Ta 152

[cactuskooler]

The main problem is the amazing instability, the tail wants to overtake the nose real bad + those jerky jaw motions makes the aiming real hard for me.
The plane behaves like as it had a very small vertical stabilizer, even though it was lenghtened, enlarged compared to the dora.

Made gunnery hard for them in real life too! The vertical stabilizer was enlarged, twice. It still wasn't enough as yet another larger vertical stabilizer was under development. They also said a larger horizontal stabilizer would solve some of the pitch stability problems.


An excerpt from a letter from the General of Fighter Pilots Oberst Gordon Gollob to Focke Wulf,

"Dear Professor!
I have to point out in the strongest way possible that an aircraft with such negative flight characteristics is totally unacceptable for service duty. Yet the fighter service branch is greatly dependent on this aircraft!

I was informed that unexpected problems in pitch stability have arisen in the first production models as well as the test aircraft of type C. The chief of the TLR has proposed, as an emergency measure, a reduction in the amount of fuel stored in the fuselage by 75-80 liters and a loading of only 70 liters of MW 50 instead of the originally designated 140 liters. Also, a ballast of 58 kg should be installed in the compartment and the fuel capacity of the rear fuselage tanks must be reduced 380 to 280 liters...

Erpobungsstelle Rechlin stated that eight Ta 152 H aircraft exhibit barely acceptable stability around the yaw axis. Gunnery runs are impossible to initiate according to the gunnery school. Use of K23 auto pilot gives only slight performance improvement. Rechlin proposed to Folke-Wulf that the tail fin be enlarged.

Stability around the aircraft's roll axis is also poor in the 8-152 H models as well as the 'C' model. Both models do not fulfill the expected minimum stability requirement.

Basically, the stability around the pitch axis could be eliminated through the non-installation of autopilot, the GM 1 power boost tank, the 115 liter fuel tank, FuG125 radio and a reduction in fuel load of 135 liters. However, under no circumstances can the reduction of even the most minute amount of fuel be tolerated."

It can! Just dont overload with 40-50 mins of fuel. Under 25% the Ta can turn fairly well.

It sure can. If Yaks are giving you a heap of trouble, you've got bigger problems.

[Debrody]

Cactus, i got it,
just cant understand, why. The tail-heavyness of the plane cause those problems, right? But even if you burn all your rear tank, use a lot from your boost (let it be gm-1 or mw-50), that bad habit remains the same.
What made that airframe that tail heavy, if not the fuel and the boost system? The engine mount was lenghtened compared to the fairly steady Dora, not the tail section. A huge engine was installe to the nose, not to the tail, yet the aircraft becomes extremely tail-heavy? Something isnt right.

It sure can. If Yaks are giving you a heap of trouble, you've got bigger problems.

Yaks dont give me trouble, but a me in a jak vs me in a 152 turnfight ends very soon...

[Karnak]

Yaks dont give me trouble, but a me in a jak vs me in a 152 turnfight ends very soon...

Those 7 Yaks were shot down in turn fights?

[Stoney]

The plane falls out of the AH skies more than it lands. It's one of the few that couldn't be air-spawned in-game (before the level airspawns) because even when loaded lightly it was tail spin all the way into the ground from 15k, 20k, whatever. That happened many a time to me. When in these tail slides, tail spins, whatever you want to call them, you cannot recover. Not with 40,000 feet below you.

There's two different things you're talking about now. That last post was about the adverse yaw characteristics.  The aspect ratio/empenage size relates to the adverse yaw.

As far as the CG issues:

Ultimately when you question the performance of an aircraft without any factual basis for your belief--that's illogical.  Do you even have a reference that tells you what the CG envelope is for the Ta-152?  Do you have any information regarding whether or not pilots were cautioned against flying the aircraft into certain situations?  Do you know what the static margin is for the Ta-152?  Do you know where the neutral point is on the Ta-152?  Do you even know how any of that stuff is determined?  Without any evidence to the contrary, how do you KNOW that the CG on the Ta-152 is wrong?  I used to own a plane that couldn't recover from a fully developed spin.  It was due to two factors, lack of sufficient rudder authority, and a very low static margin.  It also possessed very strong adverse yaw characteristics in certain maneuvers.  It is possible for an aircraft designer to create an aircraft that focuses so heavily on other performance aspects that they design in some fairly serious flaws.  That aircraft had an 10 year production run and is generally considered to be one of the highest performance two-seat GA aircraft in the fleet, despite those warts.  I have no idea if that's the case here, but what I do know is that HTC's flight model has sufficient fidelity with all the other aircraft in-game that I figure it must be pretty close to capturing the performance and flight characteristics of the Ta-152, at least the one that HTC modeled for the game using the research and resources they had available.  So, unless you can provide some sort of evidence to the contrary, HTC is going to have a tough time "fixing" a problem they don't know exists.

Look, you have as much or more enthusiasm for this game than anyone else on these boards.  I really wish you'd pick up a copy of some aerodynamics primer and spend as much time teaching yourself that as you do reading history and combat reports.

[EDIT]  Looking at Cactus's excerpt, its clear to see that stability issues were illuminated during development.

[cactuskooler]

Cactus, i got it,
just cant understand, why. The tail-heavyness of the plane cause those problems, right? But even if you burn all your rear tank, use a lot from your boost (let it be gm-1 or mw-50), that bad habit remains the same.
What made that airframe that tail heavy, if not the fuel and the boost system? The engine mount was lenghtened compared to the fairly steady Dora, not the tail section. A huge engine was installe to the nose, not to the tail, yet the aircraft becomes extremely tail-heavy? Something isnt right.Yaks dont give me trouble, but a me in a jak vs me in a 152 turnfight ends very soon...

Well I don't know the specifics of why it's tail heavy. I'd imagine there's more to it than just draining the aft fuel tanks. After the first prototype was destroyed while landing after an in-flight emergency on its second flight, Oberst Edgar Peterson, commander of the Rechlin Test Center, filed a report saying the center of gravity was "dangerously" aft, among other issues.

We know there was major issues with stability and CG. Enough for the General of Fighter Pilots to say that, "with such negative flight characteristics [it] is totally unacceptable for service duty", and the commander of the test center to refer to the CG as "dangerous". I'm hesitant to talk aerodynamics as I know so little on the subject, but I don't see how there couldn't be some nasty stall lurking somewhere. Does that mean our 152's tail stall correct? I don't know; that's not my department.

[Krusty]

Cactus: It's funny you cite a letter to the company, when JG301 stated they found no such flaws as stated in the Rechlin report. The guys actually flying it in combat refuted these claims. They said it was a stable platform. It's also funny that he's describing a Ta-152C prototype. It's trebly funny because Rechlin did not say it was impossible to perform tests, they did NOT perform gunnery tests. There is a difference. I think you're reading a bad translation. The Rechlin tests DID describe instability... But in PITCH, and only at high speeds (dive tests) over 600kph.

There are a lot of myths around the 152. They range far and wide. This one of instability seems to persist.

Re: balance:

While longer H-stabs were contemplated, they weren't necessary. Remember JG301 had no problems with stability. Another comment that keeps coming up is the GM-1 tanks in the tail, only those weren't GM-1 tanks. They were a few small compressed air canisters to power the Mk108 gun. That doesn't explain the tail weight. The GM-1 was in a tank directly behind the pilot's seat (just like a 190d, or a 109k). Further flying with less and less gas in AH should improve the condition or eliminate it entirely if it's "only" a heavy tail causing it. In fact in this game nobody in their right mind takes full fuel, most take 50% or less, with the entire AFT tank being empty instantly. There should be in fact a slightly heavy nose with all that gas gone, and we should never see these adverse tail problems because we are never loaded out with full weight, but this does not seem to be the case.

Eric Brown described it as more stable than the 190D. Interestingly enough, when NASM started working on their aircraft they found that the engineers at Wright field had feared that the wood was damaged either by sabotage or bad glue and reinforced it with heavy steel plates to keep the stabilizer on the tail. Further they also moved the H-stabs several inches forward. This compromised flight safety, creating a dangerous craft to fly. This would be AFTER Eric Brown said it was a stable platform. It makes me wonder if this impression in instability was a slip-shod reconstruction effort that ruined the lone working example (upon which American opinion was later formed?). I wonder if HTC is using Wright field commentary?

Stoney, if it were as you describe there'd be no reason the Mossie was ever fixed. Balance and handling are subjective, things that tests cannot fully describe. Somebody else once said on a past discussion, "It's funny how everybody accepts the same issue is a problem on the mossie but just because it's on the 152 they fight tooth and nail to claim it's correct the way it is" [paraphrase].

Analogy: I can drive a car. I can know how to drive other cars. I don't need to know all the physics involved with the force of the tires on the ground and vice versa, the engine on the frame, etc. I can move from car to car and despite different handlings quirks, maybe one jumps off the line an the other's a yugo, I can still say they'll handle along the expected physics ideals a car should. It won't suddenly drive sideways while I'm going down the highway, nor flip inverted 3 times do a bounce and resume its driving. There's a certain uncanny valley where realistic expectations on an object can be predicted. </Analogy>

I'm not saying it [the Ta152] was perfect. But is so obviously was not "this" that we have.

[kilo2]

Cactus: It's funny you cite a letter to the company, when JG301 stated they found no such flaws as stated in the Rechlin report. The guys actually flying it in combat refuted these claims. They said it was a stable platform. It's also funny that he's describing a Ta-152C prototype. It's trebly funny because Rechlin did not say it was impossible to perform tests, they did NOT perform gunnery tests. There is a difference. I think you're reading a bad translation. The Rechlin tests DID describe instability... But in PITCH, and only at high speeds (dive tests) over 600kph.

There are a lot of myths around the 152. They range far and wide. This one of instability seems to persist.

Re: balance:

While longer H-stabs were contemplated, they weren't necessary. Remember JG301 had no problems with stability. Another comment that keeps coming up is the GM-1 tanks in the tail, only those weren't GM-1 tanks. They were a few small compressed air canisters to power the Mk108 gun. That doesn't explain the tail weight. The GM-1 was in a tank directly behind the pilot's seat (just like a 190d, or a 109k). Further flying with less and less gas in AH should improve the condition or eliminate it entirely if it's "only" a heavy tail causing it. In fact in this game nobody in their right mind takes full fuel, most take 50% or less, with the entire AFT tank being empty instantly. There should be in fact a slightly heavy nose with all that gas gone, and we should never see these adverse tail problems because we are never loaded out with full weight, but this does not seem to be the case.

Eric Brown described it as more stable than the 190D. Interestingly enough, when NASM started working on their aircraft they found that the engineers at Wright field had feared that the wood was damaged either by sabotage or bad glue and reinforced it with heavy steel plates to keep the stabilizer on the tail. Further they also moved the H-stabs several inches forward. This compromised flight safety, creating a dangerous craft to fly. This would be AFTER Eric Brown said it was a stable platform. It makes me wonder if this impression in instability was a slip-shod reconstruction effort that ruined the lone working example (upon which American opinion was later formed?). I wonder if HTC is using Wright field commentary?

Stoney, if it were as you describe there'd be no reason the Mossie was ever fixed. Balance and handling are subjective, things that tests cannot fully describe. Somebody else once said on a past discussion, "It's funny how everybody accepts the same issue is a problem on the mossie but just because it's on the 152 they fight tooth and nail to claim it's correct the way it is" [paraphrase].

Analogy: I can drive a car. I can know how to drive other cars. I don't need to know all the physics involved with the force of the tires on the ground and vice versa, the engine on the frame, etc. I can move from car to car and despite different handlings quirks, maybe one jumps off the line an the other's a yugo, I can still say they'll handle along the expected physics ideals a car should. It won't suddenly drive sideways while I'm going down the highway, nor flip inverted 3 times do a bounce and resume its driving. There's a certain uncanny valley where realistic expectations on an object can be predicted. </Analogy>

I'm not saying it [the Ta152] was perfect. But is so obviously was not "this" that we have.

Everything I have read is instability in the yaw axis. The only thing that I think may be off is the dive speed and I am working on testing that. One report has the plane diving to 0.96 mach.

[cactuskooler]

Cactus: It's funny you cite a letter to the company, when JG301 stated they found no such flaws as stated in the Rechlin report. The guys actually flying it in combat refuted these claims.

I haven't looked through all my info lately, but I don't remember reading about JG 301 addressing that report nor could I find it just now. Do you mind telling me where to look?

It's also funny that he's describing a Ta-152C prototype.

No he's not. He's writing about the Ta 152H "as well as the test aircraft of type C".

It's trebly funny because Rechlin did not say it was impossible to perform tests, they did NOT perform gunnery tests. There is a difference. I think you're reading a bad translation.

I don't know whether or not gunnery tests happened or not. The point was "Rechlin stated that eight Ta 152 H aircraft exhibit barely acceptable stability around the yaw axis".

This translation is from Hitchcock's new book. If there's a better translation I'd be happy to read it.

The Rechlin tests DID describe instability... But in PITCH, and only at high speeds (dive tests) over 600kph.

I don't recall reading that. Here's the summary of Rechlin's assessment according to Hermann's book:

• Trim changes around the pitch axis as a result of lower landing flaps bearable.
• Stall behavior is not comfortable, but can be seen as acceptable.
• Stability about the vertical axis weak. Aircraft has a tendency to skid.
• The aircraft is stable about the pitch axis at the center of gravity positions (to 0.665) flown to date.

Eric Brown described it as more stable than the 190D.

That he did. I wonder why the difference in opinions.

I'm not saying it [the Ta152] was perfect. But is so obviously was not "this" that we have.

I'm certainly not going to say ours is perfect. I think it's the most beautiful plane the Luftwaffe made and I was disappointed ours didn't live up to its reputation. I started digging in hopes of finding proof it was wrong. The problem was the deeper I dug the more correct it seemed to me. I'd be more than happy to be as wrong as can be and to have a better 152 tomorrow.

[mtnman]

I wonder if the CG can be tested in-game, in a similar test used to test RC airplane CG's? 

1/2 throttle, trim for level, and then enter a 30 degree dive.  Hold the dive while speed builds, then release the stick.  A nose-heavy plane will nose up fairly sharply, a tail-heavy plane will nose down more (or "tuck").  A plane with a good CG will just continue the dive, or bring the nose up slightly.  Essentially I guess it's just testing pitch stability.

In-game, I'd expect you'd need to have CT disabled to try the test, and since the airfoil isn't symmetrical, that might skew things a bit too.  Might be interesting anyway.

I'd say that I'd expect a tail-heavy plane to need a bit of down-trim (which the 152 does) for level flight at cruise, but then, most planes in AH do IME, so that may not be a good test either.  With the high-aspect wing I guess I'd expect the CG location to be more sensitive to change (or at least have less "range") than a lower-aspect wing?

I still think the films I've seen look like adverse yaw to me. 

The only thing is that IME the wing with the down-aileron should eventually drop, and I haven't seen too much of that.  Left aileron leads to right yaw, then right roll, which gets worse as you panic and give more left aileron.  I flew it for a bit the other night in a fight against an F4U-1A, and didn't find it to be nearly as bad as I'd expected.  I kept losing the "edge" in my turns, but didn't see anything out of the ordinary really (I wasn't using flaps).  I don't have much experience in it though.

[Stoney]

Stoney, if it were as you describe there'd be no reason the Mossie was ever fixed. Balance and handling are subjective, things that tests cannot fully describe. Somebody else once said on a past discussion, "It's funny how everybody accepts the same issue is a problem on the mossie but just because it's on the 152 they fight tooth and nail to claim it's correct the way it is" [paraphrase].

So in the end its just another luftwhine conspiracy?  Nice!  In the end, if we don't feel like doing any aerodynamic analysis, we can just default to discussing how the airplane is just porked because "we know it is".  IIRC, Karnak and others presented a good deal of evidence supporting their position about the Mossie.  You guys have not.

And this:

I don't need to know all the physics involved

is one of the most ignorant things I've ever seen you post.  Why not?  Why not take some of your considerable energy for the aircraft and the game and focus it on learning some aerodynamics?  You're obviously smart enough and have the discipline to read through numerous historical resources.  It can't do anything but help your understanding of the period aircraft.  Oh well, I can't force you to want to learn, but I guarantee that HTC is going to require more than a mere hunch before they take your opinion seriously.

[Wmaker]

See Rule #4

Sorry Skuzzy....alcohol talking.

[Krusty]

Stoney, that's foolish. This is not some luftwhiner conspiracy and you know I'm not that type of person.

So, please enlighten me, exactly WHAT aerdynamic info was provided on the mossie to prove the stability was buggy, instead of intentional?

I recall a lot of anecdotes and pilots descriptions and ... frankly... SUBJECTIVE materials being thrown about at the time.

I don't recall any tests anywhere that indicated "Ah-HAH! Here! THIS proves the game is bugged!" because it hit all the markers for speed, climb, turn, etc. It simply didn't have the stability it should have.

So tell me what they provided that conclusively proved (in your technical documentation demanding demeanor here) the CoG was porked?

Cactus, sorry if I seemed a bit abrupt with you, was unintentional (but hopefully understandable from the way I'm being treated here).

[BnZs]

I'm going to have to agree with Krusty here, that pilot reports ARE valid evidence, if you have enough of them consistently reporting the same phenomenon.

There would be no need for test pilots if all aspects of aircraft behavior, especially stability and stall/spin behavior, could be practically extrapolated.

[Stoney]

I'm going to have to agree with Krusty here, that pilot reports ARE valid evidence, if you have enough of them consistently reporting the same phenomenon.

There would be no need for test pilots if all aspects of aircraft behavior, especially stability and stall/spin behavior, could be practically extrapolated.

Well, flight testing is absolutely required.  All I caution is how we digest the information in those flight reports.  If a pilot reports benign handling, but there's little description of the test regime, what have we really learned?  Conversely, if the pilot says the aircraft is unstable, but the flight regime shows some very demanding maneuvers, you can qualify those statements.  Heck, even the U.S. Navy's Flight Test manual discusses these problems when it talks about how to determine stall speeds of aircraft.  First, there has to be an agreement on what constitutes a stall, given the myriad different ways you can classify it.  If one report shows a stall speed of 90 mph, and another report on the same plane shows a stall speed of 95 mph, which one is correct?  Was there a difference in weights?  Was there calibration error on the IAS gauge?  Were there two different definitions of "stall" used?  We maneuver these planes in ways that were never tested back in the day.  In Krusty's film, he's pulling a lot of alpha at slow speeds.  Do we have data that shows the Ta-152's handling in that regime?

@Krusty:  In regards to the Mossie, I made that statement with respect to all the various tweaks that Karnak and Mossie guys suggested were necessary.  I don't remember everything that got discussed regarding the Mossie CG issue, but I do remember there being a lot of data with regards to the speeds, etc. on some of the other aspects for which they were arguing changes should be made.  I don't even know that the Ta-152 as it is modeled in-game is correct.  Just bring more to the argument than "the CG must be wrong", especially when you don't know much about the aerodynamics or physics of the situation.  To claim a problem with the CG without understanding the physics is illogical.  To blow someone off when they say that the "high aspect ratio wing" may have a part to play, when you don't understand how aspect ratio affects the aircraft is illogical.  Finally, when someone answers with those types of arguments, and you challenge them to "prove it" to you, its exasperating.  Because proof sometimes demands hours of work in a spreadsheet or in research, just to show you something that you didn't know in the first place.  

[STEELE]

Well, let's see, how did they fix the Mossie's almost un-recoverable stall (similar to the 152), they adjusted the CoG.

Cactus: It's funny you cite a letter to the company, when JG301 stated they found no such flaws as stated in the Rechlin report. The guys actually flying it in combat refuted these claims. They said it was a stable platform. It's also funny that he's describing a Ta-152C prototype. It's trebly funny because Rechlin did not say it was impossible to perform tests, they did NOT perform gunnery tests. There is a difference. I think you're reading a bad translation. The Rechlin tests DID describe instability... But in PITCH, and only at high speeds (dive tests) over 600kph.

There are a lot of myths around the 152. They range far and wide. This one of instability seems to persist.

Re: balance:

While longer H-stabs were contemplated, they weren't necessary. Remember JG301 had no problems with stability. Another comment that keeps coming up is the GM-1 tanks in the tail, only those weren't GM-1 tanks. They were a few small compressed air canisters to power the Mk108 gun. That doesn't explain the tail weight. The GM-1 was in a tank directly behind the pilot's seat (just like a 190d, or a 109k). Further flying with less and less gas in AH should improve the condition or eliminate it entirely if it's "only" a heavy tail causing it. In fact in this game nobody in their right mind takes full fuel, most take 50% or less, with the entire AFT tank being empty instantly. There should be in fact a slightly heavy nose with all that gas gone, and we should never see these adverse tail problems because we are never loaded out with full weight, but this does not seem to be the case.

Eric Brown described it as more stable than the 190D. Interestingly enough, when NASM started working on their aircraft they found that the engineers at Wright field had feared that the wood was damaged either by sabotage or bad glue and reinforced it with heavy steel plates to keep the stabilizer on the tail. Further they also moved the H-stabs several inches forward. This compromised flight safety, creating a dangerous craft to fly. This would be AFTER Eric Brown said it was a stable platform. It makes me wonder if this impression in instability was a slip-shod reconstruction effort that ruined the lone working example (upon which American opinion was later formed?). I wonder if HTC is using Wright field commentary?

Stoney, if it were as you describe there'd be no reason the Mossie was ever fixed. Balance and handling are subjective, things that tests cannot fully describe. Somebody else once said on a past discussion, "It's funny how everybody accepts the same issue is a problem on the mossie but just because it's on the 152 they fight tooth and nail to claim it's correct the way it is" [paraphrase].

I'm not saying it [the Ta152] was perfect. But is so obviously was not "this" that we have.

Also, another thing about that letter to the company, there's no mention of any Yaw instability or unrecoverable stalls.  Only pitch instability .  Pilot accounts of climbing hard to stall speeed then flipping over on top of enemy would not work with our 152, they would have fell tail-down to the earth.