The 'no-nonsense' twin-engined fighters for 1938-1943

[tomo pauk]

The 'no-nonsense' part meaning the fighter is of the 'classic' layout (like the Fw 187 or the Whilrwind; no twin boom or push-pull etc.), 1 crew member, tail-dragger, engines are 'tractors' and the widely available types - nothing fancy like the sleeve-valve types, X24, no air-cooled V12s, no turbo (yes, USAAC was big on turbo, but even them relented when needed). Engine swap/upgrade is allowed, much like it was the case with many 1- and 2-engined types. Start date of 1938 means the type has the 1st prototype flying in the 1st half of 1938, meaning the initial work on pper needs to begin many months in advance. High-lift devices are okay, just let's not overdo it.
Guns - what was available, or what was on the market in the timely manner; guns upgrade is allowed. Fuel of the day is used, better fuel might come some day in future, but it is not known when back in second half of 1930s, and in what quantities.
Naval aircraft that fit description are also part of the topic.

What airforce benefits the most? For whom going full steam 2-engined is actually a bad idea, not least because of industry, logistics and budget limitations (Italy, Japan?)

 

[herman1rg]

Shame the DH.98 Mosquito hadn't started development then, this would have led to earlier deployment of the DH.103 Hornet.

 

[tomo pauk]

Shame the DH.98 Mosquito hadn't started development then, this would have led to earlier deployment of the DH.103 Hornet.

Hmm - perhaps DH makes a 2-engined fighter for 1938, and scale-up it into a bomber by 1941?

 

[EwenS]

Hmm - perhaps DH makes a 2-engined fighter for 1938, and scale-up it into a bomber by 1941?

DH were too busy from the beginning of 1936 designing the DH91 Albatross to meet an Air Ministry Spec for a transatlantic mail plane. Its wooden construction built on the experience obtained with the 1934 DH88 Comet Racer and introduced the balsa sandwich fuselage construction technique later used in the Mosquito. The Albatross flew in May 1937. There was also the DH93 Don multi-role trainer with a wooden stressed skin construction to meet a 1936 Air Ministry Spec which flew in June 1937. Both types entered limited production before WW2.

Their next major project under the new designer RE Bishop, appointed late 1936, was then the company's first all metal stressed-skin aircraft, the Perseus powered DH95 Flamingo which first flew in Dec 1938. Production was limited by the start of WW2 and the cancellation of RAF orders to allow DH to concentrate on producing Tiger Moths.

So the DH design team had their hands pretty full in the 1936-39 period. It is on record that thoughts of a fast bomber based on the Albatross didn't appear until early 1938 with DH pushing it from late 1938, but no one at the Air Ministry was listening. It was late in 1939 before the DH98 Mosquito design emerged.

 

[GrauGeist]

Grumman's XP-50 project held potential - speed, range and weapons on the centerline (no convergence issues or interruption from prop-sync).

In the case of the Mosquito, Gloster had a "heavy fighter" proposal, the F.9/37, which held great promise before the Mossie got off the drawing board.

 

[Glider]

It doesn't qualify as a 'No Nonsense aircraft. On the other hand, it was built and being tested as a serious contender only stopping when Germany invaded.

So I give you the Fokker DXXIII. The testing was done using small 530hp engines, but the proposed engines were RR or DB

 

[GrauGeist]

But the D.XXIII was a twin-boom, push-pull configuration, thus is disqualified per Tomo's criteria:

no twin boom or push-pull etc.

 

[Shortround6]

. Start date of 1938 means the type has the 1st prototype flying in the 1st half of 1938, meaning the initial work on pper needs to begin many months in advance. High-lift devices are okay, just let's not overdo it.

Well, that restriction takes out just about every historical aircraft.
F5F didn't fly until April of 1940,
The Whirlwind didn't fly until the Sept of 1938.

Leaves in the FW 187 however

no twin boom or push-pull etc

as noted by GrauGeist, that takes out most of the rest.

1 crew member, tail-dragger, engines are 'tractors' and the widely available types

And that takes out just about anything except the Fw 187.

Guns - what was available, or what was on the market in the timely manner; guns upgrade is allowed.

And here we get into the problem.
The Fw 187 was designed for a pair of MG 17 machine guns.

If you don't upgrade the guns there is little point to the exercise.
The Fokker G1 (first flight 16 March 1937)

has got eight 7.9mm Brownings. It is also twin boom and 2-3 seats.
But unless you can get you hands on some cannon then it is hard to see much heavier armament and the British already had the eight 7.7mm Browning battery covered.

You also have to be a bit creative with the engines. Production for the Germans using the Jumo 210 engines aren't going to work well so you are really designing an aircraft to use DB 601 engines and MG FF guns, neither of which are in actual production in early 1938 although in trials.

For the US it is .30 cal and 50 cal guns, and the Allison is being purchased in small handfuls.
Or the Cyclone 9 engines which are the size of Pegasus engines.

The Japanese stuffed a pair of 7.7 mm Vickers guns into the nose of the KI-45 prototypes and that 20mm HO3 cannon and that was in Jan 1939. Ki-45 use 820hp 9 cylinder radials.

Pretty much nothing you can up with that used 1937-1938 engines and guns is going to be useful in 1942 without serious upgrades.

Extending the time line by 6 to 12 months gets more guns in the pipe line and some different engines, it also starts bringing in 100 octane fuel. In 1937 they new it was coming but they didn't know if would show up in commercial quantities (mass production) in 1939 or in 1941 or later.
Howard Hughes set a World speed record in Oct 1935 using 100 octane fuel, however at the time 100 octane fuel was special order and it cost about 10 times per gallon as normal aviation fuel.

 

[Glider]

The Fokker G1 was designed for a number of different set ups which included cannons. I don't have access to my records at the moment, but I am sure that was the case

 

[tomo pauk]

Well, that restriction takes out just about every historical aircraft.
F5F didn't fly until April of 1940,
The Whirlwind didn't fly until the Sept of 1938.

Thread is not about the historical aircraft, but rather about the plausible designs that could've been, as well as their possible impact on prosecuting the air battles in the specified era (if the country in question has the means of manufacturing them in required quantity, and enough fuel to burn - these things are not always a given). Say, British make a fighter with 300 sq ft wing, powered by two Kestrels, armed with 10-12 Brownings, later up-engined with Merlins. Or, Americans make a similarly sized fighter powered by two R-1830s, later up-engined with V-1710s, armed with two 37mm cannons, later with 6-8 .50s. Germans - something like Fw 187, with a dozen of MG 17s.

And here we get into the problem.
The Fw 187 was designed for a pair of MG 17 machine guns.

If you don't upgrade the guns there is little point to the exercise.

You also have to be a bit creative with the engines. Production for the Germans using the Jumo 210 engines aren't going to work well so you are really designing an aircraft to use DB 601 engines and MG FF guns, neither of which are in actual production in early 1938 although in trials.

So let's upgrade both the guns and engines once available - really not something unheard of by late 1930s.

 

[Shortround6]

The Fokker G1 was designed for a number of different set ups which included cannons. I don't have access to my records at the moment, but I am sure that was the case

I think you are right, perhaps a pair of Madison 23mm guns plus 2 MGs?

 

[FLYBOYJ]

I think this might have made the cut.

Speed, decent range, excellent climb and lots of armament options. It did first fly in early 41' with design work starting in 39. If pursued, I think it could have been available in numbers by 1943

 

[GrauGeist]

If we go back a few years, there were twins designed for competition, like de Havilland's DH.88, which was powered by two Gipsy Six R engines and achieved a top speed of 237mph. As noted, these could have been upgraded as time went by.

 

[Shortround6]

Say, British make a fighter with 300 sq ft wing, powered by two Kestrels, armed with 10-12 Brownings, later up-engined with Merlins. Or, Americans make a similarly sized fighter powered by two R-1830s, later up-engined with V-1710s, armed with two 37mm cannons, later with 6-8 .50s. Germans - something like Fw 187, with a dozen of MG 17s.

So the idea is to dream up a fighter that would be effective in 1940-43 and try to back date it to a primitive version that might have been assembled in early 1938 using crappy engines and crappy gun set up?

British were trying to keep a lot of their planes around 24-28lbs of wing loading. The Hurricane, Spitfire, Blenheim, Hampden and Whitley all fall into that area, I haven't checked on others. The later versions do increase in wing loading.
A Hurricane is going to use a 1000hp engine to get eight guns in the air and do a bit over 300mph and do it at around 6,000lbs.

Twin Kestrels are going to weigh about 1950lbs (about 600lbs more than a single Merlin.) and they are going to give you about 1500hp at 14,500ft. Now you need the radiators coolant (water, not glycol) oil coolers/oil, accessories and propellers (being British we can use lightweight fixed pitch props

Compared to the Hurricane you have the drag of the Fuselage plus the drag of the two engine nacelles.
Now your 300 sq ft wing (without high lift devices) is good for about 8,100lbs for 27lbs sq ft wing loading.
That 8,100lbs is just a few hundred pounds lighter than the Whirlwind weighed empty, The Whirlwind went right on through the low wing loading "rule" of most British aircraft and was criticized for it. And they were sometimes restricted as the airfield's they could use even in 1941/42 when a number of airfields had gotten larger (or had obstructions removed)

An extra 50 sq ft of wing, especially without good flaps, is not going to buy enough space/weight to change to Merlins at a latter date.
We all know there was letter with two sentences that claimed it could be done. But there was no explanation of how it was to be done (extend the wing 2 feet on each side? Build a whole new wing? Upgrade the landing gear? add 200lbs of ballast into the rear? fit 4 bladed props because you don't have enough room for larger 3 bladed props?)
I like the Whirlwind, I do have a hard time swallowing that changing to Merlins would be quick or easy. Given enough time and money it could be done, but where on the spectrum are we?

Same sort of questions about the Twin R-1830 plan.
Production R-1830s in 1938 were giving about 850hp at 8,000ft.
Engines in prototypes were giving 900hp at 10,000ft or 1050hp at 8500ft. The newer engines were well over 100lbs heavier and had new cylinders and a new larger supercharger.
Look at many of the engines used in the Martin 167s, Hudsons or early DB-7s, single speed superchargers. You don't get two speed superchargers until late in 1940 or 41.
You don't get the short nosed Allison engines until almost the middle of 1941.
And for a good guess on what the performance would be, just see the Lockheed 322 if you can find it.

for the Germans you have swap engines to the DB 601s (which you don't have enough of) and stick with a lot of MG 17s or invent bigger drums for the MG FF cannon. you don't want the 2cd crewman to be loader for the cannon (remember that the first 400 Beaufighters had the guy in the back to change drums on the Hispano cannon)

 

[herman1rg]

Make a twin-engined Hurricane

 

[wlewisiii]

I think this might have made the cut.

View attachment 690048

Speed, decent range, excellent climb and lots of armament options. It did first fly in early 41' with design work starting in 39. If pursued, I think it could have been available in numbers by 1943

Always wondered if it could have handled 2 R-2800s...

 

[FLYBOYJ]

Always wondered if it could have handled 2 R-2800s...

With 1820s it did pretty good, but it did kind of morph into the F7F which did have 2800s.

 

[Shortround6]

If we go back a few years, there were twins designed for competition, like de Havilland's DH.88, which was powered by two Gipsy Six R engines and achieved a top speed of 237mph. As noted, these could have been upgraded as time went by.

Upgraded to what?
you had a 5,500lb plane that was carrying two people, 940lbs worth of engines and about 1850lbs of fuel.

It was a very streamline plane and carried a lot of weight for it's size (212 sq ft wing) but race planes are NOT combat aircraft. They are not stressed for combat or High G forces.

This is like taking a formula I race car and trying to figure out how much cement you could get it to carry.

Amelia Earhart's Lockheed 10 was rated at about 10,500 lbs gross weight as an airliner. For long distance record flying they were approved (or OKed by Lockheed ) for over 14,000lbs of weight. Doesn't mean you could turn the Lockheed 10 into a long range bomber and operate it anything close to 14,000lbs. For one thing It would take hundreds of miles for the Lockheed burn off enough fuel to even get the plane to 10,000 feet.

The DH 88 wasn't that different to Piper Apache 250 in size weight and power. Or some other 6 passenger twins.
Put a skinny fuselage on one of them and then scheme how you could put even 450-550hp WW II era piston engines it and try to fly it at even 6 Gees.

 

[GrauGeist]

I'm trying to put my mind into the timeframe when they were trying to find a solution to the day's military doctrine.
This was the era emerging from biplanes and open cockpit monoplane, a time of heavy fighters, turret fighters and big interceptors.
The DH.88 in principle was no different than the Fw187 or Gloster F.9/37 - to meet a military spec (along Tomo's lines), eliminate the second seat, bring the aircrame up to spec, incorporate the latest engines available and apply at the very least, four or six .303 MGs in the centerline.

As we all know, many concept aircraft manifested through several iterations until a production type was finalized. There is also a large difference between the technology available in 1934 and 1939 (or even 1937) so a military version of the DH.88 would have time to be developed. It's no coincidence that de Havilland had success with the Mosquito.

The DH.88 had a wing area just over 212 sq.ft. (with a span of 44 ft.) and the XP-50 had a wing area of 304 sq.ft. (with a span of 42 ft. for comparison.

 

[Shortround6]

The DH.88 had a wing area just over 212 sq.ft. (with a span of 44 ft.) and the XP-50 had a wing area of 304 sq.ft. (with a span of 42 ft. for comparison.

well. that could buy about 50% increase in gross weight.

As far as the DH 88 goes, take out about 160 imp gal of fuel. That still gives you a few gallons more than Hurricane and gives you about 1300lbs to use for other things. getting rid of the 2nd crew man gives you another 200lbs.
Six .303s with 500rpg is about 400lbs. Or go for eight guns and less ammo per gun.

Some structural reinforcement to take higher G loads. ???

Around 1000lbs for better engines and propellers?

If you can keep the same external drag you might be able to hit 300mph using a pair of 480hp engines (?) at low level.

But nobody makes 400-500hp straight 6 engines.

You also need to change props. The 2-bladed Ratier 2-position variable pitch props could only be changed in flight once ?
OK for racing/record setting, not so good for service use. but they were light.

The F5F may have been good for 312mph at sea level and 358mph at 17,000ft ?
The F5F had very good take-off performance. Landing speed might have been a bit high for British taste. But better than a Whirlwind.