The Story Of Swiss International Air Lines Flight 850

In July 2002, a Swiss International Air Lines Saab 2000 (registered as HB-IZY) operating Flight 850 failed to land at its intended destination at Fuhlsbüttel Airport in Germany due to inclement weather. The pilots made multiple unsuccessful attempts at nearby airports before deciding to land at Werneuchen.

Upon landing, the aircraft hit an embankment, and all three legs of the undercarriage ripped off the aircraft. The crippled turboprop airliner eventually came to a complete rest on its belly – fortunately, only one passenger received minor injuries, though the aircraft had to be written off.

Weather misses and aircraft changes

On July 10th, 2002, Swiss International Flight 850 was scheduled to depart Basel, Switzerland, for a relatively short flight to Fuhlsbüttel Airport in Hamburg, Germany. The chosen aircraft for that route was an Embraer 145, but mechanical issues forced an aircraft change. A Saab 2000 was selected as its replacement.

The flight’s departure time was delayed for two reasons: the change in aircraft in addition to some discussions regarding the forecasted weather conditions near Hamburg at the estimated time of arrival (ETA). The crew decided to carry extra fuel in case an instrument hold was required.

Related

What Are METAR Weather Reports & Why Are They Useful For Pilots?

These are meteorological reports generated at most airports.

Fuhlsbüttel’s Meteorological Terminal Air Report (METAR) indicated a line of thunderstorms near the airport. Forecasted winds of up to 45 knots at Hamburg and the selected alternatives of Hannover and Bremen caught the pilots’ attention during the briefing, which, unfortunately, did not include a review of Significant Meteorological Information (SIGMET) reports issued about an hour before the flight departed Basel. Those reports were not made available to the flight crew.

The SIGMETs indicated a front was developing in the area and would likely produce thunderstorms with tops at FL380 (38,000 feet, 12,000 meters) in the Bremen area. The Terminal Aerodrome Forecast (TAF) for Fuhlsbüttel Airport called for steady winds at 20 knots with gusts to 40 knots near the expected convective weather.

A bumpy ride

After a 10-minute departure delay, Flight 850 left the gate at 17:55 and took off at 18:09, carrying four crew and 16 passengers bound for Hamburg. As they expected, the pilots soon encountered turbulence and asked for air traffic control vectors around cells of heavy precipitation en route.

At 19:36, the Saab 2000 initiated an ILS approach to Fuhlsbüttel’s Runway 23. Upon reaching 3,000 feet, the aircraft encountered heavy turbulence associated with a thunderstorm cell that had positioned itself over the airport. The crew initiated a go-around intending to request an instrument hold near the area.

The Saab’s fuel tanks had enough for a 45-minute hold. Even though the weather at Bremen was better than Hamburg’s (winds at 9 knots with visibility just over 6 kilometers), diverting there was not a viable option since a line of convective weather had formed between Hamburg and this alternate airport.

Landing options become limited

At 19:49, air traffic control advised Flight 850 that another aircraft was able to land on Runway 33 at Hamburg, but the crew decided against attempting a landing due to the still-present strong winds. Instead, the pilots opted for a diversion to Hanover and requested leaving the hold for this purpose.

At 20:18, Flight 850 proceeded to Tegel Airport in Berlin after receiving the airfield’s Automatic Terminal Information Service (ATIS), indicating clear skies and other favorable conditions. The crew requested priority handling due to 40 minutes of fuel remaining. Unfortunately, the frontal system that prevented passage to Bremen had now approached Berlin, and severe turbulence was again encountered during their approach.

Yet again, the crew requested an alternate airfield from ATC. The controller suggested landing at Eberswalde Finnow, just 27 nautical miles away. The crew eagerly accepted, but once again, the weather limited the crew’s options when thunderstorms covered that airfield, and massive cells eliminated landing at other nearby options, including New Brandenburg.

Aware that fuel was a serious concern at this point, additional communications between air traffic control and Flight 850’s pilots eventually focused on landing at Werneuchen Airfield, which was 20 nautical miles away. In addition to the ongoing weather threats, the airport poses its own challenges.

Related

How Do Pilots Interpret Weather Reports?

Learning how to read various weather reports and charts is a key part of pilot training.

The good news was that it offered a long runway formerly used by military aircraft. On the other hand, however, part of the landing area was unusable. An earth embankment had been constructed on part of the runway to dissuade illegal car racing on the airfield. Therefore, the usable runway distance for Flight 850 would be 4,900 feet (1,500 meters). If that wasn’t challenging enough, the runway was not lighted and had no visual aids since it was currently only used for ultralight operations.

Touchdown (and unexpected slowdown) on the runway

At 20:40, radar controllers cleared Flight 850 for an approach at the non-towered airport. The pilots were advised to touch down further down the runway due to the embankment.

Without runway lighting or any other visual aids, the first officer landed the Saab 2000 before the obstacle, causing all three landing gear to be sheared off before the aircraft slid down the runway approximately 1,150 feet (350 meters). Engine No. 2 fire warnings were activated, and the crew discharged the fire extinguishing systems for both powerplants. Fortunately, of the 20 souls onboard (16 passengers and 4 crew), there were no fatalities.

An in-depth and lengthy investigation

The German Federal Bureau of Aircraft Accidents Investigation (BFU) conducted the accident investigation, which took over eight years to complete. There was no explanation why the investigatory process took so long, but the BFU’s findings were definitive. The agency faulted the lack of available and accurate weather data as one of the contributing factors. Specifically, the pilots’ pre-flight briefing did not benefit from having the SIGMETs, which clearly indicated deteriorating forecasted conditions throughout parts of Germany.

Related

Why Do Air Crash Investigations Take So Long?

Air crash investigators can take years to conclude their findings.

In addition, the faulty ATIS broadcast at Berlin’s Tegel Airport reported fine weather when, in fact, the opposite was true. Systemically, BFU cited inadequate information at the Werneuchen Airfield due to “an ambiguous map display as well as misleading or lack of communication” and “inadequate labeling/marking of the operational and non-operational areas of the airport.”

What do you think about Swiss International Flight 850? Share your views in the comments section.