Flight History
On 14 January 2004 at approximately 11:50 local time, the Yak 52 departed from Koblenz-Winningen airfield for a local flight. After about one hour, the airfield control attempted to contact the aircraft but received no response. A missing person report was filed with the search and rescue service (SAR) around 16:40. Multiple days of searching by SAR, police, and private individuals from air and ground followed. On 21 January 2004 at about 12:40, the wreckage was located by a police helicopter crew in a forested area near Stephanshausen, approximately 7 km north-northeast of Rüdesheim. The aircraft had impacted with a pitch angle of about 20° in wooded, hilly terrain. Both occupants were fatally injured and the aircraft destroyed.
Persons Involved
The pilot held a Private Pilot License (PPL A) issued in August 2001, with a total flight experience of 156 hours, including about 17 hours on the accident type. His last flight on the accident type occurred in December. He possessed a recognition certificate from the Lithuanian aviation authority valid until 31 October 2003, which authorized him to fly Lithuanian-registered aircraft. He was undergoing training for an aerobatic rating. The passenger had held aviation licenses until 2003, including a Commercial Pilot License with instrument rating, a flight instructor rating, and an aerobatic rating. He had over 6,000 total flight hours, about 200 on the accident type. From 1997 to 2002, he was the owner of the accident aircraft.
Aircraft Information
The Yak 52, serial number 822514, was manufactured in 1982 by Aerostar in Romania. It is a two-seat sports and aerobatic aircraft (tandem configuration) with low-wing, all-metal construction and partially fabric-covered control surfaces. It was equipped with a 9-cylinder radial engine rated at 360 hp, a wooden controllable-pitch propeller, and a retractable tricycle landing gear. Maximum takeoff mass was 1290 kg. After a major overhaul by the Lithuanian company Termikas, the aircraft had been operated since September 2003 under a Lithuanian registration. It was accepted in flight-ready condition in Lithuania on 2 October 2003 and ferried to Germany. Between 12 October and 12 December 2003, 11 flights were conducted from Koblenz-Winningen.
Accident Site and Findings
The accident site was located in a large mixed forest area about 7 km north-northeast of Rüdesheim and 1 km northeast of the village of Stephanshausen. The aircraft entered the deciduous forest and cut a swath approximately 65 m long in a direction of 250°. It then struck the forest floor with a 20° pitch angle and high energy. No fire occurred. All parts of the aircraft were found at the main wreckage site. There was no evidence of parts separating in flight. Both occupants were within the main wreckage and had severe injuries leading to immediate death.
Meteorological Information
According to the official report from the German Weather Service, at the time of the accident, a gusty wind from the southwest to west was blowing at the surface, with average wind speeds between 10 and 20 kt. Horizontal visibility at the surface ranged from 20 to 50 km, occasionally dropping to 10–15 km over higher terrain. The low cloud cover was 2–5/8 cumulus with bases between 3000 and 3500 ft MSL; above this was 5–6/8 stratocumulus. No significant weather phenomena were likely at the accident time. Precipitation began later in the afternoon and evening from the west.
Flight Data Recording
The aircraft was not equipped with a flight data recorder. Radar recordings allowed a flight path reconstruction, which showed that aerobatic maneuvers were flown several kilometers north of the accident site. Multiple witnesses also reported seeing the aircraft performing aerobatic figures.
Technical Examination
During the technical examination, a metal ball approximately 25 mm in diameter was found in the rear fuselage. This ball was identified as the locking knob of the rear sliding canopy. After opening the skin, contact marks and paint transfers were found at the rear fuselage, including on the elevator control pushrod and its guide. Paint analysis confirmed that the metal knob had transferred yellow paint from the pushrod's protective coating, and black and white paint from the knob was found on the rear fuselage structure. A positive fit was established between the knob and indentation marks on the rear fuselage opening for the elevator control segment. The knob had been pressed between the elevator control segment and the edge of the opening, restricting elevator movement. The foreign object likely became dislodged during the flight and moved into the rear fuselage, where it impeded elevator control.
Medical and Pathological Information
Autopsy findings indicated that death resulted from multiple severe injuries and acute heart failure. No fire occurred upon impact. The high-energy impact precluded survival.
Search and Rescue Operations
Search operations began on the evening of 14 January 2004 using police helicopters, concentrating initially on the Dietz area near Limburg. The initial radar track showed a primary target heading into that area. The search was hampered because the aircraft had no emergency locator transmitter (ELT) and the transponder was found switched off. After three days, the official air and ground search by police and SAR was suspended. Private search efforts continued, including ground searches and private aircraft flights, with significant media interest. The radar data was re-evaluated by helicopter crew pilots, revealing a track from the north ending near Rüdesheim. Precise position determination allowed the accident site to be located and the white aircraft wreck found in the sparse forest on 21 January 2004.
Previous Occurrences
In the past, multiple incidents involving unrecognized foreign objects in the rear fuselage tube of this aircraft type have resulted in restricted elevator control. Reports from affected pilots and accident descriptions often show a recurring scenario: after aerobatic maneuvers, elevator control restrictions were noticed, and if the aircraft was landed successfully, foreign objects were found in the tail section near the elevator segment passage. Some accidents with this type have involved the aircraft being flown into obstacles after completion of aerobatic figures.
Conclusions
The accident was attributed to a foreign object in the fuselage that, due to a change in its position during flight, severely restricted the movement of the elevator control segment. The impairment of control was so great that the pilot could not avoid striking obstacles.