Rough translation:
During initial climb, there was a problem with the engine(s). While turning back to the airport, the aircraft crashed into a meadow.
The pilot stated that he planned a multi day excursion together with his wife and an acquaintance. On 24.05.2012 at 07:00 he took off with his DA 42 at Berne/Switzerland for a flight to Sylt [German North Sea island, at the Danish border]. The passengers were supposed to be dropped off there while the pilot continued to Billund/Denmark for a business meeting and was supposed to return on the following day. The flight from Berne to Sylt was without problems at first. While approaching Sylt, the pilot noticed a drop in power in the right engine of about 5-10% which he compensated for by increasing the power.
During takeoff run at Sylt for the trip to Billund there was engine roughness and the right engine stopped. The takeoff was aborted. Mechanics of the German Diamond service station were ordered to come to Sylt. On site, maintenance and an error diagnosis were performed, during which a prop governor valve was replaced. After a test run and test flight, the aircraft was returned to the pilot the following day.
On 26.05.2012 the pilot took off for the follow on flight to Parchim with the passengers on board. The 90 minute flight was uneventful according to the pilot.
The flight back to Bale was planned for 28.05.2012.
At 13:27, the pilot reported on the radio and requested a startup clearance for an IFR flight to Bale. At 13:40 a takeoff clearance was issued on runway 24 by the control tower Parchim. The pilot reported at 13:41:19: "We do a right turn as planned [...] and I am rolling now." The next report occured at 13:43:03: "[...] I need to return to the field I have an engine failure on the right engine." In response to a request by the tower, the pilot confirmed that he intends to return to the airfield due to an engine failure and wants to land on runway 06. The tower then issued a landing clearance for all runways at 13:43:41. At 13:43:44, the pilot issued his last report: "All runways (incomprehensible) to the field to (broken up)". Witnesses saw the aircraft, coming from the north west, in a right turn with low bank over the airfield.
Shortly thereafter, the aircraft crashed into a meadow close to the airport Parchim.
[Skipping pilot details, aircraft, details, weather as nothing special, weather CAVOK, etc.]
Engine examination
The engine was examined by the BFU [German aircraft accident investiation authority] at the manufacturer's premises. While disassembling the gearbox, it was noticed that within the gearbox there was a larger quantity of thread-like material. The friction disk was completely worn down. At the edges were cracks. There were traces of a liquid on the gearbox entry shaft and abrasion on a bearing...
[some FADEC graphics]
Due to design, the timelines on the FADECs are not synchronized. In the chart, the moment of power increase were aligned (start of take off run). From this, it can be determined that both engines were running for about 3 minutes.
The data for both engines ends prematurely. The RPM of the engines at the time of impact:
right engine: 2 579 rpm
left engine: 3 944 rpm
The FADEC data on the right engine shows a slowly but steadily increasing overspeed up to 4 517 rpm (about 270 prop rpm), instead of 300/min engine rpm (200/min prop rpm). The overspeed starts about 40 seconds after setting the power lever to maximum and ends about 85 seconds after setting the power lever to maximum. After that, the pilot fully pulls back the power lever of the right engine (LOAD to 0%). The altitude reached during these 85 seconds corresponds to a pressure difference of 16 mbar.
The right engine settles on a speed of 1500-1600 rpm, roughly corresponding to idle speed. About 78 seconds after the pilot reduces the power setting to 0%, it is increased for a short moment to 11%. The speed increases to 2 447 engine rpm and remains on this value, even though the power setting was reduced again after one second.
Fire
There was no fire.
Last edited by achimha; 24th July 2012 at 15:37.