WI: an early 2-engined fighter for RAF

Ok, this is for the people that really knows. The traditional answer for a "Merlin" Whirlwind is the C.G. cuestions. So what about placing a Defiant turret to compensate? The additional weight would probably be (at last party) compensate by the increased engine power. But there. would be probably fuel/endurance cuestions. So places for fuel tanks should probably have to be found, with cross feeding valves and external drop tanks.
But this would have been a monster...


Er....no, just no. Please.
 
For the F7/30 Boulton Paul submitted its P.67.

From James Goulding’s Interceptor.

Although never built, the most unusual project submitted in the F7/30 competition was J.D. North’s twin engined design from Boulton Paul Ltd. Powered by two Napier Rapiers of 395hp the Boulton Paul P67 had a wing of constant chord using the Boulton Paul system of standard spar size and duralumin wing ribs. The wing was wire-braced to the fuselage and nacelles.

The armament was four 0.303” Vickers MkIII guns with 2,000 rounds was installed around the pilot’s cockpit, which was set well forward to give a good view, as required by the Specification. The two rapier engines, 16-cylinder H configuration in-lines, were mounted beneath the wings with the main undercarriage retracting backwards into the rear of the nacelles. The wingspan of the P67 was 40ft and the overall length was 29ft 4”, much the same as the Hawker Hurricane for comparison.

The P67 had an estimated top speed of 227mph at 12,500ft to which height it could climb in 6.55 minutes. It had a maximum rate of climb at ground level of 1,800ft/min, increasing to 1,960ft ft/min at 12,500ft, and falling off to 1,135ft/min at 20,000ft. It could climb to 20,000ft in 11.5min, at which height it could attain 217mph. Service ceiling was 30,000ft. The P67 could also land at less than 60mph.

The Boulton Paul proposal was not accepted.

Note it had a retractable undercarriage and the drawing in the book looks like it has it carrying a small bomb under the fuselage.


A good showing here could generate earlier interest in twin engined fighters.
 
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Why not add another engine to an early "push" configuration WW1 fighter to get a pull/push configuration?
Could be an expedient to get a "Zeppelin killer" interceptor in service.
 

Driftless

Donor
Ok, this is for the people that really knows. The traditional answer for a "Merlin" Whirlwind is the C.G. questions.

Another set of questions, coming from the CoG: Though the fuselage is very narrow, could one or two of the 20mm guns been moved from the nose to the fuselage behind the pilot? Those aft guns would fire through blister mounts, either over the wing or under. That move shifts weight from the nose to the rear and expended ammunition weight loss should also be shifted as well. Or, was there just not enough room behind the pilot for the guns and the ammo drums? Also, what aerodynamic drag impact from the gun blisters?
 
Ok, this is for the people that really knows. The traditional answer for a "Merlin" Whirlwind is the C.G. cuestions. So what about placing a Defiant turret to compensate? The additional weight would probably be (at last party) compensate by the increased engine power. But there. would be probably fuel/endurance cuestions. So places for fuel tanks should probably have to be found, with cross feeding valves and external drop tanks.
But this would have been a monster...
The Merlin issue was the carburettor etc. interfering with the undercarriage. It was finally resolved and a Merlin Whirlwind offered to the AM. A Defiant turret would mean an entire new fuselage and, with adding Merlins, mean one may as well start a new design. The turret so severely degraded trials with Beaufighters and Mosquitos that the idea was dropped. The Whirlwind can look after itself as a fighter. Loaded with bombs it was escorted over France and the Low Countries but more in the spirit of tempting the Luftwaffe to battle than needing fighter escort. Actually more of a CofG issue was the change proposed from drum to belt feed for the cannons with a greatly increased ammunition capacity. Hence the trials with the cannon arranged in one row of four instead of two above and two below. Martin Baker were the kings of these sort of installations viz their squeezing x12 .303 into the same space. Allegedly the concentration of fire with the x12 .303 would almost 'saw the enemy in half'. Armouring the important mechanical bits won't work if a Whirlwind has sawn off a wing or rear fuselage.
 

Ramontxo

Donor
Well very probably you are right. But think of the Whirly Bird in a big melee firing its front 4 guns and the aft mounted turret it's own 4 Brownings..
 
And about as slow as the Bristol Blenheim IVF. The drag from the turret is fatal to speed, unless you try for a low profile remotely controlled turret. That's really pushing the technology of the 1930's.
 

Driftless

Donor
And about as slow as the Bristol Blenheim IVF. The drag from the turret is fatal to speed, unless you try for a low profile remotely controlled turret. That's really pushing the technology of the 1930's.

Plus, there's a significant weight penalty: turret and turning mechanism, guns, ammo, and gunner.

From: The Battle of Britain Net
Its firepower consisted of four .303 Browning machine guns in the removable Boulton Paul A Mk IID hydraulically operated dorsal turret. The .303 guns were belt fed, all with 600 rounds of ammunition and the hydraulic system formed an integral part of the turret itself. The turret itself weighed in at 361lbs (164kg) and to this can be added 88lb (40kg) for the four guns, 106lb (48kg) for the ammunition and finally 35lb (16kg) for the oxygen equipment and gunsights.
Add 175lbs(80kg) +/- for the flight-suited gunner. That's 765 lbs (348kg).
 

marathag

Banned
Ok, this is for the people that really knows. The traditional answer for a "Merlin" Whirlwind is the C.G. cuestions. So what about placing a Defiant turret to compensate? The additional weight would probably be (at last party) compensate by the increased engine power. But there. would be probably fuel/endurance cuestions. So places for fuel tanks should probably have to be found, with cross feeding valves and external drop tanks.
But this would have been a monster...

Not just CoG, but overall size. Too small a wing for installed power, not enough fuel tankage for thirstier engines, and so on
 
Maybe if Bristol had got the wings right in the 1927 Bristol Bagshot the RAF would have insisted heavy fighters be included in each generation of service aircraft.

https://en.wikipedia.org/wiki/Bristol_Bagshot

Bristol_Bagshot.jpg
 
If we combine the "bomber scare" caused by Douhet & Co's writings, the whole idea of "the bomber always gets through" and the RAF's own WWI experience, with the V400/1500, how far before WWII can we go? During WWI René Fonck used a 37mm on a SPAD, so I don't see why post-war a "bomber killer" could no be fited with such a gun...

Let's say the RAF starts spending real time and money in the 1929-1932 era. Could it not get a decent twin-engined bomber-destroyer fited with a 37mm, or another similar weapon?
 
as stated previously by other posters, have De Haviland build a fighter based on the D.H.88 but enlarged to take two RR Kestral engines. XVI engines producing 740 HP, first flight in early 1937, provision for 4x20mm Cannons. With the D.H. 88 weighing in at 2.5 tons loaded with 460hp for a top speed of 237mph, maybe our big brother would weigh between 3.5 and 4 tons but with 1,480hp I would suggest a top speed aroun 340mph might be possible depending on how clean you can get the design. In 1936 that IMVHO would be some fighter!
 
as stated previously by other posters, have De Haviland build a fighter based on the D.H.88 but enlarged to take two RR Kestral engines. XVI engines producing 740 HP, first flight in early 1937, provision for 4x20mm Cannons. With the D.H. 88 weighing in at 2.5 tons loaded with 460hp for a top speed of 237mph, maybe our big brother would weigh between 3.5 and 4 tons but with 1,480hp I would suggest a top speed aroun 340mph might be possible depending on how clean you can get the design. In 1936 that IMVHO would be some fighter!

And you could easily trade much of the 88's massive range for room for the guns & ammo. Cut it down to, say 1500 miles?
 

Driftless

Donor
DH.88 cutaway drawing:

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It was a great plane for its time, but you would need a mostly clean sheet of paper start, in order to come out with a fighter. Still, there was potential to use the lessons-learned from the Comet.
 
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