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-   -   Can an airliner make it around the world unrefueld (https://www.pprune.org/questions/549637-can-airliner-make-around-world-unrefueld.html)

Big Pistons Forever 19th Oct 2014 18:43

Can an airliner make it around the world unrefueld
 
The endurance thread got me thinking. Could an 777ER make it all the way around the world (equator distance) nonstop ? I am assuming stripped airframe, extra fuel, over gross takeoff, and optimized routing.

Capetonian 19th Oct 2014 19:12

As a matter of pure interest, apart from record-breaking, what would be the purpose of such an exercise? It sounds a bit like some of the Top Gear team's stunts.

Wizofoz 19th Oct 2014 19:14

No, but maybe close.

A777 200LR or 777F would be better.

Still, you are talking at least 40 hours endurance (probably 50), which would be 300-400 tonnes of fuel.

A VERY optimistic DOW would be 120T, so a BRW of AT LEAST circa 420 tonnes- 70T over MTOW.

But, yeah, experimental category it would fly at that.

Ex Cargo Clown 19th Oct 2014 20:03

Just plugged it into a L/S. Can be done but the MTOW is so exceeded, you'd be crazy to have a go.

onyxcrowle 19th Oct 2014 22:44

My geography isn't that great but isn't the circumference of the equator something in the region of 25000 miles ?
So given the range of your 777ER which can't fly non stop even from Heathrow to Brisbane without a drink (which is pretty direct as the crow flies) And that's what 11000 miles?.
So ok you strip out seats , some galley equipment all but two toilets. Overhead bins. Thsts not going to give you much of a saving in weight.
Bear in mind it's got to still be balanced.
No FAN or anyone else would allow any further stripping down due to the need for all the installation and structure and so on to maintain pressure.
You'd have to basically refill your 777 with a massive fuel tank tuning the length of the cabin. (Like when the tv show was flying some small Aircraft halfway round the world.
So for starters you'd need a quiet airport with at least 10,000 feet of runway.
Then and im no pilot but am I right in thinking that on long crossings (you see often on FR24 for example where I used to live south of the humber in the Uk) A main air corridor. Almost as most of the Ams departures on very long hall would be always reaching their cruise altitude just as they got ott. My location was close to the M1.
The 'Boston and new York stuff would already be at FL360 for example. But stuff going further . West coast and Mexico ive seen pass over as low as 29000 feet at cruise.
That im told is a step climb having to burn off the weight . Otherwise like that crash in South America a while back they flew to high too heavy too quick.
So with a flying gas tank. Probably being the only way.
Your step climb woukd take hours. And probably put you way below normal cruising height abd in the way of regional aircraft.
By the time yiud hauled that lot up to (whatever an optimal fuel saving altitude was - is it 41000? ).
You'd probably still not make it.
And of course yiud need to land right back where you started.
Out of morbid curiosity.
Why the question ?

wiggy 20th Oct 2014 07:05

Trouble with the question is once you start ignoring pesky things like structural limits the whole thing is moot. I could get a 777-200 round the world non-stop if I assumed a 2000 knot tailwind or the burn was a tonne an hour.......

Anyhow in the real world and honouring at least Max take-off weight (structural) here's a very ballpark, very much back of the envelope stuff/top of the head stuff/extrapolation so I hope the purists/performance folks will forgive me. IMHO the answer is : No, nowhere near.

Here's why: Take London-Singapore - great circle distance is near enough 10,000km ( the circumference of the earth is 40,000 km). In the real world on a favourable day your average 777-200 can lift full'ish tanks plus perhaps 40-50 tonnes of payload and fly it from London to Singapore, (probably with a tail wind), and get there with legal reserves, maybe worth another 1 hour and a half's flying max) - remember that was taking off out of London at or close to maximum allowable structural weight...

I guess if you stripped out all internal fittings but left the basic structure intact, you could maybe swap your 40-50 tonnes of payload to 40-50 tonnes of fuel, carried presumably in using some fuselage tank(s). That will only probably give you maybe another 7'ish hours in the cruise at normal burn. I suppose it's just possible that if you assume the burn/hour value will gets lots lower than we normally see in the cruise, because the aircraft weight is going to be unusually low, so all in all you might get out towards 10 hours of extra cruise but no promises (I'm not going to dive into the manuals at the moment so I might be being very generous) .....Looks like you might just perhaps squeeze out another 10,000 km of travel beyond the norm if you had very favourable winds and burnt all reserves i.e. ran to tanks dry :eek:


So, if you're lucky, close to halfway around the world (great circle distance), give or take.

Of course if you go back to the OP's scenario and have an infinite runway and ignore max take-off weight it may be possible, but I guess you might then be able to taxi all the way ..oh hold on, there's the maximum allowable taxi weight to consider :uhoh:

Denti 20th Oct 2014 08:13

If i remember correctly boeing once did a demonstration flight eastbound from hongkong to london in a 777-200LR. Took them close to 23 hours and they had a crew of eight pilots doing it. But i have no idea if they had any passengers or payload. Probably just an empty frame, some catering and the flight crews.

SeenItAll 27th Oct 2014 02:56

Maybe not an "airliner," but the Rutan Voyager made it unrefueled around the world via the equator. Only took 9 days. See Rutan Voyager - Wikipedia, the free encyclopedia

Boeing 777LR did fly from Hong Kong to London easterly. More than halfway around the earth -- which is all the reach any plane needs for nonstop travel anywhere. For passenger transport purposes, there is no point in having any further range. See "It was like no other flight"

glendalegoon 30th Oct 2014 02:32

there was a plane called the beech airliner (B99), if you put it inside the C5 Galaxy (I am sure it would fit) and then flew the plane (C5) around the world using refueling in flight, you could say an airliner flew around the world without being refueled.


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