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Gimli Glider
- 464192002d7fe1c 10y agoI can highly recommend the Mayday (Air Crash Investigation/Air Emergency/Air Disasters/whatever its called this week) episode that deals with this, https://youtu.be/Bct1mWUp8to https://youtu.be/Bct1mWUp8to, and the show in general.
- JamilD 10y agoI've watched this show since I was a kid — I think it's one of the reasons I went into engineering. It makes you think about the different reasons that air accidents happen, and illustrates that there's almost never a single attributable cause. What seems initially just like pilot error may also be due also to workplace conditions, bad training, a lack of communication, or fatigue — a chain of events and circumstances that culminates in the accident. It's fascinating.
- sumitgt 10y agoSame here. Watched this show with my dad (who is an Engineer). Ended up becoming an Engineer myself. I credit this show and MythBusters for pushing me into Science and Tech.
- 464192002d7fe1c 10y agoAs much as I watch and enjoy Mythbusters, I rarely come out of watching that show feeling like I really learned something new or am particularly more knowledgable on a subject. Mythbusters is fun and entertaining, Mayday is educational and entertaining.
- computator 10y ago> Mythbusters, I rarely come out of watching that show feeling like I really learned something The earliest episodes were more scientific and educational. They spent quite a bit of time explaining how they were going to construct something and then showing how they actually built it. It became pure entertainment--devoted especially to blowing things up--once the show achieved success. Another example of a show descending to the lowest common denominator: The first years of "Biography" on the A&E Network had stories about explorers, scientists, and world leaders--Michelangelo, Henry Ford, Julius Caesar, Marconi, Marco Polo--but now it's nothing but celebrities.
- 464192002d7fe1c 10y agoAgreed, the earlier episodes were better, but I still don't think they were great. The last season of the show (when it was just Jayme/Adam) was actually fantastic though. I've never actually seen any of the biography series (I just associate it with shallow celebrity profiles) I'll have to dig up the earlier episodes, thanks!
- protomyth 10y agoI do wonder how the show by the assistants will do on Netflix. I too cannot say I'm a fan of the original. Their snowplow episode hit way too close to home and came to entirely the wrong (and a dangerous) conclusion. Testing anything having to do with snow, ice, and curved road surface on a flat, dry runway is doomed to failure with horrific reporting of results. [I get it, no criticism of Myth Busters allowed]
- tajen 10y agoThe problem I have with Mayday is that there is only about 10min of footage repeated over an hour (45min + ad breaks). Most of the time is filled with summaries (after ad breaks), suspense (obtained by temporarily truncating explanations), questions and hyperboles. Also, it's very US-centric, as if no citizen of other nation were as competent as US ones. Multiplied explanations for the same fact feel like they think I'm 5, and the repetion feels like brainwashing. I come out of watching feeling like it would fit in 2 minutes, even though the original non-repeated content is probaboy more than that. I'd love if they could do a cross-season episodes: "It has been found that (spoiler alert) flight XYZ failed because of reasons A, B and C. The cause A happens over 3 accidents, let's study the 2 other causes. C happened when landing the space shuttle too and in the building collapse in another country. (etc)"
- protomyth 10y agoThat's pretty common and makes the show way cheaper to make. Discovery did a what if dragons were real "documentary" which probably had a whole 10 minutes of footage stretched in an hour. The constant repeats after every commercial were hideous.
- geon 10y agohttps://youtu.be/7MFtl2XXnUc https://youtu.be/7MFtl2XXnUc
- Gracana 10y agoThe important thing about Mythbusters is that they have an idea and they test it. Their methods aren't always the best (or even good at all), but they take the right approach: they get an idea, and they try to verify or invalidate it. Pretty much anyone who watches an episode can think of a way to improve the experiment, and I think it's good that the show provokes that response.
- kozak 10y agoI see the value of Mythbusters in being able to calibrate your perception to those aspects of real-life physics that you don't typically see in normal life. How does it look like when there is a gas explosion in a house? A hand grenade blow? A bicycle trying to be ridden on the bottom of a pool? Thanks to Mythbusters, I really do understand these things pretty well now. A more recent mini-show that gives you a similar discovery experience (albeit at a smaller scale) is the MrGear channel at YouTube: https://www.youtube.com/channel/UCo6DJdltbIub80bLiyJRv3w https://www.youtube.com/channel/UCo6DJdltbIub80bLiyJRv3w
- sumitgt 10y agoMaybe you won't learn a lot from MythBusters, but it went a long way to imbibe a maker spirit in you. That I think is crucial to becoming a better engineer.
- 464192002d7fe1c 10y agoI think the very cool thing with this show is that it really illustrates how crashes are virtually never the byproduct of a single failure. The most fascinating ones to me are the ones where there is a completely survivable mechanical failure, combined with human failures that lead to crashes. The one that comes to mind there is the plane where the engine was leaking fuel, so the tanks were not equal so the pilots engaged the cross-feed valve, causing BOTH tanks to drain leading to an out-of-fuel situation. If they hadn't done that, they could have easily made it to their ETOPS airport with minimal issues. Also, that show makes me sound smarter than I am. I've had conversations with pilots, who will ask if I'm a pilot. Its great fun for parties when you run into pilots (GA and commercial).
- sitharus 10y agoYou're thinking of https://en.m.wikipedia.org/wiki/Air_Transat_Flight_236 https://en.m.wikipedia.org/wiki/Air_Transat_Flight_236, another Canadian flight. In this case the pilots followed standard procedure for a fuel imbalance, which is the alert they got.
- 464192002d7fe1c 10y agoThe fuel imbalance check-sheet also points out to make sure that the fuel imbalance isn't the result of a leak, and they did (somewhat -- it was dark outside) try to check for a leak. They could also have looked at the rate of fuel consumption across both tanks to determine that the fuel consumption on the right tank was way higher than the engine could consume, but that was not SOP at the time (it is now, and the A330 [and probably other planes] now compute that information and alarm on it). Its all layers, planes, with minimal exception, really don't crash from a single failure.
- FabHK 10y ago> how crashes are virtually never the byproduct of a single failure There is the wonderfully named "Swiss Cheese model of accident causation" [1] elaborating on that. An accident happens when all the holes in the cheese line up... [1] https://en.wikipedia.org/wiki/Swiss_cheese_model https://en.wikipedia.org/wiki/Swiss_cheese_model
- goodcanadian 10y agoYes, I am always slightly annoyed by findings of pilot error. It is not that the finding is wrong, but the terminology leads the general public to blame the pilot when the reality is usually that the error was due to the pilot having misleading, incomplete, or just plain wrong information, or the controls behaving in a non-intuitive manner or whatever.
- 464192002d7fe1c 10y agoI suppose after watching this show, I now understand it better. But I now realize that pilot error is never just pilot error. Without some other failure or extraordinary circumstance, pilots have a damn hard time crashing a plane on their own.
- pavel_lishin 10y agoWith the sad exception of the Germanwings flight.
- waqf 10y agoAnd the EgyptAir flight and the SilkAir flight if you're going to count deliberate pilot actions. (https://en.wikipedia.org/wiki/Suicide_by_pilot#By_pilots_in_control_of_whole_flight https://en.wikipedia.org/wiki/Suicide_by_pilot#By_pilots_in_...) But Air France 447 is a recent example where it's really tempting to say that sheer pilot incompetence was the biggest factor: https://en.wikipedia.org/wiki/Air_France_Flight_447 https://en.wikipedia.org/wiki/Air_France_Flight_447
- hueving 10y agoYes, I think they were definitely incompetent in the AF case. It's fair to question if their incompetence is a result of poor training by AF, but not recognizing a stall very squarely falls into "incompetent" IMO.
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- kriro 10y agoYes it's usually a very interesting mixture of human factors and technical problems. Often in combination, e.g. some technical device not taking human factors into account and leading to usability issues. Quite often a disconnect between software developers and domain knowledge is the cause of mild to very serious issues. One anecdote of a serious aircraft problem due to a programming shortcut I remember from a conference roughly and very simplified translates to this pseudo code for something related to landing/takeoff: if wheels_rolling()==false: in_air=true The problem was of course...plane with wheels on the ground but not rolling due to ice (more like sliding and there was some sensor mishap that also). And well relying on the rotation of the wheels as a height indicator and many other things...
- 464192002d7fe1c 10y agoReplying to myself to point out that basically every single air incident that people are bringing up in this thread is also covered on this show. Its well worth a watch.
- bendeming 10y agoOutstanding program. Watching it will teach you a lot about flying. You'll become a more informed traveler and understand just how safe modern aviation is.
- qwertyuiop924 10y agoAh. I read about this in Uncle John's Bathroom Reader (which is an excellent set of books for anyone who is compulsively knowledgable, by the way) It's a fascinating case study in failure recovery in the worst possible scenerios, and how systems fail to begin with. ...Come to think of it, those are all subjects Cantrill likes to talk about. If you like playing Bryan Cantrill Bingo, I think this might make its way onto your scorecard soon...
- jasoncartwright 10y agoSemi-related story - https://en.wikipedia.org/wiki/British_Airways_Flight_9 https://en.wikipedia.org/wiki/British_Airways_Flight_9 "Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress"
- 464192002d7fe1c 10y agoHow delightfully British.
- techdragon 10y agoSo British I can't help but think of the Airline Pilots skit from "How to Irritate People" - https://en.m.wikipedia.org/wiki/How_to_Irritate_People https://en.m.wikipedia.org/wiki/How_to_Irritate_People
- pavel_lishin 10y agoWere the effects from volcanic eruptions not known at this time?
- toyg 10y agoAs the page says, they did not detect the cloud, because it was not clearly visible and onboard instruments dedicated to detecting ashes did not work with that particular dry type of ash.
- jbarham 10y agoEven better: https://en.wikipedia.org/wiki/Air_Transat_Flight_236 https://en.wikipedia.org/wiki/Air_Transat_Flight_236
- musha68k 10y agoYay, Canadian glider pilots! ;)
- Waterluvian 10y agoShould I be proud or ashamed? :)
- j1vms 10y agoYa, those Canadians glider pilots, always finding some way to make full use of their skills. ;)
- david-given 10y agoI remember seeing an entertainingly bad TV movie of a very similar incident. I think it was this one, not the Gimli incident. But we learnt about the Gimli Glider in my university computer risks course. It was a masterful piece of flying (and you'll note that most people who've tried to reproduce it in simulators fail). Sobering reading: https://en.wikipedia.org/wiki/List_of_airline_flights_that_required_gliding https://en.wikipedia.org/wiki/List_of_airline_flights_that_r... There's a lot of flights there with casualties (including one in 2005 where a pressurisation failure caused the crew to pass out; the autopilot flew the plane to Greece where it entered a holding pattern until it ran out of fuel; interceptors spotted a flight attendant trying to land the plane with portable air equipment, but he didn't make it. No survivors). Airliners don't really glide well.
- rpeden 10y agoMany airliners glide quite well - they can glide quite a bit further from a given altitude than can general aviation aircraft that are (probably) more likely to run into a scenario where they'll need to glide. Air Transat 236 managed to glide 120km and land safely after running out of fuel. The Helios flight in 2005 was unfortunate. The flight attendant trying to control it had some pilot training, but not enough to handle an out-of-fuel airliner at relatively low altitude.
- rpeden 10y agoI remember reading about this in Reader's Digest back in the 80s, or possibly early 90s. One of the passengers mentioned that during the last-minute sideslip manoeuvre, he could almost tell what clubs the golfers on the course below them were using. :)
- webtechgal 10y ago>I remember reading about this in Reader's Digest... Yes, that is where I had first read about it too. Don't remember exactly, but probably under the section called Drama in Real Life.
- koliber 10y agoSo it turns out that passenger jets do not carry backup batteries. This poses problems when all engines fail, as many functions are fly-by-wire, and require power. Th RAT comes to the rescue in such situations. Its a Ram Air Turbine which pops out of the body when called upon. The turbine spins and generates just enough electricity to power the crucial instruments and controls. I was touring a Hamilton Sundstrand factory a long time ago that manufactured these RATs. They had a tally board up that listed situations where the RAT was deployed and the number of people that survived the incident. Talk about being motivated to do a good job!
- repiret 10y agoThe RAT is backup power for the hydrolics. Do you have a citation that there's no backup battery for the electronics, because I don't believe it. Even for the crappy 25 year old not-approved-for-IFR GPS I had in my Cessna needed the engine/alternator to fail plus two separate batteries to drain before it would turn off. I can't believe the electronics on a fly-by-wire airliner are less redundant.
- DougBTX 10y agoApparently also for electronics: https://en.wikipedia.org/wiki/Ram_air_turbine https://en.wikipedia.org/wiki/Ram_air_turbine
- koliber 10y agoI was trying to paint a picture of why the RAT is needed, in order to share my admiration about the people who build it. I don't know exactly which systems it powers, but have been told that in the case of engine failure, the plane cannot fly without it. You may be correct about the specifics.
- 464192002d7fe1c 10y agoRAT provides electrical generation too. Its all layers of protection, there are batteries for limited duration and limited equipment. RAT provides more (duration and functionality). There are some components that are considered like that GPS that have small enough power requirements and are critical enough that they can have significant battery and others that are powered by the RAT, and yet others that just don't work with a main engine failure. Highly suggest watching some of the Mayday episodes about the power failure incidents like Gimli, its very educational.
- lucio 10y agohttps://www.youtube.com/watch?v=Bct1mWUp8to https://www.youtube.com/watch?v=Bct1mWUp8to MAYDAY Air Crash Investigation S05E02 Gimli Glider Air Canada Flight 143
- j1vms 10y agoPearson and Sully would certainly share some interesting words, were they to ever meet.
- mrfusion 10y agoInteresting, a modern glider can have a glide ratio of 60! A flying squirrel, 2! https://en.m.wikipedia.org/wiki/Lift-to-drag_ratio https://en.m.wikipedia.org/wiki/Lift-to-drag_ratio
- maxerickson 10y agoTo be fair, modern gliders are bad at climbing trees.
- mikeash 10y agoThe Concordia, a one-off built to utterly crush the souls of the competition in races, can supposedly hit about 75.
- DuskStar 10y ago"The Crash of Flight 232" is also really interesting. In some ways it's the opposite of the Gimli Glider in that 2/3 engines were still functioning fine, but total hydraulic loss meant that there was no elevator/rudder/aileron/flaps control. http://clear-prop.org/aviation/haynes.html http://clear-prop.org/aviation/haynes.html
- edblarney 10y agoIt's hard to believe that there is not training for a situation in which all engines are out. Heyzeus, just a little bit of knowledge (i.e. glide ratio, etc.) might save a lot of lives.
- vic-traill 10y agoI expect that most folks would be surprised to hear that Captain Bob Pearson was demoted for six months [0] after this landing, in which he side-slipped a commercial airliner with no functioning engines, and dodged two kids on bicycles on the Gimli 'runway' (read drag strip). Talk about a uniquely Canadian story - running out of fuel because of a mistake in Imperial to Metric unit conversion. This from someone who was in high school in 1978, The Year Dope Dealers Got an 'A' in Math. And if you don't get that joke, you're not a Canadian who grew up in the transition from Imperial to Metric. [0] https://en.m.wikipedia.org/wiki/Gimli_Glider https://en.m.wikipedia.org/wiki/Gimli_Glider [edit: duh, added the reference. I get it, after having it being explained to me. Thanks folks. ]
- boterock 10y agowhy do you do [0] and never put any [0]() =(
- vic-traill 10y agoCS man! What can I say? :-)
- ythn 10y agoNo, he means, where's the reference? I would be like if I said: Scientists recently proved the existence of a soul inside of all life forms [0].
- vic-traill 10y agoWell played, sir!
- nkozyra 10y agoEvery CS paper I've had to write required valid references [1]
- qwertyuiop924 10y agoIndeed. Unterminated references are a sure sign of sloppy thinking[0]. They can also be dangerous[1]: gaze into the void, and the void gazes back. Cast into void, and you might get a null pointer exception.
- cpncrunch 10y agoI would recommend reading "Freefall" by William and Marilyn Hoffer, which is a great account of this event.
- gregmac 10y agoI just watched this a couple days ago on Today I Found Out: https://youtu.be/snVifFDoAG8 https://youtu.be/snVifFDoAG8 (9 minutes)
- pavel_lishin 10y ago> Following the successful appeal against their suspensions, Pearson and Quintal were assigned as crew members aboard another Air Canada flight. As they boarded the aircraft, they realized that airplane was the same one involved in the Gimli incident. That's great, but I wonder how big of a coincidence this is - how many aircraft did Air Canada have, especially running on presumably the same leg that Pearson and Quintal would have been running?
- ihunter 10y agoA few things came out of this incident: 1) Per my first flight instructor, this is the reason students now learn how to forward slip. Up until then it was just viewed as a glider move. Thankfully the captain was an experienced glider pilot. It's required to demonstrate this maneuver for your private license (not sure about sport license). 2) This ultimately led to overhaul and standardizations for fuel / weight calculations. 3) Because the engines powered the electrical systems via the alternator, the plane lost a number of electrical systems until the ram air turbine kicked in (amazing little invention and kinda saved the day). Afterwards, many subsequent aviation systems were designed to be operated independently from requiring the alternator to be running. Good documentary/recreation on the incident: https://www.youtube.com/watch?v=Bct1mWUp8to https://www.youtube.com/watch?v=Bct1mWUp8to. Miraculous that everyone survived, the captain deserves an accolade for quick thinking.
- crikli 10y agoPretty sure #1 isn't accurate. I wasn't required to forward slip (or side slip, for that matter) on my FAA checkride nor have I been required to do so during any biennial flight review. Edit: I'm dead wrong. :)
- phumbe 10y agoLooks like forward slip to landing has been in the Private Pilot Practical Test Standards [1] since at least Nov 2011 [1][PDF] https://www.faa.gov/training_testing/testing/test_standards/media/faa-s-8081-14b.pdf https://www.faa.gov/training_testing/testing/test_standards/...
- crikli 10y agoHuh. I'm wrong then obviously. Wonder if it's never come up as I tend to forward slip on crosswind landings. Don't recall a DPE ever even mentioning slips.
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- nnx 10y agoA similar incident happened on Air Transat 236. Pilot had to glide further, about 120km over the Atlantic, before landing on an emergency landing strip in the Azores. https://en.m.wikipedia.org/wiki/Air_Transat_Flight_236 https://en.m.wikipedia.org/wiki/Air_Transat_Flight_236
- edem 10y agoThey can understand now the pain of working with fragmented standards (I look at you Unicode and friends).
- daemonhunter 10y agoInteresting, Ram Air Turbine - https://en.wikipedia.org/wiki/Ram_air_turbine https://en.wikipedia.org/wiki/Ram_air_turbine
- jv22222 10y agoWhy isn't this Bruce Willis movie yet? ;)
- vatotemking 10y agoThose 2 kids on bicycles would surely have a helluva story to tell.
- homero 10y agoCaptain Pearson was an experienced glider pilot, so he was familiar with flying techniques almost never used in commercial flight.
- khazhou 10y agoI can honestly say that after spending the whole day worried about some presentations I have to do this week, reading this makes me believe I can do anything!
- RichardCA 10y agoNot sure if anyone's posted this yet. https://www.youtube.com/watch?v=sbE1S-i_gz4 https://www.youtube.com/watch?v=sbE1S-i_gz4
- collinmanderson 10y agoI'm amazed that the plane was flown for another 25 years after the incident!