Swiss International Airlines Flight 850

The museum locomotive in 1999 in Zurich

Swiss flight LX 850 was an international scheduled flight from Basel to Hamburg. On 10 July 2002, the aircraft Saab 2000 could not be landed at Hamburg airport due to bad weather. After attempts to divert the flight to Berlin and Eberswalde, the crew decided to land in Werneuchen. After touchdown, the aircraft crashed into an earth wall, which broke all three legs, and came to the fuselage with a burning engine to a halt. One of the sixteen passengers on board suffered minor injuries. The aircraft had to be written off as an economic total loss.

The investigation into the accident by the Federal Bureau of Aircraft Accidents Investigation (BFU ) lasted more than eight years. She threw a variety of questions, including a poor crew resource management, insufficient dissemination of weather information to the crew of Flight 850 and incorrect runway markings at the airfield Werneuchen where the runway was shortened from 2400 m to 1500 m, without the runway markings adapt to the new dimensions.

Aircraft

In the affected aircraft, it was a Saab 2000 with the registration number HB- IZY and name doldenhorn, named after a 3643 m high mountain in the Bernese Alps. The aircraft bore the serial number 047 and had its maiden flight on 30 April 1997. Time of the accident it had completed 12,303 flight hours and 12,069 landings.

Course

All times according to UTC, the local time was UTC 2

Originally flight should be operated with a 850 engine of the Embraer ERJ -145 family. As an Embraer 145 was not ready, was evaded on a Saab 2000 and the briefing for the flight was extended by 15 minutes. The actual departure time is therefore shifted towards the planned 10 minutes 14:55 UTC. Weather reports showed a cluster of thunderstorms with expected wind speeds of up to 83 km / h at Hamburg Airport and the named alternatives Hanover and Bremen. Several SIGMET warnings were issued about an hour before the flight departs from Basel, but did not get the crew. The SIGMET warnings indicated a -winding storm front that reached in the area around Bremen FL380. The scheduled departure time at the Basel - Mulhouse airport was 14:45. There were four crew members next 16 passengers on board. The TAF Aviation weather forecast for Hamburg Airport, valid 1:00 p.m. to 22:00 was: 101200Z 101322 31010KT 9999 TAF EDDH FEW025 TEMPO 1320 29020G40KT 3000 TSRA BKN013CB Tempo 1922 4000 RA BKN014.

Runway 23 was the active runway at Hamburg Airport. When landing due to a thunderstorm developed serious turbulence and the crew broke the landing from falling below 3300 ft. Later it was found that a derecho had formed. Winds of 81 knots were recorded and seven people were in the Berlin area for the storm victims. The storm was described as the worst summer storm in the last 50 years in Berlin. The crew decided to queues, while the alternatives were examined. Proposed alternate airport was the Bremen airport, located about 55 nm (nautical miles ). To get to Bremen, had to be flown by a frontal system. Another plane was successfully landed on runway 33 in Hamburg and reported strong winds. The crew of Flight 850 refused an attempted landing on Runway 23 and requested a diversion to the airport Hannover- Langenhagen. Neither hit the air traffic control (FRP ) other alternatives, nor was a request from the crew asked.

In the further course of flight, the front system prevented a change of course towards Hanover. It was decided to divert the flight to Berlin 's Tegel Airport. The ATIS at Berlin-Tegel airport indicated good weather conditions and calculated with no significant changes. On the approach to Runway 08L at Berlin- Tegel, the crew requested priority and called a remaining fuel reserve for 40 -minute flight. Again came when landing heavy turbulence, as the frontal system had reached the meantime Berlin. The flight was canceled and the crew asked for the air traffic control to an alternate airport. Finow airfield was proposed in Eberswalde, which was accepted by the Department, with the remark, "Okay, we'll take anything at this point ." From this moment the situation of the aircraft from the FRP was evaluated as an emergency. On the way to Finow thunderstorms were observed and searched by the FRP for alternatives to the target.

Air traffic control FRP proposed the Neubrandenburg Airport, which was refused by the crew of flight 850 after checking the weather. Then the airfield Werneuchen was offered, which was about 20 nm away and had a runway with 1500 m length. Werneuchen was accepted by the Department. The FRP was able to contact the chairman of the residents in Werneuchen Air Sports Association. This was the length of the landing area at 2400 m, but pointed to a mound on the runway, so de facto 1500 m length remained. A landing in the direction 08 therefore meant a usability of the runway exclusively to the mound. Almost an hour after termination of the approach to Hamburg Airport Flight 850 began the approach to Werneuchen. The crew reported the runway in sight and were advised by air traffic control Werneuchen that they had to land in the eastern part of the runway. During the final approach the Captain noted that the runway was " longer than Bern " and instructed the co-pilot to land wherever he wanted. Although the locked section of the runway had been labeled as such, the markings were severely weathered over the years, so that the original markings were easier to see than the actually valid. Poor visibility and lack of runway lighting helped that the crew did not see the mound.

The co-pilot put the plane on after passing a threshold marking, which then collided with the embankment, with all three legs broke off and the aircraft came to a halt on the abdomen. A fire alarm for the left engine was triggered and the crew activated the fire extinguisher equipment for both engines. A female passenger was wearing a leg injury from it. The aircraft was later declared as economic total loss and then disposed of.

Investigation by the AAIB

The Federal Bureau of Aircraft Accidents Investigation (BFU ) began an investigation into the incident, which was to last 3005 days ( over eight years). She gave as an accident cause a combination of several factors. Had to get the SIGMETS the crew - so the assumption of BFU - it would have probably the thunder recognized as part of a system rather than as isolated. So that other decisions of the crew would have been possible.

The METAR reports for Berlin- Tegel Airport and Berlin- Schönefeld denominated CAVOK and NOSIG what was sharply criticized by the AAIB. 17:50 clock the following METAR report was published in Berlin- Tegel: EDDT 04001KT CAVOK 30/17 Q1002 A2959 0998 2947 NOSIG.

At this time, the cold front was located 30 km southwest of Berlin- Tegel and had moved on in the last hour 100 km. The AAIB was of the opinion that NOSIG not in the METAR report should have come up, and that a SPECI would have been necessary. At 18:20 a new METAR report was published in Berlin- Tegel: EDDT VRB01KT 9999 FEW040CB SCT120 BKN260 29/17 Q1002 A2959 0998 2947 TEMPO 27025G55KT 2000 TSRA BKN009 BKN015CB COMMENTS: OCNL LTNG AND CB SW OF STN. This METAR report was issued two minutes before Flight 850 began the approach to Berlin -Tegel.

The decision to abort the landing approach to Hamburg Airport was supported by the BFU, but not the decision to divert to Hanover. The decision to divert to Berlin -Tegel, based on the erroneous information CAVOK and NOSIG in Berlin- Tegel, was confirmed by the AAIB. When landing at the airfield Werneuchen air traffic control did not use the correct terminology. It was also noted that the runway markings at the airfield Werneuchen did not meet the required standards.