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-   -   A380 - combined threads (https://www.pprune.org/spectators-balcony-spotters-corner/197059-a380-combined-threads.html)

admiral ackbar 29th Apr 2005 11:04

Thanks for the heads-up to the gear retraction video.

Is it me or is it quite fast. Plus as someone mentionned before, the main bogies seem to retract straight up into the bay.

Any reason why they would do it this way, other than it looks really neat?

Plastique 29th Apr 2005 11:36

The body gear retracts backwards. The 6 wheel bogie remains level with respect to the aircraft so that teh gear can stow. This gives the impression of a vertical retraction.

mikedurward 4th May 2005 08:35

A 380 Again
 
Hiya All


Sorry if this as been asked and aswered already, but can anyone tell me the runway length needed for this beast to land and tak-off please.


Thanks


Mike

Gargleblaster 4th May 2005 09:23

I wouldn't expect anybody to know at this stage !

Would guess that this needs to be determined by by test flights.

BOAC 4th May 2005 10:51

Mike - impossible to answer your question, even given test flights.

A 'minimum' length for PLANNED operations will no doubt be published but actual distances depend on too many other factors.

panda-k-bear 4th May 2005 12:14

At what weight, with what engines at what thrust with what derate, under what atmospheric conditions (temperature, runway altitude etc.)? Mere details but significantly altering any and all performance...

Swedish Steve 4th May 2005 12:23

A380 film on discovery
 
Discovery Channel in Sweden announced that there will be a documentary on the A380 on Sunday evening the 8th May. Looked in Discovery web site but could not see it. But keep your eyes open.

mikedurward 4th May 2005 12:39

OK Maybe I should have made my question a little more specific.


Which airports will the A380 be able to land at. eg would Glasgow be long enough at 2658m.
If not how much space will it need?


Mike

Gargleblaster 4th May 2005 12:45

The thingy has only flown once or a maybe few times and probably not at MTOW yet.

So I dare stating that at this stage, nobody in the known universe has any idea what the official safe distances are.

I think they'll have to do a lot of test takeoffs and landings in all kinds of weather and temperatures to determine the distances.

spekesoftly 4th May 2005 13:21


Which airports will the A380 be able to land at. eg would Glasgow be long enough at 2658m.
AFAIK, Heathrow and Gatwick are the only two UK Airports that are presently making specific preparations to handle the A380.

I would imagine that an A380, at typical landing weight, could probably land quite safely at Glasgow, but wing tip clearance and Apron space would be one of a number of limiting factors, in subsequently taxiing and parking the aircraft.

panda-k-bear 4th May 2005 13:41

I wouldn't be surprised to see STN added to the list for FedEx. My back of fag packet calcs show that it would get in to GLA, but it wouldn't get out at MTOW (nor would a 747-400 - which requires a good 1500 ft more at MTOW than the A380 does).

In short, if a 747 can do it, an A380 can do it - and about 10% better.

mikeyuk 4th May 2005 13:44

spekesoftly

--------------------------------------------------------------------------------


quote:
--------------------------------------------------------------------------------
Which airports will the A380 be able to land at. eg would Glasgow be long enough at 2658m.
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AFAIK, Heathrow and Gatwick are the only two UK Airports that are presently making specific preparations to handle the A380.


I think you will find Manchester is also.

MikeeB 4th May 2005 13:58

Add Doncaster to the list

MarkD 4th May 2005 14:09

There's an Airport Planning Doc at airbus.com (see under the 380 family on the main site rather than the reveal site) which gives graphs for temps/alts/weights and runway lengths required for Trent and GP engines, freight and pax versions.

As has been pointed out, many aircraft can beat the "standard" runway restriction if the performance penalty is worth it (say a ferry after an emergency landing at a short field, using min fuel and no pax/cargo)

ORAC 4th May 2005 14:44

A380 flight schedule
 
Airbus A380 takes off on second test flight
05.04.2005, 10:35 AM

TOULOUSE, France (AFX) - The superjumbo Airbus A380, the world's largest commercial airliner, took off over southwestern France today for its second test flight.

The European aircraft maker, based in the French city of Toulouse, said the second flight -- which came a week after the A380's maiden voyage -- would last about four hours.

A third flight is planned for later this week, probably on Saturday, followed by three flights next week, a company source told Agence France-Presse.

The plane may fly at an altitude slightly higher than the 10,000 feet achieved in the first flight, and could climb up to 13,000 feet, the source said.

panda-k-bear 4th May 2005 14:57

Doncaster will make a nice alternate. Methinks pax ops there are a wee bit optimistic, don't you?

Packsonflight 12th May 2005 11:33

A380 Take-off field lenght (m sea level ISA) 2050m (2900m for the freighter). On top of that, she climbs straight to FL350
Just for fun the B777300 Take-off field lenght (m sea level ISA) 3700m. and she only clims to FL330 on MTOW.

NWSRG 12th May 2005 22:22

One thing about the A380 confuses me...

Do a simple sum based on pounds of thrust and maximum take-off weight, and compare the A380 to other aircraft.

The 757 comes out at a healthy 0.34, the 747 comes out at around 0.28, while the lethargic A340-300 comes out at 0.22.

The A380 is just better than the A340-300 at 0.25.

So will the A380 be a lardy beast? Or will the massive wing area overcome the relative lack of power?

...and here are some figures for the insomniacs out there...(information from manufacturer sites)...

Aircraft Thrust MTOW Thrust / Weight
Airbus A340-300 136000 608300 0.2236
Airbus A380-800 308000 1232000 0.2500
Airbus A340-500 224000 818400 0.2737
Boeing 777-200ER 180000 654632 0.2750
Boeing 747-400ER 253200 908105 0.2788
Airbus A330-200 144000 514580 0.2798
Airbus A330-300 144000 514580 0.2798
Boeing 767-400ER 127000 449064 0.2828
Boeing 777-200 154000 543862 0.2832
Boeing 777-200LR 220200 764394.4 0.2881
Airbus A340-600 240000 809600 0.2964
Boeing 777-300ER 230600 773374.8 0.2982
Boeing 777-300 196000 654632 0.2994
Boeing 767-300ER 126600 411136 0.3079
Boeing 737-700 48400 154314.6 0.3136
Boeing 737-800 54600 173822 0.3141
Boeing 737-900 54600 173822 0.3141
Boeing 737-600 45400 143198 0.3170
Airbus A318 47600 149600 0.3182
Airbus A320 54000 169400 0.3188
Boeing 757-300 87000 271920 0.3199
Airbus A321 66000 205700 0.3209
Airbus A319 54000 166100 0.3251
Boeing 757-200ER 87000 254496 0.3419

Charley 13th May 2005 10:26

Interesting experiment NWSRG, but in reality it's only of limited, if any, relevance. Aircraft designers generally design aircraft to be as powerful as they need to be, as this has an impact on the economics of the aircraft.

Here are some notional examples why that might be the case. They are illustrative rather than scientific.


More power is good, right?

Well, not necessarily. Let's say we took an airframe and we put on a tiny turbojet engine, just enough to get the aircraft airborne and into the cruise. The engine weighs, for example, 1 Smidgen. The aircraft flies, cruises, descends and lands. Life is good.

Let's take the same fuselage, and attach four big turbofans to it. Let's say each turbofan, being a big beast, weighs 10 Shedloads each (40 in total). That means the aicraft is now significantly heavier and more powerful than before.

The problem is that because the aircraft is heavier, it needs to generate more lift to support its weight in flight. Lift has a bitter/sweet relationship, like many things in life. If you eat cream cakes, you will get fat. If you smoke, you will get cancer. If you need to create more lift, you will also create more drag.

Assuming the only difference is the engines, more lift would be obtained by flying faster. This means using those powerful engines to their potential. But more lift means more drag, which reduces efficiency. More power also means a higher fuel consumption, which means you need to carry more fuel. More fuel means more weight. Which needs more lift. And creates more drag. Etc etc.

In reality, design engineers have to carefully balance the various characteristics of an aircraft to ensure that everything is in equilibrium. There comes a point where a bigger, more powerful engine would end up actually being counter-productive -- it would weigh too much more, drink too much more fuel, and therefore cost more.

In our example, if an engine that weighs 1 Smidgen provides enough power to do the job, why put on anything bigger?


Extra power is a waste...

In commercial aviation, if you have more power than you need to get airborne, you don't generally use it.

In a light aircraft, once you get lined up, you open the taps and hurtle down the runway at the speed of paint. Life is good.

Jet aircraft don't generally do this. If you have a runway that is 5000 metres long and taking off at full power would get you airborne in 1000 metres, you would generally elect to apply less-than-full power during the take-off. This uses more runway, and also generally uses more fuel. So why do it? Well, engines can be expensive to fix so they tend to be operated with as much sympathy as possible. A reduced-power take-off, using only the power that is really necessary to do the job, saves wear-and-tear on the turbines and prolongs engine life.

Therefore on a 757 'pocket-rocket' you may find that the crew fly reduced-power T/O's a fair bit.


Jet operating efficiency

Finally, jet engines operate at their most efficient when they are generating about 90% power. If you have a very light airframe with very powerful engines, you might find that (at cruise altitude) you only need 50% power before you hit your limiting top speed (known as Mmo).

This means that the engines are running off-optimum. This costs money. Ergo, more spare power available is not necessarily more good.

This is also the reason why some military aircraft, e.g. the Nimrod in the UK, actually shut down an engine when they are on-station. Doing so means the other three can be revved up to a more economical cruising power.


The bottom line?

Well, the bottom line is that manufacturers generally equip aircraft with engines that are powerful enough to do the job, and not much more. Remember: they are designing commercial aircraft, not hod-rods. These things are designed to make money, not burn it.

There is, evidently, some variation between aircraft and manufacturers. If you do a search on other forums, you'll find that Boeing have in the past been slightly more likely to put 'a bit extra for Mum' into the engine selection they offer on each type, giving them slightly more spare power. Airbus, on the other hand, jokingly get slagged off for being slower in the cruise and by seemingly climbing only by virtue of the curvature of the earth. Yet they are often identified as being more more economical in the cruise than some older Boeings.

The A380 designers will have looked at their aircraft. They will have looked at how economical the airframe is, looked at the airfields it's likely to use (along with their altitudes and temperatures), looked at the speeds and altitudes they'd like it to cruise at, and worked out how much power they will need from the engines. While it may seem underpowered according to your stats, it will (in theory) deliver the economies they are looking for.

Power-to-weight ratio is an interesting stat but it needs to be considered in context, most airlines wouldn't be worried about it and would be more concerned with 'operating cost per km' and similar figures.

HTH
Charley :)

p.s. have you noticed, as an aside, how your list seems to be in order of 'long-haul' to 'short-haul'? Think about it... ;)

NWSRG 13th May 2005 12:08

Charley...

A very eloquent post...

However, I'm still wondering how Airbus achieve similar field lengths etc. to the 747, with a poorer power / weight ratio? Both being 4 engined, the comparison should be fairly straightforward.

Are we saying that the 747 has proportionately more surplus thrust than the A380 for any given situation? Or does the larger wing of the A380 trade drag for lift better than the 747 (presumably the answer is yes, it being a much newer aerofoil).

I'm guessing that a more modern wing design, with less drag for a given amount of lift, requires less powerful engines to achieve similar results??

Saying that, the pure numbers still suggest that the A380 will have 'relaxed' performance.;)

casual observer 16th May 2005 16:38

NWSRG:

A simplified answer is the A380 has a big wing which can create a lot of lift, so, it doesn't need a lot of thrust. Also, Airbus planes tend to have better low-speed performance than an equivalent Boeing airplane. Boeing planes tend to have better high-speed performance. That's why Boeing planes can cruise faster than an equivalent Airbus plane, yet they don't burn more fuel.

The A340-300 has a relatively small wing (highly loaded) and relatively low thrust. (You can compare the wing loadings, MTOW/wing area, of different aircraft, then you'll know what I mean.) That's why it has been the center of a lot of slow-climb jokes. Nevertheless, it was adequately designed for its intent.

ATCO1987 10th Sep 2005 18:02

A380 at Filton?
 
Hi All,

Dont know if this is the right place for this message, but I heard the A380 is coming to spend a couple of days in Filton in October, can anyone confirm or shed some further light on this?

Thanks!

Dan.

Squealing Pig 10th Sep 2005 23:25

If the 380 lands at EGNR the wings might be floating down the River Dee for the second time, or become a permanent monument of European technology at the traffic island at the end of 23. EGTG sounds more plausable.

ATCO1987 11th Sep 2005 03:38

Just going to say! Thats like having an AN225 land at EGGD! <G>.

Dan.

sam dilly 11th Sep 2005 10:43

Visits to other countries are a bit slow.
However sincr the A380 visited Lourdes on
10 Aug LDE LFBT all seems to be a lot better.Another
miracle!

aaaaa 11th Sep 2005 15:15

So what actually is the answer to ATCO1987's question, if of course it is possible to give an exact answer as things to seem to change a bit!?

Thanks
aa

Ghostie31 11th Sep 2005 17:34

whos gunna go watch it?

ATCO1987 11th Sep 2005 20:02

Damn right I'll be there! If I have work someone make sure it lands around midday <G>, so I'll be finished in time to see it! Dream on...:)

Dan.

aaaaa 12th Sep 2005 07:07

Me too, so where is a good place to watch it, when it happens?

aa

PPRuNeUser0211 12th Sep 2005 09:56

Best place to watch? Surely that would be in the traffic jam just off the end of it (sorry, M5!) in our seemingly random 40mph limit?

VnV2178B 12th Sep 2005 10:46

I used to have the ideal place to watch movements at Filton, my old desk in the upper portakabin at the back of 07L, but I guess the top floor of 07S would be better these days...

For those not 'fortunate' enough to work on the site: the last time something new came in (A340-600, I think it was) I was waiting for the number 75 bus just outside Filton College on the A38, where the footbridge isn't now. That's as good a place as any assuming that it approaches from England and not the Welsh end!

VnV...

Lost_luggage34 12th Sep 2005 10:55

Surely one of the News channels will cover this ?

The rollout was covered by most of them.

Can anyone confirm ?

ATCO1987 12th Sep 2005 12:10

07L? Filton is 27/09, where did 07L come from?

Dan.

VnV2178B 12th Sep 2005 14:12

Aha,

sorry, should have been clearer, for the benefit on non-AUK (Airbus UK) people '07L' refers to one of the office buildings not a runway ! It's the one on the bottom corner, near to the A38 and railway which enables inmates to see pretty well all of the airfield.


VnV...

ATCO1987 12th Sep 2005 19:04

A388...A346....slight size difference there! How about apron space too aswell as strength?

Dan.

Wycombe 12th Sep 2005 22:56

Boss,

At Airshow time, Farnborough can wind back the displaced thresholds to the physical threshold, as there are no precision approaches during this period. The physical runway length is 2400m.

I'm sure the larger visitors use this facility. Last years show saw the first ever 747 movements (believe it or not) at Farnborough.

Boss_Hogg 12th Sep 2005 23:44

ok....fair enough!

I just saw a 747 land at Exeter the other day, and the runways are of similar dimensions.

I still believe that an empty 380 can operate from Hawarden.

Boss:*

ETOPS773 14th Sep 2005 21:29

Good A380 Info
 
Just spent about an hour reading one of the best articles on the A380 I've seen so far. Hope you find it interesting :D


Good A380 article here

Cut away drawing

hei yu 16th Sep 2005 11:47

A380 plans to visit SIN/SYD/BNE in November
 
From today's Australian....

A380 plans quick visit in November
Steve Creedy, Aviation writer
September 16, 2005

QANTAS and Airbus are optimistic one of the new A380 superjumbos will visit Australia in November.

An Airbus source confirmed yesterday planning had begun for the double-decker aircraft to visit Singapore, Sydney and Brisbane. While the trip was still subject to final approval, the source said the French manufacturer was keen to show off its new plane.

Qantas has ordered 12 of the aircraft, which can carry up to 555 people in three classes and more than 800 in an all-economy configuration, and wants one to visit Brisbane as part of its 85th birthday celebrations on November 16.

The flying kangaroo's request gained significant leverage after manufacturing problems that delayed deliveries of its first planes by six months.

Sydney and Singapore are among the cities destined to see the first commercial A380 services. Singapore Airlines will start using the A380 on the kangaroo route to London at the end of next year. The plane visiting Australia would be a test aircraft, the source said, without the luxurious fit-outs airlines are promising in the commercial versions.

However, it would give Australians their first look at the giant plane and a still rare opportunity to see it in flight.

Brisbane Airport's Jim Carden said the airport's runway could handle the plane, but it would have to get dispensation from the Civil Aviation Safety Authority because the A380's 80m wingspan was wider than its taxiways.

Mr Carden said the airport expected interest in the A380 to be high enough to warrant building grandstands.

Sydney Airport also confirmed yesterday that it would be ready to handle the giant plane by November.

Airlines flying the A380 are promising a new era in comfort and facilities.

Qantas will fly the A380 with about 500 passengers in three classes, Emirates with 489 and Singapore Airlines with fewer than 480.

Qantas passengers in all classes will get special lounge areas as well as more personal space, video on demand, internet access and bigger screens.

chrisstiles 16th Sep 2005 23:14

Why the A340?
 
What was the idea with the 4-engined A340 ? Given that there are twin engines jets with ETOPS flying the same routes ?


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