Boeing 777x Cockpit Layout - Wingtip Folding Controls

[Woozie 732]

As you may know, the 777X features wingtip folding to allow it to fit into standard 777 gates, as the new generation of Triple7's has increased wingspan. Boeing recently revealed cockpit renders and i find the location of the folding controls quite special, so close to the Seatbelt switch, and without any flip cover. I'm sure there are a myriad of checks to prevent accidental midflight folding but i'm still amazed they deem this to be the best location for the switch. 

 

"Ladies and Gentlemen, as we prepare for decent, the captain has now folded the wings. Please fasten your seatbelts and enter the brace position. We will arrive at our destination soon, VERY SOON!"

(credit @AvWeekGuy at twitter)

 

 

[Captain Kevin 586]

If you were trying to turn the seatbelt sign, you turn the switch to the right. If you were trying to fold the wings, you turn the switch to the left. So if you're trying to turn the seatbelt sign on and you accidentally grab the switch to fold the wings, presumably, when you turn it to the right, nothing would happen since it's already in the right most position. Probably be more of a concern if you were trying to turn the seatbelt sign off, but I would hope they have a way to safeguard against that happening electronically or something.

[Woozie 732]

15 minutes ago, Captain Kevin said:

If you were trying to turn the seatbelt sign, you turn the switch to the right. If you were trying to fold the wings, you turn the switch to the left. So if you're trying to turn the seatbelt sign on and you accidentally grab the switch to fold the wings, presumably, when you turn it to the right, nothing would happen since it's already in the right most position. Probably be more of a concern if you were trying to turn the seatbelt sign off, but I would hope they have a way to safeguard against that happening electronically or something.

Yup, turning the sign off has much more potential for disaster.... ;)

Conclusion is: Climb phase is much more dangerous than descent phase ;)

[dmwalker 603]

One safeguard is the different shape of the switch knob.

[Chock 17,769]

I should think there will be some kind of inhibitor for the actuators which stops the mechanism folding when there's no weight on the wheels, much like there are inhibitors for other stuff you'd not want to do whilst airborne, i.e. thrust reverse, opening the doors etc. Really, it's never been an issue for naval aviators to be flying stuff with folding wings, and they don't often have a co-pilot to check their switch selections either.

With regard to the positioning of the switch, it's pretty close to the landing light switches, which would be something you'd turn off as you came off the runway, and that's apparently when the wings would be folded up too, since that would give it better clearance on taxiways, so it actually makes sense to have the switch there, it also makes sense to have the switch in a location where both the P1 and P2 could operate it so the sectors can be properly shared, unlike some stupid stuff relating to switch positions on some Boeings over the years, i.e. try putting the parking brake on from the left seat, or trimming it from the right seat in a Boeing B-17 lol.

Needless to say, for take-off, the reverse would also fit that scenario, i.e. flipping the landing lights on when taking to the runway and also lowering those wingtips at that point, so again the switch location makes sense. I'm sure there will be T/O config warning horn and all kinds of flashing lights going off if you try to open the throttles up past a certain percentage with those wings still folded.

[HighBypass 2,339]

6 hours ago, Chock said:

......Really, it's never been an issue for naval aviators to be flying stuff with folding wings, .....

..(cough)... F-8 Crusader... (cough) ..

Actually the Crusader flew ok with wings folded..

 

[Chock 17,769]

15 minutes ago, HighBypass said:

..(cough)... F-8 Crusader... (cough) ..

Actually the Crusader flew ok with wings folded..

 

Well, that thing looked like it was falling in half anyway with its variable incidence wing. Yup, I'd read about someone taking off with the wings folded and actually managing to land it again. Pretty amazing story but apparently true it would seem.

[HighBypass 2,339]

..and apparently it happened more than once. Not to the same pilot though. 

[Chock 17,769]

3 hours ago, HighBypass said:

..and apparently it happened more than once. Not to the same pilot though. 

Yup, I'm pretty sure you wouldn't forget to do it a second time, things like that tend to teach you harsh but memorable lessons, like the time I was so nervous about flying a new single seater (well, new to me) for the first time, that I strapped myself in mega-tightly, it was when I took off and found out I couldn't reach the radio panel because of those straps that I learned one of those lessons. Never done that again. LMAO. 

[Matthew Kane 1,343]

I bet you that 777x would also fly if that portion of the wings folded as well. From the way those wings look it would end up being a clipped wing, perfect for aerobatics, get Tex Johnson on the controls and sell those aircraft 

[Chock 17,769]

Yup, I'd put money on it flying okay with the wings folded, in fact I wouldn't mind betting they'd try it as part of the certification process, at the very least in a wind tunnel or a simulation, if not actually for real, just to see what happened if the thing did have one fold up in flight (never say never, right?). I bet some of the old test pilot dudes such as Tex Johnson and Chuck Yeager would've jumped at the chance to try it lol.

[BrianW 124]

One of the big differences with the FWT in the 777-9 is that the wing folds just enough to meet ICAO code E requirements and doesn’t include any control surfaces, so it’s a much simpler design than the proposed 6.9 meter fold for the 777-200.  When folded the wingspan is similar to the 77W.  So yeah I suppose technically it could fly with them folded, however structurally they’re not being designed to take those type of loads while folded.  

 

As Alan mentioned the proposed design will have failsafe elements.  It will be isolated in flight, have redundant load paths, command paths, and actuators. The obvious things such as EICAS indications, takeoff warning system, and a RAAS type warning for the tip position are also planned.   The SOP will be to unfold the wings as part of the runway entry procedure, and fold them as part of the after landing procedure. This will allow the taxiing and parking that meets ICAO code E requirements with the longer and more efficient code F wing.