# How often has an airliner failed at cruising altitude? **URL:** \ **Category:** Factual Questions\ **Created:** [March 8, 2014, 8:58pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218 "2014-03-08T20:58:18Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [March 8, 2014, 8:58pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/1 "2014-03-08T20:58:18Z")
Has anything disastrous ever happened to a commercial airliner at cruising altitude that was _not_ caused by a deliberate human act? I can’t think of very many at all. I remember reading about a case in which a large portion of the top of a passenger liner’s fuselage tore off in mid-flight, basically giving the plane a sunroof, but the pilot simply reduced altitude to compensate and the aircraft landed safely. I don’t think anybody was killed or even seriously injured, but I could be wrong. There must have been at least a few other cases of something bad happening to a plane at cruise elevation, but for all intents and purposes, large passenger liners never seem to just fall out of the sky. How often does this happen, and what are some notable examples? ---
**Author:** ![Martin\_Hyde](https://avatars.discourse-cdn.com/v4/letter/m/47e85d/32.png) [@Martin\_Hyde](https://boards.straightdope.com/u/Martin_Hyde)\ **Post date:** [March 8, 2014, 9:02pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/2 "2014-03-08T21:02:43Z")
There’s a few I’m aware of off the top of my head: [Alaska Airlines Flight 261](http://en.wikipedia.org/wiki/Alaska_Airlines_Flight_261) first noticed problems that ultimately resulted in the loss of the aircraft and all onboard while at cruising altitude. There’s another one I couldn’t find the name of on google, but I believe it was from the late 80s and a piece of one of the jet engines actually ripped off mid flight and hit a key weak point of the plane where all three redundant hydraulic lines met, taking out all hydraulics on the plane. The two pilots (and an instructor for that model aircraft who was by coincidence on the flight) were able to land it by using differential speeds for the plane’s engines to bring it down but were not able to extend the landing gear and the crash landing killed a good number (but not all) of the passengers. The [Gimli Glider](http://en.wikipedia.org/wiki/Gimli_Glider) ran out of fuel at 41,000 feet but was safely landed. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [March 8, 2014, 9:07pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/3 "2014-03-08T21:07:38Z")
> [@Martin\_Hyde](#): > > There’s another one I couldn’t find the name of on google, but I believe it was from the late 80s and a piece of one of the jet engines actually ripped off mid flight and hit a key weak point of the plane where all three redundant hydraulic lines met, taking out all hydraulics on the plane. The two pilots (and an instructor for that model aircraft who was by coincidence on the flight) were able to land it by using differential speeds for the plane’s engines to bring it down but were not able to extend the landing gear and the crash landing killed a good number (but not all) of the passengers. That was United Flight 232 which crashed at Sioux City, Iowa. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [March 8, 2014, 9:14pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/4 "2014-03-08T21:14:09Z")
British Airways flight 9 (aka Speedbird 9) lost all four engines due to volcanic ash. They were eventually able to restart the engines but couldn’t keep them all running. They managed to land the plane safely. > **[British Airways Flight 009](https://en.wikipedia.org/wiki/British_Airways_Flight_9)** > > British Airways Flight 009, sometimes referred to by its callsign Speedbird 9 or as the Jakarta incident, was a scheduled British Airways flight from London Heathrow to Auckland, with stops in Bombay, Kuala Lumpur, Perth, and Melbourne. > On 24 June 1982, the route was flown by the City of Edinburgh, a Boeing 747-200 registered as G-BDXH. The aircraft flew into a cloud of volcanic ash thrown up by the eruption of Mount Galunggung around 110 miles (180 km) south-east of Jakarta, Indonesia, resul... This incident was featured in one episode of the show Mayday (Air Crash Investigations). In Aloha Flight 243 (the incident I believe the OP is talking about where the top of the plane’s fuselage came off) one flight attendant was sucked out of the plane during the decompression/failure and plummeted to her death. There were no other fatalities. ETA: There was a similar failure to the Sioux City crash that occurred in Japan, but that plane was unable to reach the airport and crashed on a high mountain top. ---
**Author:** ![engineer\_comp\_geek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/engineer_comp_geek/32/504_2.png) [@engineer\_comp\_geek](https://boards.straightdope.com/u/engineer_comp_geek)\ **Post date:** [March 8, 2014, 9:22pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/5 "2014-03-08T21:22:26Z")
The De Havilland Comet is also probably worthy of mention. It was the first commercial jetliner, and metal fatigue wasn’t as well understood back then. They had several break up in mid-flight, and the investigation of those incidents led to a lot of the modern methods for air crash investigations. Pressurization tests eventually found that the fuselage would develop stress fractures and would fail at altitude. The plane was eventually redesigned with smaller windows and other changes, but its reputation never recovered. ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [March 8, 2014, 9:28pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/6 "2014-03-08T21:28:09Z")
[TWA Flight 800](https://en.wikipedia.org/wiki/TWA_Flight_800). Probable cause was the center fuel tank exploded. Only 12 minutes after takeoff, so not sure if that would be close enough to cruising altitude. ---
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [March 8, 2014, 10:07pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/7 "2014-03-08T22:07:44Z")
I would count that, yes. I’m looking for anything that didn’t happen while taxiing, or immediately after takeoff or immediately before landing. ---
**Author:** ![dofe](https://avatars.discourse-cdn.com/v4/letter/d/7ba0ec/32.png) [@dofe](https://boards.straightdope.com/u/dofe)\ **Post date:** [March 8, 2014, 10:43pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/8 "2014-03-08T22:43:46Z")
If we take the OP’s definition liberally to mean if a flight cruising at altitude has ended in disaster, then [Air France 447](http://en.wikipedia.org/wiki/Air_France_Flight_447) would also qualify. Granted, pilot error was at play, but this was a flight that was basically cruising without much significant problems (except the faulty pitot tubes) one minute, crash into the ocean the next. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [March 8, 2014, 10:45pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/9 "2014-03-08T22:45:30Z")
[Air France Flight 447](http://en.wikipedia.org/wiki/Air_France_Flight_447) crashed in the middle of the Atlantic. > [@](#): > > the aircraft crashed after temporary inconsistencies between the airspeed measurements—likely due to the aircraft’s pitot tubes being obstructed by ice crystals—caused the autopilot to disconnect, after which the crew reacted incorrectly and ultimately led the aircraft to an aerodynamic stall from which they did not recover. ETA: ninjaed by two darn minutes _grumble_ ---
**Author:** ![dofe](https://avatars.discourse-cdn.com/v4/letter/d/7ba0ec/32.png) [@dofe](https://boards.straightdope.com/u/dofe)\ **Post date:** [March 8, 2014, 10:47pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/10 "2014-03-08T22:47:25Z")
> [@Washoe](#): > > Has anything disastrous ever happened to a commercial airliner at cruising altitude that was _not_ caused by a deliberate human act? I can’t think of very many at all. I remember reading about a case in which a large portion of the top of a passenger liner’s fuselage tore off in mid-flight, basically giving the plane a sunroof, but the pilot simply reduced altitude to compensate and the aircraft landed safely. I don’t think anybody was killed or even seriously injured, but I could be wrong. There must have been at least a few other cases of something bad happening to a plane at cruise elevation, but for all intents and purposes, large passenger liners never seem to just fall out of the sky. How often does this happen, and what are some notable examples? There was actually one fatality in the incident you’re thinking of ([Aloha Airlines 243](http://en.wikipedia.org/wiki/Aloha_Airlines_Flight_243)) when the flight attendant was sucked out of the open section of the fuselage. ---
**Author:** ![Mdcastle](https://avatars.discourse-cdn.com/v4/letter/m/958977/32.png) [@Mdcastle](https://boards.straightdope.com/u/Mdcastle)\ **Post date:** [March 8, 2014, 11:08pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/11 "2014-03-08T23:08:00Z")
Japan Airlines 123 lost the vertical stabilizer and all hydraulic systems due to an explosive decompression due to an improper repair. They amazingly managed to more or less control it for a time but unlike the United 232 they lost control and it fell out of they sky before they could line it up with a runway. Lauda Air 004 the crew lost control due to an uncommanded deployment of a thrust reverser in mid flight. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [March 8, 2014, 11:18pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/12 "2014-03-08T23:18:51Z")
Going in the wayback machine we have P[an-Am flight 6.](http://en.wikipedia.org/wiki/Pan_Am_Flight_6) ---
**Author:** ![suranyi](https://avatars.discourse-cdn.com/v4/letter/s/e36b37/32.png) [@suranyi](https://boards.straightdope.com/u/suranyi)\ **Post date:** [March 9, 2014, 12:00am UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/13 "2014-03-09T00:00:22Z")
It’s certainly not the most common situation for an airline accident, but it’s happened plenty of times without being caused by a deliberate human act. ---
**Author:** ![Tapioca\_Dextrin](https://avatars.discourse-cdn.com/v4/letter/t/3d9bf3/32.png) [@Tapioca\_Dextrin](https://boards.straightdope.com/u/Tapioca_Dextrin)\ **Post date:** [March 9, 2014, 12:10am UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/14 "2014-03-09T00:10:57Z")
> [@Martin\_Hyde](#): > > There’s a few I’m aware of off the top of my head: > > [Alaska Airlines Flight 261](http://en.wikipedia.org/wiki/Alaska_Airlines_Flight_261) first noticed problems that ultimately resulted in the loss of the aircraft and all onboard while at cruising altitude. The same failure caused [Aeroflot FLight 8641](http://en.wikipedia.org/wiki/Aeroflot_Flight_8641) to crash ---
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [March 9, 2014, 12:39am UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/15 "2014-03-09T00:39:29Z")
> [@Tapioca\_Dextrin](#): > > The same failure caused [Aeroflot FLight 8641](http://en.wikipedia.org/wiki/Aeroflot_Flight_8641) to crash Aeroflot doesn’t count. There was a joke going around during the Gulf War: Q. What’s the difference between Aeroflot and an Iraqi Scud? A: Aeroflot has killed more people. ---
**Author:** ![Desert\_Nomad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/desert_nomad/32/177_2.png) [@Desert\_Nomad](https://boards.straightdope.com/u/Desert_Nomad)\ **Post date:** [March 9, 2014, 1:35am UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/16 "2014-03-09T01:35:45Z")
A China Airlines 747 broke apart at altitude due to metal fatigue on a poor repair job from a tail strike 22 years earlier. > **[China Airlines Flight 611](https://en.wikipedia.org/wiki/China_Airlines_Flight_611)** > > China Airlines Flight 611 (CI611/CAL611) was a regularly scheduled passenger flight from Chiang Kai-shek International Airport (now Taoyuan International Airport) in Taiwan to Hong Kong International Airport in Hong Kong. On 25 May 2002, the Boeing 747-209B operating the route disintegrated in midair and crashed into the Taiwan Strait, 23 nautical miles (26 mi; 43 km) northeast of the Penghu Islands, 20 minutes after takeoff, killing all 225 people on board. The in-flight break-up was caused b... ---
**Author:** ![txtumbleweed](https://avatars.discourse-cdn.com/v4/letter/t/278dde/32.png) [@txtumbleweed](https://boards.straightdope.com/u/txtumbleweed)\ **Post date:** [March 9, 2014, 4:57am UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/17 "2014-03-09T04:57:13Z")
In the late 1950’s, the[Lockheed L-188 Electra](http://en.wikipedia.org/wiki/Lockheed_L-188_Electra), a four engine turboprop, suffered from “whirl mode flutter.” Because of a poor engine mount design, the outboard propellers could induce oscillation and flutter through the engines to the wings. This would cause the wing to depart the aircraft while at cruise. There are also the ever popular pressurization system failures, be they mechanical or human, that result in “Flying Dutchman” aircraft cruising along with dead or otherwise incapacitated crew and passengers until they run out of fuel and crash. The crash of the [Learjet carrying golfer Payne Stewart](http://en.wikipedia.org/wiki/1999_South_Dakota_Learjet_crash) was perhaps the best known at the time as the aircraft flew for some 4 hours before fuel exhaustion, but there are [several similar incidents, including a 737.](http://en.wikipedia.org/wiki/1999_South_Dakota_Learjet_crash#Similar_incidents) ---
**Author:** ![bob\_2](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bob_2/32/3341_2.png) [@bob\_2](https://boards.straightdope.com/u/bob_2)\ **Post date:** [March 9, 2014, 11:50am UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/18 "2014-03-09T11:50:33Z")
> [@engineer\_comp\_geek](#): > > The De Havilland Comet is also probably worthy of mention. It was the first commercial jetliner, and metal fatigue wasn’t as well understood back then. They had several break up in mid-flight, and the investigation of those incidents led to a lot of the modern methods for air crash investigations. Pressurization tests eventually found that the fuselage would develop stress fractures and would fail at altitude. > > The plane was eventually redesigned with smaller windows and other changes, but its reputation never recovered. The important re-design was that the metal failed at the corners of the square windows. The change made them round, but as you say, it was the end of De Havilland. Boeing bought the technology and leapfrogged into the lead with the 707. ---
**Author:** ![Wendell\_Wagner](https://avatars.discourse-cdn.com/v4/letter/w/8491ac/32.png) [@Wendell\_Wagner](https://boards.straightdope.com/u/Wendell_Wagner)\ **Post date:** [March 9, 2014, 12:05pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/19 "2014-03-09T12:05:29Z")
From a current news story about the missing Air Malaysia plane: \> Just 9 percent of fatal accidents happen when a plane is at cruising altitude, \> according to a statistical summary of commercial jet accidents done by Boeing. [http://www.aol.com/article/2014/03/09/air-force-chief-malaysia-jet-may-have-turned-back/20845957/?icid=maing-grid10|htmlws-main-nb|dl1|sec1\_lnk3%26pLid%3D452009](http://www.aol.com/article/2014/03/09/air-force-chief-malaysia-jet-may-have-turned-back/20845957/?icid=maing-grid10%7Chtmlws-main-nb%7Cdl1%7Csec1_lnk3%26pLid%3D452009) ---
**Author:** ![LSLGuy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lslguy/32/5813_2.png) [@LSLGuy](https://boards.straightdope.com/u/LSLGuy)\ **Post date:** [March 9, 2014, 1:57pm UTC](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218/20 "2014-03-09T13:57:10Z")
Airline pilot here … The folks above have covered most of the well known climb / cruise / descent mishaps over the years. Except for the midair collisions. There have been a few. Jets have crashed after engines fall off, or cargo doors open, or a big hunk of fuselage structure fails. They’ve crashed from failure of hydraulics, engines, pressurization, electrics, or instrumentation. They’ve crashed because they were flown into severe weather, volcanic ash, the sea, or solid mountains. Overall aircraft are more reliable every year. As are the crews and the ground support ATC, operating procedures, international standards, etc. OTOH, at one time almost all airline aviation was first world people operating in first world conditions. Nowadays a lot bigger percentage of the industry is from the rest of the world. The safety record of second tier operators today compares very favorably with the relatively poor safety record of first tier folks in the 1960s. But there is still a significant safety difference between the various “layers” of today’s airline industry. Bottom line: The OP’s apparent assumption that sabotage or on-board violence is the most likely cause is fundamentally faulty. Is sabotage/violence on the list of things to consider? Yes. Should it be the default assumption? No. [Next page](https://boards.straightdope.com/t/how-often-has-an-airliner-failed-at-cruising-altitude/683218.md?page=2)