REPUBLIC AVIATION PERFORMANCE DATA - P-47 "M" and
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the lancaster kicks ass
Major General
- 19,937
- Dec 20, 2003
an interesting idea...........
cheddar cheese
Major General
What, the remains of the French army?
DAVID just how much fuel do you think the P-47N needed to escort bombers to Germany and back ? Or for a fighter-sweep maybe ?
Which is why I said "Thats how it would be" and not "thats how it was".
I was obviously implying that 'if' they met, those would be the conditions.
Sure, and do you know why ? Because by 44-45 the U.S. pilots flew against newly recruited Jap. rice famers
Also the -47M didnt beat the "Frank" in the climb, but by the traditional team-work in which even a P-38 could wax any Jap. single seat fighter. (The Jap pilots were real poor at teamwork )
Which is why I said "Thats how it would be" and not "thats how it was".
I was obviously implying that 'if' they met, those would be the conditions.
Sure, and do you know why ? Because by 44-45 the U.S. pilots flew against newly recruited Jap. rice famers
Also the -47M didnt beat the "Frank" in the climb, but by the traditional team-work in which even a P-38 could wax any Jap. single seat fighter. (The Jap pilots were real poor at teamwork )
FLYBOYJ
"THE GREAT GAZOO"
DAVIDICUS said:
I believe heavy bombers late in the war started seeing autopilots and many of the later transport aircraft (C-54s). The 2 major manufacturer's were Sperry and GE. I believe the Sperry units were all electric and the GE used a hydraulic/ electrical system.
You cannot use autopilot in tight formation flying. When you fly formation you are picking up a reference on the lead plane and establishing a rough 45 degree angle off the plane you're following. All the time you are constantly changing power settings and adding slight control inputs to maintain the desired distance from your element leader. I've done a lot of formation flying in light aircraft and in the L-29 and learning it is very challenging (as a matter of fact I'm still learning!) but when you get a good formation going, nothing looks better in the air! I believe on long WW2 missions autopilots might be used and the "formation" would be kept very wide and open to facilitate its use. When the need came to fly in a tight formation, I'm sure the autopilot was turned off.
Ah the ole "relief tube." Yep many WW2 aircraft had them and some modern fighters still facilitate them. I got 2 funny stories about relief tubes:
I had an uncle who washed out of flight training. He told me one story where he and a friend were walking around a base somewhere in Idaho. His buddy decided to jump into a P-40 sitting on the line and pick up the "mike," place it close to his mouth and simulate an comic air-to-air combat narrative. What this guy didn't know, he was speaking into the "relief tube." Soon a gaggle of cadets gathered around this guy who thought he was the funniest thing since Bob Hope as he continued his narrative. When he was told what he was doing, he immediately ran to the nearest head as he turned violently ill!
Another story involves an A-4. An A-4 driver once reported a squawk on an aircraft stating the "Relief tube was too short." The corrective in the
"Vids Maf" form was something like "relief tube and system checked for proper installation. Entire Airframes department performed an actual functional test of tube with no problems. It is recommended that the writer of this discrepancy contact medical to report that he is anatomically inferior to normal Naval maintenance personnel. Perhaps a relief tube extender may be authorized."
8)
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- #28
"DAVID just how much fuel do you think the P-47N needed to escort bombers to Germany and back ? Or for a fighter-sweep maybe?"
Compared to the amount of fuel it was designed to be able to carry for missions in the PTO from, say Le Shima, not much! If operating in the ETO, there would be no reason to fill an "N" model's internal fuel tanks to maximum when they could carry drop tanks to the hot spot, drop the tanks, engage the enemy and still make it back using far less than 570 gallons.
"Also the -47M didnt beat the "Frank" in the climb, ..."
Soren, the P-47M model never flew in the PTO. I'm not sure what the climb rate of the Ki-84 was but have read that it was 3,600fpm (I no not know at what altitude this figure is for or even if it is accurate).
Since you now know the climb rate of the P-47M (3,775fpm at 5,000ft and Combat Gross Weight) and are asserting that the Ki-84 would be able to beat an "M" model in climb, I assume that you possess knowledge that the Ki-84's climb rate was in fact higher than this.
Please don't keep me in suspense any longer. Do tell.
Compared to the amount of fuel it was designed to be able to carry for missions in the PTO from, say Le Shima, not much! If operating in the ETO, there would be no reason to fill an "N" model's internal fuel tanks to maximum when they could carry drop tanks to the hot spot, drop the tanks, engage the enemy and still make it back using far less than 570 gallons.
"Also the -47M didnt beat the "Frank" in the climb, ..."
Soren, the P-47M model never flew in the PTO. I'm not sure what the climb rate of the Ki-84 was but have read that it was 3,600fpm (I no not know at what altitude this figure is for or even if it is accurate).
Since you now know the climb rate of the P-47M (3,775fpm at 5,000ft and Combat Gross Weight) and are asserting that the Ki-84 would be able to beat an "M" model in climb, I assume that you possess knowledge that the Ki-84's climb rate was in fact higher than this.
Please don't keep me in suspense any longer. Do tell.
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- #29
wmaxt
Staff Sergeant
Soren said:
Your right even inexperianced P-38 pilots with tactics (boom and zoom) and teamwork had little trouble with Japanese single seat aircraft. A number of experianced pilots could, even with early P-38s, take the Japanese on 1:1 in any situation.
wmaxt
Use drop tanks instead of internal fuel ? That would be even more expensive...
I could concede that the -47N might not carry more than 75% of its full internal fuel load in the ETO, but no less. It needs a good chance of making it home again.
I know, meant the -47N, accidently typed "M"
As you could see I was responding to your saying: The P-47N did, however, do quite well in the PTO, waxing late war Japanese rice rockets like the Ki-84 Frank which, I might add, boasted a very high rate of climb
FLYBOYJ
"THE GREAT GAZOO"
plan_D said:
Oh he was! "Uncle Joe" washed out because he wasn't too serious about flying and was made a Flight Officer immediately after "resigning" from pilots training and agreeing to become a bombardier. He told me it also paid more. My mom tells me he was a real ladies man and was the type of guy who had 2 girls on each arm on a Saturday night. Unfortunately he was badly injured in a B-24 crash in Idaho, he was on a training mission and was the only survivor on an 11 man crew! Attached is 2nd Lt Joe Colon as an enlistee....
Back to the subject....
Do you guys really believe that ETO P-47s would be sent out without full tanks? There has always been a rule of thumb to land with 1/2 hour reserves in your tanks if possible. I would think that unless there is an ordnance issue anytime an aircraft went out on a mission they did so with full tanks all around!
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Well, Flyboy, the P-47N wasn't an ETO P-47. We were just entertaining the hypothetical that it was.
The P-47N had a far greater internal fuel capacity than the "M" model as it was specifically designed for escort duties in the PTO where the distances involved were far greater than the distances involved in escort duties in the ETO.
If the "N" model had been deployed to the ETO as opposed to the PTO, why would they use full internal tanks?
The P-47N's internal fuel tank capacity enabled it to carry 2,500lbs of fuel over and above the internal fuel tank capacity of the "M" model.
Soren said, "Use drop tanks instead of internal fuel ? That would be even more expensive... "
And your point is?
"I could concede that the -47N might not carry more than 75% of its full internal fuel load in the ETO, but no less. It needs a good chance of making it home again."
I appreciate the concession but would apprise you of the following. The "M" model had no different internal fuel loading than the preceding "D" model. A P-47N, even at 75% internal fuel capacity, carries 16% more internal fuel than the full internal fuel load of the "M" and "D" models. In fact, the P-47N needs but 64% of its internal fuel capacity to equal 100% of the internal fuel capacity of the "M" and "D" models.
With respect to the climb rates of the P-47M and Ki-84, as I indicated, I really don't know. I do know that relying solely on power and wing loadings is a problematic method of estimating climb rates as evidenced by much of the debate on this thread that preceeded my posting official performance test data from Republic Aviation. My favorite example, which you have heard several times now, is the change in climb rate for the P-47D after the paddle blade propeller was installed which resulted from no change in weight, horsepower or wing area.
Different aircraft will have wing designs that afford different amounts of lift. Different aircraft will have differential efficiencies with respect to their propellers' abilities to move air. Different aircraft will have different drag coefficients. Lastly, unless you get a hold of reliable data, you can't rely on the power, weight and horsepower figures to begin with.
I have a book that lists the following data for the Ki-84:
Wing area - 226 sqft
Weight - 5,864lbs
H.P. - 1,900
The climb rate is just listed at 3,600fpm
You do the math. It certainly doesn't coincide with the power and wing loading data you presented. (My point is not that your data is incorrect just that there is a lot of different data out there that isn't reliable)
BTW - Where did you get your power and wing loading figures from?
The P-47N had a far greater internal fuel capacity than the "M" model as it was specifically designed for escort duties in the PTO where the distances involved were far greater than the distances involved in escort duties in the ETO.
If the "N" model had been deployed to the ETO as opposed to the PTO, why would they use full internal tanks?
The P-47N's internal fuel tank capacity enabled it to carry 2,500lbs of fuel over and above the internal fuel tank capacity of the "M" model.
Soren said, "Use drop tanks instead of internal fuel ? That would be even more expensive... "
And your point is?
"I could concede that the -47N might not carry more than 75% of its full internal fuel load in the ETO, but no less. It needs a good chance of making it home again."
I appreciate the concession but would apprise you of the following. The "M" model had no different internal fuel loading than the preceding "D" model. A P-47N, even at 75% internal fuel capacity, carries 16% more internal fuel than the full internal fuel load of the "M" and "D" models. In fact, the P-47N needs but 64% of its internal fuel capacity to equal 100% of the internal fuel capacity of the "M" and "D" models.
With respect to the climb rates of the P-47M and Ki-84, as I indicated, I really don't know. I do know that relying solely on power and wing loadings is a problematic method of estimating climb rates as evidenced by much of the debate on this thread that preceeded my posting official performance test data from Republic Aviation. My favorite example, which you have heard several times now, is the change in climb rate for the P-47D after the paddle blade propeller was installed which resulted from no change in weight, horsepower or wing area.
Different aircraft will have wing designs that afford different amounts of lift. Different aircraft will have differential efficiencies with respect to their propellers' abilities to move air. Different aircraft will have different drag coefficients. Lastly, unless you get a hold of reliable data, you can't rely on the power, weight and horsepower figures to begin with.
I have a book that lists the following data for the Ki-84:
Wing area - 226 sqft
Weight - 5,864lbs
H.P. - 1,900
The climb rate is just listed at 3,600fpm
You do the math. It certainly doesn't coincide with the power and wing loading data you presented. (My point is not that your data is incorrect just that there is a lot of different data out there that isn't reliable)
BTW - Where did you get your power and wing loading figures from?
FLYBOYJ
"THE GREAT GAZOO"
DAVIDICUS said:
I understand that. I just couldn't see the thought of going out on a mission over Europe in any fighter/ fighter bomber aircraft and not having the aircraft bagged full of fuel, unless there was a bomb load/ takeoff weight requirement, but I would only see that happening in multi-engine bombers.
DAVIDICUS said:
You mean you don't know ? Think about it DAVID, what would be the most economical and safe way...
DAVIDICUS said:
Your absolutely correct DAVID, and therefore I acquired that data before I posted those stress-load figures.
First of all I think we can clearly agree that the Ki-84 is more aerodynamically clean than the P-47, right ?
Second comes the statistic Figures:
Ki-84
Empty weight: 5,864lbs.
Loaded weight: 7,955lbs.
Max loaded weight: 8,576lbs.
Wing area: 226 sq.ft.
Wing span: 36' 10".
Engine: Nakajima Ha-45 Radial.
Power: 1900 HP.
Power-loading: 4.18 lbs/hp.
Wing-loading: 35.19 lbs/sq.ft.
The Ki-84's airfoil was supposedly overall thicker than the Ki-56 and Ki-61's while using the same shape(NACA 2R1 16 - NACA 2R1 or NACA 24000), resulting in a airfoil thickness ratio of about 16-17% at the root and about 10% at the tip. So the Ki-84's wing has a higher CL-max than any of the P-47's, and on top of that the Ki-84 has wing aspect ratio of 6.0 while the P-47 has a max ratio of 5.62. All this is more than enough to totally negate any prop design advantage to the P-47.
So yes, in reality the Ki-84 would outclimb even a P-47M, and certainly the P-47N.
In initial climb rate, the P-47M might have a small advantage because of its very high top speed, but the Ki-84 will quickly overtake and clearly beat the -47M in a sustained climb.
DAVIDICUS said:
What book is that ? And why does it quote the Ki-84's empty weight figure ?
DAVIDICUS said:
No its much more favorable to the Ki-84 than the data I presented, but unfortunately also wrong.
My data comes only from a few books (listed below) and mostly from websites, as not much is written about this aircraft, so how accurate it is, is uncertain. However weight and HP figures are aquired from NACA, so they should be correct.
Sources: "The Complete Encyclodepia of World Aircraft - 1997" and a very old book "Japanese Aircraft of the Pacific War - 1979"
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- #40
"You mean you don't know ? Think about it DAVID, what would be the most economical and safe way... "
When I said, "And your point is?" I was being tongue in cheek Soren. (I don't make widespread use of emoticons as you do so comedy runs the risk of being misunderstood) We are talking about war here. Let's not be naive. Considerations of expense, economy and safety often take a back seat to other considerations that make for results that are more expensive, and dangerous.
In further contravention of your point, I could easily argue (which I have already done above) that, hypothetically speaking, sending pilots into combat in the ETO with P-47N's that are unnecessarily heavy, due to a reliance on their massive internal fuel capacity designed for operations in the PTO and not the ETO, would in fact be more expensive and dangerous in terms of more shot down aircraft, lost pilots and lower morale than the cost of utilizing jettisonable drop tanks and a much reduced internal fuel load. (Remember that the "N" model needs but 64% of it's internal fuel capacity to equal 100% of the internal fuel capacity of the "M" and "D" models.)
In fact, if the "N" were sent into combat under a Normal Gross Weight of 13,854lbs (that would be the empty weight of 10,998lbs plus 2,856lbs of ammunition and fuel), it's climb rate would be very close to the "M" model's at Combat Gross Weight (13,275lbs) which we know to be 3,775fpm at 5,000ft.
See my prior post on this thread:
A full internal ammunition and fuel load in an "M" model weighs 2,833lbs.
A full internal ammunition and fuel load in an "N" model weighs 5,332lbs.
The "N" model would thus carry an additional 2,500lbs (2,499lbs) of fuel over and above the "M" model (under circumstances where the ammunition load is the maximum) in "Combat Gross Weight" configuration.
See also my prior post on this thread:
Given the "M" model's ability to cliimb at 3,775fpm at 5,000ft, it would appear likely that the maximum climb rate at sea level would be in excess of 4,000fpm. (That, of course, would be under a "Combat Gross Weight" loading. Under a "Normal Gross Weight" loading, the climb rate would be significantly higher.)
Given the "N" model's mere 579lb heavier weight in "Normal Gross Weight" configuration and lower wing loading of 43lbs as opposed to the "M" model's 44.25lbs, I would expect the "N" model to have a climb rate within 100fpm or so of the "M" model's figures reflected above.
Soren, I will accept your Ki-84 data. I have never argued with you on the data you presented. To quote my prior post, "With respect to the climb rates of the P-47M and Ki-84, as I indicated, I really don't know." Additionally, when I quoted those figures from the book I have, the purpose was expressly set out as, "(My point is not that your data is incorrect just that there is a lot of different data out there that isn't reliable)".
BTW - The book I quoted the figures I posted from was "Axis Aircraft 1939-1945" by Charles Dumont.
When I said, "And your point is?" I was being tongue in cheek Soren. (I don't make widespread use of emoticons as you do so comedy runs the risk of being misunderstood) We are talking about war here. Let's not be naive. Considerations of expense, economy and safety often take a back seat to other considerations that make for results that are more expensive, and dangerous.
In further contravention of your point, I could easily argue (which I have already done above) that, hypothetically speaking, sending pilots into combat in the ETO with P-47N's that are unnecessarily heavy, due to a reliance on their massive internal fuel capacity designed for operations in the PTO and not the ETO, would in fact be more expensive and dangerous in terms of more shot down aircraft, lost pilots and lower morale than the cost of utilizing jettisonable drop tanks and a much reduced internal fuel load. (Remember that the "N" model needs but 64% of it's internal fuel capacity to equal 100% of the internal fuel capacity of the "M" and "D" models.)
In fact, if the "N" were sent into combat under a Normal Gross Weight of 13,854lbs (that would be the empty weight of 10,998lbs plus 2,856lbs of ammunition and fuel), it's climb rate would be very close to the "M" model's at Combat Gross Weight (13,275lbs) which we know to be 3,775fpm at 5,000ft.
See my prior post on this thread:
A full internal ammunition and fuel load in an "M" model weighs 2,833lbs.
A full internal ammunition and fuel load in an "N" model weighs 5,332lbs.
The "N" model would thus carry an additional 2,500lbs (2,499lbs) of fuel over and above the "M" model (under circumstances where the ammunition load is the maximum) in "Combat Gross Weight" configuration.
See also my prior post on this thread:
Given the "M" model's ability to cliimb at 3,775fpm at 5,000ft, it would appear likely that the maximum climb rate at sea level would be in excess of 4,000fpm. (That, of course, would be under a "Combat Gross Weight" loading. Under a "Normal Gross Weight" loading, the climb rate would be significantly higher.)
Given the "N" model's mere 579lb heavier weight in "Normal Gross Weight" configuration and lower wing loading of 43lbs as opposed to the "M" model's 44.25lbs, I would expect the "N" model to have a climb rate within 100fpm or so of the "M" model's figures reflected above.
Soren, I will accept your Ki-84 data. I have never argued with you on the data you presented. To quote my prior post, "With respect to the climb rates of the P-47M and Ki-84, as I indicated, I really don't know." Additionally, when I quoted those figures from the book I have, the purpose was expressly set out as, "(My point is not that your data is incorrect just that there is a lot of different data out there that isn't reliable)".
BTW - The book I quoted the figures I posted from was "Axis Aircraft 1939-1945" by Charles Dumont.
