# Tag Info

39

The FAA has decided/proposed (Nov 2017) that the folding mechanism must comply with certain standards, of which: The wingtips must have means to safeguard against unlocking from the extended, flight-deployed position in flight, as a result of failures, including the failure of any single structural element. All sources of airplane power that could initiate ...

25

Many modern aircraft have been designed with winglets, and older ones have been retrofitted with them. They allow a wing to produce more lift with less drag. However, the benefit is even greater if the wingspan is simply extended. The downside of increasing wingspan is that wingspan affects many aspects of airport infrastructure, especially taxiways and ...

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The Boeing 777X website states that this is to enable a more efficient wing (read: wider span) while maintaining the airport gate and taxi footprint of the classic 777 (which ensures airlines can use the 777X on roughly the same airports and intermix operations with the classic fleet).

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The folding wingtips are found mostly in naval aviation. The reason is the space constraint inside the hangar of the aircraft carrier. "US Navy 070128-N-9712C-003 Aircraft fill the hanger bays on board USS Ronald Reagan (CVN 76) after recently embarking Carrier Air Wing One Four (CVW- 14)" by U.S. Navy Photo by Mass Communication Specialist 2nd Class John P....

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Well, for starters, the drooped wing is not producing any lift in subsonic speeds. So, the flat area (the fixed part) should be significantly larger for producing the lift. This increases weight, which leads to a vicious cycle. Another thing is the wing would panels would not clear the ground while the aircraft was on its landing gear. For testing the wing ...

13

why cant this apply to all airliners? It can It can apply to any new or redesigned airliner. It's probably not something you'd need, want or be economically feasible to retrofit to existing in-service airliners. Disadvantages Whether the manufacturer or operators want the associated disadvantages is another matter. additional expense, complexity, weight ...

13

The wing folding mechanisms (in aircraft) and rotor folding mechanisms (in helicopters) are different. The V-22 Osprey falls somewhere in the middle. In case of aircraft, the wing folding mechanism is usually made of high grade steel (or titanium in some cases) and actuated either hydraulically (or in recent cases) electrically. The outer wing rotates about ...

12

As several of the comments have mentioned, the F-4 have the option of folding the outermost section of their wings, as shown in the picture below. The main purpose of this was simply to save precious space on aircraft carriers, it had no use when flying. There have been some incidents where wings have either started to fold during flight or where the pilot ...

10

The Blackburn Ripon -- a British carrier-based torpedo bomber -- is such example (first flight 1926): Source: aviadejavu.ru via Flight Source: Imperial War Museums -- seen here landing on HMS Furious Earliest mentions I found -- not necessarily carrier-based, and not necessarily real(?): Source: Flight -- 1911 Source: Flight -- folding wings on the ...

8

In U.S. Navy and Marine Corps F-4 Phantoms, the wing fold mechanism was controlled and powered by hydraulics, since the pilot had to fold the wings after landing for taxiing around on the deck. The USAF versions of the Phantom, on the other hand, had this hydraulic capability removed, and there was a pin in the top of the wing, (if I recall), just inboard of ...

6

First, you need more wing area at low speeds in order to have a reasonable landing speed. Second, you want downward turned wingtips at supersonic speeds to create compression lift. At supersonic speeds the center of lift moves aft making the airplane pitch down. You have to trim this change away and that creates drag. In the case of Concord you pump some ...

6

It's not that big a deal. It's fairly easy to make a latching mechanism that is incapable of operating under load, a great example is extension ladders or an over-center dog mechanism on a ship door. Even mechanisms which aren't actually intended for that, are very hard to release under load simply because they bind. Try to release one of these under ...

5

As Ron notes in the comments to another answer this is a perfect situation for a Ferry Permit/Special Flight Permit. The FAA via your local FSDO can authorize aircraft to fly for the purpose of being fixed elsewhere via a ferry permit. This question covers whats needed for that. However in some cases it may be cheaper to fly (or drive) in a maintenance team ...

4

So it can fit into standard size airport gates and taxiways. One reason the A380 didn't see wider adoption was it exceeded the maximum wingspan that most airports are set up for, requiring airports to build special gates and widen taxiways to accommodate it... which is expensive so very few did that. Even the airports that did make the A380 mods found ...

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Fairey Swordfish, operated off Royal Navy carriers in WW2. Supermarine Walrus, a single engine pusher flying boat carried on cruisers. Similar vintage.

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It looks like these wings have ends that fold up to become winglets, for drag reduction at high speed, and down to increase wing area, and thus lift, at low speed for takeoff and landing.

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It would allow an aircraft to have a wingspan of >80 meters yet still be able to be serviced at a standard airport gate. There are a variety of benefits to longer wingspan, but the major drawback is that commercial passenger airports are designed around that 80 meter box.

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Not with one tip up and one tip down, but it could be possible to ferry with BOTH tips folded, or removed, if Boeing has tested it. A scenario might go like this: Airline can't get one wing tip to unfold, or the tip gets physically damaged somehow, at a location where required equipment is unavailable. Airline contacts Boeing customer support (why not; ...

1

I don’t believe Boeing authorizes flight of the 777x with a wing fold failure. To be blunt, if you can afford a \$425 million airplane, you can afford a \$30,000-\\$40,000 maintenance call where an AOG team is dispatched to the airport to repair the airplane and return it to service. Even if Boeing approved flying the airplane with a wing fold failure, I ...

1

The B777x share most of the characteristic of B777. However, while B777 is Code E(ICAO)/Group V(FAA), due to b777x wingspan, it falls into Code F(ICAO)/Group VI(FAA) catalog. Currently only A380 and b748 is in Code F/Group VI catalog, which the fleet size is limited (317+123), only a few airliners has such planes and not many airport can parking place and ...

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