Which is better: P-47 or Fw-190?

[evangilder]

I also show the Hellcat climb rate at 3,240 fpm. That is according to Encyclopedia of the World'd Combat Aircraft by Bill Gunston. According to that same book, the climb rate of a P-47 (typical) was 2,800 fpm. the weights and sizes of these airplanes are fairly similar as well.

 

[DAVIDICUS]

The "tyical" P-47 was the toothpick propeller model that is usually referenced at 2,770 or 2,780 fpm (2,800 appears to be a rounded figure). The paddle blade on the "D" added another 400 fpm on to that.

I haven't read about tests between the "N" model and the Hellcat but it does seem reasonable that they would have been conducted as the petformance of the Hellcat against a variety of enemy fighters was well known. Thus, it seems that it would have been a valuable exercise to test the P-47N against the Hellcat since they would be facing the same opponents.

 

[evangilder]

The book did not specify which type, and I do know the paddle blade do make a difference. I haven't seen the numbers documented, but the number you quote seem reasonable.

Perhaps they did not test the -47N and the Hellcat against one another as they are fairly equal in size, weight and performance. They were probably more focused on getting the planes out to the theater to put an end to thing, I would guess.

 

[DAVIDICUS]

The "N" model was considerably heavier and had a much more powerful powerplant. As to performance, much of this thread is speculation and debate about the climb rate of the "N." It is clear though that the P-47N was about 90 miles per hour faster than the Hellcat and its engine could retain more horsepower way up high due to the turbosupercharger.

 

[Soren]

Yes it was an "A" model. But for that matter, the the P-47 was a Razorback D-4 with the toothpick propeller.

Sure, but the D-4 was afterall lighter.

The excerpt that people appear to sieze upon in asserting that the engine was not working properly is the following:

The engine seems to run rough at all times and the vibration transmitted through the control column almost completely destroys any feel of the flying characteristics.

And here's why that excerpt is so important:

The Fw-190 has been explained by its pilots as a dream to fly, with no vibrations and excellent controls with very good feel to them. so thats why that excerpt is so important.

But let's also not forget this other gem of an excerpt:

The FW-190 was in exceptionally good condition for a captured airplane, and developed 42 inches on take-off which is believed to be slightly above normal maximum boost

In exceptional good condition for a captured a/c Something was wrong with it..

The fact that the engine "seemed" to run rough and vibrated may have been in part a reflection of the FW-190's engine's natural state of operation rather than an indication that the engine was not operating correctly.

The BMW-801 ran very smoothly DAVID, as described by its pilots, and the 190's controls had excellent feel.

Radials were not as smooth as in-lines

True, however that does not at all mean you can't make it run smooth.

and the German radials were known to run rougher than the American radials.

Who ever told you that ?

 

[Soren]

Yes, 18lbs of boost. There was more boost available as I have seen 25lbs of boost on data before.

Sure, but thats for the 5.1min time, with 25lbs of boost it could probably make it in 4.9min. So nothing has changed.

 

[DAVIDICUS]

Yes the D-4 was lighter ... than a destroyer.

You left out the "... and developed 42 inches on take-off which is believed to be slightly above normal maximum boost." from your critique of that excerpt.

I have never read about Fw-190 pilots reporting "no vibration" or that the controls had an excellent feel. I defer to you.

I have read that the German radials ran rough. I don't recall where I read it and am not going to vouch for its accuracy. Again, I defer to you.

I do not see the Mk. XIV climb data as fatal to the WEP P-47M data I presented.

If you look at the chart I presented for the climb of the Mk. XIV at 18lbs of boost, you will note that the initial climb rate is 4,700fpm! Obviously at 25lbs of boost, the initial climb rate would be even higher. The initial climb figure I estimated from the 4.75 minutes to 20K feet for the P-47M at WEP was about 4,500fpm based on the average of 4,200fpm over the entire climb.

You earlier claimed that the WEP P-47M data I presented indicated a higher climb rate than the Mk. XIV. You said, "Seriously DAVID, that's faster than a Spit XIV...." Obviously this isn't so.

 

[Soren]

Yes the D-4 was lighter ... than a destroyer.

It was lighter than most other -47's.

I do not see the Mk. XIV climb data as fatal to the WEP P-47M data I presented.

If you look at the chart I presented for the climb of the Mk. XIV at 18lbs of boost, you will note that the initial climb rate is 4,700fpm! Obviously at 25lbs of boost, the initial climb rate would be even higher. The initial climb figure I estimated from the 4.75 minutes to 20K feet for the P-47M at WEP was about 4,500fpm based on the average of 4,200fpm over the entire climb.

With 25lbs of boost, the Spit XIV's max initial climb rate was 5,040ft/min, and it would according to tests reach 20,000ft in 4.9min with this amount.

You earlier claimed that the WEP P-47M data I presented indicated a higher climb rate than the Mk. XIV. You said, "Seriously DAVID, that's faster than a Spit XIV...." Obviously this isn't so.

Whoops, there you seriously stumbled DAVID !

I wasn't talking the initial climb rate, but the time to 20,000ft.

The -47M is quoted as reaching 20,000ft in 4.75min, which is just not true ! The Spit XIV would reach 20,000ft in 5.1min, or 4.9min at best.

And clearly in reality the -47M wont be climbing faster than the Spit XIV ! It wont even be close.

 

[DAVIDICUS]

First off, I find it hard to believe that the time would go from 5.1 to 4.9 when the boost goes from 18lbs to 25lbs.

As to my "serious stumble," this entire discussion has always been about the initial climb rate for the P-47N. The "M" and "J" figures were employed only to discern and estimate the intial climb rates.

I have only listed time to altitude figures (because that's all I have to work with) in order to estimate the initial climb rate. Can you find anywhere where I have argued time to altitude figures except in response to your claims?

Lastly, I promise not to inject a smiley face at your "serious stumble" in citing my quoted WEP P-47"M" 0-20K flight time as 4.15minutes. It was 4.75 minutes Soren. As the altitude increased, the P-47"M" didn't suffer from as much loss of horsepower as the Mk. XIV due to the turbosupercharger. Remember that the P-47 was literally designed around the turbosupercharger to give it high altitude superiority.

 

[DAVIDICUS]

I see you have corrected your stumble.

 

[Soren]

First off, I find it hard to believe that the time would go from 5.1 to 4.9 when the boost goes from 18lbs to 25lbs.

Why ?

As to my "serious stumble," this entire discussion has always been about the initial climb rate for the P-47N. The "M" and "J" figures were employed only to discern and estimate the intial climb rates.

Your "Serius stumble" was that you left out what I was actually saying, in effect you were putting words into my mouth.

Here's what I said: 20,000 feet in 4.75 min !

Seriously DAVID, that's faster than a Spit XIV....

Lastly, I promise not to inject a smiley face at your "serious stumble" in citing my quoted WEP P-47"M" 0-20K flight time as 4.15minutes. It was 4.75 minutes Soren.

DAVID dont take offense that easely, I put that smiley there to indicate "NO offense is to be taken"

As the altitude increased, the P-47"M" didn't suffer from as much loss of horsepower as the Mk. XIV due to the turbosupercharger. Remember that the P-47 was literally designed around the turbosupercharger to give it high altitude superiority.

DAVID that difference only really kicked in at 30,000ft, the Spit enjoyed a huge power-loading and wing-loading advantage all the way up to 20,000ft . Nontheless all the numbers are against the -47 making that time, even with full boost all the way.

 

[DAVIDICUS]

Actually the emoticon you used after saying, "Whoops, there you seriously stumbled DAVID !" is called "Very Happy."

At any rate, misunderstandings aside and back to the topic at hand, the the "M" model's initial climb rate under the cited WEP figure would not exceed the Mk. XIV's under even 18lbs of boost let alone 25lbs of boost. I am only interested in initial climb rates for ther purpose of estimating the initial climb rate for the P-47N.

Oh, and the turbosupercharger on the P-47 did not initially kick in, or otherwise become effective, starting at at 30K. For example, at 25,000ft when other aircraft's engines were feeling the strain of the thin air, the P-47 was not similarly strained because it's turbosupercharger was not yet operating and making a difference.

Lastly, as you well know, there is more to the picture than simply wing area/weight and horsepower. Propeller efficiency plays a big role too as evidenced by the additional 400fpm of climb that the paddle blade propeller afforded the "D" model under conditions where the wing area/weight and horsepower of the "D" remained the same.

 

[Soren]

Actually the emoticon you used after saying, "Whoops, there you seriously stumbled DAVID !" is called "Very Happy."

You read the emotions description rather than looking at it ? It was ment to represent a reassuring smiling face, which it did. I wanted to make it clear that I wasn't after you in any way.

Btw where is the reassuring smiley after you said I stumbled ? Thats not fair, I want one too !! (Ok I'll stop now )

I am not prepared to verify your assertion of the 4.9 and 5.1 minutes to 20K ft. altitude.

You don't have to, I'll just give it to you instead: http://www.spitfireperformance.com/jf319.html

I am only interested in initial climb rates for ther purspose of estimating the initial climb rate for the P-47N.

Ok.

Oh, and the turbosupercharger on the P-47 did not initially kick in, or otherwise become effective starting at, at 30K. For example, at 25,000ft when other aircraft's engines were feeling the strain of the thin air, the P-47 was not similarly strained because it's turbosupercharger was not yet operating and making a difference.

I didnt mean the Turbocharger would initially kick in, I meant the difference would only initially begin to kick in at around 30,000ft.

 

[DAVIDICUS]

"I didnt mean the Turbocharger would initially kick in, I meant the difference would only initially begin to kick in at around 30,000ft."

I said , " ... or otherwise become effective starting at 30K." I followed that up with the example that at 25K feet it was making a difference.

I just took a look at your data on the Mk. XIV. The climb rate at 1,700ft was 5,110fpm for 18.3 lbs of boost (remember there was the potential for 25lbs of boost which represents a 38% increase over 18lbs.).

I speculated that the maximum initial climb rate of the P-47M at War Emergency Power might be as high as 4,500fpm which is 600 fpm less than the Mk. XIV utilizing just 18.3lbs of boost. I also speculated that the climb rate for the heavier "N" might initially be around 3,500fpm (near the rate of the Fw-190D-9).


Why don't we just throw in the towel and agree to disagree Soren.

 

[Sal Monella]

Whatever the time to altitude figures are, I think those estimates for initial climb sound pretty reasonable David.

 

[lesofprimus]

Great stuff, but i dont really see how this applies to the -47 vs. the -190...

 

[DAVIDICUS]

Cheddar Cheese raised the issue of a head to head match between the FW-190D-9 and the P-47N. Because no reliable climb data appears available for the "N" model, the "M" and "J" data was referenced which gave rise to a side discussion on the reliability of the "M" data.

 

[lesofprimus]

I followed that much... But why is the initial climb data so topically important?? Thats just a small part of what the combat would evolve into...

 

[DAVIDICUS]

Well Les, it could have been about armament, dive speed, roll rate, (you get the idea) or any of a host of other specific attributes that end up being hashed about on this forum that individually make up only a small part of what combat involves.

So in response to your question, and a response I might add that you have probably given your kid on more than one occasion, "Just because."

 

[Soren]

I said , " ... or otherwise become effective starting at 30K." I followed that up with the example that at 25K feet it was making a difference.

I wasnt talking the -47 alone, but the difference between the -47 and the Spit XIV. At 25,000ft the Spit XIV still climbs noticably better.

I just took a look at your data on the Mk. XIV. The climb rate at 1,700ft was 5,110fpm for 18.3 lbs of boost (remember there was the potential for 25lbs of boost which represents a 38% increase over 18lbs.).

According to this doucment on the production model the climb rate was 4650-4700ft/min with 18lbs boost, which was the max allowable boost: http://www.spitfireperformance.com/spit14climbchart.jpg

With 25lbs boost, the max initial climb rate would likely have risen to 5200ft/min. (I don't know where you get 38% increase from)

In any case, 20,000ft was reached in 5.1min during that test, and with 25lbs boost it would most likely reach this in 4.9min.

Can we agree that the -47M would never reach 20,000ft in 4.75min ?

Even the Spit 21 couldnt reach 20,000ft in under 5.2min, or 5min at best.

I speculated that the maximum initial climb rate of the P-47M at War Emergency Power might be as high as 4,500fpm which is 600 fpm less than the Mk. XIV utilizing just 18.3lbs of boost.

I could go along with 4,000 ft/min for the -47M as a max, but it would slow down very quickly, much more quickly than the Spit XIV.

I also speculated that the climb rate for the heavier "N" might initially be around 3,500fpm (near the rate of the Fw-190D-9).

I speculate the -47N's climb rate to be around 3,150ft/min, but I could go along with 3,500ft/min souly because of its sheer starting speed, however it would slow down REAL quick.

Why don't we just throw in the towel and agree to disagree Soren.

Lets see if we can't agree to agree with the above first