Improve That Design: How Aircraft Could Have Been Made Better

[wuzak]

For the P-39

1. The M-4 cannon was not particularly useful. Replace it with something like the 20 mm HIspano (its production problems were due to idiocy within the Army's bureaucracy, not intrinsic flaws in the manufacturing process).
2. The car-doors were dumb. I know they were fashionable (iirc, the Tempest started with the same arrangement). Sliding canopies were definitely the way to go.
3. One of the problems of the mid-engined layout is that it puts the engine, a big, heavy lump, exactly where one wants to put the fuel. While moving the engine would, in essence, change the P-39 to the P-40, fuel tankage could be increased by a small increase in wing span, and putting tanks in the wing roots.
4. The original XP-39 had such a poor turbocharger installation that it actually impaired performance at altitude by increased drag. I think this could be fixed by lengthening the fuselage to permit a proper installation.

For the P-39 I'd have changed it into a pusher type with a Y-type tail (like the Bugatti P100), move the cockpit forward, install 2 x 20mm on each side of the nose (probably end up with 4 x 0.50", since it was American), possibly more fuel near the engine.

House the radiator below the fuselage, similar to the P-51. Who knows, you could even fit a turbo in that!

 

[wuzak]

Maybe the bomb doors would need to be bulged? In any case the Mosquito was pretty much limited to four 500lbs until 1944 and even then not all bombers carried much more on every mission.

The Mosquito could carry 6 x 500lb bombs after the introduction of the universal wing in mid 1943.

I would also note that it was possible to carry 1 x 1000lb and 2 x 500lb, but that was not used operationally.

 

[Shortround6]

Sorry, I should have said four 500lb bombs internally.

Germans were masters at hanging bombs on the outside but the performance with such drag producing configurations are rarely listed.

The Mosquito seemed to take either drop tanks or a pair of 500lb bombs without too much of a hit to performance.

 

[gjs238]

For the P-39 I'd have changed it into a pusher type with a Y-type tail (like the Bugatti P100), move the cockpit forward, install 2 x 20mm on each side of the nose (probably end up with 4 x 0.50", since it was American), possibly more fuel near the engine.

House the radiator below the fuselage, similar to the P-51. Who knows, you could even fit a turbo in that!

How about something like this?
SAAB 21 - Wikipedia

 

[wuzak]

How about something like this?
SAAB 21 - Wikipedia

That's what the XP-54 should have been (and similar to what was originally proposed).

That with a 2 stage Merlin pusher could have been quite good.

For the Saab 21, dump the 13.2mm mgs and 1 20mm for 4 x 20mm.

A ground attack version of the Saab 21 may have been able to fit a 40mm gun in the front of each boom.

Still would have kept the P-39 more conventional.

 

[PAT303]

MAP told Fairey to make a navalised Spitfire. Fairey said NO!

Well I suppose they were busy building masterpieces such as the Barracuda, a plane of such brilliance that it was replaced with the plane it was designed to replace!!!!!.

 

[Zipper730]

The M-4 cannon was not particularly useful. Replace it with something like the 20 mm HIspano (its production problems were due to idiocy within the Army's bureaucracy, not intrinsic flaws in the manufacturing process).

I'm not sure why they classified 20mm cannon as anti-aircraft artillery. The USN did not do this. An aircraft mounted weapon can't always been built to the same standards as standard artillery.

Some of the decisions seemed odd, I was told that they enlarged the chamber: I have no idea why you'd do that unless they had flirted with the idea of making a bigger casing.

The original XP-39 had such a poor turbocharger installation that it actually impaired performance at altitude by increased drag. I think this could be fixed by lengthening the fuselage to permit a proper installation.

Me and P-39 Expert did an intellectual exercise on that. It didn't seem to really work.

Short of totally redesigning the plane, you wouldn't be able to get the turbocharger in there.

For the P-39 I'd have changed it into a pusher type with a Y-type tail (like the Bugatti P100), move the cockpit forward, install 2 x 20mm on each side of the nose (probably end up with 4 x 0.50", since it was American), possibly more fuel near the engine.

House the radiator below the fuselage, similar to the P-51. Who knows, you could even fit a turbo in that!

A pusher would have been a bad idea, attempt to bail out and you turn into salsa.

 

[Zipper730]

That's what the XP-54 should have been (and similar to what was originally proposed).

It was supposed to be smaller, like the SAAB 21. That said, if I recall, the problem was mostly that it was originally designed for low/medium altitude operations. I'm not sure why they did that, as the USAAC seemed to generally favor high altitude aircraft

1. Y1P-37: Based on a P-36 with an inline engine and a turbocharger. The radiator & intercooler seemed to have screwed the design up. The P-40 was procured because it would be simple, and it turned out okay -- but it couldn't fly as high as the P-37
2. XP-39: Designed with a turbocharger, though it didn't fit well, and the design needed modifications that got rid of the turbo.
3. P-38: Designed as a high altitude fighter with supercharger, it was successful.
4. P-47: Designed with altitude capability in the overall design, and proved successful.

 

[Zipper730]

MAP told Fairey to make a navalised Spitfire. Fairey said NO!

You know, that would have been a good argument for designing the Firefly as a single-seater.

The design probably would have been lighter, and potentially a bit faster if it was free of the need of an extra crew-member, and things of that sort.

 

[wuzak]

It was supposed to be smaller, like the SAAB 21.

I believe that's what I said.

That said, if I recall, the problem was mostly that it was originally designed for low/medium altitude operations. I'm not sure why they did that, as the USAAC seemed to generally favor high altitude aircraft

I don't believe it was designed as a low altitude aircraft. It was supposed to have higher performance than aircraft then in production and the performance of fighters in development.

1. Y1P-37: Based on a P-36 with an inline engine and a turbocharger. The radiator & intercooler seemed to have screwed the design up. The P-40 was procured because it would be simple, and it turned out okay -- but it couldn't fly as high as the P-37
2. XP-39: Designed with a turbocharger, though it didn't fit well, and the design needed modifications that got rid of the turbo.
3. P-38: Designed as a high altitude fighter with supercharger, it was successful.
4. P-47: Designed with altitude capability in the overall design, and proved successful.

Don't know what we'd do without you.

Actually, the P-47 was designed as a light weight fighter powered by an altitude rated V-1710.

That was cancelled in favour of the P-47B, which was the turbo R-2800 aircraft.

 

[GrauGeist]

The car-doors were dumb. I know they were fashionable (iirc, the Tempest started with the same arrangement). Sliding canopies were definitely the way to go.

On the P-39, the cockpit was a modular structure and the canopy frame was part of the framework.
A conventional canopy would not have worked because of that and because of the air intake directly behind the cockpit.

 

[swampyankee]

Pushers are cool, but also have a numbers of practical problems, pilots being minced being just one: the prop is operating in dirty air during flight, it's more likely to get fodded by stones and gravel kicked up by the tires, and it either restricts AoA on takeoff and landing enough to increase both distances or it requires stalky, heavier landing gear.

One of the flaws of the P-39's mid-engine configuration is that Bell put this huge, massive lump right in the best place for the fuel tanks, and compounded that by putting heavy weights that would be discarded during combat far ahead of the c/g

 

[Ivan1GFP]

No doubt that BMW 801 earned it's place in aircraft history. What it lacked in early service was reliability, and later (mid/late 1944 on) it lacked a better supercharger. We also have a thing that 801 was not not contributing to the Axis cause for the 1st 20-22 (24?) moths of the war - 'my' RLM would've supported BMW staying in V12 business even after they acquired Bramo.

Hello Tomo Pauk,
I guess the our "What-If" conditions are just a bit different. I was thinking minimal adjustments to the industry and fairly small changes in the existing environment while it seems like you were thinking of much larger series of cascading changes and management direction.

I had forgotten that the changes to the Allison engine series was mostly just a change in supercharger gear ratios.

- Ivan.

 

[Simon Thomas]

I do believe that one or two Short Stirlings were trialed with Wright R-2600s and perhaps they could have been used on the Halifax?

From "Short Stirling, The First of the RAF Heavy Bombers" – Pino Lombardi

The Hercules II engines fitted to the Stirling Mk I were expected to be replaced by US-made Wright Cyclone engines for the Mk II. However, Hercules engine production was accelerated to meet demands, and when three aircraft-N3657, N3711, and R9188 -were fitted with Wright Cyclone engines at Swindon, performance and fuel consumption trials to assess performance and fuel consumption produced disappointing results. They offered no improvement over the Hercules and were much noisier, therefore a contract was not given.

HP would no doubt have been briefed on the performance of the Cyclone powered Stirlings.

 

[tomo pauk]

No but the Germans had some problems coordinating fire. If we are going to trouble of designing ideal aircraft why are we using 2nd rate armament?
The MG FFM had a few problems, yes it was better than A machine (or even two) but you have the drum feed problem and the mixed ammo load problem, sometimes only 40% of the ammo was the mine shell. Bigger drums are not a real problem for the fuselage mounted gun but more of a problem with the wing mounted guns. Japanese may have shifted to some sort of box magazine? details/translations are not good. When you are dealing with 1000-1200hp there is only so much you can do, but when better engines are available (and faster targets) it doesn't give quite the return for investment.

Nobody in 1939/40 have had ideal guns - they were either of a too light a punch, or could not be synchronised (or can, bad with great reduction in RoF), or have too small ammo count, or are too heavy for installed HP, or have low MV. A lot of countries don't even have cannons ins service in 1940 in more than token amounts.
We can't remove away the of limitation of a platform - Bf 109 will carry two small & light FFs, but how easily two Hispanos or equivalent? Important when we have 1000-1200 HP engines indeed. Two MG FF weight as much as one Hispano, they will throw ~1050 rd/min vs. 600 rd/min for one Hisso. Once DB 601N is in German fighters, they can carry another cannon in center position, for three cannons total (or a combination with HMGs).
German 90 rd drum was barely wider and taller than the 60 rd drum (Oerlikon was also offering 75 rd drums for their FFs). WIth MG FFM, I'd go exclusively with M-shells - dissimilar trajectory is a shortcoming, so is the enemy pilot being alerted with tracers.

My German is practically non existent. In the early part of that manual is some reference to 650kph but I don't what it refers to.

Blatt 4 (?) near the end of the first paragraph?

'Gleit' will be 'glide' - so it's about as close to permissible dive speed as possible for a big aircraft without dive brakes?

BTW the manual shows some rather strange drawings of a Zerstorer near the end. it appears to have a single cannon firing through each prop hub and no other changes to armament.
Unsold proposal? Magazines under the gun? notes seem to indicate Oerlikon FFS guns which used the same ammo as Allied AA guns (very comparable to the Hispano.
Export to Sweden?

All correct, although Sweden never got any DO 215s.
Dornier was trying hard to find a new lease of life for the Do 17 line

Like but disagree:-
Mig-3. No change. Discarded as unsuccessful design for Eastern Front.
Sea Hurricane I from 1939 for service on carriers not Sea Gladiator. No folding wings ever as interim type pending arrival of Seafire. Sea Hurricane Ib (1939), IIb (1940), IIc (1941). Replaced by Seafire in 1942.
Spitfire III to form basis for Seafire to be put into production by Westland in 1941. Maybe Seafire Ic (c for carrier version) not Spitfire I's in 1941 for training, hook only and Merlin 20. Seafire IIc as per Spitfire III without folding wings in 1942 with late Merlin 20 series, but with hook and catapult spools. Seafire LIII as per Spitfire III with folding wings service intro early 1943 using Merlin 32, first deliveries late 1942. Cunliffe Owen to build Seafire XV based on Spitfire IV with Griffon engine service intro 1943, limited edition. Seafire FR 17 to appear in 1944. Should all be feasible. Supermarine leads the way for land based versions with Castle Bromwich being the mass producer. Westland uses their design skills to turn the Spitfire III/IV into World beating carrier fighters.
Zero and Oscar with Kinsei from 1943 on.
Ki-100 service intro 1944. No Ki-61-II. Replaces Shoki phased out of production in favour of Ki-84. Performance not quite as high as Raiden but more reliable. Better range and dive speed.

I know that MiG-3 was not a great success. My proposal rectifies lack of firepower (there was a hostorical small series of MiG-3s with two cannons, so nothing ground-breaking there), lack of engine power under 3-4 km (where it was actually needed; such MiG-3 was tested, achieved 600 km/h) and propensity for pilots to fly with open canopies (that robbed the speed).
Zero and Oscar with better motors only from 1943 means that Japan has still lost not just battles, carriers, aircraft and men, but also pilots to fly them.

 

[Kevin J]

I know that MiG-3 was not a great success. My proposal rectifies lack of firepower (there was a hostorical small series of MiG-3s with two cannons, so nothing ground-breaking there), lack of engine power under 3-4 km (where it was actually needed; such MiG-3 was tested, achieved 600 km/h) and propensity for pilots to fly with open canopies (that robbed the speed).
Zero and Oscar with better motors only from 1943 means that Japan has still lost not just battles, carriers, aircraft and men, but also pilots to fly them.

Bigger engines, same fighter means less range. Even the F4F-3 Wildcat was delivered without self sealing fuel tanks. It was all about range. I'm suggesting 1943 because clearly that's the point where the Jap Empire has expanded to its max extent. You need a defensive mentality after that, aircraft too.

 

[tomo pauk]

Hello Tomo Pauk,
I guess the our "What-If" conditions are just a bit different. I was thinking minimal adjustments to the industry and fairly small changes in the existing environment while it seems like you were thinking of much larger series of cascading changes and management direction.

Think big

I had forgotten that the changes to the Allison engine series was mostly just a change in supercharger gear ratios.

- Ivan.

Not just that. Change in type of reduction gear type meant increased reliability at higher powers, improvements in carankcase and crankshaft were also crucial in passing WER tests more reliably (so the engine can be rated for higher power by the user), there was improvement in valve gear in 1940/41 so the engine can actually make listed HP etc. We also have 2-stage supercharged versions, thata) came a bit too late, and b) were installed in aircraft irrelevant to the ww2. Water injection was also a plus, but again only for 2-stage versions.

 

[tomo pauk]

Bigger engines, same fighter means less range. Even the F4F-3 Wildcat was delivered without self sealing fuel tanks. It was all about range. I'm suggesting 1943 because clearly that's the point where the Jap Empire has expanded to its max extent. You need a defensive mentality after that, aircraft too.

Delivery of F4F-3s without self sealing tank was a bug, not a feature.
Bigger engines = bigger payload (fuel included) + less drop in performance once you start adding protection. Better performing aircraft can meant the difference between carrier being sunk and the one afloat, they are a better asset both in offense and defense.
Defensive mentality does not work after you've lost bulk of your trained & experienced armed forces, and enemy is out-producing you 5:1 or better.

 

[pinsog]

Why not a turbocharged F4F-3? No magical time line, just using what we already have. Bugs won't get worked out of turbocharger until early 1942, but plane should perform awesome. Wish I could calculate increase in climb.

Original 2 speed 2 stage P&W R-1830-76:
1200 hp for takeoff
1100 hp from SL-2500 feet
1050 hp from 4800-11000 feet
1000 hp from 12200-19000 feet

with a P&W R-1830-47 with a turbocharger (same engine as the P43 Lancer)
1200 hp from SL-25000 feet, still producing 1,000 hp at 30,000 feet.

SL speed increases from 278 to 286
Speed at 5500 goes from 295 to 308
Speed at 13000 goes from 313 to 332
Speed at 19000 goes from 330 to 350
Speed at 22000 goes from 326 to 351

The F4F-3 speed numbers above included 150 pounds of armor and a self sealing fuel tank.

P&W 1830 or Wright 1820 uses lowest geared supercharger so less power to turn supercharger. Turbocharger is only used as air begins to thin out so at low altitude, SL-2500 or so, turbocharger isn't even being used, flap to intercooler remains completely closed. As F4F-3 gains altitude, flap to intercooler is only opened enough as needed, cutting down on drag. Engine needs less power to run supercharger allowing more power to turn prop, meaning less boost from turbocharger, meaning less heat, meaning less use of intercooler, meaning less drag. (At least that is the way it works in my head)

Drop tanks from day 1

 

[pinsog]

The other plan I actually prefer is ditch the F4F-3 all together and tell Grumman to develop the XF5F Skyrocket. Original plan was for long nose and long nacelles, then they went to short nose (lower stall speed, super gentle and predictable stall) and short nacelles (no reason that I know of). Long nose and long nacelles added 15-18 mph top speed. For carrier work I would build long nacelles and a short nose, giving added top speed from the nacelles but slower stall for carrier work of the short nose.

Weight of original came in at 10,892 in overload with 278 gallons of fuel, radio installed and apparently ballasted for 4 50's and 400 rpg. I would redesign the center section between the engines for a self sealing tank (apparently the original had some internal bracing that made it difficult or impossible for self sealing liner to be added), add armor and add turbochargers to give engine 1200 hp apiece from SL-25,000 feet.

10,900 pounds with 278 gallons of fuel, 4 50's and 400 rpg, add 200 pounds for self sealing tank (Corsair had 177 pounds of self sealing material for 237 gallons) add 150 pounds for armor and 500 pounds for turbochargers.

Total weight: 11,750 with 2,400 hp from SL-25,000 feet.

original on 2000 hp SL 312 mph turbocharged 2400 hp 331 mph
original on 2000 hp at 4500 ft 326 mph turbocharged 2400 hp 346 mph
original on 1800 hp at 7300 ft 324 mph turbocharged 2400 hp 356 mph
original on 1800 hp at 14000ft 346 mph turbocharged 2400 hp 380 mph
original on 1500 hp? 20000ft 352 mph turbocharged 2400 hp 411 mph
original on 1000 hp? 30000ft 315 mph turbocharged 2000 hp 397 mph

I would also have added tanks in the outer wing panels like a Corsair (64 unprotected but purged by CO2) or P38 (55 gallon protected)

Adding about 650-700 pounds of weight in fuel, no idea what the unprotected 64 gallon tanks would weigh empty or what 55 gallon protected tanks would weigh empty.

Climb should be phenomenal considering it has an extra 100 hp over early P38 and weighs about 3000 pounds less without the wing tanks and probably about 2000 pounds less if the wing tanks are full giving it around 400 gallons of fuel without drop tanks.

If Grumman dropped the Wildcat, the F5F should be on about the same timeline

Essentially, we have a plane with early P38 speed performance, should have significantly higher climb performance, exceptional weight lifting performance and docile to land on a carrier with 2 counter rotating engines