Revo1059
Topic Author
Posts: 133
Joined: Thu Mar 02, 2006 11:14 pm

777X wing questions

Thu Feb 06, 2020 7:52 pm

If this has been discussed at some point my apologies for a re-post............

So with the folding wings, how does it work procedure wise? Do they unfold the wing tips as soon as they push back or do they have to wait until they get to the runway? If the latter is the case could that cause small delays as they line up and wait for the wings to unfold? Conversely what if they won't fold after landing, are they stuck going to remote parking and using buses because it won't fit in the gate?
 
BravoOne
Posts: 3863
Joined: Fri Apr 12, 2013 2:27 pm

Re: 777X wing questions

Thu Feb 06, 2020 9:28 pm

I think there is an "auto-fold" section that retracts the wing tips as you exit the runway. Probably based on ground speed. Obviously if they won't you might not into the original gate assignment. These things work fairly quickly so as they approach the active runway, they are positioned for flight. Don't think the folding wing tips are that big of a deal when looking at the flow needed for before and after flight issues.
 
zuckie13
Posts: 238
Joined: Fri Mar 02, 2018 8:23 pm

Re: 777X wing questions

Thu Feb 06, 2020 10:16 pm

From what I've read, it takes about 20 seconds for the wing fold down for flight, and would be done when approaching the runway once clear of any obstacles where the extra width is a problem. Probably takes at least 20 seconds from "cleared to takeoff" until the plane is actually on the runway ready to go anyway, so no big deal. The pilots have an indicator to show what position they are in, or if they are in transit, and if they are not down and locked, it will trigger the same takeoff warning alarm they'd get if say flaps weren't out. On landing, they will fold automatically once the speed drops under 50 knots.
If they get stuck, they can go use the A380 gates that will be vacant soon...
 
User avatar
DocLightning
Posts: 21661
Joined: Wed Nov 16, 2005 8:51 am

Re: 777X wing questions

Fri Feb 07, 2020 1:08 am

zuckie13 wrote:
If they get stuck, they can go use the A380 gates that will be vacant soon...


And I'd like to point out that the folding/locking mechanism on the wingtips is much less complicated than the actuation system for the flaps. And yet, we rarely worry about "what if the flaps won't extend/retract?" There have been very few incidents or accidents (yes a few) caused by a failed flap mechanism (typically when that happens it's secondary to another cause such as an uncontained engine failure ejecting debris into the mechanism or a hydraulic failure). It's also much less complicated than the landing gear and while gear retraction/extension failures exist, they are still uncommon.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
-Carl Sagan
 
User avatar
Stitch
Posts: 26726
Joined: Wed Jul 06, 2005 4:26 am

Re: 777X wing questions

Fri Feb 07, 2020 1:26 am

Details of how they operate are available in Appendix B at the end of the 777-9 ACAP: http://www.boeing.com/resources/boeingd ... 9_RevA.pdf

With the 777-9 test flights, we have seen the wingtips extend as the plane approaches the active threshold and flip-up on the runway as the airframe decelerates after landing and prepares to vacate the active. The process takes under 30 seconds in each case.
 
User avatar
Starlionblue
Posts: 19634
Joined: Fri Feb 27, 2004 9:54 pm

Re: 777X wing questions

Fri Feb 07, 2020 1:41 am

Stitch wrote:
Details of how they operate are available in Appendix B at the end of the 777-9 ACAP: http://www.boeing.com/resources/boeingd ... 9_RevA.pdf

With the 777-9 test flights, we have seen the wingtips extend as the plane approaches the active threshold and flip-up on the runway as the airframe decelerates after landing and prepares to vacate the active. The process takes under 30 seconds in each case.


Prior to the hold short line makes sense. You would normally want to be fully configured for take-off, with the checklist done, before you pass the hold short line. Same as any other airliner.

The ACAP does mention that this is not always possible, so there is an alternate procedure for extension on the runway. You'd have to ask for a short delay in these cases.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
User avatar
crimsonchin
Posts: 553
Joined: Fri Feb 07, 2014 8:16 pm

Re: 777X wing questions

Sun Feb 09, 2020 6:51 pm

zuckie13 wrote:
If they get stuck, they can go use the A380 gates that will be vacant soon...


Define soon? 10 years? Or do airlines immediately throw away planes once the OEM stops making them.
 
zuckie13
Posts: 238
Joined: Fri Mar 02, 2018 8:23 pm

Re: 777X wing questions

Sun Feb 09, 2020 7:12 pm

crimsonchin wrote:
zuckie13 wrote:
If they get stuck, they can go use the A380 gates that will be vacant soon...


Define soon? 10 years? Or do airlines immediately throw away planes once the OEM stops making them.


For the love of god, do not interpret my sarcasm literally. If a pinch, they could park at an A380 sized gate - that'll have the clearance needed if the wings don't com up.

Yes, I agree there will be A380s flying for a while, there are already signs that the number is going to begin slowly decreasing - the basic fact that there seems to be no secondary market developing and we're reaching the point where they will be coming off their first leases, is the biggest one.

Who is online

Users browsing this forum: No registered users and 45 guests

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos