A380 vs B747, which one is faster?

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A380 vs B747, which one is faster?

Unread post by airbusa346 » Tue Jul 17, 2012 4:46 pm

Having flown on both, and with both being technological advanced behemoths I was wondering which one rules the roost in terms of speed?
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Re: A380 vs B747, which one is faster?

Unread post by Christo » Tue Jul 17, 2012 5:47 pm

Jets aren't flown at top speed, but the most economical speed which change everytime they fly, not so?
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Re: A380 vs B747, which one is faster?

Unread post by FoxTROT » Tue Jul 17, 2012 10:38 pm

Depends which type of B747 you are referring to.

If you Google and Wiki, you'll probably find the A380 has a typical cruise speed higher than that of B747-100/-200/-300; about the same or slightly higher than B747-400 and B747SP; but slower than the B747-8/8F.
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Re: A380 vs B747, which one is faster?

Unread post by three eighty » Wed Jul 18, 2012 6:06 am

Typically the 380 will cruise at 0.86.
Maybe a 747 pilot out there can fill us in on it's cruise speed.
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Re: A380 vs B747, which one is faster?

Unread post by Richard Smit » Wed Jul 18, 2012 7:46 am

M0.86 used to be normal cruise on the SAA B747-400's until the fuel price began to get nasty. Toward the end we operated them closer to M0.83 most of the time.

While not economical, it is easy to cruise the B744 well above M0.86.
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Re: A380 vs B747, which one is faster?

Unread post by airbusa346 » Wed Jul 18, 2012 8:50 am

Will the B747-800 be faster than the B747-400?
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Re: A380 vs B747, which one is faster?

Unread post by 2000andmore » Wed Jul 18, 2012 8:54 am

The A380 was designed to have an economical cruise speed, and a high speed cruise. The design turned out such that the fuel burn was higher than expected at the economical cruise speed (due to the lower than desired aspect ratio of the wing) and so they tend to only use the high speed cruise of around 0,86. There are no/ minimal gains by cruising slower in the A380 unless the aircraft is partially filled.
You will see that Airbus is changing the wing twist from next year, and increasing the washout by another 1.5 degrees in order to try and resolve this problem.
The basic problem stems from the fact that you want to carry 555 pax, making this a large aircraft, so you need a certain wing area, but you are restricted in span due to existing airport infrastructure. The net result is that the wing chord is increased, with a fixed span, so the aspect ratio of the wing reduces. Induced drag is inversely proportional to aspect ratio. So they have a bit of a problem!
Boeings new 747-8 has a high aspect ratio, raked wingtip design wing, that is very efficient, with a low fuel burn per pax......hard to beat. Not to mention the B787 and B777 and their very efficient wings.
Cruise speed depends on how much fuel you want to burn, in general.
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Re: A380 vs B747, which one is faster?

Unread post by airbusa346 » Wed Jul 18, 2012 4:37 pm

I would think that the B747-800 Intecontinental is now the quickest commercial airliner around, beating the -400. I am beginning to like this plane more an more. It just boggles the mind how Lufthansa can have the A380-800, B747-800 and B747-400 in their fleet, I cannot think of any other airlines that have these three planes in their fleet.
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Re: A380 vs B747, which one is faster?

Unread post by trees » Thu Jul 19, 2012 4:10 pm

remember that lufthansa is replacing the -400 with the -8
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Re: A380 vs B747, which one is faster?

Unread post by airbusa346 » Thu Jul 19, 2012 5:31 pm

oh ok, didn't know that ,so I suspect that over the next decade we will see more and more airlines replacing the 400 with the 800 to modernise their fleets

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