Currently, the way you describe an aircraft’s landing gear is very simplistic.
Each gear is just described as one contact point. Even if the gear consists
of, to take a typical airliner main gear as an example, a bogie with two
axles, with two wheels on each axle. The bogie is able to rotate a bit around
its axle, which is attached to the oleo strut. The simulator has no idea about
this, to it the gear is just described as if it was a single wheel with no
other degrees of freedom than that which the vertical compression of the oleo
strut gives.
Until such functionality is implemented in the sim itself, I guess one could
use a WASM module (or perhaps JS) to make sure the bogie is horizontal while
even a small weight is on the gear when landing (in a prominent nose-high
attitude, like for instance delta-winged aircraft tend to do) or when rotating
for take-off. At landing, the bogie would be in the typical tilted attitude
where the aft wheels are lower, at the exact moment the aft wheels of the main
gear touches the ground. A few seconds later when the plane is a bit lower the
bogie would be horizontal (even if the aircraft is still in a more lr less
prominent nose-up attitude, after the flare, or because it is a delta that
lands like that) and all wheels are touching ground, and only then does it
actually carry weight and the oleo (simulated as a spring) starts compressing.
Sigh, sounds complicated.
Oleo compression is already handled with the static and max/static values of
the contact points. I would think maybe that you would describe the contact
point as being directly below the oleo at the appropriate distance. Handling
the rotation animation of bogie could be achieved by using the AOA SimVar or
some other appropriate variable (on lunch break so can’t dig too deep) that
describes the current angle of the aircraft relative to the ground and
animating the rotation based on that. IIRC they did mention something about
animations for airliner gear in a recent dev update.
See this video for the problem…https://youtu.be/ZXQG66NK-Zw?t=888
@tml I believe I’ve found a video showing what you are describing:
https://youtu.be/b3VTN6iAxQ0?t=78 For comparison:
https://youtu.be/bj0KTzg_pew?t=19 IIRC, even when only the rear wheels of
the A330 landing gear are touching the ground, the main oleo can already
absorb some of the forces and compresses a little. It is not simulated in XP11
but will be in XP12, enjoy: https://youtu.be/xxL_hUqo64s?t=1224
@tml is this what you’re looking for?
<X-Plane 12 Flight Model Report - X-Plane Developer
report/#Gear_and_Tires>
The A330 has an Eagle-Claw landing gear system that is NOT just for looks…
I just wanted to ask a simular question and found this one.
To simplify the request of this thread:
- Could there be a way to connect the wheel-contact point to a fuselage-contact-point?
There are a lot of aircraft out there that have angled landing gear, be it a nosegear sticking forwards from the fuselage, or for instance the main gear that actually mounts either more forwards, backwards or even more to the side (think of the BF-109’s main gear)
In the case of the one aircraft i helped a bit with, the landing gear struts are actually mounted about a meter towards the rear of the airplane, making the static or on-ground center of gravity more towards the rear of the airplane’s fuselage. (i had to drag the fueltanks more forwards to achieve the goal of it not sitting on it’s tail due to the weight distribution) We actually wanted the fuel tanks to partially sit in the tailbooms… but couldn’t because of the contact point having to be at the exact point of the wheels, technically making the strut vertical, whereas it’s near diagonal in the 3d-model.
I know this is probably a future dream, to have the actual landing-gear fully simulated, (i’ll wait for flightsim34) but starting off with a fuselage-contact-point in connection to the ground-contact-point would open up a lot of possibilities already.
Why did i ask the same question?
Well, in the fuselage animation from the Global Preview-video, i noticed the fuselage being displayed (CFD) fully yet the landing gear only had one drag component as the aircraft took off (and that drag component disappeared as soon as the landing gear up button was pressed), so that gave the impression that the landing gear is still one point in time and space: only the ground contact point.
It’s still the technical alpha we were looking at, so there’s that. Just think of the possibilities in verhicles if we’d have a “landing _gear_geometry = 1” option for expert mode in there, and “landing _gear_geometry = 0” to keep things simplified.
But yeah, FS34 will have it, i’m sure.
Looking forwards to MSFS24, very much looking forwards to the work you’ve all done! Can’t wait! Thank you!
Kindest Regards,
Steiny