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An-225 pitch trim

Posted: Mon Jun 29, 2020 1:28 am
by jetmech
Hello All,

I'm curious as to how the An-225 achieves longitudinal pitch trim. As far as I can tell, the An-225 has a fixed horizontal stabiliser and hence, the elevators are the only way to provide pitch trim.

Image

Yet as per the photos below, there appears to be appreciable main wing flaps selected without any up elevator to compensate.



Regards, JetMech

Re: An-225 pitch trim

Posted: Mon Jun 29, 2020 3:38 pm
by scbriml
Looking at this picture, there seems to be three moveable sections on each side of the horizontal stab. Whether or not they're actually used, I'm afraid I can't say.

Image
Image from https://en.wikipedia.org/wiki/Antonov_An-225_Mriya edited by me for clarity.

Re: An-225 pitch trim

Posted: Wed Jul 01, 2020 12:09 pm
by zanl188
If I’m not mistaken both AN124 and AN225 use a fly by wire flight control system. That would certainly provide an opportunity to use elevators for pitch trim.

Re: An-225 pitch trim

Posted: Wed Jul 01, 2020 1:24 pm
by jetmech
scbriml wrote:
Looking at this picture, there seems to be three moveable sections on each side of the horizontal stab.

Yes, it's an interesting elevator setup. The outboard sections look to be double or triple hinged.

zanl188 wrote:
If I’m not mistaken both AN124 and AN225 use a fly by wire flight control system. That would certainly provide an opportunity to use elevators for pitch trim.

Sure. I'd say it's doable with a mechanical flight control system too. Pitch trim would have to be provided by the elevators if the tailplane is fixed unless they have some sort of movable ballast system. Speaking of the An-124, it appears the same thing is happening, appreciable main wing flaps with no up elevator and what appears to be a fixed tailplane.



Regards, JetMech

Re: An-225 pitch trim

Posted: Fri Jul 03, 2020 12:50 pm
by roby11
What about Stratolaunch?