Lauda Air Flight 004

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Lauda Air Flight 004
178am - Lauda Air Boeing 767-3Z9ER, OE-LAE @ ZRH, 06/29/2002 - Flickr - Aero Icarus.jpg

An identical Boeing 767-300 from Lauda Air
Accident summary
Accident type Loss of control after deploying the thrust reverser in flight
place Phu Toey, Suphan Buri , Thailand
date May 26, 1991
Fatalities 223
Survivors 0
Injured 0
Aircraft
Aircraft type Boeing 767-300ER
operator Lauda Air
Mark OE-LAV
Surname Mozart
Passengers 213
crew 10
Lists of aviation accidents

The Lauda Air flight 004 was a scheduled flight of the Austrian airline Lauda Air from Hong Kong via Bangkok to Vienna , on which the Boeing 767-300ER in use crashed in western Thailand on May 26, 1991 at 11:17 p.m. local time after it crashed during the Climb had unexpectedly activated the thrust reverser on an engine itself. All 223 people on board were killed. It is the worst accident in Austrian aviation history .

plane

The aircraft involved in the accident was a Boeing 767-300ER with the registration OE-LAV and the name "Mozart". It was delivered new to Lauda Air on October 16, 1989 and has been continuously operated by it since then. So she was only about one and a half years old when the accident happened.

course

The plane took off on May 26, 1991 at 11:02 p.m. local time at Don Mueang Airport , where it had made a stopover on the way from Hong Kong to Vienna. There were 213 passengers on board, mainly Austrians, Germans, Swiss, French and Hong Kong Chinese, as well as ten crew members. The captain was Thomas John Welch (48 years old) with 11700 flight hours of professional experience, copilot was Josef Thurner (41 years old) with 6500 flight hours.

5 minutes and 45 seconds after take-off, Thurner noticed a visual warning that indicated a possible imminent activation of the thrust reverser (it was a control light labeled “REV ISLN”, a similar display on the EICAS screens, or both). Welch and Thurner discussed this ad for 4 minutes and 30 seconds, while Thurner also read in the manual how to react to this ad. However, since it was noted there that no intervention was necessary (since the thrust reverser is only used during a landing - and this was not the case) and the display went out automatically, the pilots paid no further attention to the display.

However, 15 minutes after take-off, the thrust reverser on the left engine of the twin-engine engine opened. Although it was switched to idle immediately, the sudden one-sided loss of thrust and other aerodynamic effects led to the stall . From a height of 24,700 feet, about 7,500 meters, the Boeing 767 crashed 5.6 kilometers from the Thai town of Phu Toey. In a dive, the tail unit and wings broke off within seconds, and the fuselage presumably broke apart immediately afterwards (into many pieces).

All 223 inmates were killed. Among the victims were the economist Clemens August Andreae and his colleague Michael Lehmann, the UN drug commissioner Donald McIntosh, Pairat Decharin, the governor of Chiang Mai province and his wife as well as Princess Chao Phongkaeo Na Lamphun, the daughter of Chao Ratchabut (Wongtawan Na Chiang May).

causes

It was found that the thrust reverser of the left engine was actually extended at a speed of Mach 0.78. According to the manual, unintentional activation of the thrust reverser in flight was considered possible with certain chain of errors . Boeing and the US aviation authority ( FAA ) had, however, considered the measures planned for this case and their training on the flight simulator to be sufficient to maintain control of the aircraft. The later tests in the wind tunnel and on the flight simulator based on the flight data , however, led to the conclusion that the pilots had got into such an unexpectedly difficult situation that, despite their skills and their level of training, they did not perform the required control maneuvers in time (within 4 to 6 seconds ) could execute. The earlier simulations at Boeing were based on a speed of Mach 0.3 when the thrust reversal began.

However, the cause of the unwanted onset of the thrust reverser could not be clearly determined. Was taken into consideration particularly that a hydraulic shut-off valve ( Hydraulic Isolation Valve , HIV ), which should prevent the deployment of the thrust reverser doors could have been been damaged opened due to faulty wiring, or, (short circuit to a thrust reverser controlled between cables solenoid ). In fact, the maintenance staff at Lauda-Air had been busy for months with warning messages about the thrust reverser of the machine's left engine, had unsuccessfully replaced hydraulic elements and a monitor module ( Propulsion Interface Monitor Unit ) and wanted to next check the cable between the cockpit and the thrust reverser system. Similar problems with the cabling were known from other Boeing 767s . However, it was not possible to determine the actual occurrence of an electrical fault during the accident flight, not least due to the high degree of destruction of the wreckage.

During the investigation, a design flaw in the hydraulic control of the thrust reverser was uncovered, which could unintentionally trigger the thrust reverser. On 15 August 1991, the FAA therefore temporarily prohibited the use of thrust reversers on all Boeing 767. The second of the thrust reverser control participated valve, a control valve ( Directional Control Valve , DCV ) dipped Although nine months on after the accident, but was apparently of unknowns in the meantime partially dismantled and reassembled changed.

The investigation of the accident was made more difficult, among other things, by the fact that the flight data recorder had become unusable due to the effects of fire on the ground (the Thai commission of inquiry recommended better heat protection). The reconstruction of what happened is essentially based on the evaluation of the voice recorder , in addition to the conversation, wind and shaking noises, various alarm tones and finally a bang can be heard (according to another source, "infernal screeching of bursting metal").

Lauda Air flight 004 is the only fatal crash of a Boeing 767 in which non-criminal acts ( pilot suicide , aircraft hijacking ) or a pure pilot error could be identified as the cause of the accident.

Effects

Memorial complex near Suphan Buri

The Boeing flight simulator for the Boeing 767 was reprogrammed to represent the situation at higher speeds - but this was more for investigation purposes. Since the assumption that the aircraft would remain controllable even when the thrust reversal began in flight had to be abandoned, further measures aimed at effectively excluding the possibility of this situation.

Boeing changed the thrust reverser system for the Boeing 767 in six points. That included

  • Replacement of the magnetically by a cylindrical coil ( solenoid controlled) hydraulic shut-off valve ( Hydraulic Isolation Valve , HIV ) by a less vulnerable, which is controlled by a motor;
  • improved routing and insulation of the cable between the cockpit and the thrust reverser system on the engine.

All Boeing 767s with Pratt & Whitney PW4000 engines were primarily affected . The upgrade was completed in February 1992.

The same thrust reverser system was also installed on the Boeing 757 , 747 and 737 . The Boeing 757 constellation with Pratt & Whitney PW2000 engines was particularly similar . The shut-off valve was therefore also replaced on these.

Recommendations for checking the cabling were also made with regard to other aircraft from Boeing, Airbus and McDonnell Douglas . Machines with other engines from Pratt & Whitney , Rolls-Royce or General Electric were considered less endangered.

In the media

The accident is the subject of the second episode of the fourteenth season of the Canadian documentary series Mayday - Alarm im Cockpit under the titles Niki Lauda: Tragedy In The Air , Niki Lauda: Testing the Limits or, more precisely, Mayday S14E02 Niki Lauda: Testing the Limits , the 2014 was produced. N24 showed a German version of it in mid-2016 under the title Lauda Air 004: Crash in the jungle .

criticism

An opinion piece in "Austria's aviation magazine Austrian Wings " criticizes the episode of Mayday - Alarm in the cockpit ( see above ) as "poorly researched"; the owner of the airline, the racing driver Niki Lauda , had been given the opportunity to portray the accident in his own favor. His allegedly energetic endeavor to quickly clarify the causes stood in contrast to the fact that the company had long illegally withheld essential documents for the search for the cause.

Austrian Wings and a Swiss Internet portal also point to an Austrian expert report that is said to be considerably more careful than the report of the Thai commission of inquiry and, in contrast to this, clearly indicated Lauda Air's responsibility for the accident. In view of the automatic warnings about thrust reversal of the left engine that have been registered for a long time, the machine should not have started again. The company ignored these concerns because it was one of only two long-haul vacation travel machines available at the time; The safety of the inmates was therefore put in the background compared to the economic view.

Similar cases

Web links

Databases
Reports
Criticism or personally colored

References and comments

  1. ↑ airfleets.net - Boeing 767 - MSN 24628 - OE-LAV (English) accessed on September 15, 2013
  2. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.1. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  3. ↑ a b Transcript of the cockpit sound recording in the Aviation Safety Network .
  4. ↑ Flight accident data and report of the flight accident with the number 35 from 1991 in the Accident Database of Plane Crash Info
  5. ↑ a b c d Aircraft accident data and report in the Aviation Safety Network (English)
  6. ↑ The report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. discusses in Section 2.3 the aerodynamic effect of the thrust reversal and the subsequent shutdown of the engine. Section 2.2 ( Memento of the original from May 27, 2011 on WebCite ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. gives traces on the wreckage, which confirm corresponding assumptions. - According to Section 2.3, the left engine required 6 to 8 seconds to “coast down” (after being switched off). The necessary measures should have been carried out during this period. After that, the fate of the inmates was sealed. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  7. ↑ The report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. reconstructs in section 2.2 the sequence of structural damage and the loads that preceded it. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  8. ↑ a b "UN drug man 'not Thai bomb target'." The Independent . Thursday 30 May 1991. Available on LexisNexis .
  9. ^ Traynor, Irian, Nick Cumming-Bruce, and Steve Vines. “Crash teams investigate plane blast.” The Independent . May 28, 1991. Available on LexisNexis .
  10. ↑ คอลัมน์: ผ่ อ ... เมือง เหนือ: อดีต ผู้ ว่า ฯ ไพ รัตน์ เดชะ ริน ท ร์ . Naew Na. February 17, 2009. Archived from the original on February 15, 2013. Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Retrieved February 16, 2013. () “ข้อมูล นี้ ผิด ผู้ ที่ สร้าง กำแพง เมือง และ ประตู เมือง ขึ้น มา ใหม่ คือ คุณ ชัย ยา พูน ศิริ ศิริ วงศ์ คน ที่นั่ง เครื่องบิน เลา ด้า แอร์ ไลน์ ไลน์ ตก ตาย หมู่ คือ คุณ ไพ รัตน์ เดชะ ริน ท ร์ พร้อม คุณ นาย ก็ ต้อง ให้ ความ เป็น ธรรม กับ ผู้ ตาย และ คณะ ที่ ตาย พร้อม กับ ผู้ ว่า ฯ ไพ รัตน์ เป็น คุณหญิง สอง ท่าน ท่าน คือ หม่อม ศรีนวล ณ เชียงใหม่ ชายา เจ้า ราชบุตร (วง ค์ ตะวัน) ณ เชียงใหม่ สาย ตรง พระเจ้า กา วิ พง และ เจ้า เจ้า เจ้า เจ้า เจ้า ษ์ แก้ว ณ ลำพูน ลูกสาว เจ้า ราชบุตร นอก นั้น อีก 10 กว่า คน เป็น คหบดี ชื่อ ดัง ของ เชียงใหม่ ทั้งสิ้น ทุก คน ที่ เสีย ชีวิต ล้วน ล้วน แต่ เป็น นัก สังคมสงเคราะห์ ช่วยเหลือ ประชาชน ประชาชน ที่ ยากไร้ มา นาน ไม่ ต่ำ กว่า คนละ 20 ขึ้น ไป “ @1@ 2Template: Webachiv / IABot / www.ryt9.com
  11. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.4. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  12. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Attachments. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  13. ↑ a b Report of the Thai Commission of Inquiry ( Memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.3. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  14. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.5. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  15. ↑ a b c Polly Lane, Byron Acohido: Boeing Tells 757 Owners To Replace Part - Faulty Thrust-Reverser Valve Blamed In 767 Accident That Killed 223. In: The Seattle Times . September 9, 1991, accessed August 7, 2009 .
  16. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 1.6 @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  17. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.6. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  18. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.5.3. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  19. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 1.17. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  20. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.5.4. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  21. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 1.16 @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  22. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.8. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  23. ↑ Report of the Thai commission of inquiry ( memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 1.18. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  24. ↑ a b The death flight of the "Mozart". In: Austrian Wings - Austria's aviation magazine. January 17, 2015, accessed on August 3, 2016 (detailed photo report, first published on May 26, 2011).
  25. ↑ a b Report of the Thai Commission of Inquiry ( Memento of the original from May 27, 2011 on WebCite ) Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. Section 2.7. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de
  26. ^ A b Lauda Air 004 - Crash in the jungle. In: prisma.de . Archived from the original on August 3, 2016 ; Retrieved August 3, 2016 .
  27. ↑ Lauda Air 004: Crash in the jungle. In: N24.de . Archived from the original on May 14, 2016 ; Retrieved August 3, 2016 .
  28. ↑ Lauda Air 004 - Crash in the jungle. In: save.TV . Archived from the original on August 18, 2016 ; Retrieved August 3, 2016 .
  29. ↑ a b E. Szeles: Lauda Air crash in 1991: still unanswered too many questions. In: Austrian Wings - Austria's aviation magazine. January 17, 2015, accessed on August 3, 2016 ( opinion piece , criticism of the episode of Mayday - Alarm im Cockpit [“inadequate research”] and of Lauda Air).
  30. ^ A b Daniel Wachter: Lauda Air flight 004: How negligence led to misfortune. In: caboruivo.ch. November 1, 2013, accessed on August 3, 2016 (criticism of the investigation report and Lauda Air).
  31. ↑ Lauda Air B767 Accident Report. (No longer available online.) Ministry of Transport and Communications Thailand; Lauda Air Aviation Corporation Boeing 767-300 $% Registration OE-LaV, Dan Chang District, Suphan Buri Province, Thailand, May 26, 1991, archived from the original on May 27, 2011 ; Retrieved on August 16, 2016 (English): "CAB-approved July 21, 1993" Info: The archive link was automatically inserted and not yet checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2Template: Webachiv / IABot / www.rvs.uni-bielefeld.de

Coordinates: 14 ° 57 ′ 0 ″  N , 99 ° 27 ′ 0 ″  E