777 with Folding Wing-tips?
 

I have just heard from a fairly reliable source that Boeing are doing a 777 with folding wing-tips, so that it can fit into smallish stands. Anyone know the full story?

It is hard to know any "full" story today...
Years ago aviation industry was very openly communicating about all their innovations. Read some old Aviation Week or Flight International, it reads like a scientific publication.
Now all you get to know about the 777X ist that it will be a great aircraft... And the wings will flex a lot according to their nice pictures.

And yes, it will most probably have folding wintips, just like the very first 777 was intending to have, until the operators said "no".
Liebherr will do the system components (they do airbus high lift components and Enbraer, Bombardier, Airbus Landing gears so far)

Likely to be ditched at the last moment, as it happened before with the original 777. It will mean increased weight and cost and as airport charges are only MTOW based, there is no financial incentive for the airline to accept those. Certification (safety) is also an issue. The airports will simply have no choice but to increase the number of F/IV compatible stands, which sounds easier than it usually is.

Liebherr's involvement in the 777X wing-folding system still figures prominently on the their website, so if Boeing have abandoned the idea they haven't told their suppliers ...

Liebherr on board the Boeing 777X - Liebherr

Oh but there IS a financial incentive. A big one in fact...

For the past 5 or 6 years Boeing has been very extensively -- but very discreetly -- examining the cost benefit of folding wingtips on the 777x. (There is even a sly hint of things to come in the wording of the opening paragraph on Boeing's page referred to above.)

But the cat has finally almost made its escape from the bag.

Boeing engineers, Boeing market research people, and Boeing aerodrome experts (hint) have all been working hard to accurately assess the benefit and examine the potential market. To understand the cost benefit to users you need to do a bit of research into "Aerodrome Reference Code" (ICAO Annex 14) and "Airplane Design Group" (FAA).

Final hint: What benefits could there be if a hypothetical aircraft could be listed in one category whilst flying but could / would revert to a different category when on the ground?

grizzled

Folding wing tips, this has been on their web site for ages and its old technology.
A bit slow there, catch up guys.

Thanks Ecam.... looks like it's painted Rolls Royce Regal Red, which might be a step in the right direction... Hi.

@Grizzled
I am very well aware of those. While landing the wingtips will still be folded out, so you still cannot operate them at a V/E classified airfield. Whatever financial incentive there is, is for the airport. As as they can only charge based on the MTOW, they cannot pass on any savings to the airline. The only thing that it can help with for an airline is with gate allocation, e.g. not being forced to use a remote stand...

And maybe stop bumping into each other while taxiing....:E

http://www.pprune.org/rumours-news/5...a-eastern.html

One of the problems with the A380 is that once it lands at an Airport it cannot park safely at the apron with its almost 80m wingspan. This makes Airport authorities hesitate a bit in accepting the A380 on diversion as it restricts airport operations.
The folding wing tip will no doubt give the B777 more flexibility to operators.

The original concept in 1990, before the 777 entered service, was based around it being used to replace DC-10s etc on what DC-10s actually did at the time, which was the likes of Chicago to LAX or San Francisco. The US domestic terminal stands at these points were already maxed out so it was proposed as a way to use the existing stand space.

Of course things moved on and widebodies are never considered, apart from the odd operating convenience, for such runs now, and 777s are exclusively long-haul aircraft using different terminals, those laid out for 747s. Among other things it wasn't much of a fold, just enough to get back to DC-10 dimensions. It wasn't like a carrier aircraft !

Folding wingtips seem an accident waiting to happen. Use of them allows aircraft to be packed in tighter ... Hmmm. Non-folding aircraft directed onto a folding-sized stand, unfold them too soon on departure, forget to fold on arrival, time wasted on the taxiway folding/unfolding, have them not deploy fully properly, etc, etc. We shan't even think about attempting to depart with them folded.

There is just NO WAY to achieve the efficiency that the 777X (777-8 and 777-9) need given their size without the increased span. Without folding wingtips the aircraft would be a Category F which places quite a few operational restrictions on it (a la the A380). I'm pretty sure the folding wing tips are a done deal.

It does present some operational issues though as you would have to keep the tips folded until entering and before exiting the runway to maintain the Category E status. Folding wings are nothing new and Boeing have been working on them for quite a while for the 777 to simplify the structure and to make their design and operation as robust as possible. I'm guessing that much of their operation will be automatic along with a pretty fail-safe takeoff configuration set-up for it to work. It will be interesting but I really don't see anything about it that would be disqualifying. I'm guessing the tower controllers at LHR may not be too chuffed about the increased time on the runway that it will require.

I remember reading a Boeing article on the original 777 wing folding design years ago that said the indications and procedures would be designed to make the chance of a wingtips up takeoff less than one in a billion.

The U.S. Navy has done the wingtips folded takeoff many times:

https://theaviationist.com/2014/02/1...-folded-wings/

Two of my retired airline colleagues were at the USAF 57th Fighter Interceptor Squadron at Keflavik in 1978 when an F-4E made it around the pattern, in burner, with wingtips folded. The locking lugs were left out of position after a trip to the paint shop.

With respect... You may not be as aware of all the implications as you think you are. There are indeed potential savings to carriers - and they have little or nothing to do with gate allocations.

The essence of where you are in error relates to your statement that they cannot operate at an "E" airport. I'd be happy to explain or discuss further via PM'S.

Grizzled