Flap Retraction - videos

[andrej]

Hello all,
YouTube algorithms surprise me yet again.
It is very interesting, how multiple parts work conjointly, from a flap lever in the cockpit to actually movement. What the engineers have to think of.


https://www.youtube.com/watch?v=exPwY3t1Z38

https://www.youtube.com/watch?v=sAamh7FTSyg

Cheers!

[Martin Baker]

Great to see this. It reminds me of a question I've been meaning to ask Hardy re flaps:

Am I right in thinking that in PS1 the time taken to move from flaps 1 to 5 (and back) was 30 seconds, but in PSX this was changed to 20 seconds?

Martin

[Hardy Heinlin]

Could be, Martin. I can't remember :-)


|-|ardy

[vnangli]

This makes me very curious, how the viscosity of that lubricant (especially on that threaded shaft) is affected at those high altitudes and still be able to provide the smooth interface...Amazing...Thanks for sharing these links...

[Jeroen Hoppenbrouwers]

I suppose the jackscrew has a ball-bearing-nut and not just a normal one.
https://en.wikipedia.org/wiki/Ball_screw

[Martin Baker]

Could be, Martin. I can't remember :-)

:-) It's a very nerdy thing to ask, but are you sure 20 secs is correct? It's probably an error of perception on my part, but I think PSX is faster to set Flaps 5 than in videos of real 747s.

[Avi]

Actually, during Alpha tests it was much faster but you need to understand, Martin, that the aerodynamic model is so fragile that a slightly change here and the result can be a very hard shake of the boat.

Cheers,

P.S. the first video is excellent, the second one...

[Hardy Heinlin]

Martin, the values in PSX agree with real-world observations and maintenance manuals. The flap system with its primary mode and secondary mode status monitoring depends very much on electronic time delay measurements and the specific speeds of pneumatic drives and hydraulic drives which vary when components other than flaps are being driven, for example. There are also certain requirements by the FAA etc. There are hundreds of parameters in the system, and they are all modeled in PSX. PS1 had a simplified model. PSX is the better reference.


Regards,

|-|ardy

[Martin Baker]

Martin, the values in PSX agree with real-world observations and maintenance manuals.

Understood - I'll shut up - sorry!

[Hardy Heinlin]

No sorry needed; your question was OK :-) There's always a risk that something goes wrong, and check-questions reduce the risk.


Best wishes,

|-|ardy