Author Topic: 152 only ac to tail slide?  (Read 721 times)

Offline Anaxogoras

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152 only ac to tail slide?
« on: January 25, 2008, 02:35:16 PM »
Will any other aircraft (besides the 152) enter a tail slide if you zoom climb straight up and do your best to keep the nose vertical?  After the 152 thread a week or two ago, I tried some offline maneuvers with some pretty funny results: lots of tail-spinning deaths in the 152, but I was unable to get any other aircraft to mimic the 'maneuver.':lol And I tried many, many times without success.

What seems clear is that the CoG is far behind the CoL.  Without rudder input, every aircraft in the AH planeset yaws during a roll.  What's different is that the 152 yaws much more violently, as if part of the v-stab were missing.  This "fishtailing" effect is due to the CoG being too far aft, and not due to the lengthened wingspan, as some have suggested.  But fishtailing is actually a bad description of the 152s behavior: what actually happens is that the heavy tail stays put during a roll, and it's the nose that wallows around (afterwards, the tail has to catch up to the pulling prop).  In other aircraft, the CoL and CoG are much closer together, so even during an uncoordinated roll or turn, there is not so much ballast swinging from side to side.

To repeat the point, what I find remarkable is that I am unable to force any other aircraft into a tail-slide or tail-spin, and in the 152 this is accomplished without hard maneuvering.  Either this aircraft was poorly designed to begin with, or it is not modeled correctly.  One of the two has to stick.

I've seen online flight sims develop over many years, and no one can deny that errors do creep in from time to time, and eventually are found out.  Yes, I'm saying HT isn't super-human, and I've seen enough of his fixes in the past not to be surprised if we see one in the future. There are always people who defend things as they are now until they're blue in the face, and then later they'll say they always knew "minor adjustments" would have to be made.  A bunch of us have already gone on record in the previous thread with opinions about the 152 fm.  We'll see who time vindicates.
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Offline 33Vortex

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152 only ac to tail slide?
« Reply #1 on: January 25, 2008, 03:54:53 PM »
:aok

Good analysis Anaxogoras. The current fm of this a/c is faulty. To the point it spoils all the fun flying it. If it was modeled correctly, it would probably become my main ride. Perked or not perked, I wouldn't care because the 190 series is my love and the Ta152 was the peak of that series. Personally I find the fm of the Ta152 a joke, to put it mildly. ;) We have the La7, Tempest and SpitXVI but no Ta152.

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Offline moot

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152 only ac to tail slide?
« Reply #2 on: January 25, 2008, 05:13:16 PM »
The info is in the other thread.  The 152 was rushed through development.  Its cog problems were never completely fixed.  It (the majority of fielded aircraft) never got the larger rudder and horstab/elevators it needed.

The F4Us also have heavy tail syndrome.  To a lesser degree but in a very similar way, their tail can get "locked" into a slide which you have to use significant force to break lose from.

I do think the 152 just doesn't seem right as it is, but nonetheless it was most likely tail heavy. The question is how and how much? If HTC would give the FM a look, we'd probably know for sure.
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Offline dtango

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152 only ac to tail slide?
« Reply #3 on: January 25, 2008, 05:24:56 PM »
Quote

Will any other aircraft (besides the 152) enter a tail slide if you zoom climb straight up and do your best to keep the nose vertical?


Yes, they do.

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« Last Edit: January 25, 2008, 05:27:03 PM by dtango »
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Offline Widewing

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152 only ac to tail slide?
« Reply #4 on: January 25, 2008, 05:53:28 PM »
Quote
Originally posted by dtango
Yes, they do.

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Indeed, many do. My favorite for tail slides is the Ki-84.. These are actually fun and enlightening.

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Offline Sled

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152 only ac to tail slide?
« Reply #5 on: January 25, 2008, 08:20:21 PM »
I know one of the subjects in the other 152 thread was the yaw when rolling. I checked several different AC,  I noticed that most AC in AH will yaw when rolling, at low speeds, to a noticeable degree. The 152 will yaw to a noticeable degree at almost all speeds, High or Low.

152 may not be the only one that can tail slide easily, but AFAICT it is the only one that yaws (significantly) when rolling at higher speeds.
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Offline dtango

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152 only ac to tail slide?
« Reply #6 on: January 25, 2008, 11:35:26 PM »
I mentioned it in the other thread sled.  The Ta-152 has a high aspect ratio which makes it more susceptible to adverse yaw (yaw when rolling).

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Offline Anaxogoras

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152 only ac to tail slide?
« Reply #7 on: January 26, 2008, 12:05:29 AM »
I will try again with the Ki-84 and F4u to see if I can do it.  In the 152 I haven't been able to recover from these tail slides.

-------------------------------

Maybe I'm not skilled enough, but I could only get the Ki-84 to do a tail slide and enter a spin, not the f4u.  The F4u would enter a normal nose-down spin, but never a tail slide.  In the case of the Ki-84, there was an important difference versus the 152: in the Ki-84 I was able to recover on my first try.  In the 152 I never recovered.

-------------------------------

Lastly, dtango, your aspect ratio explanation seems sound, but it is not a complete explanation of the behavior we see.  It does not explain why the Ta-152 so easily enters a tail slide/spin; that's a cog problem, which doubtless also contributes to the yaw issue.
« Last Edit: January 26, 2008, 01:18:40 AM by Anaxogoras »
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Offline Ack-Ack

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152 only ac to tail slide?
« Reply #8 on: January 26, 2008, 02:35:07 AM »
P-38 does them nicely, though they were much easier to pull off in AH1.


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Offline moot

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152 only ac to tail slide?
« Reply #9 on: January 26, 2008, 05:08:07 AM »
The 152's loose tail could be just as much a cog issue as an aerodynamic one.  It probably would still spin out flat much like it does now with no cog problems but the same relatively small vertical tail surface.

What I'd really like to have is a way to see where the air is going while in these spins.  Something like the developmen airflow display screenshots Pyro posted with an F4U.  I can't make heads or tails of what's going on over the control surfaces while in the really bad spins.

The F4U is a lot easier to recover than the 152 (I think it might even do it on its own), but it is the closest plane in terms of the tail stepping out of line like the 152 does.  The helicopter-induced spins aren't a real problem.  
You can reverse at the top of a rope at ~50-60mph in the 152 almost instantly if you do it right, with barely any stall.
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