Pyro, AH's 190A5 SL speed??

[Urchin]

Originally posted by funkedup:
Yep looks like 12 mph faster on the deck than the AH A-5.  Whoever scanned this needs to get in touch with HTC.

However statements like "absolutely off target" and "WAY slower" are hyperbole, and don't help your case.  In terms of normally occuring differences in test results between aircraft of the same type, 12 mph is not a huge difference.

[ 11-17-2001: Message edited by: funkedup ]

I wouldn't say that describing a difference of 12-15 mph as WAY OFF is hyperbole.  I'd say that is pretty much dead on.  I'd DEARLY love to see the squeaking and moaning if someone found a chart that said the P-51D could make 385 mph on the deck, while ours *may* reach 370 ( a difference of 4.5%).  Bottom line, if these charts are accurate, which would be PROOF that the A-5 is to slow by somewhere between 3.5 to 4.5%, then it is a big deal in my opinion.

It isn't like the 190A5 is suddenly going to be running down La-7s or runstangs on the deck, so I don't quite see what the fuss is over.

[funkedup]

Urchin:
   

It isn't like the 190A5 is suddenly going to be running down La-7s or runstangs on the deck, so I don't quite see what the fuss is over.

My thoughts exactly.

Wingnut:  
   

I don't see exactly where u believe any were corrected funked. Just seems it shows 3 power settings and their related engine powers/speed up thru 10k meters. With any figures applying to all 3 curves.

Are we looking at the same chart?  There are six (6) curves on the one that RAM posted.  I just realized that Niklas (who presumably scanned the chart) has a similar explanation to mine.  Maybe you'll find his words more helpful:  

 

the left one is corrected for the error of the speed indicator due to the macheffect, the right one is not. So the left one is indeed TAS, the right one is the value a pilot gets when he uses standard conversion factors from IAS to TAS without mach-correction.
This means, if a pilot reads IAS and uses the standard conversion factor for TAS, the error due to mach effect is ~15MPH in 600m@650km/h.
If this effect is neglected... well, maybe one of many a reason for several high speed claims from pilots, especially when they flew in high altitudes at high mach numbers (or the mach0,93 speed claim for a spit reached in a dive)

[ 11-17-2001: Message edited by: funkedup ]

[Glasses]

If the chart shows it give it to us HTC Ram if you have more charts keep them pumping them out Funkey here wants more info give him more untill he gets overly saturated.

[Wingnut_0]

Funked, yes I am looking at the same chart as you and yes his words were helpful.  But what I was referring to was that the 2 equations noted on the chart are arrowed out to show that they were applied to all 3 power setting lines.  That was my point.

So are u saying the left (test #3) is more accurate or are u just referring to the left line of each test aircraft?  That's where I didn't follow you, cause the left test is obviously at a much different engine settings than the other 2.

[R4M]

<BUMP>

[funkedup]

Wingnut there are three tests 1, 2, and 3.  For each test there are two curves on the graph.  The left curve in each pair was converted from ASI readings using the equation on the left.  The right curve was converted using the (less accurate) equation on the right.

[Voss]

Ram, you are assuming that ambient air temperature for the test in question is the same as that found within AH. We don't even know what temperature HT programmed AH for, but aircraft performance certainly DOES vary by temperature. Further, this report you cite is insignificant, in that it DOES NOT report the temperature in which the tests were conducted (not that I can make out anyway).

In that temperatures range from approximately zero degrees centigrade to forty degrees centigrade (in Europe) you cannot tell under which conditions the tests were conducted.

And that's just one test condition.

I am not at all surprised to see a variation on the order you suggest. It is quite within the norm given the variation possible.

[R4M]

Voss at wich tempterature is the AH's P51 performance modelled?. At wich temperature is the AH's Fw190A8 performance modelled?. At wich tempereature is every plane in AH modelled?. Many planes are modelled using factory data, the A8 being the most evident example. Factory charts are the most reliable data you might find about a plane. Much more than tests done on captured planes in foreign nations. Why the A5 can't use that data?.

Any reason not to follow the chart posted is a simple excuse. The plane is 15mph slower at SL than what it should be, and generally slower than what it should be under 9000 feet. Period.


and <BUMP> , BTW  

[ 11-19-2001: Message edited by: R4M ]

[funkedup]

Voss I agree that the variation here is within the range of variation we have seen from one test to the other of various other aircraft.  However I think the leftmost set of curves related to the equation on the left indicates that there was indeed a temperature correction applied to the data.  We need Niklas to give us a bigger scan and some of the other pages from this document but I think I'm right about that.

[ 11-19-2001: Message edited by: funkedup ]

[funkedup]

Urchin:

 

I'd DEARLY love to see the squeaking and moaning if someone found a chart that said the P-51D could make 385 mph on the deck, while ours *may* reach 370 ( a difference of 4.5%).

Actually there have been data like that for P-38L, F4U-1D, and F4U-4 that have all been presented on this forum in the past.  Nothing came of it.  It seems that maybe the fastest data aren't always the most accurate.

[ 11-19-2001: Message edited by: funkedup ]

[Voss]

You're arguing apples against oranges RAM. It's turning into a whine now.

Your factory data, whether from North American, Lockheed, Junkers, Messerschmitt, or Supermarine, must all be substantiated with all variables in consideration. One of these variables is air temperature.

Until, you can provide evidence that the P51D is acting out of accordance with established norms for the AH standard temperature at SL (which should not change given that we have no wind, etc.), then you can't say that X results from NA factory do not match.

Similarly, you can't say under what temperature your test results were conducted, so how can you argue that they disagree with AH's standard temperature (also an unknown)?

Also, I can tell you a few things by what is included upon the chart above. For instance, the date of the report would suggest that the test was conducted in mid-fall, where temperatures in Germany would probably range somewhere between seven degrees Celsius and twenty-three degrees Celsius (let's say - get a weather report today for Germany if you care to). If, we find that the standard SL temperature for AH is intended to be thirty degrees Celsius, then you would have a drop off in performance over the factory reports. How much, exactly, I couldn't say, but I can post examples from General Aviation types of today should it go that far.

Certain aircraft of this type  can require an additional one-hundred fifty meters of runway for such a climactic change, so I don't see any deviation from the norm in your figures (as I stated).

Finally, I must add that certain tests results have been invalidated over the years, as they were 'fudged' by factory reps (such as W. Messerschmitt himself) for propaganda reasons. I'm not saying your chart is bogus, but I am saying it is only one small piece of the puzzle.

What would be incredibly interesting, is if Pyro and HT got together, gave us Winter maps, and the performance of these aircraft were pushed up to match those conditions.

Nah.......

[Voss]

Funked? Temperature correction? I don't buy it. If, such a 'correction' has indeed taken place, then it invalidates the entire chart.

[R4M]

in short voss, if the P51 was 15mph slower than what it should in AH, then you couldn`t say a thing istn it? because you dont know wich is AH's temperature, and the temp of the P51D data, right?.

That's rediculous.

And I'd like to know where have you seen falsified factory data from messerschmitt, please?

[ 11-19-2001: Message edited by: R4M ]

[Voss]

Originally posted by R4M:
in short voss, if the P51 was 15mph slower than what it should in AH, then you couldn`t say a thing istn it? because you dont know wich is AH's temperature, and the temp of the P51D data, right?.

That's rediculous.

And I'd like to know where have you seen falsified factory data from messerschmitt, please?

[ 11-19-2001: Message edited by: R4M ]

The one thing I am sure about is that Pyro has modelled the P51D as closely to reality as he could. All other things remaining under like conditions should act accordingly. Your statement, though, is unintelligible as it stands and I can't make out your line of thought. However, if we found that the P51D is indeed 15mph slower then tests conducted at zero degrees Celsius, then I would not be surprised at all.

It is not ridiculous.

As to W. Messerschmitt: Early on in the development of the 109 Wily boosted an engine beyond the point of reasonable care. It was during one of his speed trials for a world record. The engine was specifically designed to perform beyond factory types so as to guarantee a record. This fact was kept from the media and German authorities until after the war.

You can read about it in "The Luftwaffe Diaries."

[R4M]

my line of thought is clear: that chart is a factory chart made under X conditions. The P51D charts of North American Aviation were made under Y conditions. Why do you assume that AH's temperature is closer to Y than to X?. I assume that AH's atmosphere is close to what we could call Standard, and that the chart I posted shows the performance of a STANDARD Fw190A5 in normal conditions; because its an official factory chart, signed by a Focke-wulf engineer who knew his plane. Maybe you trust more the tests done by americans who had no clue on the qualities of a captured plane, completely new to them; and a plane they didnt knew if it was tweaked in any way.

 I dunno you, but what is me, I tend to trust the data coming from the factory itself, taken from a STANDARD plane, with DETAILED power settings for each performance curve represented.

You don't. After all you dont know the temperatures, right? (lol. is so rediculous I dont know wether to laugh or to take it seriously)

About your affirmation on the "false/faked charts",well is FULL of it. What's the deal, were the allies the only ones knowing how to conduct aircraft tests , voss?. Did the germans had no clue? They tested the planes on extreme conditions to get better (and false) results, right?. So they had no idea on how to make a proper chart and did it on extreme conditions? . And sure, after they completed the test they added a couple of MPH just for the sake of it, for making the plane seem better to their eyes, true?.

Sure.They were so idiots. That chart is not to be taken seriously because no german factory chart is as reliable as an american-made one, true?. Lol. I'm sure that the engineers working for Focke-Wulf were 3rd grade kids, and the ones working at Rechlin had no work to do,nor a clue on HOW to do it. I'm sure they were all day long drinking beer and singing bavarian songs with blonde-haired women.  


The 109 you are talking about was the one wich broke the world speed record for propaganda reasons. BUT WAS NOT AN ACTUAL combat plane wich needed accurate charts for the pilots and engineers. And I'm sure if there were any charts made for that plane,they were accurate anyway (the plane was highly modified, and thus not a standard 109, but the results WERE for real, the plane reached the speed they said it did. Or maybe you say they falsified that record, too?). W. Messerschmitt did not fake ANYTHING. He made a plane, tested it and got a world record. That the RLM chose to say it was a 109 without detailing the extent of the modification is a COMPLETELY DIFFERENT ISSUE.

Voss,the official factory charts were made,between many other things, to put them in the pilot's manuals. WTF are you saying, they were going to put a wrong chart in a pilot manual?.  

I stand on what I said: rediculous.

But, wait...we all know germans didnt know how to do a proper performance chart,right?    

get lost, Voss

[ 11-19-2001: Message edited by: R4M ]