Author Topic: 190A vs 190D (Read 587 times)

MANDOBLE · « **on:** April 05, 2002, 03:55:44 AM »

Why a so noticeable degradation of control above 300 mph between 190D and 190A? Doras outmaneouvering 190As at hi/med speeds is just a myth?

Vermillion · « **Reply #1 on:** April 05, 2002, 08:14:06 AM »

Mandoble, I don't have an answer myself, but on a different BBS recently, Wilbus asked the same thing and Wells provided an answer. Here it is for what its worth to you.

Quote

Wilbus wrote: Hey all, lately there have been a discussion over in the AH forums about why the Dora compresses easiler then 190 A5 and A8 version, it's basicly the same plane with a longer nose and tail and a different engine, it uses the exact same wing.
So can anyone explain to me why it has worse high speed handeling then the earlier A variants, seems very odd, specially since the Dora was designed for high speed and accelerates/dives better, did it have worse high speed handeling in R/L?

Wells wrote: I don't have a direct reference for the 190D, but the Ta-152 was found to have a higher stick force per g, than the BMW powered 190s, according to Eric Brown. It would be reasonable to assume the same for the 190D with it's tail surfaces moved farther aft.

MANDOBLE · « **Reply #2 on:** April 05, 2002, 10:25:48 AM »

This may be reasonable for the Ta152 at hi speeds due its much larger surfaces, but that is not the case of 190D9. The effect here is the opposite, Ta and A series have both good control at hi speeds, D9 is a brick. You get few degrees quickly, pure AOA gain and then it becomes a pure brick depending absolutelly on the trims (very slow reactions).

Also, at any speed it is very susceptible to trim changes, specially to elevator trim. In RL there were only a small trim control for the elevator (+5/-5 dgrees), and no more than that. It seems that this plane rarely needed trimming adjustment. Here the D9 is very trim dependant.

Naudet · « **Reply #3 on:** April 05, 2002, 11:42:25 AM »

Vermillion, the stick forces per G that wer increased were the roll input forces.

They increased due to the greater wingspan.

And as i mentioned in previous posts, Kurt Tank test flew both a FW190A7 and a FW190D9.

They had the same diving characteristics. Stable, good handle no shaking.

Tank mentioned that the D9 did a bit better in speed accel etc. due to the new engine.

This time i won't post sources, cause last time it didnt even help.

Fact is:

in AH FW190D compresses earlier than FW190A, but all the data i have from about real D9 and A-Series, say the D9 was better in dive (most must have been better acceleration, cause critical mach was the same on both, cause the used the same wing)

So in AH the D9 and A-Series FW should compress the same.

And about elevator authority, the tailplane of the FW190 is longer, which actually gives it a longer handle when pulling out the elevator. The D9 should from this point have lighter elevators than the A at speed, cause with the same elevator deflection, you get a greater force moving the plane up or down, cause the handle is somewhat longer.
Or do those physical laws dont apply to aircraft?

@Mandolbe: i wonder that you still try to post those things, i totaly have stopped all comments on such things cause the only reaction i get is ...none.

HFMudd · « **Reply #4 on:** April 05, 2002, 11:59:29 AM »

Hitech did respond to it in another thread but the response was not very useful. The *impression* I got from Hitech's response was that he had seen Kurt Tank's report sometime in the past but did not feel it was reliable. Hitech did not say why he felt this way nor did he provide a counter source.

I'll try to locate that post and reference it here.

MANDOBLE · « **Reply #5 on:** April 05, 2002, 12:11:15 PM »

Naudet, I see no other way to have a minimal hope of HiTech revising the "brick".

Mudd, good luck in your search, didnt remember any comment of HT about this matter.

Sikboy · « **Reply #6 on:** April 05, 2002, 12:26:26 PM »

It's very simple. You post your thoughts/data here. HiTech reads the boards. If he feels that you have a valid point, I'm sure that he'll make a change to the model, or at least look into it further. If your data trumps his data, BINGO flight model change. As customers, we can expect a degree of progress with the game. I believe that we get that. What we can't expect (in my opinion of course) if for HiTech to come in here and explain to everyone everything related to anything that anyone wants to complain about. I believe his quote was "Could it be that we just dissagree and get tired of posting the same things..." I've said it before, we don't know what information they model on. We don't know if there is one standard source, or multible sources depending on nationality of the plane, or if the planes are modeled after a combination of many sources (an average of certain avaliable sources for example). Anyway, I don't think that you can consider it being "ignored" just because HiTech doesn't respond in here. I think that he just doesn't want to get into a fight with his customers every week.

Just my observation,

-Sikboy

HFMudd · « **Reply #7 on:** April 05, 2002, 12:28:05 PM »

Ok, found it in the "Torque Effect" discussion.

Hitech 3/29: "So far when people think they have found problems with it, it's has been do to unclear specs they are reading. When you dig deaper you find what the varence is in the test data. See the 190 f8 thread. We have seen report data that has been requoted down threw the years that is so obviously wrong,but none technical types just take it for granted. (the 205 comes to mind)"

My assumption was/is that hitech is refering to the D9 vs F8 compression and the Kurt Tank flight report.

Or he could be talking about something else altogether...

(BTW, what is the 205 issue he is talking about?)

Raubvogel · « **Reply #8 on:** April 05, 2002, 12:34:50 PM »

Quote

Originally posted by Naudet

And about elevator authority, the tailplane of the FW190 is longer, which actually gives it a longer handle when pulling out the elevator. The D9 should from this point have lighter elevators than the A at speed, cause with the same elevator deflection, you get a greater force moving the plane up or down, cause the handle is somewhat longer.
Or do those physical laws dont apply to aircraft?

That's what I've been trying to say Naudet. Lengthened tail should make for a longer "lever", which should keep elevator authority the same or possibly better, despite the change in CG from installing the Jumo.

lord dolf vader · « **Reply #9 on:** April 05, 2002, 12:58:23 PM »

well we are waiting, evidence has been presented from what seems to be a unquestionable source. tests have been done showing results that are indicating the flight model is wrong. hts responce dosent seem to have anything to do with this situation . how can you missunderstand

" PLANE NO SHAKE OR FREEZE UP LIKE ROCK AT 400 ias at 19 k"

Kurt Tank= guy who knows more about aircraft design that any two that have ever read this bbs including ht

the plane is way off, its not a technical missunderstanding just fix it ?

or mayby Kurt Tank and Kelly Johnson were just lieing

(refeference to still screwed up compression on 38 )

Sikboy · « **Reply #10 on:** April 05, 2002, 01:07:22 PM »

Just a question then... Why wouldn't HTC fix it if they know it's wrong?

FLS · « **Reply #11 on:** April 05, 2002, 01:20:35 PM »

What exactly are the FW190 compression speed differences in AH? I've compared the FW A and D and don't see the big disparity that Mandoble claims.

--)-FLS----
Musketeers

lord dolf vader · « **Reply #12 on:** April 05, 2002, 01:41:24 PM »

if you take both up hi and run them into compression the onset of compression and loss of controll happens much more slowly in the a8 as speed increases. its not a small difference if you are in a d9 and you feel buffeting you got about 2 sec of little control and then a brick ( all this at speeds kurt tank himself found the plane to be vibration free and quite controlable ) , silence from htc so far.

MANDOBLE · « **Reply #13 on:** April 05, 2002, 01:49:10 PM »

FLS, vader described that perfectly.
Compression speed of the Typh is lower but it also keep full control where D9 is just a brick.
We are not talking about the compression itself, but the control at a range of speeds between 300 mph and the total loose of control (even with trim).

LUPO · « **Reply #14 on:** April 05, 2002, 02:40:57 PM »

Quote

HFMudd wrote:
(BTW, what is the 205 issue he is talking about?)

Perhaps HT is talking about the 202 and the issue is about Breda SaFAT MG rate of fire.
I have to say that in this case HT not just answered to my questions and considered the data I posted but also modified in version 1.09 the wrong data about bredas mg rof.
So we have the evidence that ht reads forums and consider the issues proposed by the customers.
As a customer and a 202 fan I thank him.

More peas per sec now!