Swiss flight 850

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Swiss flight 850
52bt - Crossair Saab 2000; HB-IZY @ ZRH; 02/27/1999 (5256723191) .jpg

The crashed machine in 1999 in Zurich
Accident summary
Accident type Landing accident
place Werneuchen Airfield
date July 10, 2002
Fatalities 0
Survivors 20th
Injured 1
Aircraft
Aircraft type Saab 2000
operator Swiss
Mark HB-IZY
Surname LX 850
Departure airport Basel-Mulhouse Airport , Switzerland
Destination airport Hamburg Airport
Passengers 16
crew 4th
Lists of aviation accidents

A Saab 2000 crashed on July 10, 2002 on Swiss flight LX 850 ( flight number : LX850), an international scheduled flight operated by Swiss from Basel to Hamburg . The plane could not be landed in Hamburg due to a thunderstorm. After unsuccessful attempts to divert the machine to Berlin and Eberswalde , the crew decided to land at Werneuchen airfield because of the scarcity of fuel . After touching down, the aircraft hit a mound, which broke off all three landing gear legs, and came to a halt on the fuselage with a burning engine. One of the sixteen passengers on board suffered minor injuries. The aircraft had to be written off as a total economic loss.

The investigation of the accident by the Federal Bureau of Aircraft Accident Investigation (BFU) lasted more than eight years. It raised a number of questions, including inadequate crew resource management , inadequate transmission of weather information to the crew and faulty runway markings at Werneuchen airfield, where the runway had been shortened from 2,400 m to 1,500 m without the markings of the new dimensions adapt.

plane

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

Course of events

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

Originally, Flight 850 was to be operated with an aircraft from the Embraer ERJ-145 family . Since an Embraer 145 was not ready, a Saab 2000 was used and the briefing for the flight was extended by 15 minutes. The actual departure time was therefore shifted by 10 minutes to 14:55 UTC. Weather reports showed a concentration 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 started from Basel, which the crew did not receive. The SIGMET warnings indicated an approaching storm front which reached FL380 in the area around Bremen . The scheduled departure time from Basel-Mulhouse Airport was 2:45 p.m. There were 16 passengers on board in addition to four crew members. The TAF aviation weather forecast for Hamburg Airport , valid from 1 p.m. to 10 p.m., read: TAF EDDH 101200Z 101322 31010KT 9999 FEW025 TEMPO 1320 29020G40KT 3000 TSRA BKN013CB Tempo 1922 4000 RA BKN014.

Runway 23 was the active runway at Hamburg Airport. During the approach, severe turbulence occurred due to a thunderstorm and the crew aborted the landing when it fell below 3300 ft. It was later found that a derecho had formed. Winds of 81 kn were recorded and seven people fell victim to the storm in the Berlin area. The storm has been described as the worst summer storm in Berlin in the last 50 years. The crew decided to hold on while the alternatives were examined. The planned alternative airport was Bremen Airport , about 55 nm (nautical miles) away. To get to Bremen, a front system had to be flown through. Another aircraft had successfully landed on runway 33 in Hamburg and reported strong winds. The crew of Flight 850 refused to attempt to land on Runway 23 and requested a diversion to Hanover-Langenhagen Airport . Neither hit the air traffic control (ATC) in front of other alternatives, nor a request was made by the crew.

As the flight continued, the front system prevented a change of course in the direction of Hanover. It was decided to divert the flight to Berlin-Tegel Airport . The ATIS at Berlin-Tegel Airport stated good weather conditions and did not expect any significant changes. When approaching runway 08L in Berlin-Tegel, the crew requested priority and stated a remaining fuel supply for 40 flight minutes. Severe turbulence occurred again on the approach, as the front system had meanwhile reached Berlin. The approach was canceled and the crew asked air traffic control for an alternative airport. Airfield Eberswalde Finow near Eberswalde was proposed , which was accepted by the crew with the comment “Okay, we'll take anything at this point”. From this moment on, the aircraft's situation was assessed as an emergency by the FRP . On the way to Finow, thunderstorms were observed at the destination and the FRP looked for alternatives.

Air traffic control FVK suggested Neubrandenburg Airport , which the crew of Flight 850 rejected after checking the weather. Thereupon the Werneuchen airfield was offered, which was about 20 nm away and had a runway with a length of 1500 m. Werneuchen was accepted by the crew. The FVK was able to contact the chairman of the aviation club based in Werneuchen. This stated the length of the landing area at 2400 m, but indicated an earth wall on the runway, so that de facto 1500 m length remained. Landing in the direction of 08 therefore meant that the runway could only be used up to the embankment. Almost an hour after the approach to Hamburg Airport was interrupted, Flight 850 began its approach to Werneuchen. The crew reported that the runway was in sight and was informed by air traffic control that they had to land in the eastern part of the runway. During the final approach, the flight captain noted that the runway was “longer than Bern ” and instructed the copilot to land wherever he wanted. Although the closed part of the runway had been marked as such, the markings had been badly weathered over the years, so that the original markings were easier to see than the actually valid ones. Poor visibility and a lack of runway lighting contributed to the fact that the crew did not see the earth wall.

The copilot landed the aircraft after passing a threshold mark, whereupon it collided with the earth wall, all three landing gear legs broke off and the aircraft came to a standstill on its stomach. A fire alarm for the left engine was triggered and the crew activated the fire extinguishing devices for both engines. One passenger sustained a leg injury. The aircraft was later declared an economic total loss and then disposed of.

Investigations by the BFU

alternative description
The railway in Werneuchen in 2019. The old railway markings were completely removed from the blocked part after the accident.

The Federal Bureau of Aircraft Accident Investigation (BFU) began an investigation into the incident, which was to last 3,005 days (over eight years). She named a combination of several factors as the cause of the accident. If the crew had received the SIGMETs - according to the BFU's assumption - they would probably have recognized the thunderstorms as part of a system and not as isolated. This would have made other decisions possible for the crew.

The METAR messages for Berlin-Tegel and Berlin-Schönefeld Airport were CAVOK and NOSIG , which was sharply criticized by the BFU. At 5:50 p.m. the following METAR message was issued in Berlin-Tegel: EDDT 04001KT CAVOK 30/17 Q1002 A2959 0998 2947 NOSIG.

At that time, the cold front was 30 km southwest of Berlin-Tegel and had moved 100 km further in the past hour. The BFU was of the opinion that NOSIG should not have appeared in the METAR report and that a SPECI would have been necessary. At 6:20 p.m. a new METAR report was issued 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 its approach to Berlin-Tegel.

The decision to abort the approach to landing at Hamburg Airport was supported by the BFU, but not the decision to divert to Hanover. The decision to reroute to Berlin-Tegel, based on the incorrect information CAVOK and NOSIG in Berlin-Tegel, was confirmed by the BFU. Air traffic control did not use the correct terminology when approaching Werneuchen Airport. It was also recorded that the runway markings at Werneuchen Airfield did not meet the required standards.

Web links

Individual evidence

  1. ↑ a b c Saab 2000 MSN 47 . Plan register. Archived from the original on July 15, 2011. Retrieved on December 18, 2010.
  2. ^ Swiss Names and Planes . Aviation News. Archived from the original on July 22, 2011. Retrieved on December 20, 2010.
  3. ^ A b H-IZY Accident description . Aviation Safety Network. Retrieved December 18, 2010.
  4. ↑ a b c d investigation report . Federal Agency for Aircraft Accident Investigation. October 2010. Retrieved November 27, 2015.
  5. ↑ Further details of the landing of a SWISS aircraft at Werneuchen, Germany . Hugin. July 11, 2002. Archived from the original on January 25, 2013. Retrieved on December 20, 2010.
  6. ↑ Terminal Aerodrome Forecast for Hamburg Airport, issued on the 10th of the month at 12:00 UTC , valid on the 10th of the month between 13:00 and 22:00 UTC: wind from 310 ° at 10 kn, visibility over 10 km, few Woken at 2500 ft. Temporarily between 13:00 and 20:00 UTC wind from 290 ° at 20 kn with wind peaks of 40 kn, visibility 3 km in thunderstorms, heavy cloud cover at 1400 ft. Temporarily between 19:00 and 22:00 UTC Visibility 4 km when it rains, broken clouds at 1400 ft.
  7. ↑ a b c d e f g h i j k Simon Hradecky: Report: Crossair SB20 at Werneuchen on Jul 10th 2002, landed before runway and impacted earth wall . The Aviation Herald . December 17, 2010. Retrieved December 18, 2010.
  8. ^ Berlin storms kill seven . CNN. July 12, 2002. Retrieved December 18, 2010.
  9. ↑ a b crash landing in Werneuchen . Werneuchen. Archived from the original on July 18, 2011. Retrieved December 18, 2010.
  10. ↑ Further update on the landing of SWISS flight LX 850 . Hugin. July 12, 2002. Archived from the original on January 25, 2013. Retrieved on December 20, 2010.
  11. ↑ METAR for Berlin-Tegel Airport: wind from 040 ° at 1 kn; Visibility over 10 km and no cloud cover below 1500 m available (= CAVOK), QNH 1002 hPa, current altimeter setting 29.59 inHg, falling to 998 hPa / 29.47 inHg; NOSIG prediction = no significant changes expected.
  12. ↑ METAR for Berlin-Tegel Airport. Wind variable at 1 kn, visibility more than 10 km, few cumulonimbus clouds at 400 ft, loosened clouds at 1200 ft, heavy clouds at 2600 ft; Current altimeter setting 1002 hPa / 29.59 inHg, falling to 998 hPa / 29.47 inHg. Forecast: Occasional wind from the west (270 °) at 25 kn, in gusts up to 55 kn, visibility 2 km with heavy thunderstorms with rain, heavy cloud cover at 900 ft, heavy cloud cover at 1500 ft with cumulonimbus ; occasional lightning and storm clouds southwest of the airport

Coordinates: 52 ° 37 ′ 58 ″  N , 13 ° 46 ′ 12 ″  E