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mSparks43 / 747-400

A Boeing 747-400 aircraft for X-Plane 11 & 12
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Main gear bouncing upon touchdown #263

Closed MCCVeen closed 3 years ago

MCCVeen commented 3 years ago

This "should" be fixed with the removal of the metal skids that ship with default.

Originally posted by @mSparks43 in https://github.com/mSparks43/747-400/issues/117#issuecomment-755738659

Still present in commit 645, caused the autobrake to disarm

https://user-images.githubusercontent.com/75425109/103982342-9d816280-5183-11eb-9a0c-f5b80a6c17e1.mp4

mSparks43 commented 3 years ago

https://forums.x-plane.org/index.php?/forums/topic/61282-landing-gear-dynamics/

MCCVeen commented 3 years ago

You can see here that it rarely happens irl https://www.youtube.com/watch?v=9fGQL7rBH8Q

mSparks43 commented 3 years ago

would you be able to try these constants in plane maker image

Plane maker->open the 747-400.acf->standard->Landing gear->Gear Cons Then file->save as->give it a new name

MCCVeen commented 3 years ago

A lot less with these settings! But I noticed the suspension is way too stiff. I can't explain it exactly so I made a video so you can see it for yourself

https://www.youtube.com/watch?v=Hl4AuBFHokQ

mSparks43 commented 3 years ago

How it should be https://www.youtube.com/watch?v=zXpGVTxZSx4

Now I'm fairly confident we're thinking the same thing, I'll try a few more, my thought for making it stiffer is to increase 2,3,4 deflection at empty weight and reduce the damping constant, but I'll try a few more and compare them to this video

MCCVeen commented 3 years ago

That is a 747-200. The landing gear on the 747-400 was modified I believe. In these videos I don't see the same bouncing effect happening either so I'm guessing Boeing adjusted the suspension to make the plane bounce less on landings https://www.youtube.com/watch?v=o0ArwP3m47A

mSparks43 commented 3 years ago

apologies I posted that video before clicking on yours thinking yours was an XP recording. Agreed, we're seeing the same thing, looks like its achievable with the right balance of absorption and extension, Ill try some more soon.

mSparks43 commented 3 years ago

How about these image

MCCVeen commented 3 years ago

Way better! In real life the shock absorber is even longer from what I've seen. It's a shame no one can remodel the exterior to the 744, that would be amazing

MCCVeen commented 3 years ago

Maybe pull back slightly, it's now impossible to bounce the aircraft. I came down with around -1400 fpm and the real aircraft with most likely around -800 fpm https://www.youtube.com/watch?v=CjuiB8JPFC4 https://www.youtube.com/watch?v=BMsJt3nV6fs