777 and the Folding Wings

Personally I’d see a folding wing 777, or anything else with folding wings, as an interim design making use of production capacity while something more radical is developed. Both Airbus and Boeing have plenty of concepts which don’t follow the ‘conventional’ layout….

If anything the “blended wing” designs I’ve seen look to be wider than current jets. The “Joined wing” (where sharply swept wings are connected to the aft fuselage by a forward swept “T” tail with a serious anhedrial issue) might be a bit narrower.

I agree, sooner or later airliners will take advantage of these NASA and RAE concepts. Perhaps as the replacement for the 777X, 787 or A350. In other words, not anytime soon.

You might need a helmet too!

Nah, we’re not airliners.net.

If you’re just talking about narrower aircraft but don’t want to go with folding wings why not use two wings instead and re-invent the bi-plane? (put’s on bullet proof vest, hides behind nearest tree!)

John

It’s not just about the aircraft.

Of course all the comments about the airlines not wanting the extra weight and complexity are true, but there’s a very important ‘airport angle’ to this too. Say you do manage to squeeze a fleet of 777s into gates designed for 737s or whatever. Suddenly your landside infrastructure has to cope with twice as many passengers in one go than it was designed for. In most airports that’s a recipe for utter chaos, even before that extra volume of people makes it as far as the immigration desks… I do no more than mention baggage handling. You get the picture, I’m sure. Airlines know from bitter experience that any upset in an airport terminal reflects on them, not the airport operator, regardless of who’s fault it is, so they won’t do it.

On the other hand, if we’re talking about new, more efficient. and now folding, wings on an aircraft of roughly the same capacity as that for which a gate was designed, then it’s a lot more plausible. Like several others, I don’t see the objection, provided there’s a demonstrable net benefit. Personally I’d see a folding wing 777, or anything else with folding wings, as an interim design making use of production capacity while something more radical is developed. Both Airbus and Boeing have plenty of concepts which don’t follow the ‘conventional’ layout, and which would deliver more people into most current gates without resorting to folding wings. My comments about airport infrastructure still apply, but over a longer development timescale the airport operators have time to sort things out.

I never understood at all why this concept was so controversial to some. It seemed like a good idea to me at the time, and still does. I wouldn’t be surprised if we saw it at some time in the future. If they A380 had it, perhaps LAX wouldn’t have to shut down half the airport whenever one was taxiing.

I was just reading the latest Aviation Week and they have a few details on the 777X concept.
Yes, they’re thinking of putting elctrically actuated folding wingtip as part of an all-new wing that features raked outer sections. The new wing has a 20 foot wider span, so making the outer 11 feet of each wing fold would enable it to fit into current 777 gates. According to the magazine, that part of the wing has no control surfaces and I’d guess no fuel (but I certainly could be wrong).

Boeing says it’s an all new system, not related to the original wing fold system designed for 777s.
It seems the launch customer, United wanted its 777s to fit into DC-10-size gates so Boeing adapted a mechanical wing folding system similar to the one found on A-6E Intruders. As mentioned previously, it was never ordered so no-folding wing 777s were built.

Boeing have recently stated they might be re-visiting the folding wing idea with they opt to re-wing the 777 in an NG project. It would allow them to optimise the wing area for reduced drag, but stay within the 80m box.

I’m sure it is an impractical idea as people say, but having folding wings making airport aprons looking like an aircraft carrier flight deck sounds rather fun at the very least.

Wouldn’t folding wings also add an extra maintenance expense/risk? after all, we are talking additional moving parts, fuel tanks in those parts (unless they are removed then you are back to a range issue).

IIRC, the proposed fold were outboard of the fuel tanks (or perhaps, the fuel tanks were shortened to allow for the fold) at about 80-90% of the span.
Not like the wartime Grumman fighters (or DH Moths) where the entire wing folded. 🙂

Wouldn’t folding wings also add an extra maintenance expense/risk? after all, we are talking additional moving parts, fuel tanks in those parts (unless they are removed then you are back to a range issue).

I believe that there are a couple of gates at LHR which the A380 can’t use because they are too tight for it to turn around there.

Tenthije is correct. No prototype was ever made, it was a paper concept but no airlines wanted it. Airlines (who deal with many airports) didn’t see the need.

Gate space isn’t a problem at miost airports. You mention BA, look at LHR’s new Terminal 5, plenty of room.
The idea that smaller gates would make room for more runways won’t work…runways have to be a distance away from terminals for safety considerations.

It might be worth revisiting if future airliners go to high aspect ratio wings for efficiency, but right now airports seem to have plenty of room for A380s, 747-800s, A340s…and 777s.

A single prototype was built

Are you sure? I thought the folding wings were a paper concept only, and that no prototypes where made.

Now with airports like Heathrow operating at 99.2% capacity, and possibly many more to follow, wouldn’t it make sense to re-open the idea.

No it would not make sense.

There are several ways in which an airport can reach capacity:

Most airports are runway and/or taxiway restricted. This includes Heathrow. Having folding wings would make no difference to them. If anything it would make matters worse. The added weight required for the folding wings will mean longer braking distances and thus longer time on runway.

Besides, with the razor thin margins that airlines operate under the folding wing would be too expensive anyway. Too heavy and too much maintenance.

Was it ever a viable proposition ?

Even if it were, and they overcame the design problems, it would surely have
a dramatic affect on the aircraft’s range.