Airbus windscreen fell out at 32,000 feet An Airbus A319 operated by China’s Sichuan Airlines lost one of its cockpit windshields at 32,000 feet on Monday, but was able to land safely. As reported by the Civil Aviation Administration of China’s south-west region, flight 3U 8633 from Chongqing to Lhasa took off as expected, reached its cruising altitude of 32,000 feet …
Yes, he is.
And the point that the windows should probably not be using a screw of the same diameter but a different length is a good one, if you made them obviously the wrong size it'd completely eliminate the problem.
It being possible for somebody to put shorter screws in something safety critical and somebody to check and say "yep, those are all in and fully tightened" is not a good thing.
"And the point that the windows should probably not be using a screw of the same diameter but a different length is a good one"
Are you aware that screw thread and head designs are standardised, and for very good reasons? If we had to have unique screw diameters for everything that might be at all safety critical, it would be rather difficult to implement. Especially as you can always put a smaller diameter screw in a given hole.
Are you aware that screw thread and head designs are standardised, and for very good reasons?
No i wasnt, im pretty sure i could buy a screw with a 13mm head , with varying length , not to mention thread pitch and even threaded-bit-diameter.
Also I call them bolts.
screws are the pointy things carpenters use
Quite right 404.
A bolt has an unthreaded portion immediately adjacent to the head, whereas a machine screw has thread starting at the head and carried over the full length of the shaft.
A set screw usually has no thread and performs functions such as locking pulleys onto shafts.
Machinery's Handbook manages a spectacular feat of abstruse obfuscation in wrongly defining these terms, which WikiP then quotes.
Remember when the UK did Engineering?
Oh dear, typical Vogon never wrong...
I used the term "screw thread". That's what they are called. Bolts, studs and machine screws all have screw threads.
Generally a bolt is something that screws into a nut, i.e. it has a head at one end and a separate nut at the other.
A machine screw is like a bolt but is designed to screw into a threaded hole in a piece of metal. I suspect that the fasteners of an Airbus windscreen could well be machine screws.
A stud has a thread at both ends and usually a non-threaded bit in the middle. One end screws into a piece of metal; the other end takes a nut. Cylinder heads are usually held down with studs. Rocker covers are usually held down with screws. Thin pieces of metal are usually bolted together as there isn't enough depth in either piece to thread it.
I completely fail to take your point about the size of the head. Usually standard screws (or bolts, to keep you happy) have a given head size for a given thread diameter. The reasons for this are (1) to keep the number of spanner sizes sane and (2) because there's a relation with thread diameter and shearing force, so the head size should ideally reflect the flats or whatever being of a size to resist the maximum safe load while not being so big that a slightly clumsy mechanic will keep shearing heads off.
There also tends to be a limited range of pitches because if there isn't enough difference sooner or later someone will try to insert a 0.95mm pitch thread into a 1mm pitch hole using BFI, and this will not be good.
Mine is the one with the copy of Machinery's Handbook in the pocket.
Peter,
You're absolutely right. This is one of those situations where having a screw and hole which is a totally different size than everything else in the build. Having parts that are the same, but slightly different causes errors and sometimes serious ones.
I can only imagine in a situation as serious as the windscreen that the maintenance worker grabbed screws that looked the same, however didn't confirm they were the right part. Being shorter, they went into the holes, and being just long enough to catch a few threads in the holes to hold on until under pressure.
Though not serious, I have seen this with some older laptops and other equipment. The old NEC 5xxxx and 6xxxx series laptops from yesteryear were famous for this, making tech work frustrating if not truly annoying, and so were some of the ancient "intelligent terminals' I used to get in from the field for repair that had either no screws in them, or in some cases screws not completely seated because whoever worked on the equipment, mostly the customer doing this, had put screws in that looked right, but were just slightly longer than they should be.
"Though not serious, I have seen this with some older laptops and other equipment. The old NEC 5xxxx and 6xxxx series laptops from yesteryear were famous for this, making tech work frustrating if not truly annoying,"
This why I'm a bit anal about laying out the screws when dismantling a laptop. There are still laptops using the same size screws other than length, just for holding the case together, In some cases, the shorter screws will "fit" into holes meant for the longer screws and if you don't manage the screw placement properly you end up with long ones which either don't go in all the way or could cause damage if tightened all the way.
Managing all removed parts such that they go back in the correct order and correct places is something I learned at the start of my career. There should never be parts left over :-)
This is one of those situations where having a screw and hole which is a totally different size than everything else in the build.
Whatever unique size those fasteners are meant to be, there's always a smaller size that appears to fit. Always. So that approach won't work, and only exacerbate the problem of having to stock all those different parts, which, being manufactured in smaller numbers than standard fasteners, will cause them to be out of stock more often.
So that's not going to be a viable solution. People following the instructions, and using only the specified parts, is.
Wasn't that where the plane had to land in Southampton after taking off from Birmingham ? The pilot was severely injured ?
Memory is hazy, but ISTR the technician followed procedure and requested new bolts from the stores to fit the windscreen. But he didn't check them with the bolts he'd removed and assumed they were what the label said.
Years of working in the family car repair business has taught me to never trust the box over a visual inspection.
@anonymous coward
Nope. The technician doing the job walked into stores, eyeballed the different screws available and found what he thought was the correct type, ignoring the recommendation of the stores officer as to what the correct type was
He got the right diameter and thread pitch but just a little too short to fully engage in the socket
(at least that's my recollection of the NatGeo Aircrash Investigation episode)
I saw a documentary about windsreen loss ( i think it was this southampton incident)
They said the design had changed so that the "recess" for the window is on the inside now , ie the frame part is outside the window , ie the pressure is pushing the window ONTO the the window frame rather than off it .
A bloody obvious design that should have been that way all along i'd say.
"hindsight is 20/20."
True, but had i been the airplane designer* I would definitely have designed it that way first time round.
I'm not saying I'm a genius , and i get a lot of things wrong first time, but that is new level of " the-bleedin-obvious"
*it wouldnt have mattered becasue had i been the airplane designer it would never have left the ground :)
True, but had i been the airplane designer* I would definitely have designed it that way first time round.
Even if that meant the entire instrument panel had to be dismantled and 100 of instruments disconnected to replace a window ?
They are plug type on some airbus because the computers mean that the instrument panel is a lot smaller and easier to work on than in the old days.
"Even if that meant the entire instrument panel had to be dismantled and 100 of instruments disconnected to replace a window ?"
Why would it need to be dismantled? If the instruments were that much in the way they'd block the view out of the window so much there'd be no point having one.
Why would it need to be dismantled? If the instruments were that much in the way they'd block the view out of the window so much there'd be no point having one.
The instrument panel can be fully below the actual window and still block access to the bottom row of fasteners keeping that window in place.
"The instrument panel can be fully below the actual window and still block access to the bottom row of fasteners keeping that window in place."
Screwdrivers and keys that can turn a screw and bolt at a 90 degree angle have been around for a while now but if thats not good enough because the bolts are too long to come out without removing the equipment I'd still say thats worth the trouble because of the extra safety confered by having the window mounted inside the frame rather than outside. There's a reason its done that way with the doors!
"Even if that meant the entire instrument panel had to be dismantled and 100 of instruments disconnected to replace a window ?"
I did give all that some thought before posting but i didnt want to muddy the waters of a simple point. You can still have a load of gear on the inside and fit the window without much manouvering.
>Prst. V.Jeltz
Yes, internally fitting plug windows would be ideal, but often there are bigger concerns. Especially in safety critical systems, not having to touch system B-Z in order to service system A is a bigger driver than making A better. A bit like software really.
Regarding the best way to fix cockpit windows—
"I'm not denying that it should have been that way in the first place, just reminding you that hindsight is 20/20."
You're right that we shouldn't be too smug with hindsight, but I'm not sure that it qualifies as such in this case, given that plug-style doors have been fitted to pressurised aircraft for decades, for this precise reason: they fit more snugly when the cabin is pressurised, and the differential ensures that they cannot open accidentally during flight. Contrast this with non-plug doors, as found used for the cargo holds of various planes, with predictable consequences including the notorious DC-10 (Windsor Incident; Ermenonville Disaster) and even B747 (United 811). If you're an aviation designer/engineer knowing perfectly well that the plane you're working on has plug doors, wouldn't you stop and think a bit when contemplating cockpit windows that were not fitted the same way?
That said, the BAC-One-Eleven incident was down to improper fixing; and this latest problem seems to have been a cracked-then-broken window, not a pressure-induced loss of the entire pane. So in fairness you could probably describe this as a borderline issue—not least, I am sure, because the glass and the fixings for cockpit windows will be over-engineered with very broad safety margins: cabin pressure is one thing, but an even bigger test is posed by airborne fowl. You may lose an engine, or even two, to some very surprised Canada geese (just ask a chap called Sully) but you really do not want to lose your entire cockpit to one of the buggers. I don't think forty pounds of exploded bird guts coming through the windscreen at 250mph wouild be conducive to a safe, tranquil cockpit atmosphere ....
"A bloody obvious design that should have been that way all along i'd say."
Everything is obvious in hindsight. But since you dont have all of the requirements that were given to the designer you're making some pretty big claims about it being a bloody obvious design.
Things like access to the screws for maintenance might have precluded such a design. It might only be possible now due to a redesign of the electronics. The positioning of other panels might not have allowed the change you consider obvious to have been made at the time.
The design worked fine, when installed correctly. Have there been any cases where the window fell out where the correct screws were installed? No. Then the design met all of its requirements and is therefore a good design. Its been redesigned now, and its somewhat more stupidity tolerant, but the previous design worked well.
Never shit on a designer for a "bad" design until you know exactly what requirements they had to meet. When you're designing something for a complex machine you're rarely making a choice between a good concept and a bad concept, you're choosing the least shit design that meets the requirements.
(from an aerospace design engineer who knows a bit about the good, the bad and the shit....)
Although if, as described, the windscreen cracked, it may have broken up and blown out in separate pieces.
The accident investigation report mentions that they found the windscreen, the outside corner post fairing strip and a number of bolts in an Oxfordshire field. There's no mention of it being in several pieces, so I take it that it wasn't. Plus, it's a five layer glass/PVB laminate; the glass layers may crack but the PVB should keep the lot in one piece.
The accident investigation report mentions that they found the windscreen, the outside corner post fairing strip and a number of bolts in an Oxfordshire field. There's no mention of it being in several pieces, so I take it that it wasn't. Plus, it's a five layer glass/PVB laminate; the glass layers may crack but the PVB should keep the lot in one piece.
Wow, that windscreen flew all the way from China to Oxford!
(one of you was talking about the new incident, one the old)
This post has been deleted by its author
They said the design had changed so that the "recess" for the window is on the inside now , ie the frame part is outside the window , ie the pressure is pushing the window ONTO the the window frame rather than off it.
There's air pressure pushing the window out, and airflow past the window on the outside pushing in. Apparently the first is the greater of the two, but it would have stayed in place had all 90 bolts been of the right diameter (84 weren't, 8-32 UNC instead of 10-32 UNF) and the right length (the remaining 6 were 2.5mm too short). And the AAIC report notes that the window will be held in place even if not all bolts are present (provided they're the correct size): "The large number of bolts are required to prevent leakage of pressurised air through the window seal but the force of internal air pressure could be satisfactorily resisted by far fewer bolts."
Most planes still have them attaching from the outside because that's the cheaper way of fitting them - getting them into the aircraft and rotating them around to fit the hole is rather difficult without disassembling large sections of the "dashboard" to make room for the maintainers to get in to do the work etc.
Years ago, I worked for a couple of years on Light Aircraft airframes, I already had reasonable experience with nuts and bolts, so would have noticed a difference in length.
In addition, even on light aircraft everything was torqued in place I had 3/4", 1/2",3/8" and 1/4" drive torque wrenches, torquing a bolt with too little bite because of too little thread would probably fail and strip the thread, especially in the kind of light alloys used in aircraft . Our boss was an ex- BA senior engineer and would allow nothing other than perfection in work quality, a not unreasonable thing for chunks of metal flying around.
Well, that WAS a lot of comments - some of which were vaguely informed!
The incident in question was BAC 1-11 flight 5390 - Birminghan-Malaga June 1990.
The accident report is here: Accident report
It turned out that the maintenance crew were proessionals of the old school, and prefered to rely on their skills rather than formal checks and drawing approved bolts from the proper box in stores. The local engineering management were content with this practice.
In this particular case a windscreen needed changeing when they were short of resources - the shift manager did the task, and used bolts that were too short. He matched them to the ones that came off, but they were also mistaken, and had presumably been wearing the small area of contact while they were on for the prior 4 years. He needed a few more bolts to make up the full 90 which were used, and used some which were too thin for this.
It was an easy mistake to make if you relied on your expertise - the proper bolts only had minor differences, and three aircraft in the fleet had ended up with the wrong bolts. The essential AIB finding was that engineering maintenance teams should have more structured work practices, and draw authorised bolts from a storekeeper rather than use their eyesight.
Of course, we don't yet know if the Chinese accident was casued in this manner or not...
"...bolts that were too short..."
Official Report: "The replacement windscreen had been installed with 84 bolts whose diameters were [too small], and 6 bolts [too short]."
The TV documentary on this incident mentioned the bolts' diameter. I don't recall them mentioning the six short bolts.
There were 90 bolts in total. The wrong bolts had been used in some aircraft for years. He used 84 that were too thin (but still held a bit) and 6 that were too short.
I think I have that the wrong way around in my explanation above, but I can't be arsed to craft an erratum...
Someone buy him a Tsing-Tao.
I have a friend whom is a Captain for Virgin Atlantic and I'm always amazed when he tells me the shit they try to pull in terms of trying to get more for less out of their flight crews considering the responsibilities shouldered by those chaps up front.
The thread discussing this is on PPRuNe here: A319 FO windshield blowout.
There is an interesting interview with the pilot in that thread. I would not like to have been in his shoes. I can only admire his competence and fortitude.
My favourite pilot landing story has to be the FedEx flight 705.
An employee seemingly intent on suicide to claim on life insurance for his family attacked the pilots while he was free-riding.
Having been hit in the head with a hammer and partially paralysed, with a fractured skull, one pilot flew the plane, while the other two fought off the attacker. In true action movie stylee he was pulling sharp dives, climbs and banks so that the fight ended up sliding out of the cockpit, then onto the wall, then the ceiling etc. Doing it all one-handed, and by the seat of his pants, due to not being able to see properly, or move one arm.
Are pilots actually trained, and forced to constantly keep their training up to date, for exactly these kinds of situations.... One of the reasons that Pilots are well paid is to ensure that they are capable of keeping the head cool and retaining their capacity to handle these situations.
I do like when the media use the word "hero" for someone that is performing his job....
I do not want to discredit pilots or their jobs, I have great admiration for what they do, they should be congratulated for handling these kinds of situations, but to go to the point of calling them heros is just plain wrong and does injustice to those who truly merit that denomination.
In my book a hero is someone that goes was over and above his call of duty often performing tasks that they were not prepared for..
I'm unaware of any full motion flight simulator that replicates having a 300 knot sub-zero wind blasting you in the face for the duration of an emergency, or a requirement to practice that scenario. So no, it's not a a situation they're actually trained for.
Also worth noting this is not an area of the world where you can immediately descend below 10,000' to avoid hypoxia so they and the passengers had to remain on oxygen for longer than you'd usually have to.
Can you simulate this? Marketing wants to know.
Well, big chiller/blower on top of the sim bay, big flexi-hose to the sim roof, integrated air ducting (nice whooshing noise) to the retracting-window-weather-injection system. Beefed-up pressurization. CO2 fog and maybe a little snow thrown in. Real oxygen masks. Barf bags.
Instructor's station completely sealed off, of course. Lexan.
"Well, big chiller/blower on top of the sim bay, big flexi-hose to the sim roof, integrated air ducting (nice whooshing noise) to the retracting-window-weather-injection system. Beefed-up pressurization. CO2 fog and maybe a little snow thrown in."
Maybe the BOFH cold sell off all that excess Halon he still has?
I'm not sure I agree being trained to handle a situation and actually handling IRL are two different things. By your logic we shouldn't call soldiers hero's as it's part of their job to get shot and wounded or killed. Ditto firemen.
Seems a trifle harsh and narrow minded to me.
I do agree that soliders doing their day jobs are not heroes. We recognise heroism among them with medals when they go above and beyond their duty. The day job of pilots is to fly planes and to be ready to hadnle emergencies. But emergencies (as other Commentards have pointed out) will always be more extreme than any trainign can supply, so we can only hope that the pilot has the extra courage and self-control to handle what by many would be considered unhandleable. So I'd say the pilot was well over the mark that differentiates heroes from 'doing their day jobs'.
Exactly. We have diluted the meaning of the word "hero", because both politicians and journalists have both interest to use it too much and out of context - the former to cover their stupid decisions, the latter to sell more.
When your life too is at stake, and you work hard to save it, you're not an hero - it's just survival instinct. IMHO an hero is someone who has a choice, save his or her life, or risk it to save others as well.
This pilot made everything right and sustained very harsh conditions, chapeau - but it had a big incentive because he would have died too, he didn't have an ejection seat to save him and let others die. A pilot who avoids to eject to avoid a damaged plane hitting houses full of people is an hero.
By your logic we shouldn't call soldiers hero's as it's part of their job to get shot and wounded or killed. Ditto firemen.
I agree with that. But I also agree with the original poster: the word "hero" is so misused as to render it almost worthless.
In my book a hero has a choice in the matter. Yeah, soldiers are ordered into battle but there are those that avoid anything they can that is risky and those that knowingly undertake risky actions they could have avoided without any penalty.
A hero is the guy who could stay safely in his foxhole, knowing he won't later be charged with cowardice but instead single-handedly storms an enemy sniper nest that is killing his comrades. Heroes like this often end up with posthumous awards for their actions.
By contrast this pilot had no real choice in the matter. He could continue to fly the plane or he could give up and let it crash. Sure, he did a superb job. Sure, his training didn't prepare him for it. But he didn't have a choice. If he'd had an ejector seat then continuing to fly the plane would have been heroic.
Which reminds me. Bomber designs in WW II often had tail gunners. It was difficult and time-consuming to get out of the tail gun position through a narrow tunnel. There were heroic pilots who continued flying a crippled bomber past the point at which they could safely bail out in order to give the tail gunner time to bail out. And there were fucking cowards, like George HW Bush, who bailed out safely knowing the tail gunner was still inside.
So yeah, this pilot did an excellent job. He deserves several beers. And a pay rise. But he wasn't a hero in the true sense of the term, only in the debased newspaper-speak sense of the term.
" If he'd had an ejector seat then continuing to fly the plane would have been heroic."
I dont think so, given he's responsible for the 300 or so lives , not ejecting is the least you can expect.
I do think 'hero' applies though as he managed to succeed flying beyond normal limits . Its not his job to fly with no windscreen , even though he didnt have a choice.
re "choice"
Look at it this way - if the pilot had been sucked out by the accident and the stewardess rushes to the pasengers with the classic "Can Anybody Fly A Plane!!!??" .
A guy puts his hands up , retired small jet pilot , and HE lands it - is that a hero?
after all - it wasnt his job but he had no choice but to try
@Prst, V.Jeltz
A guy puts his hands up , retired small jet pilot , and HE lands it - is that a hero?
after all - it wasnt his job but he had no choice but to try
Nope. Not a hero. Just somebody trying to save his own life. Maybe another superb pilot. Worthy of great praise. But not the appellation "hero."
Another example (from memory, so details may be slightly wrong). RAF pilot. Something goes very bad (I think engine explosion, but could be wrong). No hope of bringing it down in one piece, or even in several pieces and surviving. Only hope of survival is to eject. Except. If he ejects it's going to crash into a built-up area, causing a lot of damage and maybe many deaths. So he stays with the plane long enough to steer it somewhere it won't do as much damage. By that time he could no longer safely eject. He could have ejected early and maybe faced a court martial, maybe never been employed by anyone ever again, but been alive. He gave his life so that others could live. He was a hero.
Yes, language changes. "Hero" no longer means what it did, to many people. What does it matter? Well, what do we call the RAF pilot? A superhero? A hero++?
Orwell got it wrong about newspeak. We didn't simplify language until we had few words and some modifiers so that we could only speak of things being good, ungood, double good, etc. We have many, many words all meaning the same damned thing, so that the true heroes must now be called double-plus heroes.
I can't stop this devaluing of language. But I can at least speak out against it.
"By your logic we shouldn't call soldiers hero's as it's part of their job to get shot and wounded or killed. "
Sadly, the media and certain charities are degrading the term "hero" by overusing it to describe all members of the armed forces, no matter what they do or have done. Even the people who really are heroes would rarely describe themselves as such and yet the media persist in degrading the term to almost becoming meaningless. A very sad state of affairs as it can mean real heroes not being appreciated as much as they ought to be. Based on what we know so far, this Chinese pilot is almost certainly a hero although others, in other places, have said it's just an instinct for self-preservation (which I don't agree with)
Go read the pprune thread and the background of the BA flight that had a similar failure. In both cases it was only exceptional airmanship that got the planes safely on the ground. With no injuries. In both cases if there had been only an average pilot flying the plane it would have most likely ended with a smoking crater on the ground. There are a number of examples of that over the years.
Based on the opinions of the *professionals*, you know, the guys with 10,000's flight hours flying these planes , Captain Liu showed piloting skills of the highest order. Far beyond what would be expected from a typical professional pilot. In order words, a hero.
While watching the interview with Captain Shults last week about the SouthWest incident I was reminded yet again why it is really good to have ex military pilots flying your plane when things go very very wrong. Her first thought when the engine blew up and all the warning lights lit up was - Here we go again.. Just like all those exercises back when she was flying fighters for the Navy.
Captain Liu was a former Chinese Air force flight instructor. Just like Captain Shults had been with the Navy.
Something to ponder the next time you fly on one of your low cost carrier Pay to Fly piloted aircraft. In the very low probability situation that something serious goes wrong, you're totally screwed. Only blind luck will save you. Because the just good enough to operate the automation airmanship of the Pay To Fly pilots most certainly wont.
the next time you fly on one of your low cost carrier Pay to Fly piloted aircraft.
It's the other way around I am afraid. A lot of low cost carriers hire ex-Eastern Europe or ex-Third World fighter pilots. That is not just experience, but experience in flying aircraft that would not pass the pre-flight checklist in a Western European or USA air force. I know personally some of the people who fly for the like of WizzAir and I know what they flew in Eastern Europe once upon a time.
It is the flag carriers which have flight schools of their own and are re-filling their pilot's ranks from those. This is especially valid for "low cost versions" of flag airlines. So do not slag the proper "low cost carriers" for something they do not need to be slagged. There is plenty of other stuff to slag them for.
the next time you fly on one of your low cost carrier Pay to Fly piloted aircraft.
The biggest accidents have all been on national flag carriers where the crew were afraid to question the actions of the famous senior highest paid and highest ranked captain.
In the last 20years one of the major aviation safety improvements in the developed world has been training first officers to tell the captain they are wrong.
Training can only partially replicate what happened in reality. Plus, the pilot is faced with possibly several different problems at once that may not be run in a simulator simultaneously or at all in some cases. See he has to make quick, accurate decisions based on his training, experience, and what is actually happening at the time to bring the plane as safely as possible with them minimum of casualties. So any when faced with a crisis, who rises to the occasion does qualify as a hero in the public's eyes.
Note may of the pilot heroes actually do not consider themselves heroes but only someone doing their job very well in a crisis. Another point in favor of calling them heroes, their actions were only done to solve a serious problem not for seeking any glory.
Most heroes do have the appropriate training for the jobs but only show any heroism when there is a serious crisis demanding someone rise up to the occasion.
Dear Sir,
since it is all relative, would you mind defining your view of what "well paid" means, exactly?
Also, as many already pointed out, this situation is untrainable, really. However I do grant that you said "these kinds of situations". Please, and again since it is all relative, what do you mean with "kinds of situations"? Did you mean the generic "emergencies", which includes a lot of turbulence, potential loss of hydraulic systems, or maybe multiple engine failures (all the stuff / emergencies that pilots do get trained for)?
Lastly, and to put you mildly in your place, a hero is a "person who is admired for their courage, outstanding achievement, or noble qualities". ( I do not know exactly what noble qualities are, but then again, I'm not in the business of feeding you the thesaurus - you can look that up yourself, I am sure. ) Why would you not call this particular pilot, or the whole crew for that matter, heros? Without knowing all the details of the incident, the feeling that these people managed to pull off an "outstanding achievement" makes the use of the word "hero" quite adequate.
I thought, as a Khaptain, you'd understand, really!
Best regards,
Guus
"Well irrespective of the definition of the word 'Hero' this chap continued to do his job in appalling conditions, with an injured crew, missing instruments and landed his aircraft without further incident or injury."
I like Brecht's observation (from Galileo, translated):
"Fortunate is the country that has such heroes"
"No, unfortunate is the country that needs them."
As others have pointed out, blown / sucked is a bit relative; however, if one were to use the "closest to normal" pressure as a baseline reference, in this case the unusual pressure would be the low one outside, so it would be "sucked". Still a matter of perspective though.
"blown out or sucked out. High to low pressure would suggest blown"
Such an important question indeed, but from the point of the pilots I would agree the window was blown out. But then again in a similar accident in the USA the woman who later died was no doubt sucked almost out of the broken window.
...High to low pressure would suggest blown, but I'm not sure...
At Last! An intelligent and serious comment on The Register, dealing with important issues. This really demands a whole series of threads and sub-threads - perhaps a paper or two, and certainly books could be written about this.
ALL pressure-influenced movement involves a higher pressure behind an object and a lower one in front. So invariably, the object is moved by the difference in forces, and one would naturally think that the most important force is the one governing the direction of the object - in other words, items are always 'blown' - not 'sucked'.
However, I am inclined to consider the initial state of the object being acted on as the baseline, at the point where motion is initiated.. Thus, if a liquid is in a container at Standard Temperature and Pressure, and a person sucks it up by a straw, the action of sucking changes the liquid's motion, and so it is specified as neing 'sucked'.
In this case, the physical action that initiated the movement of the object/pilot was the windcreen blowing out, exposing him to low pressure. So he was sucked. An explosion in the cockpit resulting in his projection through the windscreen would mean that he was 'blown'...
In other recent airliner accident news, an Asiana A330 knocked the tail off a Turkish Airlines A321 at Istanbul airport over the weekend. Which is more or less the opposite end of the scales in terms of pilot competence. And places Asiana firmly on my no-fly list...
https://www.mirror.co.uk/news/world-news/it-sounded-like-bomb-going-12533701
This post has been deleted by its author
Because he should have looked in his rear view mirror before the ground handling staff signalled him to pull back ?
The Turkish Airlines jet had just landed and was taxiing to its assigned gate when it stopped 30 meters short of its parking position. The Asiana then whacked its rear for sticking out too much. There's no pulling back involved.
Kind of like our cats, one tends to be really tardy getting out the cat flap which then makes one of the others poke his bum, signifying "Get a move on, okay?"
There's also the fact that jets can't move backwards under their own power, they need a tractor for that. Which would make the tractor driver responsible, not the pilot.
An interesting comparison which comes back to the pilot dealing with life-threatening challenges in real time and getting the required outcome - safe delivery of everyone on board back to terra firma.
Initially the Hudson simulations were done to assess whether the aircraft could have made it back to La Guardia if the captain had made different decisions (at the time there weren't any commercial simulators that could simulate the water landing; might still be the case). Of the landing simulations only half of them (and none where real time pilot response was included, like trying to work out WTF was going on) actually had a survivable outcome, and the NTSB eventually concluded Sullenberger had acted correctly.
There's a good deal of other stuff that could have gone wrong after the landing (the aircraft had the overwater features, the river was calm, there were ferry boats in the vicinity, etc) so even with the heroic efforts of the crew to get the plane down it still needed a lot of luck to result in the fairly happy outcome.
https://www.ntsb.gov/news/press-releases/Pages/CREW_Actions_and_Safety_Equipment_Credited_with_Saving_Lives_in_US_Airways_1549_Hudson_River_Ditching_NTSB_Says.aspx
nobody has yet managed to replicate the successful landing on the Hudson River using a simulator.
Not quite - what the NTSB simulator tests tried to do was establish whether a return could have been made to the original (or alternate) airport. But even with the crew prepared for the engine failure it wasn't always possible to return and land safety.
The concern was that in this phase of flight with both engines out the checklist procedure was too long and to see if this could be improved to have allowed them to get back to a runway.
This post has been deleted by its author
This post has been deleted by its author
The missing parts of the instrument panel next to the window is the auto-pilot. As long as one of two joy-sticks and the central throttle is still left in place, it's not a big problem. Though nevertheless a rather uncomfortable flight for the pilots due to extreme weather exposure (cold wind, wind speed, ...) and injuries from broken glass pieces flying around.
Actually FCU failure/departure is a major problem on an Airbus, actually; an incredible number of systems need to know what you're doing to the aircraft, in order to work properly (e.g. pressurisation, autothrottles, autopilot, fuel-management, lift-dump, auto-brakes, etc, etc.)
"Rather uncomfortable" is one hell of a euphemism for what would have been a frankly hideous nightmare of a day at the office.
I'm not exactly a huge fan-boy of Asian pilots generally, but this was bloody a case of bloody good piloting skills and airmanship. Chapeau to the Captain.
I'm slightly surprised that the pressure dropped. The outside pressure is about 1/4 sea level (isn't it?) , and there was a sodding great hole, right at the front, with the plane presumably going at 600ish mph?
Anyone do the maths / physics for this?
Does the data recorder log cabin pressure?
(I'm not in any way saying that it wasn't appallingly windy, cold and tricky to fly...)
The Vmo for an A319 is 350 knots. That is - dont exceed 350 kts indicated airspeed. That they do 500 kts true airpseed is a function of reduced air pressure. If you leaned out the window at 30000 ft and true of 500 kts the wind in your face would be in the 250-300 range aka indicated airpseed.
If you've got 600 knot wind through that windscreen your problems are MUCH bigger. Wings and engines falling off etc.
That 300 kt wind the article indicates was blasting the cockpit means, using a Scotty-esque phrasing "She's going as fast as she can Cap'n".
Neither. In the case of an aeroplane, it's a window.
As it is for most vehicles. Especially submarines. Though submarines don't always have them, and, if they're circular, sometimes they're also called portholes. A windshield/windscreen is for a car or a motorcycle or a motorcycle sidecar.
The AAIC is a Japanese organisation, isn't it? It wouldn't be my go-to authority for aircraft terminology in English.
Clearly all three words are in use by journalists, at least. But common sense would seem to prefer "window" for a transparent section in a sealed and pressurised vehicle, while the thing on a motorbike, or an open-top car, is almost certainly not a "window".
What about a perspex screen round the edge of a balcony, I wonder?
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
