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#### Wild_Bill_Kelso

##### Senior Master Sergeant

- 3,231

- Mar 18, 2022

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- Thread starter Wild_Bill_Kelso
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Ad: This forum contains affiliate links to products on Amazon and eBay. More information in Terms and rules

- Thread starter
- #301

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- Mar 18, 2022

This incredible collection of WW2 USAAF and NAF pilot survival and bail out gear is on loan to my museum by former Forum member Dustin. It's about as complete a display as can be seen. There isn't much that he is missing, and I'm proud to be the caretaker of it for the time being.

www.usmilitariaforum.com

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- Dec 6, 2006

This website shows a lot of examples of American pilots with RAF dinghys and shows the American copy of it. Americans fighter pilots seemed to have a preference for RAF googles helmets gloves boots and Mae Wests

They still have a preference for the RAF gloves.This website shows a lot of examples of American pilots with RAF dinghys and shows the American copy of it. Americans fighter pilots seemed to have a preference for RAF googles helmets gloves boots and Mae Wests

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- #307

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- Mar 18, 2022

This is what we found for top speed for Sea Hurricanes

View attachment 707452

Here is what we have for Wildcat / Martlet and Hurricane

F4F-3

Top speed 330 mph, rate of climb ~2,500 fpm (to 16,000 ft)

F4F-4

Top Speed 316 mph at 17,200 ft, climb ~1,820 fpm

Martlet II

Top Speed 317 mph at 14,000 ft, climb 7.5 minutes to 15,000 ft

FM-2, top speed about 312 at 4-12,00 ft, 328 mph at 18,000 ft,

British Wildcat VIa data card says 307 mph at 3,500 and 319 mph at 16,750 ft

British Wildcat VIb data card shows 307 and 328 mph at 12,800 ft

Hurricane IIs at low and high boost

Notice Hurricane IIC top speed 327. Hurricane IIC 'Trop' 301.

I think Sea Hurricane II is a bit less than IIC, due to extra drag from arrestor hook etc.

Based on the numbers here, with 147 gallons maximum internal fuel, the F4F-3 has a range of 1280 miles. The Hurricane IIC has a range of 460 miles. Three times 460 is 1380. So is it really a shocking lie to point out that a Wildcat had almost three times the range of a Hurricane II? No, it isn't.

When external tanks become available and actually implemented in the field, the numbers change a bit needless to say, but external fuel tanks seem to be rather late arrival for the Hurricane.

It's also worth noting that here, we can see that the Hurrciane IIC Trop can barely make

The Hurricane IIC trop is making

For comparison of the Sea Level speeds:

F4F-3 278 mph

F4F-4 275 mph

FM-2 300 mph (military power)

Kittyhawk IA 292 mph @ 42" Hg (Boscombe)

P-40K 344 mph @ 57" Hg

P-51A 317 mph (at 1,000 ft) @ 42" Hg

P-51A 360 mph (at 1,000 ft) @ 56" Hg

Spitfire VB / Merlin 50 334 mph (at 2,000 ft) (+18 Boost)

Spitfire Mk VIII - 309 mph (+12 lb Boost)

Spitfire Mk VIII - 338 mph (+18 lb Boost)

P-47D 333 mph @ 56" Hg

P-51B 360 mph @ 60" Hg

P-51B 380 mph @ 67" Hg

A6M2 277 mph (USN test)

A6M3 280 mph

Ki-43 IIb makes 320 mph at altitude, Ki-43 II Kai makes 335 mph at altitude. I couldn't find any estimate of speed at sea level.

The above would give the F4F-4 a better range on internal fuel than a Zero! You do know that those numbers were estimates? Don't you find it interesting that 'normal' fighter has 110USG of fuel and weighs 6895lb and has a range of 880miles, yet when we increase weight by 537lb and fuel by ~35% range increases by ~45%!View attachment 757837

Based on the numbers here, with 147 gallons maximum internal fuel, the F4F-3 has a range of 1280 miles. The Hurricane IIC has a range of 460 miles. Three times 460 is 1380. So is it really a shocking lie to point out that a Wildcat had almost three times the range of a Hurricane II? No, it isn't.

When external tanks become available and actually implemented in the field, the numbers change a bit needless to say, but external fuel tanks seem to be rather late arrival for the Hurricane.

The F4F-4 SAC data shows:

830 miles at 161mph at 5000ft with 120IG internal fuel

The above is a no reserve, no allowance range.

The Hurricane IIA US Army testing showed a range of

597 miles at 185mph at 5000ft with 94IG (112USG). At 15000ft and 196.5 mph range was 680 miles.

The above is a no reserve, no allowance range.

View attachment 757838

It's also worth noting that here, we can see that the Hurrciane IIC Trop can barely make300 mphat altitude, and this is with +12 lb boost.

The Hurricane IIC trop is making238 mphat Sea Level.

For comparison of the Sea Level speeds:

F4F-3 278 mph

F4F-4 275 mph

FM-2 300 mph (military power)

Kittyhawk IA 292 mph @ 42" Hg (Boscombe)

P-40K 344 mph @ 57" Hg

P-51A 317 mph (at 1,000 ft) @ 42" Hg

P-51A 360 mph (at 1,000 ft) @ 56" Hg

Spitfire VB / Merlin 50 334 mph (at 2,000 ft) (+18 Boost)

Spitfire Mk VIII - 309 mph (+12 lb Boost)

Spitfire Mk VIII - 338 mph (+18 lb Boost)

P-47D 333 mph @ 56" Hg

P-51B 360 mph @ 60" Hg

P-51B 380 mph @ 67" Hg

A6M2 277 mph (USN test)

A6M3 280 mph

Ki-43 IIb makes 320 mph at altitude, Ki-43 II Kai makes 335 mph at altitude. I couldn't find any estimate of speed at sea level.

I'm fairly certain he Trop data is wrong and that it's actually an aircraft that was also carrying two drop tanks or other external loads . Max boost for the IIC was 16lb:

Unfortunately, I have run across multiple US range charts for various aircraft that have the range values shifted (as well as the occasional speed or climb values) one column to the left, thus giving the impression of greater than actual range (speed and/or climb). This should not be something unexpected, as there was not an in de]th quality control check for such things in WWII, particularly during the immediate pre- and early-war.

This occurred in other nations documents as well, though it seems to be significantly more common in US documents than in other nation's - particularly pre-/early-war. I tend to check on the values in most of the official documents for the US, UK/Commonwealth, French, Japanese, and German, when possible.

There are some basic engine and aerodynamic physics - along with the actual practical achieved performance of the engine and/or airframe - that will totally rule out some values.

We have run across this type of thing in the recent past on this forum, ie:

The estimated/claimed Vmax and ROC of the P-39C as presented in the Bell chart and test results. The ROC, for example, the attributed ROC was not possible with the attributed engine BHP - except perhaps in a zoom climb.

The range claims for the B-24 (limited by engine physics, as well as detail problems with the engine/installation) were not possible in practice. The estimated 6000+ mile range claimed by Consolidated in one of its charts was not possible, to the point where I have to assume some of the people at Consolidated knowingly lied. Even with today's engine control systems it would not be possible. Also, the initially claimed ROC for the B-24 was not achievable due to engine problems with overheating and cooling airflow drag.

The initial ROC of 3070 ft/min at sea level listed in the F4F-3 Detail Specifications chart posted above was not possible operationally due to overheating problems. Actual achievable initial sustained ROC would be ~2300 ft/min. The 1280 mile range with 147 USgal is not achievable due to a combination of engine/aerodynamic physics and practical problems with the engine/installation.

As a general rule, if there are 2 aircraft with similar technology airframes, similar sizes, similar weights, similar usable engine BHP, and similar fuel loads, the will have similar performance.

The Martlet/F4F-3/-4 and SeaHurricane Mk I/II did not use particularly advanced airframes/aerodynamics, had similar size and weight, and the usable engine BHP was similar (although the Merlin III was significantly behind in altitude performance). While the slight differences in aerodynamics and engine performance might make a difference in speed, ROC, and range performance, the differences would be just that - slight.

Engine overheating problems with the R-1830-76/-86 during climb were never (I think) solved, and the problem severely limited the F4F-3/-4 usable climb rates. The addition of the folding wings and the 2 extra guns had a small but significant impact on the weight and drag.

The major advantage the F4F had over the SeaHurricane Mk II was greater internal fuel, primarily due (initially) to a lighter fuselage and wing monocoque structure (maybe engine installation also?). With the addition of the folding wing and the 2 extra guns the F4F lost the lighter structure advantage, but maintained the internal fuel advantage - hence the F4F-3/-4 will have more range.

The SeaHurricane Mk I should probably be compared to the earlier single-stage Martlets rather than the F4F-3/-4. The single-stage Martlets also had a difficult time achieving 300 mph.

Just some thoughts and data.

This occurred in other nations documents as well, though it seems to be significantly more common in US documents than in other nation's - particularly pre-/early-war. I tend to check on the values in most of the official documents for the US, UK/Commonwealth, French, Japanese, and German, when possible.

There are some basic engine and aerodynamic physics - along with the actual practical achieved performance of the engine and/or airframe - that will totally rule out some values.

We have run across this type of thing in the recent past on this forum, ie:

The estimated/claimed Vmax and ROC of the P-39C as presented in the Bell chart and test results. The ROC, for example, the attributed ROC was not possible with the attributed engine BHP - except perhaps in a zoom climb.

The range claims for the B-24 (limited by engine physics, as well as detail problems with the engine/installation) were not possible in practice. The estimated 6000+ mile range claimed by Consolidated in one of its charts was not possible, to the point where I have to assume some of the people at Consolidated knowingly lied. Even with today's engine control systems it would not be possible. Also, the initially claimed ROC for the B-24 was not achievable due to engine problems with overheating and cooling airflow drag.

The initial ROC of 3070 ft/min at sea level listed in the F4F-3 Detail Specifications chart posted above was not possible operationally due to overheating problems. Actual achievable initial sustained ROC would be ~2300 ft/min. The 1280 mile range with 147 USgal is not achievable due to a combination of engine/aerodynamic physics and practical problems with the engine/installation.

As a general rule, if there are 2 aircraft with similar technology airframes, similar sizes, similar weights, similar usable engine BHP, and similar fuel loads, the will have similar performance.

The Martlet/F4F-3/-4 and SeaHurricane Mk I/II did not use particularly advanced airframes/aerodynamics, had similar size and weight, and the usable engine BHP was similar (although the Merlin III was significantly behind in altitude performance). While the slight differences in aerodynamics and engine performance might make a difference in speed, ROC, and range performance, the differences would be just that - slight.

Engine overheating problems with the R-1830-76/-86 during climb were never (I think) solved, and the problem severely limited the F4F-3/-4 usable climb rates. The addition of the folding wings and the 2 extra guns had a small but significant impact on the weight and drag.

The major advantage the F4F had over the SeaHurricane Mk II was greater internal fuel, primarily due (initially) to a lighter fuselage and wing monocoque structure (maybe engine installation also?). With the addition of the folding wing and the 2 extra guns the F4F lost the lighter structure advantage, but maintained the internal fuel advantage - hence the F4F-3/-4 will have more range.

The SeaHurricane Mk I should probably be compared to the earlier single-stage Martlets rather than the F4F-3/-4. The single-stage Martlets also had a difficult time achieving 300 mph.

Just some thoughts and data.

Last edited:

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- Mar 18, 2022

Range for F4f-3 with external tanks is given as 1,420 miles. Ferry range is 1,635 miles.

And in fact, various British pilots repeatedly pointed out that the Martlet or Wildcat had vastly longer range and endurance than the Sea Hurricane. Eric Brown specifically gave a flight endurance figure of the following for the Martlet: "With its excellent patrol range –

Several people here insisted this range was impossible, or that the numbers showing 3.5 hours endurance were 'cooked' by US military (even though Boscombe down showed the same numbers for a Wildcat IV). Then they shifted goal posts and started a lot of B.S. about cruising speed, as if a Hurricane can cruise at 300 mph. Then they claimed that Wildcat engines burned fuel faster than any other fighter. All B.S.

The actual Hurricane IIC range is what i said it is. The effects of the Vokes filter (also repeatedly commented upon during the war) were what they were. There are more figures on that too. I know that certain people will continue to deny, to attempt to spin, and refuse to acknowledge the information which disagrees with what he prefers to be true, but that really doesn't matter even a little bit to me. There is one agenda of determining the truth of what actually happened, and what aircraft actually did during the war. Then there is another agenda of flag waving, or LARPing, or living in fantasy land. That is between you and your psychiatric councilor.

I'll post what appears to be the true data. You'll have to forgive me but I trust wartime documents and the interviews and memoirs of combat veteran pilots who actually flew the planes, commanders who directed them into combat and so on, over the theories of certain people posting on forums today who believe they are experts whose knowledge overrides the WW2 era sources on... WW2. I had a whole bunch of people make claims about Wildcat and Hurricane range in this thread and others, and they turned out to hold as much water a screen door.

This data about the Hurricane, as distasteful as it may be to some people, also does help explain

The rest can continue to believe in anything they like, and often do.

First off an early fixed wing Martlet is not an F4F-4 and weighs considerably less, and has greater internal fuel due to the lack of self sealing tanks in the early variants. The discussion around the Hurricane II/F4F/ Ki-43 is set in the late 1942-45 timeframe when these early Martlets were extinct. By late 1942 DTs were available for the F4F-4 and the Hurricane IIA/B/C.

Range for F4f-3 with external tanks is given as 1,420 miles. Ferry range is 1,635 miles.

And in fact, various British pilots repeatedly pointed out that the Martlet or Wildcat had vastly longer range and endurance than the Sea Hurricane. Eric Brown specifically gave a flight endurance figure of the following for the Martlet: "With its excellent patrol range –I actually flew one sortie of four-and-a-half hours in this fighter". A FAA carrier commander was also quoted on Armored Carriers as noting the extreme problems he had operating the Sea Hurricane for CAP due to it's very short endurance, as he was constantly having to launch and recover aircraft. I can quote that too if necessary.

Several people here insisted this range was impossible, or that the numbers showing 3.5 hours endurance were 'cooked' by US military (even though Boscombe down showed the same numbers for a Wildcat IV). Then they shifted goal posts and started a lot of B.S. about cruising speed, as if a Hurricane can cruise at 300 mph. Then they claimed that Wildcat engines burned fuel faster than any other fighter. All B.S.

The actual Hurricane IIC range is what i said it is. The effects of the Vokes filter (also repeatedly commented upon during the war) were what they were. There are more figures on that too. I know that certain people will continue to deny, to attempt to spin, and refuse to acknowledge the information which disagrees with what he prefers to be true, but that really doesn't matter even a little bit to me. There is one agenda of determining the truth of what actually happened, and what aircraft actually did during the war. Then there is another agenda of flag waving, or LARPing, or living in fantasy land. That is between you and your psychiatric councilor.

I'll post what appears to be the true data. You'll have to forgive me but I trust wartime documents and the interviews and memoirs of combat veteran pilots who actually flew the planes, commanders who directed them into combat and so on, over the theories of certain people posting on forums today who believe they are experts whose knowledge overrides the WW2 era sources on... WW2. I had a whole bunch of people make claims about Wildcat and Hurricane range in this thread and others, and they turned out to hold as much water a screen door.

This data about the Hurricane, as distasteful as it may be to some people, also does help explainthe dismal combat record that the Hurricane had after 1941 in both the Mediterranean Theater and in Burma / Indiaand the Pacific. And in Russia. Which again, will be denied, spun, resisted, and rejected by this individual. But "He who has eyes to see, let him see, and he who has ears to hear, let him hear."

The rest can continue to believe in anything they like, and often do.

The Hurricane II combat DT = 2 x 45IG and the ferry DT was 2 x 90IG DTs.

The Martlet IV-.F4F4B data card is here:

range is 695 miles at 15K ft at 213mph with a 25IG allowance for TO and climb to 15K ft. Fuel = 120IG (SS tanks) and the aircraft has full armour.

endurance is 3.4 hours at 181mph.

Martlet VI data card:

internal fuel = 98IG; with 2x DT = 182IG

Range is 595 miles / 1080 miles with allowances for TO and climb to 15K ft.

Sea Hurricane IB data card:

range is 555 miles at 208mph at 20K ft with a fuel allowance of 21IG for TO and climb to 20K ft.

range with two 45IG DTs was 1030 miles or 1100 miles if DT tanks jettisoned with a 22IG allowance for TO and climb.

Hurricane I data card (late model with armour and SS tanks):

range is 585 miles at 212mph at 20K ft with an 20IG allowance for TO and climb to 20K ft.

Hurricane IIA data card:

range is 500 miles at 212mph at 20K ft with a 29IG allowance for TO and climb to 20k ft. These numbers are in good agreement with the no reserve/no allowance range figure as per the US Army tests:

Range for the IIB/IIC Hurricane variants will be moderately less as weight and drag increase. Boscombe down testing showed 990 miles for the IIC with 2 x 45IG drop tanks. This is an excerpt from 'The Secret Years' regarding the 90IG ferry tanks:

"

larger (90 gal) tanks. The latter gave a total capacity of

274 gal and all up weight of 9130 lb. Even the smaller

tanks enabled a 5 hI' 45 min endurance flight to be flown,

and the larger tanks gave a maximum range of 1,500 miles

provided the tanks were jettisoned when empty. Handling

after take-off (taking a run of 348 yd from a concrete

runway) was unpleasant due to instability, and the pilot

was unable to see the tanks.

Last edited:

<snip>.

I was expecting better scholarship instead of cherry-picking.

Alas.

I can only reiterate that the laws of physics control certain aspects of aircraft performance. If 2 aircraft have the same Vmax as the same altitude using the same power, everything else being approximately equal, then their effective CD is the ~same. If the aircraft also have the same wing loading then their best cruise speeds will be similar - not necessarily exactly the same but close - which means that they will use a similar amount of fuel per hour (sfc) at cruise. Any significant difference in sfc will be due to the efficiency of the engine or some unusual characteristic not present in the other aircraft (such as the Meredith effect or efficient high lift devices used during cruise).

The Merlin had an sfc of ~.48 lb/bhp-hr at best economic cruise for range over a fairly wide power/speed range, the R-1830-76/-86 had approximately the same best sfc but over a more narrow power/speed range. With the same CD and the same sfc at best cruise for range using the same approximate BHP you will use the same amount of fuel for a given range. As an example of the similarity, the F4F-3 V for max range was ~145 mph IAS, the F4F-4 was about 150 mph IAS, and the Hurricane Mk II was about 152 mph IAS.

If we remove all other fuel usage variables such as fuel used for warm-up, taxi, TO, and any reserves for combat and safety, then we can see what the max possible ratio of ranges can be for the Hurricane and Wildcat.

1st example

Now pick your preferred number for the maximum range of one of the aircraft in question. The F4F in this example has 147 USgal while the SeaHurricane has 112.8 USgal. Now divide the 147 by 112.8 and you will get 1.3 for the range ratio if we use all internal fuel for range. This indicates that under these conditions the F4F would have 30% more range.

If you choose to use the estimated 1280 mile range of the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters - of 1280 / 1.3 = ~985 miles.

But "AHA!" someone might say, "this is not a realistic scenario", which would be true.

2nd example

So let's make it more realistic and subtract the usual ~15 USgal for warm-up, taxi, TO, and climb to 5,000 ft. Using the same method of calculation as the first example the F4F now has 132 USgal for range while the SeaHurricane has 97.8 USgal. When we figure the range ratio we now get 132 / 97.8 = ~1.35, indicating that under these conditions the F4F would have ~35% more range. If we again use the 1280 miles for the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters - of 1280 / 1.35 = ~948 miles.

But "AHA! AHA!" someone might say, "this is still not a realistic scenario" which would be true.

3rd example

So let's make it even more realistic and subtract the usual ~15 USgal for warm-up, taxi, TO, and climb to 5,000 ft - AND subtract another 24 USgal (~30 minutes reserve at best cruise for range). Using the same method of calculation as the first example the F4F now has 108 USgal for range while the SeaHurricane has 73.8 USgal. When we figure the range ratio we now get 108 / 70.8 = ~1.52, indicating that under these conditions the F4F would have ~52.5% more range. If we again use the 1280 miles for the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters - of 1280 / 1.525 = ~839 miles.

But "AHA! AHA! AHA!" someone might say, "this is still not a realistic scenario" which would be true.

4th example

So let's make it even more realistic and subtract the usual ~15 USgal for warm-up, taxi, TO, and climb to 5,000 ft - AND subtract another 24 USgal (~30 minutes reserve at best cruise for range) - AND subtract another 45 USgal for the standard USN 20 minutes combat. Using the same method of calculation as the first example the F4F now has 63 USgal for range while the SeaHurricane has 28.8 USgal. When we figure the range ratio we now get 63 / 28.8 = ~2.19, indicating that under these conditions the F4F would have ~119% more range - or over twice the range. If we again use the 1280 miles for the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters -

of 1280 / 2.19 = ~584 miles.

The problem of course is that all of the above examples cannot yield the 1280 mile range ie if the 1st example is correct for the F4F-3's 1280 mile range then the other 2 examples cannot be.

But "AHA! AHA! AHA! AHA!" someone might say, "what if we use the Hurricane Mk IIA range and fuel availability for range, maybe this will yield the 1280 mile range for the F4F-3". Might this be true? Lets's find out.

5th example

You have claimed that the maximum range of the Hurricane Mk IIA as liste in the ADS is correct (by the way i agree that this is a correct value) so let's use those values - ie range is 500 miles at 212 mph TAS at 20,000 ft with a 34.8 USgal (29 IG) allowance for TO and climb to 20,000 ft. The Hurricane Mk IIA in this example has 116.4 USgal (97 IG) internal while the F4F-3 has 147 USgal. When we subtract the 34.8 USgal from both of the internal fuel loads we get 81.6 USgal remaining for the Hurricane Mk IIA and 112.2 USgal for the F4F-3. This yields a range ratio of

112.2 / 81.6 = ~1.38, indicating the F4F-3 will have a 38% range advantage over the Hurricane MK IIA - so using one set of your preferred numbers the F4F-3 range would be 1.38 x 500 = 690 miles under the same parameters. So still no 1280 mile range for the F4F-3, at least not using this particular document.

So which of the above scenarios is the correct one for the F4F-3 having a 1280 mile range while the SeaHurricane has only a 500 mile range? Or which example would yield a 1280 mile range and not make the other documents incorrect. Either some of the documents are wrong, or the altitudes and/or speeds and/or fuel loads in the documents are wrong/not measured under similar circumstances.

Incidentally, the reason I say that the 1280 mile range is not possible is that the R-1830-76/-86 would have to have an sfc better than any other WWII petrol powered engine that saw service, down close to the sfc for aircraft diesel engines.

NOTE

1. The F4F-3 had 147 USgal internal if the SSFT were not incorporated, while with SSFT the internal fuel load was 144 USgal, however 3 USgal is not enough to make any serious difference in the above calculations.

2. The Merlin maintained the .48 lb/bhp-hr over a wider range of power than the R-1830-76/-86. This seemed to be fairly normal for liquid-cooled engines in the WWII era.

3. The SeaHurricane would have used only about 36 USgal for the 20 min of combat in the 3rd example above - when using approximately the same power as the R-1830-76/-86. In reality the Merlin XX had significantly more power available below about 15,000 ft so if the combat was below 15,000 ft the SeaHurricane might have used as much as 40-42 USgal, but with significantly improved energy maneuverability vs the F4F - ie climb, acceleration, sustained turn.

There have been hundreds of errors in historical documents pointed out on this forum. Many have been regarding technical details such as speed, ROC, and range of aircraft - this is why I pointed to the B-24 range errors and the P-39 speed and ROC.

The USAAF may have believed the B-24 range estimates originally, but after the RAF started flying them and realized that the max range as told to them by [someone] was not correct they did their own tests, the results of which they then sent back to the USAAF. This information lead the USAAF to undertake their own range tests on the B-24 and B-17 in early-1942, before significant deployment to Europe, which results are given in the "B-17/B-24 range comparison"document posted below.

This as opposed to the "B-24D range estimate" document from Consolidated Vultee Aircraft Corporation dated July 1943 (kindly posted by Geoffrey Sinclair) claiming ~6300 mile range under certain conditions. Again, I could not find any possible combination of fuel loads with achievable Vcruise for max range and sfc that would allow anywhere near 6300 miles.

Bleh

The Merlin had an sfc of ~.48 lb/bhp-hr at best economic cruise for range over a fairly wide power/speed range, the R-1830-76/-86 had approximately the same best sfc but over a more narrow power/speed range. With the same CD and the same sfc at best cruise for range using the same approximate BHP you will use the same amount of fuel for a given range. As an example of the similarity, the F4F-3 V for max range was ~145 mph IAS, the F4F-4 was about 150 mph IAS, and the Hurricane Mk II was about 152 mph IAS.

If we remove all other fuel usage variables such as fuel used for warm-up, taxi, TO, and any reserves for combat and safety, then we can see what the max possible ratio of ranges can be for the Hurricane and Wildcat.

1st example

Now pick your preferred number for the maximum range of one of the aircraft in question. The F4F in this example has 147 USgal while the SeaHurricane has 112.8 USgal. Now divide the 147 by 112.8 and you will get 1.3 for the range ratio if we use all internal fuel for range. This indicates that under these conditions the F4F would have 30% more range.

If you choose to use the estimated 1280 mile range of the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters - of 1280 / 1.3 = ~985 miles.

But "AHA!" someone might say, "this is not a realistic scenario", which would be true.

2nd example

So let's make it more realistic and subtract the usual ~15 USgal for warm-up, taxi, TO, and climb to 5,000 ft. Using the same method of calculation as the first example the F4F now has 132 USgal for range while the SeaHurricane has 97.8 USgal. When we figure the range ratio we now get 132 / 97.8 = ~1.35, indicating that under these conditions the F4F would have ~35% more range. If we again use the 1280 miles for the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters - of 1280 / 1.35 = ~948 miles.

But "AHA! AHA!" someone might say, "this is still not a realistic scenario" which would be true.

3rd example

So let's make it even more realistic and subtract the usual ~15 USgal for warm-up, taxi, TO, and climb to 5,000 ft - AND subtract another 24 USgal (~30 minutes reserve at best cruise for range). Using the same method of calculation as the first example the F4F now has 108 USgal for range while the SeaHurricane has 73.8 USgal. When we figure the range ratio we now get 108 / 70.8 = ~1.52, indicating that under these conditions the F4F would have ~52.5% more range. If we again use the 1280 miles for the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters - of 1280 / 1.525 = ~839 miles.

But "AHA! AHA! AHA!" someone might say, "this is still not a realistic scenario" which would be true.

4th example

So let's make it even more realistic and subtract the usual ~15 USgal for warm-up, taxi, TO, and climb to 5,000 ft - AND subtract another 24 USgal (~30 minutes reserve at best cruise for range) - AND subtract another 45 USgal for the standard USN 20 minutes combat. Using the same method of calculation as the first example the F4F now has 63 USgal for range while the SeaHurricane has 28.8 USgal. When we figure the range ratio we now get 63 / 28.8 = ~2.19, indicating that under these conditions the F4F would have ~119% more range - or over twice the range. If we again use the 1280 miles for the F4F-3 as the correct value, then the SeaHurricane would have a range - under the same parameters -

of 1280 / 2.19 = ~584 miles.

The problem of course is that all of the above examples cannot yield the 1280 mile range ie if the 1st example is correct for the F4F-3's 1280 mile range then the other 2 examples cannot be.

But "AHA! AHA! AHA! AHA!" someone might say, "what if we use the Hurricane Mk IIA range and fuel availability for range, maybe this will yield the 1280 mile range for the F4F-3". Might this be true? Lets's find out.

5th example

You have claimed that the maximum range of the Hurricane Mk IIA as liste in the ADS is correct (by the way i agree that this is a correct value) so let's use those values - ie range is 500 miles at 212 mph TAS at 20,000 ft with a 34.8 USgal (29 IG) allowance for TO and climb to 20,000 ft. The Hurricane Mk IIA in this example has 116.4 USgal (97 IG) internal while the F4F-3 has 147 USgal. When we subtract the 34.8 USgal from both of the internal fuel loads we get 81.6 USgal remaining for the Hurricane Mk IIA and 112.2 USgal for the F4F-3. This yields a range ratio of

112.2 / 81.6 = ~1.38, indicating the F4F-3 will have a 38% range advantage over the Hurricane MK IIA - so using one set of your preferred numbers the F4F-3 range would be 1.38 x 500 = 690 miles under the same parameters. So still no 1280 mile range for the F4F-3, at least not using this particular document.

So which of the above scenarios is the correct one for the F4F-3 having a 1280 mile range while the SeaHurricane has only a 500 mile range? Or which example would yield a 1280 mile range and not make the other documents incorrect. Either some of the documents are wrong, or the altitudes and/or speeds and/or fuel loads in the documents are wrong/not measured under similar circumstances.

Incidentally, the reason I say that the 1280 mile range is not possible is that the R-1830-76/-86 would have to have an sfc better than any other WWII petrol powered engine that saw service, down close to the sfc for aircraft diesel engines.

NOTE

1. The F4F-3 had 147 USgal internal if the SSFT were not incorporated, while with SSFT the internal fuel load was 144 USgal, however 3 USgal is not enough to make any serious difference in the above calculations.

2. The Merlin maintained the .48 lb/bhp-hr over a wider range of power than the R-1830-76/-86. This seemed to be fairly normal for liquid-cooled engines in the WWII era.

3. The SeaHurricane would have used only about 36 USgal for the 20 min of combat in the 3rd example above - when using approximately the same power as the R-1830-76/-86. In reality the Merlin XX had significantly more power available below about 15,000 ft so if the combat was below 15,000 ft the SeaHurricane might have used as much as 40-42 USgal, but with significantly improved energy maneuverability vs the F4F - ie climb, acceleration, sustained turn.

There have been hundreds of errors in historical documents pointed out on this forum. Many have been regarding technical details such as speed, ROC, and range of aircraft - this is why I pointed to the B-24 range errors and the P-39 speed and ROC.

The USAAF may have believed the B-24 range estimates originally, but after the RAF started flying them and realized that the max range as told to them by [someone] was not correct they did their own tests, the results of which they then sent back to the USAAF. This information lead the USAAF to undertake their own range tests on the B-24 and B-17 in early-1942, before significant deployment to Europe, which results are given in the "B-17/B-24 range comparison"document posted below.

This as opposed to the "B-24D range estimate" document from Consolidated Vultee Aircraft Corporation dated July 1943 (kindly posted by Geoffrey Sinclair) claiming ~6300 mile range under certain conditions. Again, I could not find any possible combination of fuel loads with achievable Vcruise for max range and sfc that would allow anywhere near 6300 miles.

Bleh

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Eric Brown flew the Martlet I

Now 136 gal imp is just over 160 US gallons. No self sealing tanks of any kind.

Now the 29gal (Imp) is 34+ US gallons and the "allowance" is for warm up. take-off,*climb to altitude and ***reserve for landing.**

Plane has 105 imp gallons for cruise to and from and whatever fuel it needs for combat for X number of minutes.

It is quite possible to stretch the duration of "flight/mission" by an hour or more if you count time from wheels up to wheels down. Quite justifiable for a pilots log or for aircraft maintenance logs. Not justifiably for mission planning.

Now for a little comparison

The Hurricane IIA with 97 imp gal total has the same 29 imp gal "allowance".

So the Hurricane has 68 Imp gal for for cruise to and from and whatever fuel it needs for combat for X number of minutes.

Without drop tanks (which the Martlet I did not have) the Martlet I has 54% more fuel for cruise and should have around 50% more range/radius*at similar cruising speed. *

and here is another place where things go to pot.

Martlet was 167-175mph at 15,000ft

Hurricane was 212mph at 20,000ft

Drag at 210mph is 1.44 times the amount of drag at 175mph for a 20% increase in speed.

Drag at 20,000ft is lower than the drag at 15,000ft due to the thinner air.

Now when you get to the US F4F-3 and -4 and later Martlets and the internal fuel drops to 144-147 US gallons (122 Imp gal. ) and you still have 29 imp gal "allowance" the Grumman fighter advantage drops to 37% for range/radius and combat.

Significant but the 3 times was ludicrous.

In many early US data sheets range was figured by magically levitating the plane to cruising speed (with a warmed up engine) and getting to cruising speed and figuring out far it could fly until the fuel ran out. Landing was a problem for another day.

As long as the two planes are compared the same way then there is some sense to it (not much) but if you are comparing US planes to somebody else's plane that figures range differently the numbers are useless.

Now 136 gal imp is just over 160 US gallons. No self sealing tanks of any kind.

Now the 29gal (Imp) is 34+ US gallons and the "allowance" is for warm up. take-off,

Plane has 105 imp gallons for cruise to and from and whatever fuel it needs for combat for X number of minutes.

It is quite possible to stretch the duration of "flight/mission" by an hour or more if you count time from wheels up to wheels down. Quite justifiable for a pilots log or for aircraft maintenance logs. Not justifiably for mission planning.

Now for a little comparison

The Hurricane IIA with 97 imp gal total has the same 29 imp gal "allowance".

So the Hurricane has 68 Imp gal for for cruise to and from and whatever fuel it needs for combat for X number of minutes.

Without drop tanks (which the Martlet I did not have) the Martlet I has 54% more fuel for cruise and should have around 50% more range/radius

and here is another place where things go to pot.

Martlet was 167-175mph at 15,000ft

Hurricane was 212mph at 20,000ft

Drag at 210mph is 1.44 times the amount of drag at 175mph for a 20% increase in speed.

Drag at 20,000ft is lower than the drag at 15,000ft due to the thinner air.

Now when you get to the US F4F-3 and -4 and later Martlets and the internal fuel drops to 144-147 US gallons (122 Imp gal. ) and you still have 29 imp gal "allowance" the Grumman fighter advantage drops to 37% for range/radius and combat.

Significant but the 3 times was ludicrous.

In many early US data sheets range was figured by magically levitating the plane to cruising speed (with a warmed up engine) and getting to cruising speed and figuring out far it could fly until the fuel ran out. Landing was a problem for another day.

As long as the two planes are compared the same way then there is some sense to it (not much) but if you are comparing US planes to somebody else's plane that figures range differently the numbers are useless.

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- Thread starter
- #316

- 3,231

- Mar 18, 2022

I was expecting better scholarship instead of cherry-picking.

Alas.

I already posted the broad data here, this is a repost from post 111:

For future reference in this discussion, I'm going to aggregate some of the data here.

Armored carriers gives the following data points for different Martlet / Wildcat variants:

Martlet Mk I - 492 km/h (305 mph) at 4,572m. Range 1884 km (1,170 miles) [Cyclone engine]

Martlet Mk II - 472 km/h (293 mph) at 2,962m and 3965m. Range 1432 km (889 miles) [Four gun, two speed Twin Wasp engine, some had 'retro-fitted' folding wings. On

Martlet Mk III - 502 km/h (311 mph) at 4,877m. Range 1328 km (825 miles) [aka Wildcat Mk III, two speed R-1830-90 Twin Wasp. Originally Greek order, went to 805 and 806 Sqn]

Martlet Mk IV - 480 km/h (298 mph) at 4,267m. Range not given. [Aka Wildcat Mk IV, six guns ... F4F-4 equivalent?]

Martlet Mk V - 512 km/h (318 mph) at 5,913m. Range not given. [Aka Wildcat Mk V, FM-1 equivalent]

Martlet Mk VI - 505 km/h (313 mph) at 4039m. Range not given. [Aka Wildcat Mk VI, FM-2 equivalent]

Eric Brown also notes that he personally flew a 4.5 hour sortie in the Wildcat.

Martlet I 870 mile range, top speed 315 mph at 14,500 ft

Martlet II 850 mile range, top speed 317 mph at 14,000 ft

Wildcat II 795 mile range, top speed 300 mph at 14,000 ft

Wildcat III 890 mile range, top speed 307 mph at 14,000 ft

Wildcat IV 695 mile range, top speed 298 mph at 15,000 ft

Wildcat V (no range given), top speed 332 mph at 21,000 ft

Wildcat VIA (no range given), top speed 319 mph at 16,750 ft

Wildcat VIB (no range given), top speed 328 mph at 12,800 ft

Data sheet for F4F-3 Speed 329 mph at 21,000', range 940 miles, ROC 2,450 fpm, weight 7,556 lbs,

Test (not spec) of F4F-4 Speed 318 - 319 mph at 22,110 and 19,400 ft, weight 7,369 lb

Test (not spec) of F4F-4 Speed 316 mph at 17,200, ceiling 33,100' ROC 1,820 ft, at 7,933 lb (this is the test with the P-40F comparison)

Data sheet / test F4F-4. Speed 320 mph at 18,800 ft, range 830 miles, combat radius 105 miles (F4F-4 internal fuel 144 gallons, 6 guns with 1,440 rounds, 7,975 lb, internal fuel)

Data Sheet / test F4F-4. Speed 305 mph at 18,800 ft, range 1,050 miles, combat radius 245 miles (F4F-4, one 58 gallon external tank, 202 gallons total fuel, 8,369 lb)

Data sheet / test F4F-4. Speed 294 mph at 18,800 ft, range 1,275 miles, combat radius 325 miles (F4F-4, two 58 gallon external tanks, 260 gallons total fuel, 8,762 lb)

Test FM-2. Speed 329 mph at military power 44.5" at 15,300 ft, 328 mph at 10,800 ft with water injection. Climb 3,480 fpm at military power, 3,670 at WEP / water injection

Test FM-2. Speed 327 mph at normal power, 328 mph at military power. Graph shows WEP gives over 325 mph at 8,500 feet instead of 12,500 feet.

This seems to provide pretty definitive data for range and speed for F4F-3, F4F-4, and the earlier export / FAA types. Combat radius for F4F-4 is helpful here.

We also have speed and climb for FM-2 in detail. Strangely range is missing for FM-1 and FM-2.

There is some variance in the data and this can be attributed (I think) to different loadouts of gear and consumables, as well as probable variation in test machines. Some of the US tests tested two machines simultaneously which is probably to help narrow this down.

The Data sheet for the F4F-3, which I know some people won't like, gives the following for basic stats as of August 1942

F4F-3 range is 940 miles range with full internal fuel (144 gallons), 1420 miles range with two 58 gallon external tanks. Obviously range as calculated this way is not the same as operational range. And just as obviously, range is considerably more than any version of the Hurricane, measured the same way. Claims that the wartime data sheets are wrong fall on deaf ears for me.

F4F-3 is the obvious comparison with the Hurricane II as they were contemporaneous and that was the land based version used by the USMC and USN from Guadalcanal etc.

The F4F-4 can be compared to the Sea Hurricane.

The second big issue for comparison with Hurricanes is with or without external fuel tanks. When did Hurricanes start being used with external tanks precisely?

Are we talking about jettissonable tanks or these weird slipper tanks and so on which made fighting almost impossible?

External fuel tanks seem to be largely absent from the operational history of the Hurricane from what I've read.

See here the Sea Hurricane (= basically a hooked Hurricane I with drop tank facility) data sheet - 1100 miles with drop tanks at 208 mph and 20000 ft, after allowance of 22 gals is subtracted.The second big issue for comparison with Hurricanes is with or without external fuel tanks. When did Hurricanes start being used with external tanks precisely?

Are we talking about jettissonable tanks or these weird slipper tanks and so on which made fighting almost impossible?

Slipper tanks on Hurricane - please, do tell.

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- Thread starter
- #319

- 3,231

- Mar 18, 2022

I believe he also flew a variety of other Martlet and Wildcat models in his capacity as test pilot didn't he?

Thank you.

Still have the 136 imp gal fuel tank/s unless it was a mistake in the data sheet?

Engine is a two speed single stage engine, not the two stage engines that most F4F-3 and F4F-4s got.

The US had some F4F-3As with the same engine engine. (65) and most went to the USMC.

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