The dreamliner has landed at Farnborough.
Impressively short braking from touch down (mind - its not loaded). Check out those airbrakes.
I love the way the new range of composite wings flex in flight, gives the plane a distinct bird like look.
www.bbc.co.uk/news/business-10676791
|
>> I love the way the new range of composite wings flex in flight
Mmm... not sure I'd want to see that from inside the plane...
|
>> not sure I'd want to see that from inside the plane...
You can't be very observant Focus if you haven't noticed the way an aircraft's wings bend upwards, a good couple of feet or more at the ends, more like six feet, as it gathers speed when taking off, and droop again when its landing speed has been braked down to about 50mph...
I can remember my father talking about the wings of a government Dakota flapping in a tropical storm over southern India, with the plane going up and down like a coalmine lift two or three hundred feet at a time and lightning all around. Sounded dramatic.
|
>> You can't be very observant Focus if you haven't noticed the way an aircraft's wings
>> bend upwards, a good couple of feet or more at the ends, more like six
>> feet, as it gathers speed when taking off, and droop again when its landing speed
>> has been braked down to about 50mph...
Well I haven't flown that many times, but IIRC the wings move but stay fairly straight, as opposed to bending in the middle like they do in that clip. Or perhaps it just looks different when viewed from outside.
|
>> ..... you haven't noticed the way an aircraft's wings bend upwards, a good couple of feet or more at the ends, more like six feet, as it gathers speed when taking off,
They can bend slightly more !!!!
www.flightglobal.com/blogs/flightblogger/2010/03/source-zy997-completes-150-ult.html
then click on the pic for a larger view and be prepared to be impressed!l
|
That's one thing on the ground in a hanger.
How would it look at 500mph with two RR turbines strapped to it at -50C ?
Edit: Forgot to mention 37000 feet & volcanic ash/ice
Last edited by: gmac on Sun 18 Jul 10 at 20:01
|
>> I can remember my father talking about the wings of a government Dakota flapping in
>> a tropical storm over southern India, with the plane going up and down like a
>> coalmine lift two or three hundred feet at a time and lightning all around. Sounded
>> dramatic.
>>
It still happens today over the Arabian Sea. My new job requires me to travel to central, southern India every few weeks. Original cruising altitude was meant to be 39k feet, started getting abit wobbly, climbed to 41k feet, still couldn't see the sun clearly, went up to 43k feet then got bounced around for an hour and a half in a pea souper. The wings looked like a seagul trying to take off.
Airbus 319 still has an impressivly short braking distance as ably demonstrated to all passengers arriving back in Cologne on Friday night from Munich. Managed to shift all the overhead locker contents to the front and crash the screen controlling the cabin systems which sent it into reboot. Anyone needing some parts for a A319 will probably find a load around the piano strip of the SW strip at Cologne/Bonn airport.
|
I can remember one occasion of sudden extreme turbulence in an aircraft, smallish I think and perhaps a Boeing 737, climbing out of Algiers over the sea. It was a single, enormous bump, as the aircraft flew through a huge bubble of hot thin air and dropped like a stone (I think that's what happened anyway), 100 metres they said. People screamed and a few trays and things got tossed around.
I bet the wings flapped then, but I wasn't looking.
|
Usually when taking off in Europe you see they use quite a bit of flaps to create the lift.
I recorded take-off from Dubai coming back to Europe, no flaps, just straight forward thrust up over the Gulf then a sharp left before hitting Iranian airspace.
The speed of approach there is something else too. Never experienced an approach like that into Dubai at midnight. Straight in and thinking about the braking once all the wheels are on the ground.
|
>> I love the way the new range of composite wings flex in flight
Mmm... not sure I'd want to see that from inside the plane...
I cannot get it out my head that 'Herr, they delaminate' is almost an anagram of ' Hey ! The Dreamliner'!
|
>> The dreamliner has landed at Farnborough.
>>
>> Impressively short braking from touch down (mind - its not loaded). Check out those airbrakes.>>
If you are referring to the flaps on the top of the wings they are not "airbrakes", they are "lift dumps" used to destroy the wings lift. They are interlocked and cannot be fully deployed until the weight of the aircraft is on the undercarriage.
|
|
if the weight of the aircarft is interlocked onto the undercarriage you dont need lift dumps.
Last edited by: Zero on Sun 18 Jul 10 at 17:25
|
>> if the weight of the aircraft is interlocked onto the undercarriage you dont need lift
>> dumps.
>>
It ws explained to me by a pal who was an airline captain, Too difficult to explain here, look it up.
|
>> Too difficult to explain here, look it up.
en.wikipedia.org/wiki/Flight_control_surfaces
"Ground spoilers are essentially similar to flight spoilers, except that they deploy upon touchdown on the runway, and include all spoiler panels for maximum "lift dump". After touchdown, the ground spoilers deploy, and "dump" the lift generated by the wings, thus placing the aircraft's weight on the wheels, which accomplish the vast majority of braking after touchdown."
|
The flaps on the wings' upper surface fulfills both purposes - increasing aerodynamic drag to slow the aircraft, as well as reducing lift, thus placing the aircraft hard on its wheels to allow full braking to be applied.
The wings on all craft bend smoothly from root to tip, as any discontinuity in bending would imply large stresses. In general terms, stress is proportional to curvature, and over a long wing, large tip deflections can build for modest levels of curvature [hence stress] distributed along the length.
I worked for a company supplying systems which are installed within the wing [the HJ member cubleader did a work placement there also] I left the company for pastures new just as the Dreamliner work came in, but, I do remember it was odd for a Boeing project in that instead of an incremental development from past Boeing practice, more radical options were considered, even for small and trivial details.
|
Hopefully the more airlines that specify the Trent engines the more work there will be for UK workers.
I do worry about all this material science though that one day they could accidently design a new Comet.
|
|
It didn't seem to have any reverse thrust which makes the short landing even more impressive.
|
|
I thought I saw the reverse thrust mechanism working on the engines as it landed. The cowls split and one part moves back to send thrust air forwards.
|
>>I do worry ...
Yes, Rattle, you do. Perhaps a bit too much.
If we want to continue to advance, we will, every now and again have a cock up, and people will die and be injured.
It's the price we've been paying all along the way from bridges collapsing as soldiers march across them, through to countless fatal boiler explosions in the days of steam, innumerable failures due to crack growth / fatigue in materials, and it would be a foolish engineer who thought that just because we have learnt from these past mistakes, just because we now do our analysis on computer, and just because our analyses are codified in national standards, we are fully protected.
|
>> >>I do worry ...
>>
>> Yes, Rattle, you do. Perhaps a bit too much.
>>
>> If we want to continue to advance, we will, every now and again have a
>> cock up, and people will die and be injured.
>>
>> ... and just because our analyses are codified in
>> national standards, we are fully protected.
I'm sure Rattle is now suitably reassured :)
Last edited by: Focus on Sun 18 Jul 10 at 20:58
|
|
Yep, there's absolutely no point in worrying about it!
|
|
Yup, in effect N_C is calling you a laboratory rat...
|
|
Nice to see that they managed to inverview the Boeing guy in from of the Airbus A380
|
>> I do worry
In the context of this thread, it's perhaps worth pointing out that the pioneer of the jet engine was named Whittle! ;-)
|
>> I worked for a company supplying systems which are installed within the >> wing [the HJ member cubleader did a work placement there also
NC
He wondered about that at the time but never did work out who you were, He's building helicopters in Yeovil now
I'm his dad, btw
Last edited by: commerdriver on Mon 19 Jul 10 at 09:44
|
>>He's building helicopters in Yeovil now
Sounds good!
I found that particular company rather Dickensian, and I didn't want to build a career there - so, at the earliest opportunity, I got out. There were a few people there of an enlightened attitude, but, alas, there were some real monsters in positions of power.
While I was there, I was a systems engineer, working mainly in the Airbus team, although I also got heavily involved in sorting out problems on a hydraulic motor for a Spanish aircraft, and getting a variable displacement hydraulic motor controller working - which was a bit scary, as if the controller failed, the motor would spin to self destruction in about 15 milliseconds.
While the work was technically very interesting indeed, I knew that staying there would drive me mad. SWMBO noticed my mood lifted significantly as soon as I left.
|
A load of incorrect technical reporting on the 787 in another leading paper today.
1.. It is stated that the cabin pressure has been reduced to allow more oxygen to be present. I guess they mean cabin altitude - that makes sense. Low pressue = low oxygen.
2. The last aircraft I flew with pneumatics in it was in 1959. However, I read that pneumatics (probably hydraulics is meant) have been removed from the 787 and replaced with electrical systems thus resulting in the removal of 60 miles of copper cable. How putting in more electrics results in less cable is a neat trick.
Don't believe too much you read in any paper
|
placed with electrical systems thus resulting in the removal of 60 miles of copper cable. How putting in more electrics results in less cable is a neat trick.
They will be using a derivative of the CANbus technology. Any Citroen owners (amongst others) who want to fly in it?
|
>> with electrical systems thus resulting in the removal of 60 miles of copper cable. How
>> putting in more electrics results in less cable is a neat trick.
Its possible, they are using sophisticated multiplexed electricl systems.
So sophisitcated in fact, Boeing cant make sense of the configuations spat out by the design computer. This is one of the reasons for its massive delays that has at times come close to crippling the company.
|
|
Airbus has been using fly-by-wire for 10 years or more. Mind you, they did have to re-teach the pilots to 'fly' "No, when the computer takes over, just let it. Otherwise you crash into the trees, like the plane at ****[Can't remember] airshow".
|
|
Paris. The footage still sends chills up my spine.
|
Not Paris, somewhere in Alsace; possibly Mulhouse?
Edit: Habsheim
www.airdisaster.com/investigations/af296/af296.shtml
Last edited by: Bromptonaut on Mon 19 Jul 10 at 17:07
|
www.airdisaster.com/investigations/af296/af296.shtml#jacquet
Well worth reading, particularly if you like conspiracy theories!
Sorry you beat me to it!
Last edited by: pmh on Mon 19 Jul 10 at 17:10
|
>> Airbus has been using fly-by-wire for 10 years or more. Mind you, they did have
>> to re-teach the pilots to 'fly' "No, when the computer takes over, just let it.
>> Otherwise you crash into the trees, like the plane at ****[Can't remember] airshow".
>>
Fly-by-wire is absolutely fantastic IMHO. The computer will never "take over"; what it will do is protect the aeroplane while guaranteeing best performance within safe limits. Flying technique is conventional, you just forget about trimming.
|
AH so the A320 here trimmed itself into the trees.
www.youtube.com/watch?v=bzD4tIvPHwE
|
>> AH so the A320 here trimmed itself into the trees.
>> www.youtube.com/watch?v=bzD4tIvPHwE
>>
No, the computer was holding it at the maximum angle of attack. A conventional aircraft at that point would have stalled and plummeted into the ground; the fact that the Airbus sank relatively gently into trees probably explains why only 3 people died in the resulting crash.
At a higher altitude, once a certain angle of attack is reached the engines would have automatically spooled up to maximum power. However, because this isn't a particularly desirable attribute when in the landing flare, it's inhibited below 100ft.
It can in the order of 10-15 seconds for engines to start developing meaningful thrust from an idle setting. Until that time you're effectively a glider, regardless of how many computers you have at your disposal.
|
>> Fly-by-wire is absolutely fantastic IMHO. The computer will never "take over"; what it will do
>> is protect the aeroplane while guaranteeing best performance within safe limits. Flying technique is conventional,you just forget about trimming.
It does takeover to stop you doing certain manoeuvres - stalling, spinning, etc. It also takes over to give similar feel and responsiveness across all Airbus aircraft types. It also can result in larger movements of control surfaces at lower speeds to ensure good response. Too large and you get the kind of accident where the tail sheered off on that American Airlines Airbus outside New York where it seems that the pilot was overcompensating on the rudder at low speed.
You are correct about trimming, but this ultimately this does have an effect on flying technique. e.g. power on usually results in nose pitch up. In an airbus it doesn't do this which is quite a shift in the way that one gets used to flying. In a 737, for example, if they abort landing and go around again the power can't be rolled on too fast because otherwise the pilot could run out of nose pitch down control.
|
Well, to an extent, but I wouldn't call the fly-by-wire protection "taking over" simply because I don't see it limiting what the aircraft can do. Sure, you could set it so you can pull back harder - but you'd stall, plummet from the sky, and die. Alternatively, you could roll it on its back... at which point you'd probably plummet from the sky, and die. Or you could overspeed it, at which point... well, you get the picture.
The American Airlines Airbus crashed because of inappropriate rudder inputs and nothing to do with the fly-by-wire, since it was an A310. Even with fly-by-wire there's a mechanical link to the rudder so in the event of a brief complete electrical failure it's still possible to maintain directional control.
I agree with you about the pitch/power couple, obviously in an Airbus in the event of a go-around a significant nose-up pitch input must be made when hand-flying otherwise you simply end up barrelling down the glideslope at full power... :-)
|
|
Well thats pretty much given away who I now work for!
|
|
Nooo, Lots of companies build helicopters in Yoevile, loads of them.
|
>> Nooo, Lots of companies build helicopters in Yoevile, loads of them.
>>
Often amazes me how many helicopter plant there are in that area :-)
|
Back to the 787. I'm intrigued by the claims being made for its cabin. Higher air pressure and bigger windows I can understand as benefits of the new structure. Similarly higher humidity, because there's less moisture-sensitive metal to corrode. I've done a couple of long trips by A380, which has a more conventional structure, and found them less dehydrating than I'd been used to, but perhaps I imagined that.
But what really piques my curiosity is the claim that passengers will have more space. I don't mean the plutocrats in the pointy end, I mean us proles in the cheap seats. Does anyone really believe that the airlines will do anything but cram us in as tight as we'll go? As I understand it the 787 cabin was designed for eight across, but already airlines are asking Boeing to fit nine, so our shoulders will be squeezed and it's hard to imagine our knees faring any better. If anyone knows who'll be flying 787s with extra-spacious economy seats, tell me where I join the queue.
|
>> If anyone knows who'll be flying 787s with extra-spacious economy seats, tell me where I join the queue.
As long as you don't end up sitting next to this guy in the 4 abreast seating:
tinyurl.com/yj2ya2u
|
Call me a Luddite, but I'd rather fly long distance (or any distance really) with four engines, rather than two.
I had a friend years ago who was once a radio operator for British South American Airways (shows it was a very long time ago) and told hair-raising tales about landing with three engines down.
|
>> Call me a Luddite, but I'd rather fly long distance (or any distance really) with
>> four engines, rather than two.
That used to be the rule for flying over the Atlantic for example, didn't it?
|
>> Call me a Luddite, but I'd rather fly long distance (or any distance really) with
>> four engines, rather than two.
>> I had a friend years ago who was once a radio operator for British South
>> American Airways (shows it was a very long time ago) and told hair-raising tales about
>> landing with three engines down.
Ran out of coal for the boilers?
|
So it was you that bashed that camera bag into my knee on your way to row 28, was it?
};---)
|
Mike, it's very seldom that major components (fan, shaft, compressor) of aero engines fail. More common - although still rare - are problems with ancillaries like pumps, but these are generally duplicated within each engine.
Big engine trouble tends to come from without - birds, volcanic dust - and then you could have ten engines and have them all stop.
I agree that a four-engined airliner somehow looks 'right' in an emotionally appealing way that a twin can't match. The Airbus A340 looks classically elegant and the Boeing 777 is pure brutal functionality, but they compete for the same buyers and the 777 is the overwhelming winner. It seems passengers in general can put aside their preference for four engines when offered the fare savings of two.
|
The A340-600 is a fantastic aircraft, and very long and sleek. In fact its the longest aircraft you can get, but people dont realise this until you see it parked next to the A380.
The market demands twins for economy and thats what is killing off the A340, although Airbus have this market covered with the A330.
There are still a few slim routes where for point to point you need 4 engines, but due to extended ETOPS these are becoming fewer and fewer
|
|
Many years ago when I flew to Canada from Manchester I was surprised the plane was a 737. I was expecting it to have four engines. I did ask someone and because it flew over/near Greenland it was deemed okay to have only two engines.
|
|
ETOPS - I guess a 737 is allowed to be about 90 minutes from land. If you were on a 4 engined aircraft then you could have gone straight across
|
Or a 180-minute ETOPS plane like the 777. That rule was introduced in 1995, which happily (for Boeing) coincided with the commercial debut of the 777.
As Mikey says, a few airlines, like Emirates, use the A340-500 where extreme range and four engines are still a necessity, but for most others the 777-300ER has them covered and costs less to operate.
|
|
OTOPS criteria are based on an engine/aircraft combination achieving a very low rate of in flight shutdowns. In some cases the stats wre "cooked" by a ropey engine being put to idle, with the flight continuing, and this did not count as a shutdown. A 4 engined aircraft must be, at any point on its planned route, within 180 minutes of a suitable diversion airfield. There are in fact only very small no-go areas in the whole world where this criterion cannot be met
|
I agree re the beauty of an A340, and the fact that a 777, particularly the 300ER, is amazingly efficient.
Where the 340 works though is a mix of freight and passengers, for instance an A340-300 has the same fuselage and therefore the same passenger capacity as an A330-300 though a much higher MTOW (max take-off weight), around 40 tonnes more, so can carry significant dense cargo alongside passengers on relevant routes.
|
Dreamliner - Focusless
