This is the way it should have been from the beginning....

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Tomo the first production V-1650-1 rolls off the line in November, 1941. The first 9.60:1 Allisons were built in October of that year. Now these 9.60:1 models couldn't pass the type/model test but neither could the V-1650-1 at this time. It took until March or April before the V-1650 was considered suitable. The V-1710-E18/F20R were rolling off the line in August. So not that much difference in time.

In hindsight I think Allison should have designed the accessory section of the E/F with the wider gears needed for the higher ratio in the first place.
 
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And some things never change. Read a book called "The Great Aircraft Engine Wars" about the hassle the USAF had with P&W when the first F-15's were flown and the problems started. Glad Herman the German was at GE, and developed an alternate engine which forced P&W to "play fair" on a more level playing ground with a now real competitor. My Father always loved "round props and round engines" and worked on every one up to the R-4360 and respected P&W just a touch more than C/W, but to say he was p****d at P&W after reading this book was an understatement. This was someone who had lived and breathed Aviation from 1942 until he retired in 1987, had seen it all and done it all, from the Flying Boats to the Concorde. Told me it just wasn't the same anymore. My life in the Auto Industry has followed similar parallels as well.

On one funny note; as stated Pops loved the sounds of the Giant Recips, but he did allude to loving the "music" coming from the sound of 4 R/R Merlins in the Canadair DC-4M's he saw!
 

Which would mean the FAA would have been without a reliable fighter for over a year, a year of critical events at sea and a year in which 30 fulmars shot down well over a 100 Axis aircraft. Without those fulmars with all their faults, which I am not denying, it would have not been possible to keep the crucial lines of communication to the critical base of malta open, it would not have been possible to deliver pinpoint attacks that led to the loss of the BISMARCK, or undertake last minute recons of the Italian battlefleet at various times, particularly at Matapan. Losses over crete to the LW would have been even more crippling than they were.

Martlets were available to the FAA from March 1941, after the fuel line and armamanet problems had been solved, but it would take several more months of development work before the wing folding issue was solved. until then, Martlets aboard RN carriers were strictly deck cargo and this severely limited the air group capacities even more than they were already aboard the RN armoured carriers.

Judging FAA requirements against assumed USN capabilities is a common mistake. The RN never had the luxury of massed firepower in the form of large deck stroke capability. Only the USN in the latter stages of WWII, then korea and finally in Vietnam had the capability of conducting saturation carrier based airstrikes. Even during the invasions of Iraq there wasn't the lift capacity in the USN to conduct the same operations as had traditionally been the case since the latter part of WWII. The RN during WWII managed to develop its carrier based assets to the point of being able to deliver surgical strikes against point targets, which it carried over into the post war era. This was the basis of high success at locations like Taranto and against the Bismarck, and later over the Korean peninsula where the CW naval force showed itself capable of punching well above its weight in terms efficiency, as compared to the USN effort. . . When the RN attempted US style saturation attacks, such as those against the Tirpitz, it was far less successful. The style of RN carrier based combat can be traced back to the early days of WWII. With an annual acceptance of just 16 pilots per year in 1939, the RN, already short of aircrew, but with the added problem of limited carrier decks and an abysmal replacement rate, simply could not afford any losses until much later. This also meant stand up fights with LW SE fighters were to be avoided at all costs. What they needed was a stable gun platform, with an emphasis on firepower (read that as "fleet defence" capability) hence the favoured 6 gun Martlet and 8 gun Fulmar, and night strike capability so that the fleet could stay away from the short range LW bombers and fighters. It was a successful recipe except on a few occasions like January 10 1941.

There is and was nothing wrong with the RN procurement policy. Aircraft like the gannet were developed for long endurance and cheap construction using existing technologies. Gannets were far superior to TBFs from the USN which were used until the 1950s, but not as capable as the Grumman S2s, mostly because of lesser endurance. The RN showed in spades in the post war period that it was still a front line innovator . One only needs to look at the achievements of its sea harriers during the falklands to see that.

I served for 8 years in the RAN in the late 70's and early 80s, aboard our carrier HMAS Melbourne. by the time I was on her wer were equipped with a mix of US and british equipment and a small amount of Australian designed stuff as well. I exercised alongside both the brits and the yanks in various exercises. USN was still very good at air defence and airstrike operations, but generally poor in ASW and ship to shore logistics. I remember in simulated attacks on a US submarine one excercise the poor b*gger being "sunk" 6 times in two days. They had no answer to our combined tracker/Sea king/NCDS/Mulloka/Ikara defences and were easy meat. Againt their own kin, the USS constellation from memory, they easily pentated the screen and "sank" the carrier. .
 
1. P51 Allison, max production, no delays, as soon as possible. Merlin following as soon as possible.

2. P43 built with actual fuel tanks from the start instead of wet wing. When production is started, keep it going as long as possible without interruption. 4 50's. Use it with US forces in the Pacific until P38 arrives. Would be helpful at Midway, Guadalcanal and in Australia.

3. P36, make them replace that ridiculous high drag landing gear with standard inward folding gear to clean up the wing and reduce drag. Add 2 speed P&W 1830 when available (not 2 stage, it is too late) Put it in a wind tunnel and work on the cowling. A P36 with a P&W 1830-23 engine could do 317 in september 1939, so if the landing gear is replaced, cowling tweaked a bit and a 2 speed P&W1830, I see no reason why the P36 couldn't/shouldnt be a 340 mph fighter in 1940. The P66 could do 340.

4. P40, put the same normal inward folding landing gear as P36, should add what 15mph to the top speed throughout the whole series? No more than 4 50's, ever. 6 50's can wait for the P51, Hellcat, Corsair, P47 etc.

5. B26, add P47 turbochargers to B26 for better performance (when historically available) since Mosquito production can't be increased.

6. Build the P39 with turbo. Period. Wing for fuel only, 2 50's in nose along with a British made 20mm

7. Wildcat, Drop tanks on the very 1st aircraft. 4 50's period. Could Grumman build folding wing -4's and non folding wing -3's on the same line? Doesn't seem like it would be a huge problem to me. At the point where wings are installed, they have 2 different sets to choose from. If so, I would build both models. No folding wing -3 might be irrelevant if a 340 MPH P36 is available.
 

2. P-43. Every additional P-43 is a delay in getting P-47s.
they ordered 733 P-47B & Cs in Sept 1940
last order for P-43s was for 125 on June 30th 1941
Oct 14th 1941 saw 850 P-47Ds ordered
March 1942 saw the last P-43 completed and 5 P-47Bs rolled out the door.

3.P-36. Every P-36, no matter how changed or streamlined is a P-40 not built.
A P-40 is a P-36 from the firewall back (at least the early ones), any and all modifications (increases in weight) to the P-40 in terms of increased armament, protection and changes in operational equipment would be mirrored by the the hypothetical P-36. Since the Allison powered P-36 (P-40) could already do over 350mph why fool around with the P-36? They would be built on the same production lines and it would take over year to get a new factory on line, perhaps closer to two years.

4. P-40s, even with crappy landing gear (and I would love to see an actual test result or wind tunnel data) were faster than the smaller 109E with the same power and just about as fast as early Spitfires at altitudes where the Allison was making about the same power. I would note that the F6F used very similar landing gear except that they had a partial door/cover attached to the strut to cover part of the wheel when retracted, but so did the P-36, the wheel cover was deleted on the P-40 but I will bet they had a pretty good idea what the difference in drag/speed was,


5. B-26. Adding turbos isn't as easy as it sounds. You are going to need 15-20 cubic feet of space in each nacelle or adjacent wing area for the turbo, the intercoolers and the associated ducting. Please look at pictures of the NA XB-28 engine nacelles and air intakes in the outer wing. It can be done but it is not easy.

6. P-39. general estimates were that a turbo P-39, no matter how good at 25,000ft, was going to be 20-30mph (or more) slower under 15,000ft than a non turbo P-39. There ain't no such thing as a free lunch. Remember that "in the beginning" there was no 100/130 fuel. British had 100/115-120 and the US had 100/100. The US couldn't use the turbo to overboost the engine to higher power levels at low altitude.
 
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2. I can't tell if the contracts for the P43 were run consecutively without interruption or not. Looks like they might have. They did convert 150 P43's to recon aircraft due to the leaking wet wings, so if designed with proper fuel tanks from the start, at least these 150 could have been used in the pacific, in combat, as fighters. I believe (with proper tanks instead leaking wet wings) they would have been a welcome addition to land based pilots who usually gave up the altitude advantage to the Japanese fighters and bombers. Guadalcanal and Australia both come to mind. It's initial climb was 2850 fpm which would have been a welcome increase at Guadalcanal over the 1500 fpm of the Wildcat.

3. If the P36/Hawk75 landing gear had been designed properly from the beginning, then engine upgrades (which all aircraft Spitfire, Hurricane, 109 were also getting continuously) should have easily kept it competitive. The P36 the British tested against the Spitfire had 1 problem, top speed. The only way the Spit could shake the P36 was to outrun/outdive it. The P36 could easily shake the Spitfire with a hard turn. The Hawk75 tested weighed 6025 pounds with 6 light machine guns. A P36B with the 1830-23 engine would do 317. Clean up the wing by changing to a standard inward retracting landing gear, use a P&W 1830 2 speed engine (smaller diameter than the Wright). The Hawk75 in the test should gain 300 pounds with the engine change so it would weigh 6325 and have good high altitude speed and climb.

4. So P40's were faster then a 109 and almost as fast the Spitfire, ok I get that. But if you can clean up the wing and lower drag (you ALWAYS bring up drag when someone wants a different engine in something) by using a regular landing gear, why wouldn't you? Many people on this forum, when talking of X or Y test plane, will say "that top speed wasn't for an operational airplane, it didn't have the drag of gun barrel openings in wings, ejection openings, radio antenna" or "the tailwheel didn't retract causing drag". Look at the P36/P40, the bulges for the landing gear were freaking huge. You can't tell me that didn't slow them down by a LOT. (I would love to see wind tunnel tests to, just to know how much it slowed them down) Just belly tank shackles on a P39 slowed it down by 10 mph




Think the P36/P40 would be faster if the bottom of the wing look like that? (Yes I know it is the prototype with no guns)




The P39 guns pods are thinner and probably much less drag than the P36/P40 landing gear

5. B26 with turbos, may not have been easy, but I think they should have worked on it. A B26 with turbos at mid to high altitude would have been a very difficult intercept in Europe and probably impossible for Japan.

6. I have read what you said about the P39 being much slower at low altitude with turbo. I know drag would go up. Without a turbo it was fast down low and had less drag than (I think) anything before a P51. I think it would've had a better career/reputation with a WELL DESIGNED turbo setup. If nothing else, it could have climbed up to altitude and fought like a P47, dive shoot and zoom, or maybe just fly top cover over low altitude planes like the P40
 
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The P-36 tested by the British had a few other problems. No self sealing fuel tanks and no armor. This is the problem with trying to build upgraded P-36s instead of P-40s.
The very early P-40s had a fuel system (tanks, pumps, lines drains, etc) that weighed 171lbs (at least on the 5th production example) this increased to 254.4lbs on P-40B #11 and then to 420lbs on the P-40C where it pretty much stayed (within 10lbs or so) for all the rest of the P-40s except the ones they yanked the forward tank on. the very early P-40s had no armor. the B & C got 93lbs of armor and BP glass. On the later ones the armor and BP glass were lumped in with armament provisions making it hard to track. communications equipment went from 71lbs to around 130lb and then to 233lbs on the P-40N (typo?). Electrical went from 193lbs to between 230-240lbs (at least on the ones that had full electrical)

Adding around 400lbs to the empty weight of the P-36 is going to hurt performance. As will filling the fuel tank/s. On the P-36 the tank behind the pilot was a Ferry/overload tank and was not supposed to be filled when performing maneuvers. There may be some confusion when the test of the P-36 with the -23 engine refers to full gas and oil as other paperwork the 57 gallons in the rear tank is called auxiliary fuel.
If you fill the rear tank, fill the oil tank with 14 extra quarts of oil for the extra fuel, fit a couple of landing flares and a gun camera you are 200lbs over the weight limit for safe flight and have to fly under restrictions. This is for a two gun P-36A.

Basically, if you add armor and self sealing tanks and extra guns you either have to really cut into the fuel supply to have a safe airplane or you have to go back and beef up certain parts ot get back the the 12G ultimate load the US wanted and the weight spiral has begun.
 

The first P36/Hawk 75 tested by the British had 4 guns and was tested at 6025 pounds and it was flown against a Spitfire I which also would not have had armor or self sealing tanks. Adding 400 pounds to the P36 will hurt performance IF YOU DONT ADD POWER. This is where the P&W 1830 2 speed comes in. The Spitfire gained weight also, so did the 109, but they added power as it did. Even the Zero got heavier but they added power along with it.

Again, look at the bottom of the wing of this P40 (as you said, firewall back its a P36). If an empty drop tank shackle cost a P39 10 mph, what did that landing gear disaster cost the P36/P40? Did it cost it 20mph? An empty drop tank shackle cost 10 mph for a P39 and there are 2 of these. So a 2 speed engine, clean this disaster up and a P36 should gain how much? (A P66 with a 2 speed P&W 1830 did 340 mph with a nice clean wing)


That's a 340 mph P66

I read that a Zero had 12% lower drag than a P40. A Zero was in the 315-330 mph range with a 950 hp engine so.....

And the rear fuselage tank being full putting a P36/Hawk 75 overgross and can't fight???? Come on Shortround, a Mustang couldn't fight with the back tank full either. It was for long missions or ferrying.
 
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A P-66 used a wing 83.4% the size of the P-36 wing which sure didn't hurt drag.


Hawks and P-36 used a fairing plate/door over the wheels and to eliminate the abrupt end to the landing gear strut fairing. I have no idea why it was dropped from the P-40 as they surely must have known the difference in drag. Not as good as a smooth wing as you say but not as bad as a P-40 set up?

Unless you can shrink the P-36 it is not going to get down to the drag of the P-66.

Point of the fuel was that you don't get a big boost in range over other fighters using the P-36. 105 US gallons is less than a Hurricane.
Things changed on the P-40. The CG moved a bit forward and the wings were beefed up. wings went from around 835-845lbs to just over 1000lbs (and over 1100lbs on the 6 gun D/E and up) and there was no restriction on flying with fuel in the rear tank, in fact on the P-40F and L the pilot was supposed to keep around 35 gallons in the rear tank at all times and use it as the reserve in comparison to the P-40E where the rear tank was supposed to drained first (after the drop tank) and the forward tank used as the reserve. The Merlin was several hundred pounds heavier than the Allison.

Slick as the Zero may be, the P-40 was supposed to have 22% less drag than a P-36. This is borne out by figures from early testing from here.
P-36 Flight Tests

and
P-40 Performance Tests

some of the early tests, even with different propellers and/or wing leading edge blisters. The P-40 needed less power to fly the same speeds even if heavier.

as for a Zero being 12% lower in drag than an early P-40????
"High speed at 15,000 ft. at wide open throttle was 352 mph at 1090 bhp at 3000 rpm, radiator shutters neutral."
"High speed at 2600 rpm at 15,000 ft. at wide open throttle, was 331.5 mph at 920 bhp, radiator shutters neutral."
Cruising data at 15,000 ft; 310 True Speed MPH......2280 R.P.M. .....720 B.H.P. ......75 % Rated BHP

Excuse me, but I am not seeing it.

BTW the 2 speed engine in the P-66 was good for 1050hp at 13,100ft military power (2700rpm) no ram.
About the best performance from a 2 speed R-1830 is going to be 1000hp at 14,500ft no ram at 2700rpm.

Allison gets a useful amount of exhaust thrust which may skew things.
 
My apologies on giving Zero 12% lower drag than P40. After reading so many different references, numbers can get jumbled. They say Zero is 'marginally' lower drag than P40C. Here is the reference. It's at the bottom of the page.



Interesting the 2 speed P&W would have a lower altitude rating than the 1830-23 which was 950 at 17,000. That being the case, I would use the 1830-23 instead, that would give it a 15 mph faster top speed 3,000 feet higher. It does not say say in the British test if that plane had pilot armor, but some of the French accounts of the Battle over France indicate that the P36/Hawk 75 they used had armor behind the pilot (I would bet they did not have armored glass or self sealing tanks)

BTW, nice P36/Hawk 75 pics.

So if we have a 317 mph@17,000 P36/Hawk75 with just an engine change to a 1830-23, wouldn't you think you could squeeze out at least 10 mph more by cleaning up the landing gear (and while we are at it, the bulges for the exhaust)? (again, if an empty drop tank shackle cost a P39 10 mph, what does the landing gear and exhaust bulges cost the P36/Hawk75 and P40?)

Quick note on rear tank. You said P36/Hawk75, without rear tank, held less fuel than a Hurricane. BUT, as I have seen it pointed out in other discussions, just to start, warmup and climb to 25,000 feet will use X (15-25 gallons?) amount of fuel. Even in a BoB type scramble, as long as they weren't over your field, you could use the rear tank for starting, warmup and climb,(putting just enough fuel in rear tank for that) then switch to wing tanks for the fight.
 
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The thing with the P-36 is not that it was a bad plane, it is just that anything short of a total redesign doesn't offer anything over what was already available or being introduced.

Perhaps you can move the landing gear attachments out closer to the guns and when they fold inwards house the wheels in wing root extensions like the P-51 (and others).

The P-36 and P-40 used what they "called" a 5 spar wing although a couple of those appear to be little more than attachment points for the flaps and ailerons.

It is not too hard to move things around when you are dealing with prototypes. It is something else when you have already built the jigs and fixtures and have hundreds of parts in the supply line. Curtiss built over 1100 domestic P-36s and export Hawk 75s from March/April of 1938 till Jan of 1941 (?).
At the end of 1940 Curtiss was building over 150 P-40s a month. A P-36 with six guns and a two speed R-1830 may have been a nice plane but what was it going to do that the P-40B &C could not do once you fitted self sealing tanks, armor and BP glass?
 

I guess if "right from the beginning" then the P36 would have had a clean, flush, inward retracting landing gear from the beginning.
I don't dislike the P40, I think it did fantastic considering the weight it lugged around with the available hp, but they went crazy with the weapons weight and it should have been a cleaner
I like the P36, short nose, outturn anything in Europe except the biplanes, great climb rate until air got thin.

I actually listen to much you say. Did you notice I did not advocate 50's on the P36?
I was mistaken earlier, the 1939 Hawk75 weighed 6025 but it had a 1050 hp P&W and 4 guns. I imagine top speed was 290 ish at 15,000. Add 2 more RCM at 111 pounds makes it 6136, another 70 pounds of self sealing tanks put it up to 6,200 or so, 1830-23 so it's at 317 mph at 17,000 with better climb. I think that plane had back armor, French pilot encounters I have read indicated they had back armor. Clean up the wing (landing gear and exhaust) to add another 10-20 mph and I think it would have been a handful at least through BoB in Europe and through 1943 in Pacific.

Also notice I'm not using time travel by trying to use heavy 2 speed 2 stage Wildcat engines, but instead using 1830-23 engines, when it became available, keeping weight down with 6 30 caliber machine guns
 
I wonder what an earlier better Spitfire could have been...or at least a better Seafire.
Bubble canopy or at least better all round visibility canopy like the Zero.
Wider track undercarriage.
20mm cannon.
More fuel tankage.
Fuel injection Merlin.
All certainly was possible by 1930s tech so not been overly anachronistic.
Even some kind of compressed air ejection seat was not impossible.
 

I don't dislike the P-36, it's just once they put the Allison in it the R-1830 and R-182 engines dropped to substitute standard.
Yes they might have done much better with the P-40s if they hadn't demanded some rather excessive gun and ammo set-ups. A P-36 carried 200 rounds for it's single .50 (Yaks and Lagg-s carried 180-220 rounds for their 12.7mm guns) The Army went to 380rpg for the cowl .50s on the P-40. Which with the under 600rpm rate of fire for the synchronized guns was an absurd amount of ammo. The P-40B was carrying 228lbs of .50 cal ammo alone if the ammo boxes were full. A P-36C with one .50 and three .30s was carrying about 296lb of GUNS AND AMMO. Cut back to 200rpg and you could save about 105-110lbs and still have enough ammo to shoot for over 20 seconds. You could also cut 600 rounds ( about 36-38lbs) of the wing gun ammo and still fire longer than a Spit I or Hurricane I.

Lets also remember that the P-36 had some pretty good looking landing gear compared to the P-35


or the infamous Gloster F.5/34 that some people are enamoured of.

P-36 exhaust look pretty good in comparison too.
 

Agreed on the P35 landing gear. Dang. Nice big jump over to the P43 which was so nice and clean.

Also, to your point, so much easier to do this in hindsight when we know what they faced and how well they historically did.

Wish we had more tests and info on the less well known planes. I'd love to see some full on more thorough test data on P43 and P36 with 1830-23 like time to climb to 30,000, top speed all the way up to 30,000 etc
 
The -23 was not some wonder engine. it was a normal -17 in which they swapped the normal 7.15 supercharger gear for an 8.0 supercharger gear. After tests it was converted back to a -17 engine. The two speed engines (aside from any experiments?) used the normal 7.15 for low gear and an 8.47 gear for high. A few engines were built using the 8.47 as the only gear (-31 engine) , these had extended shafts and were used in the Curtiss XP-42 and Seversky XP-41. They offered no more power at altitude than a two speed engine and less at low altitude/take-off. The -17 made 1200hp at 2700rpm (using US 100 octane) the -23 was limited to 1100hp at 2700rpm and the -31 was limited to 1050hp at 2550rpm, all at take-off. Because of the different gear ratios the -31 engine was turning the impeller at 21,598 rpm while the -17 was turning it at 19,305 rpm despite the different take-off rpm.
P & W may have done very little development on the R-1830 engine as they concentrated on the R-2800. I don't have a definitive timeline but it looks like they were working on the two stage R-1830 well before they built any two speed single stage engines.

Had the Allison flopped or Allison had more difficulty in ramping up production then perhaps more effort would have been put into a better P-36.
Please note that an R-1830 making 1200hp for take-off was running at 48in MAP or about 9lbs of boost which was pretty extreme for 1940/41. It was 4in more than the Allison used and 6in more than a Merlin at 6lbs. (rounded off, not getting into fractions here
 
Gloster F5/34 Zero?
Can you imagine if the RAF or FAA had them in the Pacific? You would have to shoot down your wingman just to be sure.
 
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