Alas Nacionales Flight 301

from Wikipedia, the free encyclopedia
Alas Nacionales Flight 301
Birgenair tcgen.jpg

The accident machine at Berlin-Schönefeld Airport in July 1995
Accident summary
Accident type Loss of control
place 26 kilometers northeast of Puerto Plata , Dominican Republic
Dominican RepublicDominican Republic 
date February 6, 1996 (local time)
Fatalities 189
Survivors 0
Aircraft
Aircraft type Boeing 757-200
operator Dominican RepublicDominican Republic Alas Nacionales
Mark TC GEN
Departure airport Puerto Plata , Dominican Republic
Dominican RepublicDominican Republic 
1. Stopover Gander , CanadaCanadaCanada 
2. Stopover Berlin-Schoenefeld , Germany
GermanyGermany 
Destination airport Frankfurt am Main , Germany
GermanyGermany 
Passengers 176
crew 13
Lists of aviation accidents

On February 6, 1996, a Boeing 757-200 crashed on Alas Nacionales flight 301 ( flight number ALW301), also known as Birgenair flight 301 , shortly after taking off from Puerto Plata airport ( Dominican Republic ). The aircraft operated by the Turkish Birgenair on behalf of the virtual Dominican airline Alas Nacionales was on a charter flight from Puerto Plata via Gander ( Newfoundland , Canada ) and Berlin-Schönefeld to Frankfurt am Main . The machine crashed about 26 kilometers off the Dominican coast in the Atlantic , killing all 189 occupants.

It is the most serious aircraft accident in the Dominican Republic and - together with American Airlines flight 77 - the worst accident involving a Boeing 757. A total of 167 passengers were German citizens ; this is the incident with the highest number of German victims in the history of civil aviation.

prehistory

In 1994, the German tour operator Öger Tours, in cooperation with the Turkish airline Birgenair, in which Öger Tours had holdings, planned to offer inexpensive package tours to the Caribbean . Because Birgenair, as a Turkish company, would not receive route rights between Germany and the Dominican Republic , the Ratioflug aviation company , based in Neu-Isenburg at the time, was involved as a third partner . Ratioflug applied for the necessary route rights from the Federal Ministry of Transport and received a corresponding authorization limited to six months to carry out the transatlantic flights . This was done with leased aircraft from Birgenair.

For the 1995/1996 winter season, Öger Tours and Birgenair aimed for a similar business model. This time the cooperation partner was the newly founded Dominican company Alas Nacionales , which had an Air Operator Certificate but no aircraft. Alas Nacionales applied for route rights for flights to Germany, which were then to be carried out with wet- leased Birgenair aircraft . In return, the shareholders of Alas Nacionales were offered a bonus of ten DM per passenger flown in. After receiving the flight rights, a Birgenair Boeing 767-200ER was transferred to the Dominican Republic and registered there on October 25, 1995 with the registration number HI-660CA for the partner company. The aircraft officially leased to Alas Nacionales continued to wear the colors of Turkish society except for a new lettering. The IT charter flights between the Dominican Republic and Germany began a week later and were operated with Turkish crews.

Independently of this, Birgenair rented a Boeing 757-200 (TC-GEN) to the Argentine Staf Airlines in November 1995 and operated it on five flight pairs between the Dominican Republic and Buenos Aires . The Boeing 757 was parked in Puerto Plata after the rental ended.

Due to a defective hydraulic pump , the regularly used Boeing 767-200ER had to be swapped for the Boeing 757-200 parked on the apron on February 6, 1996 for the flight ALW301 from Puerto Plata via Berlin-Schönefeld to Frankfurt am Main . This machine had been unused in Puerto Plata for 20 days. It was later suspected that a blockage had formed in one of the pitot tubes during the standstill .

The speedometer in the cockpit needs the dynamic pressure that builds up in this probe for correct display ( pitot static system ). The small openings of the pitot tubes are usually covered if they are left on the ground for a long time, as they can be clogged, for example, by insects or dirt. This cover should have been omitted. However, such clogging can also be caused by insects during the rolling process, for example.

The Boeing 757-200 with the registration TC-GEN had been delivered brand new to Eastern Air Lines in the spring of 1985 . Birgenair took over the machine in 1993 and leased it to Caribbean Airways that same year .

Flight history

Pitot tube for measuring the speed of an Airbus A380
Memorial stone for the victims in Puerto Plata in Spanish
Memorial stone for the victims in Puerto Plata in German
Memorial stone at the Schönefeld village church
Memorial stone for the victims in the Frankfurt main cemetery

The Boeing 757 began its take-off roll on February 7, 1996 at 3:42 a.m. UTC (February 6, 1996 at 11:42 p.m. local time) . When the aircraft reached a speed of 80 knots (approx. 150  km / h ) and the co-pilot routinely called this out, the captain noticed that his speedometer was not working. The copilot's instrument, however, showed correct values. Although the so-called decision speed for an aborted take-off ( V 1 ) had not yet been reached, the crew decided to continue the take-off run.

Shortly after take off, the captain's speedometer also began to work. The pilots switched on the autopilot and selected the appropriate modes for the further climb . Due to the partially blocked pressure tube, however, the master's instrument indicated a significantly higher airspeed than actually existed. While the pilots were trying to find the cause of the captain's wrong display, the warning messages Rudder Ratio and Mach Speed ​​Trim appeared on the EICAS monitor in the cockpit . Both indicated problems with deviating speeds of the two air data computers on board. They were triggered by the incorrect measurement data from the data computer on the left, which also supplied the captain's airspeed indicator on the left. However, this was not known to the pilots. Birgenair used the original documentation from the manufacturer Boeing as the manual for the aircraft . Although there had already been various incidents in the past and some airlines (including United and Delta ) had subsequently changed their own, internal manuals, the wording in the Boeing manual did not name a serious problem as the cause of this error message.

While the machine was still climbing, a speed of 353 knots (approx. 650 km / h) was indicated on the master's display at an altitude of 6700 feet (approx. 2000  m ). The autopilot fed with this data and the automatic thrust control system now took measures to correct the supposedly excessive speed. The engines were throttled and the machine increased its angle of attack . In fact, the speed at that time was only 199 knots (approx. 370 km / h). This speed was shown on the display of the copilot (right). The captain's instrument triggered a high-speed warning ( overspeed warning ), which warned of a supposedly excessive speed. If an aircraft flies too fast, there is a risk that essential parts of the structure will be damaged or even tear off. Ten seconds later which occurred stick shaker , a vibrating the steering column , which the pilot of an impending stall ( stall to warn).

The pilots were irritated by the conflicting warnings ( overspeed and stick shaker ) within just ten seconds, especially since each warning in itself requires immediate "remedial action" in the opposite direction. In the event of an overspeed , the speed must be reduced, which is aided by raising the aircraft's nose and throttling the engines, whereas the stall warning requires that the nose be lowered and the engine power increased. According to the recordings on the voice recorder and the flight data recorder, the master identified the overspeed warning as a false warning and tried to prevent the impending stall. However, counteracting his interception maneuvers, the autopilot switched itself back into action and increased the critical angle of attack again by automatically adjusting the elevator fin . A few seconds later, the Boeing's left engine stalled (engine stall). The machine then rolled upside down over the left wing and hit the surface of the sea at 03:47:15 UTC.

All 176 passengers and 13 crew members were killed in the accident.

Accident investigation and final report

The crash was investigated by the Dominican Republic's civil aviation authority , Dirección General de Aeronáutica Civil. A further complicating factor was that the chief investigator in charge, Major Emanuel Souffront, had only a rudimentary knowledge of English and was primarily dependent on the support of colleagues from the US investigative authority, the NTSB . Some serious mistakes were made during the investigation. For example, the voice recorder transcript in the United States was translated from Turkish (the crew spoke Turkish) into English. Some translation errors were made. The English version was then translated into Spanish (national language in the Dominican Republic). Various statements were incorrectly attributed to the captain , even though they were from the first officer .

After several delays in drafting the investigation report, the Commission came to the following conclusion:

“The probable cause of the accident was the inability of the flight crew to recognize the activation of the stick shaker as an immediate warning of the transition to the excessive flight condition, and the inability to carry out the appropriate procedures to remedy this flight condition. Before the warning from the Stick Shaker, an incorrect display of the increase in airspeed and the warning that the maximum speed was exceeded had confused the crew. "

Criticism of dealing with relatives

With the support of the NTSB, a great deal of effort was made to recover the wreckage, in particular the cockpit voice recorder. Some of the rubble, located at a depth of over 2000 meters, was brought to the surface with the help of diving robots. They deliberately limited themselves to the wreckage and therefore only accidentally transported the victims' personal belongings and their remains from the depths. Two years after the disaster, even body parts were discovered on a rubbish dump in Puerto Plata among the wreckage, next to rotten travel bags.

The media catastrophe

The accident was taken up in the Canadian television series Mayday - Alarm im Cockpit in the episode False Alarm (season 5, episode 8). In simulated scenes, animations and interviews with investigators, reports were made about the preparations, the process and the background of the flight.

Similar events

literature

  • Expert opinion for the public prosecutor's office in Frankfurt am Main, file number 58 UJs 30369/96 from December 1998
  • Tim van Beveren : They always come down. The hidden risks of air travel. 6th edition. Campus, Frankfurt am Main 2000, ISBN 3-593-35688-0 , p. 258.
  • Jan U. Hagen: Fatal errors - Or why organizations need error management . 2nd, corrected edition. Springer Gabler , Berlin / Heidelberg 2017, ISBN 978-3-662-55484-5 , section flight ALW 301: Chaos and Stille , p. 27–41 ( limited preview in Google Book search).

Web links

Individual evidence

  1. ↑ a b c d e Die Zeit, online archive, volume 1996, issue 8 of February 16, 1996, page 5 , accessed on July 30, 2017
  2. ↑ JP airline-fleets international, Edition 1996/97
  3. ↑ independent.co.uk - Crash plane may not have been serviced (English) February 10, 1996
  4. ↑ Welt.DE: The Birgenair accident; The end came like lightning
  5. ↑ airfleets.net - Entry on the Boeing 757-200 with the registration number TC-GEN (English) accessed on June 1, 2011
  6. ^ BFU reconstruction of Birgenair flight 301 (with German commentator) accessed on July 11, 2015
  7. ↑ Alexander Missal: The legend of the low-cost airline. In: Berliner Zeitung . September 30, 1999, accessed June 10, 2015 .
  8. ^ Van Beveren, Tim and Hubacher, Simon: Flight Swissair 111 - The Halifax catastrophe and its consequences , WERD Verlag Zürich 2000

Coordinates: 19 ° 53 ′ 45 "  N , 70 ° 22 ′ 47"  W.