The newest 747 has an additional fuel cell not currently used (tail). They discovered the extra weight causes flutter problems when they lose an engine. When they get the bugs worked out it will extend the range even further along with an engine mod that’s suppose to gain 1.8%.
That flight is only non-stop in one direction, though. The westbound flight has to stop in Brisbane, and sometimes it can’t make it that far and also has to stop in Auckland or New Caledonia.
In flight refueling would increase range of existing shorter range aircraft as well. Making them far more versatile
The versatility isn’t desirable, as has been explained. Nobody wants to be on a 737 for 12 hours.
I’m in coach too. Basically I tend to sleep one leg and stay awake the other. If it was all in one I’d just plan on doing the same. Having a bit of a walk between the awake and sleeping sections doesn’t make much difference. It’s going to suck any way you do it. I’d just rather the suckage was over quicker.
If I had to guess, I’d also say that airliners are generally loaded and trimmed with maximum fuel efficiency in mind, whereas many military aircraft are more interested in maximum payload, hauling a great many heavy things, in the cases of bombers and fighters, many heavy things that are often slung below the airplane where they generate additional drag which burns more fuel.
Thus, the benefit of being able to tank up the military jet once its airborne, in addition to the previous cited tidbit about civilian airplanes being generally welcomed in far more countries at any given time than any particular country’s military aircraft.
At the cost of being more expensive to buy, operate, and service. The airlines have much more economical solutions to service flights of those ranges. Margins are razor thin in the airline industry and saving fuel and operating costs are the most important factor. Mid-air refueling goes counter to both of those.
Aren’t pilots limited to the number of hours they can fly at any one time anyway? Or do commercial airliners habitually carry relief crews on board?
nitpick: That’s still well short of half the Earth’s equatorial circumference of 20,000 km.
Half of the Earth’s circumference of 40,000 km you mean?
For the long haul flights, yes they do.
Depends on how you parenthesize the expression. It’s either:
[ul]
[li]Left Associative: That’s still well short of (half the Earth’s equatorial circumference) of 20,000 km.[/li][li]Right Associative: That’s still well short of half (the Earth’s equatorial circumference of 20,000 km.)[/li][/ul]
The former is correct, the latter is not.
Err per wiki
I can’t read the source of that claim here at work. Can you summarize where they calculate the fuel savings if you include the cost of adding the hardware to the planes, maintaining a fleet of refueling planes around the world and the infrastructure to support them, etc? It’s certainly possible but without the calculations and costs listed I find it hard to believe.
Yes and Yes.
Almost 20 posts ago, I wrote:
No one has commented on this. Am I to understand that all of you would willingly get on a plane, when you knew in advance that it didn’t have enough fuel, and was dependent on an in-air refueling operation?
Okay, well, I guess the people who are posting on this thread know enough about the procedures that an in-flight refueling doesn’t worry them. But do you think that is true of the typical passenger? I would imagine that these fears would worry many passengers, to the point that it might make such flights un-marketable.
Arguably, fuel savings are orthogonal to the cost of planes and maintenance. The fuel savings are probably a bit like a less drastic version of the rocket equation. If you can take off with much less than a full fuel load, and continue to fly with much less than one, you will reap significant fuel savings. The tanker only has to fly up to meet you, so although it does have to take off with your fuel for the next part of the leg, it doesn’t have to go far with it, and will return to the same runway. But saving money, that wasn’t claimed. However, if we reach the day when we have to synthesise jet fuel from scratch, maybe the economics might work. I doubt it though.
Where the whole idea falls apart is the simple logistics of travel. People want to go all sorts of different places, and the number of people that explicitly want to go London-Sydney is a minuscule fraction of the International air traffic. That is why the hub model exists. If I were to fly to London I would go via Dubai. Why? There is a daily direct flight to Dubai from where I live, and any number of Dubai-London flights. I would go to New York the same way. Similarity I can go almost anywhere in Europe and the Middle East via Dubai. I have zero interest in catching a flight to Sydney (1.5 hour flight) so I can catch a non-stop flight that will take an additional 1.5 hours in the air to get me to London (retracing most of the initial journey). Indeed doing that would probably get me there later than going via Dubai, and I would spend an additional 3 hours in the air. There is zero chance that there will ever be an Adelaide New-York, or Adelaide-Munich flight say. Just not enough passengers to ever make it viable.
The sweet spot for airplane distance is inter-hub legs. As economic range has increased some hubs have dwindled in importance, but just like trains and buses, the hub model is needed to get the majority of travellers to where they want to go. The tension between the A380 and 787 is the interesting one, and that comes down to the margins of exactly who is going where. Probably both models work equally well. Both planes sell rather well.
Let’s see. An airline schedules a flight of 10,000 miles with plane 1 that will need refueling half way through. The airline has two options:
a) land plane 1 at a halfway point, refuel and take off again.
b) have a tanker (plane 2) with a crew ready at the halfway point, take off, rendezvous with plane 1, refuel the plane and land plane 2 while plane 1 continues on to its destination.
I have to think that any possible fuel savings you save with plane 1 will be more than used up by plane 2.
Just because a couple of fighter jocks says it is not big deal, think who you are asking.
Ask any of the guys that absolutely have to have fuel how they like it when the weather does not cooperate. Ask them how easy it is.
How much would it cost to train the 10% of airline pilots that would need to be certified.
What if more senior pilot ( seniority #1234 ) can not cut it but a newer pilot ( with # 14321 ) can do it? Miles, time in the air & in a lot of cases, weight, determine a large part of the pay scale. Think the APA is going to let that happen?
Also, the boom operator is as important as the pilots. How you going to pay to find them & train them?
It is not a simple & easy thing to do.
Right and good point – the only way the airline could pay for it would be to charge enough more for the nonstop service. Not to mention the insurance!