marseille jr
Airman
- 52
- Mar 28, 2005
Which is better: P-47 or Fw-190?
- Thread starter mosquitoman
- Start date
Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules
the lancaster kicks ass
Major General
- 19,937
- Dec 20, 2003
does that seem out of context to anyone else??
DAVIDICUS said:
First of all let me make two small corrections:
P-47D
Max. Engine power is 2535 HP. (Not 2300 HP)
Power-loading is therefore 5.75 lbs/hp.
----------------------------------------------------------
Now comes my opinion.
Since this debate started I've been searching my books and the internet for data on the P-47M,N,D and XP-47J. What I have found is that all the data is roughly similar to the data below, and that your presented site seems to be unique with its specifications, and therefore I find it slightly unreliable so far. (wouldn't you ?)
However my #1 reason for doubting some of your presented site's data, is that they just don't add up with the rules of physics and aerodynamics.
Anyways, on to the -47D and -47N issue....
The data below is roughly consistent with all five of my books, and at least 10 other websites, and AFAIK only your presented website's specifications arent consistent with these numbers:
P-47M:
P-47M-1-RE:
Initial climb rate: 3500 feet per minute at 5000 feet and 2650 feet per minute at 20,000 feet.
P-47M:
Initial rate of climb: 3500 ft per minute at 5000 ft and 2650 ft per minute at 20,000 ft
P-47D:
P-47D-25-RE :
Initial climb rate: 2780 ft/min at sea-level, 1575 ft/min at 30,000ft.
Climb: 6.2 min to 15,000, 14 min to 30,000.
P-47D-35-RA:
Max initial climb: 3120 ft/min.
P-47N:
P-47N:
Rate of climb: 2770 ft per minute at 5000 ft and 2550 ft per minute at 20,000 ft
P-47N-5-RE:
Initial climb rate was 2770 feet per minute at 5000 feet and 2550 feet per minute at 20,000 feet.
Climb to 25,000 ft in 14.2 minutes.
Now here comes the part where I agree with you...
According to the -47N's overall specifications, it 'should' in theory be climbing slightly faster than the -47D or at least equal to it, but according to the data it doesn't. Now why is that ? Something seems to be wrong with the -47N's data....
I believe the -47N should be climbing with atleast 3,150ft/min+.
The rest of the specifications above on the -47D and -47M, all seem perfectly reasonable to me.
I am not comfortable with the P-47D's HP at 2,535 as quoted by you. You will find figures quoted from 2,000 to the 2,535 figure across the net and in books. It just doesn't pass the smell test for the following reason.
If the "C" series engine developed only 265 more hp, how could it have propelled the P-47's top speed so high. ("D" 429mph to "N" 467mph where the "N" weighs 1,700lbs more!) The 500hp increase of the "C" series engine over the earlier 2,300hp figure is more reasonable.
How is my presented data unique? I don't think it is and have been careful to source it for you so that you can verify that I am not making it up.
I have also presented evidence that the paddle blade afforded an additional 400fpm climb rate which you are discounting.
From:http://home.att.net/~jbaugher1/p47_4.html
It added 400 feet per minute to the climb rate, but during landings and takeoffs there was only a scant six inches of clearance between blade tips and the ground. Takeoffs and landings must have both been hair-raising.
At any rate, you are comfortable with the post-paddle blade "D" initial climb rate of 3,120fpm and an initial climb rate forthe "N" of 3,150fpm "plus".
By "plus" do you mean possibly an additional 350fpm?
I am just having a hard time swallowing a mere 30fpm increase for the "N" over the "D". And I frankly don't know what "plus" means. Why don't you just come out and say what the figure is that you have in mind?
Again, I do think your hp figure is off. We both have seen a range of hp values ascribed to the P-47D and I think we both can agree that the figure you have selected is the highest either of us has ever seen. To quote you, "... and therefore I find it slightly unreliable so far. (wouldn't you ?)"
How does my data not add up to the rules of physics and aerodynamics? It is you who have offered up a mere additional 265hp on a 1,700lb heavier aircraft as explaination for an increase in speed from 429mph to 467mph.
Speaking of the rules of physics and aerodynamics, is there any other aircraft that you can think of that could realize such a large increase in performance with an increase of just 265hp even though it is also 1,700lbs heavier? Does this sound like its adding up to the rules of physics and aerodynamics as you say? Is it not more reasonable to accept the also widely cited 2,300hp figure for the "D"?
You saud, "According to the -47N's overall specifications, it 'should' in theory be climbing slightly faster than the -47D or at least equal to it, but according to the data it doesn't. Now why is that ? Something seems to be wrong with the -47N's data...."
I think we have a breakthrough! I have only been arguing this for a while now Soren. I have pointed out time and again that your data shows the "N" model climbing literally slower than the pre-paddle blade "D" data.
Why don't you just tell me what you think the P-47N's initial climb rate would have been based on of your understanding of the post paddle balde "D" and "M" models. Please do not include a "plus". At this point, I really don't care to hash this about anymore so I agree to accept that you and I are not going to agree on this.
If the "C" series engine developed only 265 more hp, how could it have propelled the P-47's top speed so high. ("D" 429mph to "N" 467mph where the "N" weighs 1,700lbs more!) The 500hp increase of the "C" series engine over the earlier 2,300hp figure is more reasonable.
How is my presented data unique? I don't think it is and have been careful to source it for you so that you can verify that I am not making it up.
I have also presented evidence that the paddle blade afforded an additional 400fpm climb rate which you are discounting.
From:http://home.att.net/~jbaugher1/p47_4.html
It added 400 feet per minute to the climb rate, but during landings and takeoffs there was only a scant six inches of clearance between blade tips and the ground. Takeoffs and landings must have both been hair-raising.
At any rate, you are comfortable with the post-paddle blade "D" initial climb rate of 3,120fpm and an initial climb rate forthe "N" of 3,150fpm "plus".
By "plus" do you mean possibly an additional 350fpm?
I am just having a hard time swallowing a mere 30fpm increase for the "N" over the "D". And I frankly don't know what "plus" means. Why don't you just come out and say what the figure is that you have in mind?
Again, I do think your hp figure is off. We both have seen a range of hp values ascribed to the P-47D and I think we both can agree that the figure you have selected is the highest either of us has ever seen. To quote you, "... and therefore I find it slightly unreliable so far. (wouldn't you ?)"
How does my data not add up to the rules of physics and aerodynamics? It is you who have offered up a mere additional 265hp on a 1,700lb heavier aircraft as explaination for an increase in speed from 429mph to 467mph.
Speaking of the rules of physics and aerodynamics, is there any other aircraft that you can think of that could realize such a large increase in performance with an increase of just 265hp even though it is also 1,700lbs heavier? Does this sound like its adding up to the rules of physics and aerodynamics as you say? Is it not more reasonable to accept the also widely cited 2,300hp figure for the "D"?
You saud, "According to the -47N's overall specifications, it 'should' in theory be climbing slightly faster than the -47D or at least equal to it, but according to the data it doesn't. Now why is that ? Something seems to be wrong with the -47N's data...."
I think we have a breakthrough! I have only been arguing this for a while now Soren. I have pointed out time and again that your data shows the "N" model climbing literally slower than the pre-paddle blade "D" data.
Why don't you just tell me what you think the P-47N's initial climb rate would have been based on of your understanding of the post paddle balde "D" and "M" models. Please do not include a "plus". At this point, I really don't care to hash this about anymore so I agree to accept that you and I are not going to agree on this.
There you go again ! You totally missunderstood me !
I said I found your presented site's data to be unique, in which I meant this site; http://home.att.net/~historyzone/Seversky-Republic7.html (Which you presented us) is unique with some of its data.
I am in no way questioning your credibility DAVID, and I have no reason to, I'm just saying your presented site is not very reliable.
Geez, you sure have a nack of twisting things
I'll address the rest later.
You won't find 2000 HP with WEP for the -47D in any book DAVID, only 2300HP for the D-20 and 2535HP for the D-35.
I picked the D-35's WEP power for comparison as it was the D-35 which did 3,120fpm, opposed to the D-20's rate of 2,780fpm.
Neither does the P-47M or XP-47J's totally 'unreal' climb figure to 20,000ft !
The P-47 had a low drag wing, which meant that a new prop or a 250 increase in HP would result in a large boost in straight out speed. Prop and engine RPM is also an important factor in this, unfortunately we have no data on the various -47's prop and engine RPM.
At any rate, you are comfortable with the post-paddle blade "D" initial climb rate of 3,120fpm and an initial climb rate forthe "N" of 3,150fpm "plus".
By "plus" do you mean possibly an additional 350fpm?
The -47N's climb rate would offcourse be below the -47M's, but it is possible that it wasnt by that much. I wouldn't be all that surprised if the -47N could do 3,350fpm, but Im more confident it would be around 3,150-3,200fpm.
Why, it was a good deal heavier, which is more than enough reason.
Come on, don't play dumb on me...
"+" means it most likely will not be below the presented figure.
This is all guesses and speculations, nothing more, so its impossible for me to set an exactly accurate figure on it.
The P-47D-20 had 2300HP with WEP, while the P-47D-35 had 2535HP with WEP.
Its not just about HP DAVID, its prop RPM and a variety of other factors aswell. And as I've already explained only the D-20 had 2300HP, the D-35 had 2535HP, and thats fact DAVID.
Nope no breakthrough, that has basically been my opinion all the way, but the data available about the -47N kinda ruled it out.
It would be somewhere around 3,150-3,300fpm if you ask me, 3,300fpm being a very optimistic figure.
Can you agree with that ?
I think we can both agree that it won't be as high as the -47M's figure, or what ?
And a quote:
The P-47B and C models were fine high altitude fighters. The P-47B had a top speed of 406 mph at 27,000 ft., an excellent rate of roll, and could dive like a stone. The Thunderbolt had great survivability; it could absorb a lot of punishment and still get home. The best climb rate was unimpressive, however, at only 1,650 ft./min at SL
By early 1943 the P-47D was coming off the production lines. The P-47D was produced in higher quantity than any other model, and in many variations. Early "D" models were similar to the previous "C" model, with only detail improvements, but as production progressed the "D" model continued to be improved. Republic built a total of 12,602 P-47D's. In addition, Curtis-Wright built 354 P-47D's under license as the P-47G.
P47D-6-RE to P-47D-11-RE models came with an under fuselage shackle for a 500 lb. bomb or a drop tank. Subsequent models, up to the P-47D-20-RE, had strengthened wings with under wing pylons and were able to carry a 1,000-pound bomb under each wing.
The "universal wing," which could carry a variety of stores, was introduced with the P-47D-20-RE. A large four-bladed "paddle" propeller was also fitted. This, along with the water-injection R-2800-21 engine, which had a war emergency rating of 2,300 hp, markedly improved the maximum rate of climb, which was now up to 2,750 ft./min. at 5,000 ft.
The P-47D-25-RE and subsequent models had a cut down rear fuselage and a teardrop canopy, adapted from the British Typhoon fighter. Internal fuel capacity was also increased. The R-2800-59 engine had a war emergency rating of 2,535 hp. Climb rate was now up to 3,120 ft./min., and top speed was 426 mph at 30,000 ft. The Thunderbolt had basically reached full flower.
The next variant to achieve series production was the P-47M. This was called the "sprint" model, and it was a response to the jet powered German V-1 "Buzz Bomb" cruise missile, and the German jet fighters. It had an up-rated R-2800-57(C) engine and CH-5 turbocharger system, which gave a top speed of 470 mph at 30,000 ft. Initial climb was 3,500 ft./min. Delivered beginning in December 1944, 130 were produced.
The last P-47 variant to achieve series production was the P-47N. This model was designed specifically for the pacific theatre, where very long range was a requirement. The "N" used the same engine as the "M"; late production models received the P-2800-77 engine. A new, stronger, wing with squared tips was designed, which incorporated eight internal fuel cells. The landing gear was strengthened to deal with the increased weight of the aircraft. From the P-47N-5-RE model on, zero length rocket launchers were added beneath the wings.
Habitability improvements included an automatic pilot, an armchair seat, and folding rudder pedals to give the pilot increased leg room. These improvements were intended to increase the pilot's comfort on long escort missions.
Maximum speed was 467 mph at 32,500 ft. Initial climb was 2,770 ft./min., and the range on maximum internal fuel was 2,350 miles. The P-47N saw extensive use in the last months of the Pacific War, and had the range to escort the B-29's all the way from Saipan to Japan. Between December 1944 and December 1945 a total of 1,816 P-47N's were manufactured.
The P-47B and C models were fine high altitude fighters. The P-47B had a top speed of 406 mph at 27,000 ft., an excellent rate of roll, and could dive like a stone. The Thunderbolt had great survivability; it could absorb a lot of punishment and still get home. The best climb rate was unimpressive, however, at only 1,650 ft./min at SL
By early 1943 the P-47D was coming off the production lines. The P-47D was produced in higher quantity than any other model, and in many variations. Early "D" models were similar to the previous "C" model, with only detail improvements, but as production progressed the "D" model continued to be improved. Republic built a total of 12,602 P-47D's. In addition, Curtis-Wright built 354 P-47D's under license as the P-47G.
P47D-6-RE to P-47D-11-RE models came with an under fuselage shackle for a 500 lb. bomb or a drop tank. Subsequent models, up to the P-47D-20-RE, had strengthened wings with under wing pylons and were able to carry a 1,000-pound bomb under each wing.
The "universal wing," which could carry a variety of stores, was introduced with the P-47D-20-RE. A large four-bladed "paddle" propeller was also fitted. This, along with the water-injection R-2800-21 engine, which had a war emergency rating of 2,300 hp, markedly improved the maximum rate of climb, which was now up to 2,750 ft./min. at 5,000 ft.
The P-47D-25-RE and subsequent models had a cut down rear fuselage and a teardrop canopy, adapted from the British Typhoon fighter. Internal fuel capacity was also increased. The R-2800-59 engine had a war emergency rating of 2,535 hp. Climb rate was now up to 3,120 ft./min., and top speed was 426 mph at 30,000 ft. The Thunderbolt had basically reached full flower.
The next variant to achieve series production was the P-47M. This was called the "sprint" model, and it was a response to the jet powered German V-1 "Buzz Bomb" cruise missile, and the German jet fighters. It had an up-rated R-2800-57(C) engine and CH-5 turbocharger system, which gave a top speed of 470 mph at 30,000 ft. Initial climb was 3,500 ft./min. Delivered beginning in December 1944, 130 were produced.
The last P-47 variant to achieve series production was the P-47N. This model was designed specifically for the pacific theatre, where very long range was a requirement. The "N" used the same engine as the "M"; late production models received the P-2800-77 engine. A new, stronger, wing with squared tips was designed, which incorporated eight internal fuel cells. The landing gear was strengthened to deal with the increased weight of the aircraft. From the P-47N-5-RE model on, zero length rocket launchers were added beneath the wings.
Habitability improvements included an automatic pilot, an armchair seat, and folding rudder pedals to give the pilot increased leg room. These improvements were intended to increase the pilot's comfort on long escort missions.
Maximum speed was 467 mph at 32,500 ft. Initial climb was 2,770 ft./min., and the range on maximum internal fuel was 2,350 miles. The P-47N saw extensive use in the last months of the Pacific War, and had the range to escort the B-29's all the way from Saipan to Japan. Between December 1944 and December 1945 a total of 1,816 P-47N's were manufactured.
You have posted some really interesting data out on the D-25.
The P-47D-25-RE and subsequent models had a cut down rear fuselage and a teardrop canopy, adapted from the British Typhoon fighter. Internal fuel capacity was also increased. The R-2800-59 engine had a war emergency rating of 2,535 hp. Climb rate was now up to 3,120 ft./min., and top speed was 426 mph at 30,000 ft. The Thunderbolt had basically reached full flower.
The "N" was tested in mock combat against the D-25.
From: http://home.att.net/~historyzone/Seversky-Republic8.html
Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. Much to everyone's surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further.
In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too. The additional horsepower allowed the N to retain its energy better than the older Thunderbolt.
Perhaps the greatest performance increase was in maximum speed. Though not as fast as the stunning P-47M, the heavier N was fully 40 mph faster than the P-47D-25-RE and could generate speeds 30 mph greater than its principal rival, the Mustang. Scorching along at 467 mph @ 32,000 ft., the N could not be caught by any fighter in regular service with any air force on earth with the single exception of its M model sibling. This combination of wing and engine had pushed the N model up to the top rank of the superlative prop driven fighters then in existence.
I assume that by, "... the new fighter proved to be notably superior in every category of performance." it was meant that the climb rate was superior as well.
The P-47D-25-RE and subsequent models had a cut down rear fuselage and a teardrop canopy, adapted from the British Typhoon fighter. Internal fuel capacity was also increased. The R-2800-59 engine had a war emergency rating of 2,535 hp. Climb rate was now up to 3,120 ft./min., and top speed was 426 mph at 30,000 ft. The Thunderbolt had basically reached full flower.
The "N" was tested in mock combat against the D-25.
From: http://home.att.net/~historyzone/Seversky-Republic8.html
Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. Much to everyone's surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further.
In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too. The additional horsepower allowed the N to retain its energy better than the older Thunderbolt.
Perhaps the greatest performance increase was in maximum speed. Though not as fast as the stunning P-47M, the heavier N was fully 40 mph faster than the P-47D-25-RE and could generate speeds 30 mph greater than its principal rival, the Mustang. Scorching along at 467 mph @ 32,000 ft., the N could not be caught by any fighter in regular service with any air force on earth with the single exception of its M model sibling. This combination of wing and engine had pushed the N model up to the top rank of the superlative prop driven fighters then in existence.
I assume that by, "... the new fighter proved to be notably superior in every category of performance." it was meant that the climb rate was superior as well.
Soren, I don't know what books you have at home regarding the P-47M. That data I presented from: http://www.geocities.com/pentagon/quarters/9485/P-47M.html was cited from the following publications:
Warren M. Bodie, Republic's P-47 Thunderbolt
Roger Freeman, Republic Thunderbolt
Enzo Angelucci and Peter Bowers, The American Fighter
David R. McLaren, Beware The Thunderbolt: The 56th FG in WWII
Warren M. Bodie, Republic's P-47 Thunderbolt
Roger Freeman, Republic Thunderbolt
Enzo Angelucci and Peter Bowers, The American Fighter
David R. McLaren, Beware The Thunderbolt: The 56th FG in WWII
I think your data on the horsepower may be correct after all.
I'm not really sure what to make of the climb rate. I'm inclined to believe that the performance of the "N" model was "notably superior in every category of performance" to the D-25 per my cited passage.
I'll give it some thought.
I'm not really sure what to make of the climb rate. I'm inclined to believe that the performance of the "N" model was "notably superior in every category of performance" to the D-25 per my cited passage.
I'll give it some thought.
Wow that is a lot of info to take in at one time. I am going to have to compare it to some info that I have in my books.
FLYBOYJ
"THE GREAT GAZOO"
Great stuff, it was fun trying to follow it all. Constructive criticism - just remember, if you show performance data try to show MP, RPM HP, or at least MP and RPM. In performance charts I've dealt with its hard to grasp real performance with one of those parameters missing. 
Very true.
I found some rpm data on the "N" model. The data comes literally from the Pilot Training Manual itself.
Maximum continuous (Normal rated power) 2,600rpm @ 43.5"
Takeoff (military power) 2,800rpm @ 54"
War emergency power 2,800rpm @ 72"
The engine can be overspeeded to 3,120rpm for up to 30 seconds without damaging the engine.
I also found some other interesting imformation.
Weight: empty - 10,998lbs. Useful load varies from 2,824 to 10,199.9lbs.
Wing Area: 322.2 sq. ft. giving a wing loading of approximately 43 lbs sq. ft. with normal gross weight 13,854lbs.
The manual I am citing to above, by the way, can be downloaded at:
http://www.lanpartyworld.com/ww2/files/air-manuals/usaaf/
I think we have been laboring under an erroneous assumption about the weight of the "N" model. We have assumed that the "N" model was necessarily heavier under all loading conditions than the "D" model. I think this assumption came about because the maximum loaded weight that the P-47N could take off at was in excess of 20,000lbs.
With respect to the "D" model (all versions, in fact) I am seeing referenced normal loaded weights in excess of the "N" model's normal gross weight iof 13,854lbs.
I would suggest (pursuant to the Pilot Training Manual) that the more powerful engine, larger wing and lighter weight of the "N" allowed for the greater fuel and armament loadings of the "N" model and that the "N" model was not, in fact, heavier in normal gross weight than the "D".
Following this line of thought, the "N" model's more powerful "C" series engine, lighter weight and larger wing area would have put the climb rate significantly (what "significantly" means is still in question) above the D-25RE as well as explain how the top speed rocketed to 467mph.
On a related note, this also coincides with the "M" model having a similar normal loaded weight of 13,275lbs and similar top speed that was achieved with the same "C" series powerplant.
Maximum continuous (Normal rated power) 2,600rpm @ 43.5"
Takeoff (military power) 2,800rpm @ 54"
War emergency power 2,800rpm @ 72"
The engine can be overspeeded to 3,120rpm for up to 30 seconds without damaging the engine.
I also found some other interesting imformation.
Weight: empty - 10,998lbs. Useful load varies from 2,824 to 10,199.9lbs.
Wing Area: 322.2 sq. ft. giving a wing loading of approximately 43 lbs sq. ft. with normal gross weight 13,854lbs.
The manual I am citing to above, by the way, can be downloaded at:
http://www.lanpartyworld.com/ww2/files/air-manuals/usaaf/
I think we have been laboring under an erroneous assumption about the weight of the "N" model. We have assumed that the "N" model was necessarily heavier under all loading conditions than the "D" model. I think this assumption came about because the maximum loaded weight that the P-47N could take off at was in excess of 20,000lbs.
With respect to the "D" model (all versions, in fact) I am seeing referenced normal loaded weights in excess of the "N" model's normal gross weight iof 13,854lbs.
I would suggest (pursuant to the Pilot Training Manual) that the more powerful engine, larger wing and lighter weight of the "N" allowed for the greater fuel and armament loadings of the "N" model and that the "N" model was not, in fact, heavier in normal gross weight than the "D".
Following this line of thought, the "N" model's more powerful "C" series engine, lighter weight and larger wing area would have put the climb rate significantly (what "significantly" means is still in question) above the D-25RE as well as explain how the top speed rocketed to 467mph.
On a related note, this also coincides with the "M" model having a similar normal loaded weight of 13,275lbs and similar top speed that was achieved with the same "C" series powerplant.
The P-47M was a modified D-27 model. The wing area for all the "D" models was 300sq. ft. as there was no alteration of the wingspan or wing area throughout the evolution of the "D" series.
In light of the data from the actual Pilot Training Manual itself which constitutes a primary data source, the following comparison emerges vis a vis the "M" and "D" data.
------------------------------------------------------------
P-47N
Wing area - 322.2 sq.ft.
Normal gross weight - 13,854 (Wing loading - 43lbs)
Horsepower - 2,800 (Power loading - 4.94lbs)
Initial climb rate - ?
P-47M
Wing area - 300 sq.ft.
Normal loaded weight - 13,275 (Wing loading - 44.25lbs)
Horsepower - 2,800 (Power loading - 4.74lbs)
Climb rate at 5,000ft is 3,500fpm (I am assuming this for the purposes of furthering the discussion. In addition, even accepting the 3,500fpm figure at 5,000ft would mean a higher initial climb rate)
P-47D-25
Wing area - 300 sq.ft.
Normal Loaded weight - 14,600lbs (Wing loading - 48.67lbs)
Horsepower - 2,535 (Power loading - 5.76lbs)
Initial climb rate is 3,120fpm.
----------------------------------------------------
I think that if the "D" climb rate is correct (I always thought it was 2,780 + 400fpm which would be 3,180fpm but I will not contest over 60fpm), then the "M" figure would have to be higher than 3,500fpm for initial climb rate. It is in any event because the 3,500fpm figure is for 5,000ft and not an initial figure.
Correspondingly, the "N" model would be very close to the "M" and certainly well in excess of 3,150fpm. I also believe it would be in excess of the 3,300fpm figure that was offered to make me happy as well.
To recap:
The power loading of the "D" vs. "N" is 5.76lbs vs. 4.94lbs (14.2% decrease in lbs. per hp.)
The wing loading of the "D" vs. "N" is 48.67lbs vs. 43lbs. (11.6% decrease in lbs. per sq.ft.)
Accepting 3,500fpm as an initial climb rate for the "M", we can extrapolate how such differences in power and wing loadings would affect climb rate.
The power loading of the "D" vs. "M" is 5.76lbs vs. 4.74lbs (17.7% decrease in lbs. per hp.)
The wing loading of the "D" vs. the "M" is 48.67lbs vs. 44.25lbs (9% decrease in lbs. per sq.ft.)
Even under the data you offered Soren, the "M" would have an initial climb rate in excess of 3,500fpm and the "N" would be very, very close. Of course, if the "M" has a greater than 3,500+fpm climb rate, then the "N" follows accordingly.
In light of the data from the actual Pilot Training Manual itself which constitutes a primary data source, the following comparison emerges vis a vis the "M" and "D" data.
------------------------------------------------------------
P-47N
Wing area - 322.2 sq.ft.
Normal gross weight - 13,854 (Wing loading - 43lbs)
Horsepower - 2,800 (Power loading - 4.94lbs)
Initial climb rate - ?
P-47M
Wing area - 300 sq.ft.
Normal loaded weight - 13,275 (Wing loading - 44.25lbs)
Horsepower - 2,800 (Power loading - 4.74lbs)
Climb rate at 5,000ft is 3,500fpm (I am assuming this for the purposes of furthering the discussion. In addition, even accepting the 3,500fpm figure at 5,000ft would mean a higher initial climb rate)
P-47D-25
Wing area - 300 sq.ft.
Normal Loaded weight - 14,600lbs (Wing loading - 48.67lbs)
Horsepower - 2,535 (Power loading - 5.76lbs)
Initial climb rate is 3,120fpm.
----------------------------------------------------
I think that if the "D" climb rate is correct (I always thought it was 2,780 + 400fpm which would be 3,180fpm but I will not contest over 60fpm), then the "M" figure would have to be higher than 3,500fpm for initial climb rate. It is in any event because the 3,500fpm figure is for 5,000ft and not an initial figure.
Correspondingly, the "N" model would be very close to the "M" and certainly well in excess of 3,150fpm. I also believe it would be in excess of the 3,300fpm figure that was offered to make me happy as well.
To recap:
The power loading of the "D" vs. "N" is 5.76lbs vs. 4.94lbs (14.2% decrease in lbs. per hp.)
The wing loading of the "D" vs. "N" is 48.67lbs vs. 43lbs. (11.6% decrease in lbs. per sq.ft.)
Accepting 3,500fpm as an initial climb rate for the "M", we can extrapolate how such differences in power and wing loadings would affect climb rate.
The power loading of the "D" vs. "M" is 5.76lbs vs. 4.74lbs (17.7% decrease in lbs. per hp.)
The wing loading of the "D" vs. the "M" is 48.67lbs vs. 44.25lbs (9% decrease in lbs. per sq.ft.)
Even under the data you offered Soren, the "M" would have an initial climb rate in excess of 3,500fpm and the "N" would be very, very close. Of course, if the "M" has a greater than 3,500+fpm climb rate, then the "N" follows accordingly.
If we suppose the -47M's climb figure is correct , which it should be according to its power and wing-loading, and we suppose that DAVID's newly found weight figure is correct aswell, then I would actually rate the -45N's climb rate either very close to, or as 3,500fpm. (=equal to the the -47M)
If the -47N uses the same prop and engine, and is only slightly heavier than the -47M, but additionally has a larger wing, then the -47N 'should' be climbing either very close or equal to the -47M. (Maybe 3,450-3,500fpm)
However what I'm questioning most at the moment, is why should the data from several books about the P-47 be wrong about the -47N's normal loaded weight figure ? Seems strange...
The -47N's normal loaded weight is quoted as being 16,300 pounds by every single one of my sources. That's allot more than 13,850lbs !
------------------------------
So my conclusion is:
If we use the DAVID's newly acquired weight figure for the -47N, then it should be climbing at very close to 3,500ft/min.
But if we use what is the most common weight figure for the -47N, then I would guess the climb rate as being somewhere between 3,150-3,200ft/min.
If the -47N uses the same prop and engine, and is only slightly heavier than the -47M, but additionally has a larger wing, then the -47N 'should' be climbing either very close or equal to the -47M. (Maybe 3,450-3,500fpm)
However what I'm questioning most at the moment, is why should the data from several books about the P-47 be wrong about the -47N's normal loaded weight figure ? Seems strange...
The -47N's normal loaded weight is quoted as being 16,300 pounds by every single one of my sources. That's allot more than 13,850lbs !
------------------------------
So my conclusion is:
If we use the DAVID's newly acquired weight figure for the -47N, then it should be climbing at very close to 3,500ft/min.
But if we use what is the most common weight figure for the -47N, then I would guess the climb rate as being somewhere between 3,150-3,200ft/min.
