequence of Events
The pilot planned a training flight. He went to a nearby gas station to refuel the aircraft, using a fuel canister found in the hangar without checking its cleanliness. During refueling, he noticed the fuel appeared cloudy but proceeded to fill the tank. He did not perform a full pre-flight inspection, omitting the fuel sump drain and visual fuel check.
After starting the engine and completing a run-up, the aircraft taxied to the runway. The takeoff roll began approximately from the midpoint of Runway 05. During initial climb, at about 5 meters altitude, the engine began to run roughly. The pilot judged that landing straight ahead would not allow stopping on the remaining runway. He initiated a shallow right turn, gaining about 10 meters additional altitude.
A ground-based instructor observed the situation and radioed a command to "land straight ahead on the grass strip." The pilot did not hear this transmission. The instructor noted the engine was producing approximately 50% power and running irregularly, and the aircraft speed was near stall.
Believing the engine was still producing some power, the pilot decided to return for landing on Runway 05 and began a left turn. During this turn, the aircraft entered a left autorotation. The passenger, an instructor, intervened and arrested the incipient spin. Shortly after, the aircraft struck a metal fence with its propeller and then landing gear. The fence had been erected for airshow security the following day.
Post-Accident Findings
Investigators examined fuel residue from the canister used for refueling and found it contained water. The carburetor float chamber, which survived the fire, also contained water. The aircraft was totally destroyed by fire. The pilot and passenger evacuated uninjured (pilot) and with minor burns (passenger).
Causes
The Polish State Commission on Aircraft Accident Investigation identified four causes: 1. Non-compliance with fueling procedures. 2. Failure to perform full pre-flight checklist. 3. Starting takeoff from mid-runway. 4. Improper pilot response to engine power loss after takeoff.
Remarks
The pilot did not hold a valid medical certificate on the day of the accident. The Commission proceeded with the investigation despite the aircraft being used by an unauthorized person, for accident prevention purposes.