Hiccup in the Flight Model
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Hi all,
Has anyone noticed that when under heavy wing loading in a turn (CAT I), that sometimes it seems as if the FLCS suddenly ‘drops’ stick input from the vpilot and the nose ‘dips’, before it picks up the stick input again and reloads the aircraft? I’ve been noticing this for a long time and haven’t seen an answer, maybe I missed it. I’ve heard other vpilots mention the same thing, with some speculation but nothing confirmed. The last time I saw something like this was a mathematical error Andre made in the breakpoints.
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Never seen it myself. That would suck.
EDIT: definitely could not be caused by hardware?
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Same as Blu3wolf, never seen this behavior before.
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Hi all,
Has anyone noticed that when under heavy wing loading in a turn (CAT I), that sometimes it seems as if the FLCS suddenly ‘drops’ stick input from the vpilot and the nose ‘dips’, before it picks up the stick input again and reloads the aircraft? I’ve been noticing this for a long time and haven’t seen an answer, maybe I missed it. I’ve heard other vpilots mention the same thing, with some speculation but nothing confirmed. The last time I saw something like this was a mathematical error Andre made in the breakpoints.
Confirm.
This happens for me aswell (although rare objectively observed, but noticed anyways), if the jet is under heavy “laod” (high AoA + Gs) while surpassing/undercutting the mach- or sound-barrier.
This phenomenon presents itself as a very short and minute “hick” interruption in the pitch attitude. If that is natural or not i can´t tell, although
it appears almost as natural as the flow dynamics from sub- to supersonic (transonic area) are very different and might have an effect on this behavior,
espcially under laod - also considering, that the transonic area is covered in the NASA Tech. 1538 and thus implemented as such and as “mach-breakpoints” into the FM definitions.Not conclusive for me, if that behavior is intented or not, i can´t tell. Mav-Jp?
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Most probably due to machsound barrier where there is a very significant drop in all lift and drag variables
Again there is no "intended " or no “intended”
You have the most accurate areo parameters ever known and you have the real.flcs code build in
Result is what it is
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Hi all,
Has anyone noticed that when under heavy wing loading in a turn (CAT I), that sometimes it seems as if the FLCS suddenly ‘drops’ stick input from the vpilot and the nose ‘dips’, before it picks up the stick input again and reloads the aircraft? I’ve been noticing this for a long time and haven’t seen an answer, maybe I missed it. I’ve heard other vpilots mention the same thing, with some speculation but nothing confirmed. The last time I saw something like this was a mathematical error Andre made in the breakpoints.
You are talking of stone age here
There are no errors in data i mean copy paste from nasa is ok, dont know if the nasa has made a mistake somwhere
Howevet such behavior could be explain by several things
Transonic barrier ?
turbulence modeling that kicks in abruptly ?
I/O peaks ?
I must admit that after years of flying i never noticed it except in transsonic region
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However such behavior could be explain by several things
Transonic barrier ?
That´s what i thought, but hard to be sure if never flown F-16 for “real” ;):mrgreen:
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Never seen it myself. That would suck.
EDIT: definitely could not be caused by hardware?
I was thinking the same.
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You are talking of stone age here
There are no errors in data i mean copy paste from nasa is ok, dont know if the nasa has made a mistake somwhere
Howevet such behavior could be explain by several things
Transonic barrier ?
turbulence modeling that kicks in abruptly ?
I/O peaks ?
I must admit that after years of flying i never noticed it except in transsonic region
I suspected something of this nature, but wasn’t entirely sure, because it typically occurs (not always), but when I’ve noticed it, it’s when I’ve gone from above mach into a turn, and am just sub mach (.87+) when the loss of lift/pull occurs temporarily. You’ll have aft stick deflection, but the nose will “bobble” or “dip” just for a second, then it resumes pulling.
It was very similar to a math error Andre made in the SP4 fm one time during testing, I saw something ‘kinda’ similar but not quite. It’s good to know it’s a natural occurrence.
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Actually now that you mention the mach, I have seen it do this through the transonic region while pulling max G.
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Perhaps a vid of this might show us a good example?
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Perhaps a vid of this might show us a good example?
One can easily try reproducing it. I really don´t think a video is required as it was well enough described in the posts before.
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@A.S:
One can easily try reproducing it. I really don´t think a video is required as it was well enough described in the posts before.
Actually Ive just tried reproducing it without much luck. CAT I, ITO (shouldnt make a difference…), 4 AIM-9s and 2 Py4s. Not sure what might have changed though.
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Actually Ive just tried reproducing it without much luck. CAT I, ITO (shouldnt make a difference…), 4 AIM-9s and 2 Py4s. Not sure what might have changed though.
Me neither. I fly my jet through the transonic rage a lot. I do not see this behavior at all. Maybe I am missing something? I wish to see a vid of this. Maybe a bit of buffing is all I notice, but no problems with HOTAS and FM still in sync.
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COULD DEPEND on altitude
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yup, easily reproducible at angels 20.
