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View Full Version : Refueling a 747 mid air?


Cargo_ramp
2nd Dec 2004, 18:53
This is a weird question I know...but bare with me here ok!
When an airline assigns an A/C to a long distance route...say NY to HK...one of the considerations is obviously..can that A/C fly the route?..does it have the fuel capacity? Now if my information is correct..why couldn't a commercial 744 or any aircraft for that matter be refueled in flight so as to enable it to complete a long sector without landing and refueling; I believe most US military 747's have that ability. Now i know that when an airline flys a long route they would obviously have the equipment to do the job..its just a question..

The African Dude
2nd Dec 2004, 20:20
Think it would be cheaper to land and refuel than to operate a tanker aircraft.

Additionally civil aviation law governs the separation distances of aircraft in flight (which is different for militay ops, including mil air-to-air refueling)

Andy

TightSlot
2nd Dec 2004, 20:48
Not sure, but I think that mid-air refuelling can be a bit risky in a lot of ways: The kind of risky that is an acceptable risk to the military, but not to civilians. If I'm wrong, then doubtless someone'll point this out shortly.

Vont phood
2nd Dec 2004, 22:31
Could be handy though if they could replenish the bar stocks whilst the refuelling was taking place.

PAXboy
3rd Dec 2004, 02:01
The cost of running a tanker aircraft and the highly trained crew AND then getting that load of go-juice off the ground? Eevn before the separation issues mentioned, the figures will never add up.

I think that you will find that commercial separation in the cruise is at least 1.5 nm in any direction. Also, one the 747 needed refuleing, it woul dbe very light and riding high, probably above FL400. The tanker would be heavy probably not able to get that high. So the commercial would have to drop height in order to refule and so it goes on. This is why we now have 'long thin' routes etc.

--------------------
"I tell you, we are here on Earth to fart around, and don't let anybody tell you any different." Kurt Vonnegut, Jr.

Tinstaafl
3rd Dec 2004, 15:40
Additional cost makes it not worth it, legalities aside. Whether or not the transport a/c stops to refuel then carries the fuel up to altitude, or another a/c does the job & transfers it to the recipient, it still costs to get the fuel up there.

If another a/c does the job then you have the added cost of the dedicated a/c, crew/maintenance/insurance for it and training for both crews to do the transfer. All just to ship some tons of fuel 30,000' upwards. Makes more sense to have the original a/c land, top-up and do the same. At the same time it can replenish stores and empty the garbage & waste created by hundreds of people packed into the small space for a lengthy period.

The SSK
4th Dec 2004, 12:14
The most fuel-efficient stage length for a longhaul aircraft like a B747 or A340 is about 4000km, beyond which the fuel consumption per km, averaged over the journey, increases slightly (the longest-range aircraft are just flying fuel tanks with a few seats installed).

So a nonstop London-Singapore, for example, will use more fuel than if there was an intermediate stop half-way - in Dubai, say.

AntiCrash
6th Dec 2004, 01:24
Airforce One 747's have this capability. I wonder how much it comes into play?