Accident Overview
On June 11, 2014, at approximately 06:50 UTC, a Piper PA-44-180T Seminole, registered YU-BWW, was involved in an accident during a training flight at Radinci airfield (LYSD) in Smederevo, Serbia. The aircraft was owned by New Age Investments Co. and operated by Linx Aviation. The flight originated from Lisicji Jarak airfield (LYBJ) at 05:40 UTC for a training session consisting of touch-and-go circuits.
Crew Information
The crew comprised a 70-year male instructor holding an ATPL(A) license with valid MEP(land)/IR and FI(A) ratings, and a 42-year male student pilot holding a PPL(A) license with a SEP(land) rating, who was undergoing MEP(land) training. Both were uninjured in the accident. The instructor had a total flight time of 13,887 hours and 12 minutes, including 1 hour and 10 minutes on the accident day. The student pilot's flight times were not considered relevant to the investigation.
Aircraft Information
The aircraft, a 1982 Piper PA-44-180T Seminole (serial number 44-8207014), had a valid Certificate of Airworthiness issued on May 31, 2013, and a valid Airworthiness Review Certificate issued on May 31, 2014. Its empty mass was 1,116.29 kg, maximum landing mass 1,723.65 kg. Total time since new was 2,089 hours and 10 minutes, with 71 hours and 10 minutes since the last inspection.
Accident Sequence
During the sixth and final circuit, the crew failed to extend the landing gear. The first contact with the ground was made by the propellers, followed by the lower fuselage. After recognizing unusual sounds and vibrations, the crew realized the landing gear was not down. The runway surface (grass) was wet, causing the aircraft to slide straight along runway 36 for approximately 600 meters before stopping. After coming to rest, both crew members exited the aircraft unassisted and notified authorities.
Damage and Injuries
The aircraft sustained substantial damage: propeller blades were damaged due to ground contact, and the lower fuselage skin was abraded. No damage to third parties occurred. Both crew members were uninjured.
Meteorological and Site Conditions
The accident occurred at Radinci airfield, elevation 71 m, runway dimensions 750 m × 30 m, orientation 180°–360°. The initial contact point was about 150 m past threshold 36; the aircraft slid to a stop approximately 200 m before threshold 18. Meteorological data from the Republic Hydrometeorological Service indicated the runway surface was wet.
Probable Cause
The investigation concluded that the probable cause was: "Failure to extend the landing gear by the crew before touchdown."