Ta 152

[icepac]

What is the altitude of these tests?

I think the ta152 flys great down low but it's stability degrades with altitude faster than any other plane in aces high to being unusable above 30k feet.....which is where it was intended to thrive.

I have a hard time believing that the Ta152 flew so much worse than the 190d at high altitude than it does here.

[dtango]

What is the altitude of these tests?

I think the ta152 flys great down low but it's stability degrades with altitude faster than any other plane in aces high to being unusable above 30k feet.....which is where it was intended to thrive.

I have a hard time believing that the Ta152 flew so much worse than the 190d at high altitude than it does here.

I don't know but FM arguments based on aeropinionautics are hard to take seriously .

Maybe it's me but opinions masquerading as facts just doesn't seem like a good way to build an argument.

[Babalonian]

The 3 frame pic is from Krusty?s film.  Primary control inputs don't show up on film so there's no telling what his rudder input is.  Sorry, I have no idea why this matters.  As I stated above cross controlling makes adverse yaw worse.

 
(Image removed from quote.)
 
Let's see...  The Ta-152's prop rotates clockwise thus torque rolls the 152 quicker left than right.  In a left roll the torque produced by the engine (running at a frick'in 2100 HP spinning a nearly 12" metal propeller) increases left roll rate (p)  which increases adverse yawing moment.  In a right roll the engine torque decreases right roll rate (p) which decreases adverse yawing moment. 

Please tell me, why would I expect adverse yawing moment to be the same in a left roll as in a right?

Well, at least you stopped chasing the CG wild goose .

Easy budy, again with such determination to prove me wrong and that the Ta-152 in AH is infallible it's almost insulting and blinding you (it almost comes across as you've taken my entire post out of context). 

You seem to of glossed over the fact the formula you provided (and those I've been looking for) do not include or take into account prop/torque effect, only yawing induced by ailerons OR by prop/torque.  I'm a little old and uncertain in my math to just mash two formulas I'm already just getting the grasp of at the moment, so I'm still looking there for one already given or trying ot understand it better first.

Second, these were in high-speed dives at an angle ~20 degrees, am I wrong in assuming that such conditions should not have any bearing on adverse yaw?

Lastly, the "goose" being that even with all those numbers crunched and the results based off the AH flight model, do you have a flyable Ta-152 in your garage we can borrow for an afternoon?

[Babalonian]

As the plane rolls left, the right airleron goes down and provides more lift on the right wing tip than the left. This increases drag on an over sized wingspan thus making the plane yaw to the right profusely. If a left roll is executed at the same time as a tight turn, the "propeller gyroscopic" as like to to call the "prop gyro precession" will also provide right yaw due to the elevator pushing the nose upward. Chopping off the throttle will also increase the chances of an unrecoverable tail skid because the airflow generated by the prop over the tail to keep it stable at slow speeds becomes obsolete even if it causes the RPM to be quite slower.

EXCELLENT post by the way! This is a must read for many players here wishing to understand more about this mysterious and unknown part of aircraft dynamics.   
Its just because the adverse yawing moment is not dependent on prop generated forces but only on aerodynamic forces. Thus a CW or CCW prop will have the very same (almost) adverse yawing characteristics for the same airframe no matter if you roll left or right.


Very interesting topic!

Good addition of gyroscopic effects lepape  .  Any pitch rates would effect yawing moments (as can be seen in the Cn diagram posted).  I left it out of the discussion along with other things like inertial moments, p-factor etc. to keep it simpler.
Well actually as I was trying to help Babalonian understand engine torque does have an effect and the effect is aerodynamic, through Cn-p.  How?  If we look at yawing moments they can be broken into the following coefficients:

(Image removed from quote.)

Cn-p (yaw due to rolling) and Cn-delta-a (yaw due to aileron deflection) are two components of adverse yaw. 

Cn-delta-a is what you're referring to in your description of adverse yaw.  Due to aileron deflection the upgoing wing produces more lift and induced drag which yaws the plane opposite roll.  The following is a nice conceptual depiction of it.

(Image removed from quote.)

However Cn-p is also a contributing factor as well - yaw due to roll rate.  Roll rate changes the local section aoa which causes the lift vector to be tilted which induces yaw opposite roll.  Here's a pic that demonstrates this:

(Image removed from quote.)

The greater the roll rate the greater the lift vector tilt and the greater the yaw.  Engine torque creates a rolling moment opposite the direction of prop spin.  For a CW prop this is a left rolling moment.  In a left roll, the engine torque adds to the left rolling moment increasing the rolling rate.  The increased left roll rate increases tilting of local lift and bingo, more adverse yaw.

BTW, thanks for the kind words.

Woah, didn't even think about the gyroscopic effect (in addition to the other two) until now!  Brain needs some oil/coffee now.


^ Yeah, that sums up very well what I mentioned in my last post, this is no casual algebra exercise... at least for me.


^ Gold.  Where did you pull this image from if you don't mind?

"The greater the roll rate the greater the lift vector tilt and the greater the yaw.  Engine torque creates a rolling moment opposite the direction of prop spin.  For a CW prop this is a left rolling moment.  In a left roll, the engine torque adds to the left rolling moment increasing the rolling rate.  The increased left roll rate increases tilting of local lift and bingo, more adverse yaw."

I've been going by this "gut feeling" for lack of anything better to call it atm that the forward momentum and weight at a high-speed shallow dive should be more powerful than what is offset in AH by what I strongly feel is the tilting of the lift vector during a fast roll.

Can you help me understand that concept more please.  How much of an effect should both forces actualy have in enough of a high-speed down-angled dive?  Or if this an adverse "side-effect" due to that the Ta-152s rather wide/large wings and fast roll rate at near any speed or forward energy state (and to make it more complicated, throwing in the relatively massive forward thrust from the 152's powerplant at full throttle ontop of its torque...)?


Lepape, thank you! (for the Eureka moment)

[Babalonian]

What is the altitude of these tests?

I think the ta152 flys great down low but it's stability degrades with altitude faster than any other plane in aces high to being unusable above 30k feet.....which is where it was intended to thrive.

I have a hard time believing that the Ta152 flew so much worse than the 190d at high altitude than it does here.

Typical routine for the shallow dive tests is I fly up to ~20k (mostly afk), then imediatley dive down ~2.5k for speed and cruise for a couple minutes to let speeds settle.  First flight of the day I usualy do some warm-up maneuvers, make sure I get my feeling back for the plane, then re-settle the plane for a couple minutes at ~17.5k (unless I goofed it and stalled out in the warm-up and lost a few K in alt).  I then nose-dive gradualy down to ~14.5k and begin a heavy roll (either wings rolled already to a 90-degree position, simulating tracking a con below me before making the decision to roll, or wings level in the dive before making my roll).


She needs speed at altitude, once she gets it she is the king.  The Dora however also is this way behaviorly, and I get what you're saying about the odd similarities.  The 152 is better without a doubt though, especialy above 30k, it retains its E and can recover alt/E signifigantly better from BnZ tactics at high alts.  But I understand what you're saying, both at say 29k seem so similar (but really aren't) to the other that it's hard to believe the vast differences both aircraft have until you start using them in combat at that alt.

[ACE]

I flew the 152 again today and its always had bad stall caracteristics.  I read what moot pointed out, he said always keep the rudder in check, I did and it never stalled.

[moot]

Babalonian I can't speak for anyone but I personally have a hard time not taking it all from A to Z with a grain of salt when you say you can't tell that the AFT tank makes no difference for the 152's agility.  It's true now and was true from day 1 in the old AH version to the AH2 physics rework.

The only thing that's changed is that way back then, in AH1, depending on whether you kept wings or FWD last, the plane would react peculiarly when you rode it real deep to the edge of stall - the wings would wag (roll) just preceding full departure.  If either one (fwd/wings) was better, neither me nor AGJV44 found it from plain practical tests.  And at the time we put so much time into the game that we could've won Eskimo's pasty skin award (not joking).

I flew the 152 again today and its always had bad stall caracteristics.  I read what moot pointed out, he said always keep the rudder in check, I did and it never stalled.

Yep as much as it might seem like it's easier said than done, it really is a conveniently dead simple solution to the problem.  The only complication is that depending on how familiar you are with the plane's FM, you might have to spend a lot of time (relatively, in terms of how much time you can afford looking into cockpit and basically handicapping your SA) looking back and forth at that sideslip ball. 
But once you get a feel for it, it becomes second nature like everything else and you won't be flying sideways -- unless you mean to

[morfiend]

What is the altitude of these tests?

I think the ta152 flys great down low but it's stability degrades with altitude faster than any other plane in aces high to being unusable above 30k feet.....which is where it was intended to thrive.

I have a hard time believing that the Ta152 flew so much worse than the 190d at high altitude than it does here.

 All my testing was done at or below 10K with full fuel,I purposely choose full fuel and lower alts.




     

[Tupac]

Whoever reccomended playing with the throttle and rocking the plane back and forth I thank you......That works very well

[dtango]

Easy budy, again with such determination to prove me wrong and that the Ta-152 in AH is infallible it's almost insulting and blinding you (it almost comes across as you've taken my entire post out of context).

Determination? What would you have me do, pretend like your rudder authority, left/right roll statement didn't defy physics?  That seems patently non-helpful if I'm trying to help you in your search for truth & understanding.  Infallibility of AH?  I've never stated such a thing.  If you think it's flawed, it's up to you, the skeptic to make a coherent argument & support your claims.  However, how is it helpful if no one points out if an argument is badly mangled?  

You seem to of glossed over the fact the formula you provided (and those I've been looking for) do not include or take into account prop/torque effect, only yawing induced by ailerons OR by prop/torque.

Deliberate simplification.  All aircraft with a CW prop experience similar gyroscopic & torque effects (plus a bunch of other things I've left out).  It's all interesting but secondary. Due to the 152's wingspan focusing mainly on adverse yaw illuminates how its different from other AH fighters to help explain its directional divergence tendencies. 

Second, these were in high-speed dives at an angle ~20 degrees, am I wrong in assuming that such conditions should not have any bearing on adverse yaw?

In short, yes.

Lastly, the "goose" being that even with all those numbers crunched and the results based off the AH flight model, do you have a flyable Ta-152 in your garage we can borrow for an afternoon?

Why can't we trust the guy who developed the basis for the science of flight?  Because he got hit in a head by an apple?  I guess I can sort of understand that .

[Babalonian]

Babalonian I can't speak for anyone but I personally have a hard time not taking it all from A to Z with a grain of salt when you say you can't tell that the AFT tank makes no difference for the 152's agility.  It's true now and was true from day 1 in the old AH version to the AH2 physics rework.

The only thing that's changed is that way back then, in AH1, depending on whether you kept wings or FWD last, the plane would react peculiarly when you rode it real deep to the edge of stall - the wings would wag (roll) just preceding full departure.  If either one (fwd/wings) was better, neither me nor AGJV44 found it from plain practical tests.  And at the time we put so much time into the game that we could've won Eskimo's pasty skin award (not joking).
Yep as much as it might seem like it's easier said than done, it really is a conveniently dead simple solution to the problem.  The only complication is that depending on how familiar you are with the plane's FM, you might have to spend a lot of time (relatively, in terms of how much time you can afford looking into cockpit and basically handicapping your SA) looking back and forth at that sideslip ball. 
But once you get a feel for it, it becomes second nature like everything else and you won't be flying sideways -- unless you mean to

Strange, I would swear that I've said otherwise, but please do provide the quote in its full context sir.  Given the subject of this thread, you should very well take any thing not backed up by hard facts or data with a grain of salt (or the whoel shaker), but I jsut think you've interpreted it mistankenly.

The 152 is quite agile, especialy at some low n slow speed manuevers with those massive wings and powerplant.  It has a fantastic roll rate like all 190s at most every speed (but not the best), and the rudder's authority is enough to slap an elephant unconscious (rediculously illogical, but it makes the point).

What you have quoted out of context though sounds awefuly familiar to my earlier complaint that the Aft tanks fuel level/weight bears no difference whatsover when an adverse yaw is induced (from what I've only recently started to realise/learn) from an overagressive roll, compiled by torque and the rapidly tilting lift vector.  I originaly described this behaviour as extremely confusing to me in regards to believing the aft fuel weight was a signifigant contributing factor (weather it was empty or not/properly modeled or not), but would say I am begining to come to the understanding now of why it's had no effect on it in the past.

I will add this though, the rudder is enough for getting most adverse yaw departures back in check, but one induced in the manner I've been describing it is never enough by itself, you need to chop throttle too and even then it's already likely too late (I don't know if it's because such an unstable yaw departure has already been induced beyond any means of bringing it back within check, or if you contentrate on any other aspect first (such as wings level comming out of the roll) causing any delay in attempting to bring the yaw back into check just in the nick of time).

I also stated the aft fuel weight bears no difference in being able to repeatedly recover the aircraft from the following tail-first stall in most fuel weight distribution conditions except one, and that's when all fuel tanks are empty except for the aft (and yeah, that makes recovering from the stall a real horse)...  this matter especialy still makes no sence to me, but recovering from a stall is a seperate matter, one thing at a time, etc..


Anyways, I feel like an enlightened idiot today already because of this topic, so it's not like I'm avoiding feeling the fool, but I intend to do more offline looking into this now with my refreshed understanding of some things.  And I welcome any constructive criticism or valuable knowledge you've all been providing and I hope keep doing.

[Babalonian]

Whoever reccomended playing with the throttle and rocking the plane back and forth I thank you......That works very well

I forget who taught me it, I'll dig around and see who was in my unit in the BoG scenario and it'll probabley pop into mind.  Grizz was the first to post/mention it in this thread though, and it is a reliable technique... almost too reliable... but that's another story.


Edit:  I think it was either A8Moray, Irish0ne, or Sukov, honestly I can't recall any better than that since the forums have long shut down for that event, but that's at least the first I ever heard/learned of that recovery technique and have used it always since.

[Babalonian]

Why can't we trust the guy who developed the basis for the science of flight?  Because he go hit in a head by an apple?  I guess I can sort of understand that .

I still maintain I've always been confounded by this unstable behavior in the 152 because either I had a poor/lacking understanding OR there was something off in the game (or maybe I'd get lucky and it was both).  Even after gaining a better understanding on it (I think), it still agitates me to a degree  .  Most will place blame for a flaw on everything before themselves in this community, but at least I don't feel like such an idiot admitting with this issue early on when I got involved that the flaw was just as likely within me as it was with everyone else sided with me on this matter.  Either way, somewhere along the lines my problem was the same as quite a few others with this specific aircraft more than many/any other in the game, and I hope this thread sticks around for a while.

[dtango]

^ Gold.  Where did you pull this image from if you don't mind?

One of my aero textbooks: Phillips, Mechanics of Flight.

I've been going by this "gut feeling" for lack of anything better to call it atm that the forward momentum and weight at a high-speed shallow dive should be more powerful than what is offset in AH by what I strongly feel is the tilting of the lift vector during a fast roll.

Generally, forward momentum doesn't effect rolling momentum so you'll hit a Newtonian brick wall trying to chase down that rabbit hole.

Can you help me understand that concept more please.  How much of an effect should both forces actualy have in enough of a high-speed down-angled dive?  Or if this an adverse "side-effect" due to that the Ta-152s rather wide/large wings and fast roll rate at near any speed or forward energy state (and to make it more complicated, throwing in the relatively massive forward thrust from the 152's powerplant at full throttle ontop of its torque...)?

The adverse yaw relationship applies no matter if you're in dive, climb, level, turning, etc.  Though increasing airspeed reduces adverse yaw, roll rate increases with airspeed (limited by stick forces) which increases adverse yaw.  So yes, because of the 152's long wings & fast roll rate it apparently has enough yawing moment to send it out of control at higher speeds.

[moot]

Strange, I would swear that I've said otherwise, but please do provide the quote in its full context sir.

To the best of my knowledge and experience in flying the 152 in-game is that the aft tank, empty or full, has barely any noticable impact on its handling, especially when compared to noticable results from draining any of the other three tanks (but those tanks are also signifigantly larger).  In terms of inducing a tail-first stall or recovering from it, I'd err closer to the aft tank being full or empty having absolutley no effect in those two departments in AH (which aint right).

What context did I miss?  The above quote was reply to simple question by me - are you saying AFT makes no difference to agility?

Regardless what the physics are, the practical bottom line is that empty AFT is easily the best config for dogfighting agility.  Including off the wall maneuvers like flying sideways and back again for shots you couldn't otherwise get.  You can maneuver over departure limit much easier without aft fuel.  Agility benefits just keep growing as total fuel drains, but aft is by far the biggest positive.

And I'm pretty sure AFT is the biggest tank. Unless you meant that the other three together add up to more than AFT.