# Boeing 777 loses power; glides to a safe landing **URL:** \ **Category:** Miscellaneous and Personal Stuff I Must Share\ **Created:** [January 17, 2008, 7:27pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917 "2008-01-17T19:27:05Z")\ **Posts on this page:** 20\ **Page:** 4
**Author:** ![Sunrazor](https://avatars.discourse-cdn.com/v4/letter/s/2acd7d/32.png) [@Sunrazor](https://boards.straightdope.com/u/Sunrazor)\ **Post date:** [January 18, 2008, 3:59pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/61 "2008-01-18T15:59:09Z")
[QUOTE=Usram] Despite the title of this thread, we do not know right now (Friday 2008-01-18) that the the plane “lost power” at any stage, or that it glided to its crash landing. AFAIK that is just rumour that comes from some airport worker who claims he talked to the pilot. [/QUOTE] BBC seems to have been reporting at least two sources for the loss of power from the beginning. I don’t know how Londoners view BBC’s credibility, but among us American journalists it is highly respected for its restraint, speed and accuracy. It is among the world’s premier news agencies. That’s good enough for me. Kudos to the crew. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [January 18, 2008, 5:16pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/62 "2008-01-18T17:16:12Z")
[The plot thickens](http://news.bbc.co.uk/1/hi/england/london/7196526.stm). They said that the pilot was white afterwards: I wonder if he’d had a seizure or minor heart attack or something. But then, who wouldn’t look white after that? OTOH BA are giving the pilot [full backing](http://www.bbc.co.uk/mediaselector/check/player/nol/newsid_7190000/newsid_7196500?redirect=7196599.stm&news=1&nbwm=1&bbwm=1&nbram=1&bbram=1&asb=1) (video), he must have been cleared by the AAIB. ---
**Author:** ![OtakuLoki](https://avatars.discourse-cdn.com/v4/letter/o/ac8455/32.png) [@OtakuLoki](https://boards.straightdope.com/u/OtakuLoki)\ **Post date:** [January 18, 2008, 5:30pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/63 "2008-01-18T17:30:13Z")
[QUOTE=Quartz] [The plot thickens](http://news.bbc.co.uk/1/hi/england/london/7196526.stm). They said that the pilot was white afterwards: I wonder if he’d had a seizure or minor heart attack or something. But then, who wouldn’t look white after that? [/QUOTE] I’m not sure that there’s any reason to suspect something wrong with the captain’s ability or health. AIUI, the loss of power was while the aircraft was already in final approach - I can imagine that trying to shift the controlling pilot from the co-pilot to the captain would have been difficult, at best, and potentially dangerous with all that was going on. Even knowing that taking control may have been more dangerous than letting the person currently flying the plane continue, the normal reaction most people have in a stressful situation is to want to take over, to do _something_. And as stressful as a landing in sub-par conditions might be, having to keep oneself from trying to take the control away from one’s junior, and being stuck _watching_ while someone else deals with the casualty may well have been more than stressful enough to leave someone white after such a landing. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 18, 2008, 5:47pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/64 "2008-01-18T17:47:53Z")
Gosh, I’m ghost white _all the time_, even after an uneventful landing (of course, that’s a natural lack of pigment, not seizure or heart attack or whatever) You don’t become a co-pilot on a passenger airliner without being _fully qualified_ to fly that airplane. “Captain” denotes seniority - with the airline, with the airplane type, whatever - and not necessarily a superior overall skill set. It is entirely possible to find a co-pilot with more total hours in the air than his/her captain. It is typical these days for the two pilots up front to take turns performing landings. As I said, neither would be in the front seat if he/she wasn’t totally qualified. This helps keep everyone in practice which is a good thing. If the co-pilot was already performing the landing then switching to the other pilot without good reason would only complicate an already nasty situation. Having the non-flying pilot move immediately to a supportive role for the flying pilot makes perfect sense to me. “Supportive role” could involve such things as declaring an emergency over the radio, using back up systems to get the landing gear down, attempting to get some power out of the engines or other systems, and so forth which would give a person PLENTY to do in an emergency and also permit the flying pilot to concentrate on controlling the airplane and making the best landing possible. In other cases, control might be ceded for a very good reason - in the Gimli Glider incident the captain handed the controls to the co-pilot because the co-pilot had extensive experience with gliders that the captain did not have. Since they were in glider (albeit a very big, very fast, and very unintentional one) it was logical to have the fellow with the most experience in that form of flight to be in charge. In any case, going pale is a fairly common reaction to high stress and to my mind in no way implies a health issue. Now, being pale AND staggering out of the cockpit while desperately clutching one’s chest, THAT’s a Bad Sign but that’s not what happened. ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 18, 2008, 6:28pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/65 "2008-01-18T18:28:53Z")
Latest from the [BBC](http://news.bbc.co.uk/2/hi/uk_news/england/london/7196962.stm): > [@](#): > > According to the Air Accidents Investigation Branch (AAIB) at about 600ft “autothrottle demanded an increase in thrust from the two engines”. > > After continued demands for increased thrust, and the “flight crew moving the throttle levers, the engines similarly failed to respond”, the report indicated. > > “The aircraft speed reduced and the aircraft descended onto the grass short of the paved runway surface.” “Autothrottle” to me implies “autoland” which means the airplane was flying itself at the time of malfunction. So… by my reckoning if it was pilot error the pilot erring was the airplane. A little more seriously - this is why we still have human pilots, even on airplanes that can be programmed to do the landing. 600 feet is awful low, that doesn’t give a person much time to react. Under the circumstances (so far) it looks like the pilots really did save the day ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 18, 2008, 10:57pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/66 "2008-01-18T22:57:23Z")
[QUOTE=Broomstick] Latest from the [BBC](http://news.bbc.co.uk/2/hi/uk_news/england/london/7196962.stm): “Autothrottle” to me implies “autoland” which means the airplane was flying itself at the time of malfunction. So… by my reckoning if it was pilot error the pilot erring was the airplane. A little more seriously - this is why we still have human pilots, even on airplanes that can be programmed to do the landing. 600 feet is awful low, that doesn’t give a person much time to react. Under the circumstances (so far) it looks like the pilots really did save the day [/QUOTE] Autothrottle is not strictly an autoland function. On modern airliners the autothrottle is often engaged for the entire flight and controls the power to achieve the speed the pilots or autopilot wants. Also if the autothrottle was fully engaged the pilots wouldn’t have to manually move the throttles in response to the aeroplane’s commands as stated in the article\*. On the subject of what controls height and what controls speed. You can’t really say that one controls speed and the other controls height. They work together. If you’re low on approach then you need to both raise the nose AND increase power. If you were to just increase power and keep the nose where it is, the aeroplane will go faster but still be low, if you only raise the nose then you’ll get back to the height you want but you’ll get too slow. Having said that, on different aircraft one control (power or elevator) may have a more immediate effect than the other. In a light piston aircraft raising and lowering the nose has a more immediate effect on airspeed than adjusting the power setting. So if you’re too slow, you need to lower the nose as a primary action but still increase power as a secondary action. This is where the idea of attitude for speed and power for height comes from but they really work together. A commercial jet, contrary to what has been said here, works the other way around. Increasing and decreasing power has a more immediate effect on AIRSPEED so the power becomes the primary control for speed on approach. I think it is mainly to do with their weight and associated inertia. This all leads to debates about how to teach people to fly. Some schools are geared toward training people to be airline pilots and some of them will teach airline techniques to students flying a Cessna C152 even though a more traditional technique is more appropriate for the aeroplane they’re flying. Some people think this is a bad way to train, others disagree. Edit: On re-reading your quote it may be that the autothrottle was asking for more power but it wasn’t being supplied so the pilot moved the throttles manually as a response to that. On first read it sounded like the autothrottle was giving throttle commands that the pilots were carrying out, it doesn’t normally work that way. ---
**Author:** ![fortytwo](https://avatars.discourse-cdn.com/v4/letter/f/f9ae1b/32.png) [@fortytwo](https://boards.straightdope.com/u/fortytwo)\ **Post date:** [January 18, 2008, 11:05pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/67 "2008-01-18T23:05:19Z")
[QUOTE=jjimm] Ah yes, I know the one you mean. It’s still down. Scariest damn site on the Web. [/QUOTE] If you’re still interested and the board is still down you can go to the homepage where it tells you the servers are busy and scroll to the bottom and select “Archive” you can get to a list of threads. I think it’s number 8131. ---
**Author:** ![fortytwo](https://avatars.discourse-cdn.com/v4/letter/f/f9ae1b/32.png) [@fortytwo](https://boards.straightdope.com/u/fortytwo)\ **Post date:** [January 18, 2008, 11:12pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/68 "2008-01-18T23:12:15Z")
As a result of reading the aforementioned thread this might also be of some interest [http://www.aaib.dft.gov.uk/latest\_news/accident\_\_heathrow\_17\_january\_2008\_\_\_initial\_report.cfm](http://www.aaib.dft.gov.uk/latest_news/accident __heathrow_17_january_2008___ initial_report.cfm) ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 18, 2008, 11:43pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/69 "2008-01-18T23:43:55Z")
There are a few interesting points there. A significant amount of fuel was leaking from the wreckage so they didn’t run out of fuel (and as someone else already mentioned, fuel exhaustion normally results in engine failures at different times as the relevent tanks empty.) And the autothrottle commanded an increase in thrust with no response from the engines, the pilots manually increased thrust as a response to that (still with no response from the engines.) ---
**Author:** ![Broomstick](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/broomstick/32/246_2.png) [@Broomstick](https://boards.straightdope.com/u/Broomstick)\ **Post date:** [January 18, 2008, 11:47pm UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/70 "2008-01-18T23:47:27Z")
[QUOTE=1920s Style “Death Ray”] Edit: On re-reading your quote it may be that the autothrottle was asking for more power but it wasn’t being supplied so the pilot moved the throttles manually as a response to that. On first read it sounded like the autothrottle was giving throttle commands that the pilots were carrying out, it doesn’t normally work that way. [/QUOTE] That’s how I read it - the pilots took over when the automatic systems didn’t work. I was under the impression that 777’s came equipped with autoland, which I am under the impression is also called Cat III approach capability BUT as I have said before I am no expert on jets so I could be very very wrong on this. I wouldn’t mind someone more knowledgeable giving me the straight dope on that one. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [January 19, 2008, 12:08am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/71 "2008-01-19T00:08:52Z")
[QUOTE=Broomstick] That’s how I read it - the pilots took over when the automatic systems didn’t work. I was under the impression that 777’s came equipped with autoland, which I am under the impression is also called Cat III approach capability BUT as I have said before I am no expert on jets so I could be very very wrong on this. I wouldn’t mind someone more knowledgeable giving me the straight dope on that one. [/QUOTE] Yes it does have autoland capability. The use of autothrottle doesn’t imply the use of autoland though. The autothrottle can be used at any time either with the autopilot fully engaged or with the pilot hand flying and the autothrottle managaing speed. Belated disclaimer: I’m a turboprop guy, not jets, but part of license requirements is to learn a fair bit about modern jet airliners including the main systems. Specifically the Australia ATP license involved a lot of systems knowledge of the B767 and performance knowledge of the outdated B727. ---
**Author:** ![JRDelirious](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jrdelirious/32/9531_2.png) [@JRDelirious](https://boards.straightdope.com/u/JRDelirious)\ **Post date:** [January 19, 2008, 12:42am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/72 "2008-01-19T00:42:37Z")
OK, so not so much loss of engines as that the throttle stopped responding to commands,\*\* both \*\* auto and manual. To do a car analogy, the cement truck is coming at you so you downshift and floor the gas pedal yet your engine fails to rev up. Regular airline fliers (or folks living under the flight path) would notice that on short approach you’ll often feel/hear they’re giving her little bursts of extra thrust. In this case they needed to and could not. You bet I’d be pale white and my shorts wouldn’t… Is the 777’s throttle function fully fly-by-wire? Could how neither the autopilot nor the levers could make it respond suggest a problem arose at the control module that actually signals the throttle actuators? **tschild** , there are tradeoffs always in design. As the article says, the most common reason for a displaced threshold is if from that direction, the topography is such that you’d have to come in as too steep an angle to land at the physical end of the runway. But if that’s not a consideration, why overbuild? I could build my airport with 5Km-long runways and 300m displaced thresholds at either end just for wiggle rom, but that would be uneconomical. ---
**Author:** ![gotpasswords](https://avatars.discourse-cdn.com/v4/letter/g/c57346/32.png) [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)\ **Post date:** [January 19, 2008, 12:59am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/73 "2008-01-19T00:59:35Z")
[QUOTE=JRDelirious] Is the 777’s throttle function fully fly-by-wire? Could how neither the autopilot nor the levers could make it respond suggest a problem arose at the control module that actually signals the throttle actuators? [/QUOTE] It’s mostly fly-by-wire. The autothrottle system actuates the mechanical throttle levers, so the pilot can grab the levers and hold them still or move them as desired to over-ride the autothrottle. By comparison, the big Airbus planes don’t have mechanical throttles, making it harder, if not impossible to over-ride an autothrottle. Pretty much everything else in the 777 cockpit other than a magnetic compass and the cupholders are some sort of virtual control or display. > [@airlinesafety.com](#): > > the throttles on the Boeing planes are “real” throttles, in the sense that the engine fuel controllers respond to the mechanical movement of those throttles, by the pilots. In other words, even if the autothrottle system cannot be turned off, the pilots can overpower any automatic movements of those throttles, just by the pilot holding those throttles in what ever position he wants them. The [page](http://www.airlinesafety.com/faq/777DataFailure.htm) that was excerpted from contains a writeup of a data systems failure in a 777 in August of 2005 - on a quick read, a controller went batty and thought the airplane was simultaneously approaching VNE and stall speed. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [January 19, 2008, 1:12am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/74 "2008-01-19T01:12:08Z")
The preliminary report linked by Vetch seems to make it clear that the throttle-response failure happened shortly before touchdown, at about 600’, with the aircraft aligned with the runway. So, while it appears the crew did about as well as they could from that point on, I’m not sure there’s anything highly commendable in their actions. They stayed lined up with the runway and descended to a roughish but fully survivable touchdown. I think you could expect as much from almost any competent crew. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [January 19, 2008, 1:28am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/75 "2008-01-19T01:28:11Z")
It also sounds as there wasn’t a total power failure – the throttle essentially got stuck in one position, so they had some power, just not quite enough. Push came to shove but only push was available. 😛 ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [January 19, 2008, 1:28am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/76 "2008-01-19T01:28:49Z")
[QUOTE=Quartz] [url=[BBC NEWS | England | London | Co-pilot controlled crash-landing](http://news.bbc.co.uk/1/hi/england/london/7196526.stm)]They said that the pilot was white afterwards … [/QUOTE] That’s especially peculiar, because he was Chinese before the incident. ---
**Author:** ![Siam\_Sam](https://avatars.discourse-cdn.com/v4/letter/s/d78d45/32.png) [@Siam\_Sam](https://boards.straightdope.com/u/Siam_Sam)\ **Post date:** [January 19, 2008, 1:33am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/77 "2008-01-19T01:33:35Z")
[QUOTE=El\_Kabong] I know there’s no particular reason to worry, but I’ll be traveling to Paris next week on an Air France 777. Hope this was a one-off problem. [/QUOTE] No, actually this is the second incident this month, although the other one involved a 747. It happened HERE, on a Qantas flight from London to Bangkok. Story [here](http://www.abc.net.au/news/stories/2008/01/09/2134442.htm). The flight was 15 minutes from landing. Our incident being much less dramatic, I guess it was not as widely reported. ---
**Author:** ![Boyo\_Jim](https://avatars.discourse-cdn.com/v4/letter/b/87869e/32.png) [@Boyo\_Jim](https://boards.straightdope.com/u/Boyo_Jim)\ **Post date:** [January 19, 2008, 1:46am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/78 "2008-01-19T01:46:24Z")
[QUOTE=Siam Sam] That’s especially peculiar, because he was Chinese before the incident. [/QUOTE] Good one! 😃 ---
**Author:** ![blondebear](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/blondebear/32/1022_2.png) [@blondebear](https://boards.straightdope.com/u/blondebear)\ **Post date:** [January 19, 2008, 2:01am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/79 "2008-01-19T02:01:41Z")
I just saw the story on BBC World. The captain was the epitome of a British top officer; not at that pleased to be in front of all the cameras, and intent on giving credit to his crew. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [January 19, 2008, 2:08am UTC](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917/80 "2008-01-19T02:08:33Z")
[QUOTE=Siam Sam] That’s especially peculiar, because he was Chinese before the incident. [/QUOTE] Say [what?](http://www.telegraph.co.uk/travel/main.jhtml?xml=/travel/2008/01/18/etheath718.xml) I’m confused. [Previous page](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917.md?page=3) [Next page](https://boards.straightdope.com/t/boeing-777-loses-power-glides-to-a-safe-landing/433917.md?page=5)