B-P Defiant Naval Cannon Fighter

perfectgeneral · Jul 6, 2015

Originally Posted by sonofpegasus
During the Height of the Invasion scare of 1940 after the fall of France Bolton and Paul took the prototype Defiant sans turret and proposed to fit the wings with up to 12 303 calibre machine guns or 4 cannons as an replacement for Spitfires and Hurricanes if supplies of either aircraft were interrupted. Nothing came of this scheme, like the Miles M20 and the Miles Master fighter, these extemporised fighters were not in the end required.

Originally Posted by MattII
Okay, even as a failed aircraft it could have been more successful, just make it so that the Defiant (or at least the carrier reworked version the P.85) wins the favour of the FAA rather the even worse Blackburn Roc, that's another 130-140 frames right there.

Originally Posted by johnboy
This is what I was hinting at. It would have been far better than some types accepted into the FAA

wiki

P.85

The P.85 was Boulton Paul's tender to Specification O.30/35 for the naval turret fighter. A version of the Defiant for Fleet Air Arm (FAA); it had a deeper fuselage and leading edge slats for lower landing speeds required of carrier aircraft. The engine would be either a Bristol Hercules radial or the Merlin. Despite a higher estimated top speed, the Blackburn Roc was selected. With Blackburn already busy producing other projects, the detail design and production of the Roc was given to Boulton Paul.[8] The only FAA use of the Defiant was as the target tug version.
P.94

The first Defiant prototype had not been initially fitted with a turret and therefore had an impressive top speed. In 1940, Boulton Paul removed the turret from the prototype as a demonstrator for a fixed-gun fighter based on Defiant components. The armament offered was either 12 .303 in (7.7 mm) Browning machine guns (six per wing) or four 20 mm Hispano replacing eight of the Brownings. The guns could be depressed for ground attack. By that time, the RAF had sufficient quantities of Hawker Hurricanes and Supermarine Spitfire and did not require a new single-seat fighter. With a calculated top speed of about 360 mph (579 km/h) at 21,700 ft, the P.94 was almost as fast as a contemporary Spitfire although less manoeuvrable.

A much better FAA fighter seems possible if you take the P.85 and the P.94 as starting off points.

Lose the turret
Clip the wings (maybe) by one or two foot each*
Add two 20mm cannon to each wing
Additional cannon ammo instead of .303 in Browning MGs
Ground attack gun angle good for anti-ship strafing
Limited leading edge slats due to cannons
Trailing edge flaps double as dive brakes
longer body means more fuel/range
Armour plate and radio behind pilot (centre of gravity fix)
Armour plate behind rear fuel tank (centre of gravity fix)

Not much of a land based fighter, but the wheels are very widely spaced and the low speed landing handles well. A merlin powered cannon fighter calling out for an earlier RR Griffon engine.

Boulton Paul could have sold a few hundred of these to the FAA. Later marks would have thinner wings, but kept the low speed handling and wide wheel track that the Seafire lacked. At this point the wings need to bulge to fit the cannon. Not when first introduced like the Spitfire.

Thinner wings set a bit further back, a smoother revised airframe and the Griffon engine powering contra-props (to limit torque rotation) could have made this the best fighter of the war. It starts closer in shape to a Seafang than the Spitfire does.

Early cannon fighter to rival the Whirlwind in the BoB?
Escort fighter? How much more fuel than a Spitfire could this carry?

*This would make slow speed handling suffer, so maybe have retractable wing tips for combat? Less wing drag. Faster dives, rolls and turns. Variable wing geometry! Or the simpler, lower lift in flight version: bigger flaps, shorter wings.

perfectgeneral · Jul 7, 2015

So what if Boulton Paul, so miffed at the Roc being forced on them proposed this, 360mph cannon fighter for aircraft carriers and intercepting bombers? I believe the Spitfire is flying about 370mph at this time with the same Merlin engine. Yet the Sea Hurricane is the competition. A design with less future.

It baffles me that:

Although the "Sea Defiant" was expected to be 85 mph (137 km/h) faster, the Roc was chosen.

How about 137mph faster? Maybe only 110mph faster for a two seat version with a navigator/radio operator.

perfectgeneral · Jul 7, 2015

Is the Air Ministry likely to supply the FAA with this clearly better performing aircraft without a requirement?
If the FAA did have one and two seater versions of this, would any air operations OTL go differently?

How about these as base defence aircraft as well as CAP over carriers?

Say an FAA squadron at each of:
Singapore
Trincomalee
Hong Kong
Malta
Gibraltar
Port Said
Scarpa Flow

johnboy · Jul 7, 2015

I think it's a machine that much more could have been made of. It suffered from a clear priority for Spitfire and Hurricane production, which was natural considering the events of 1940.

sonofpegasus · Jul 7, 2015

There are so many what if's around the choice of FAA aircraft in the period 1935-38. Using our 20/20 hindsight here are some alternatives to the Sea Gladiator, Skau, Roc and Albicore.
Folland Derifitive of Gloster F5/34
Sea Hurricane,
Sea Hotspur/ Sea Defiant (both in single or two seat versions)
Bristol 148
Boulton and Paul P85.
Fairey P4/34 (developed as torepedo plane not as Fulmar) instead of Albicore
Hawker Henley (harricane wings as fleet fighter bomber instead of Skua)
I could go on and On

merlin · Jul 7, 2015

sonofpegasus said:
There are so many what if's around the choice of FAA aircraft in the period 1935-38. Using our 20/20 hindsight here are some alternatives to the Sea Gladiator, Skau, Roc and Albicore.
Folland Derifitive of Gloster F5/34
Sea Hurricane,
Sea Hotspur/ Sea Defiant (both in single or two seat versions)
Bristol 148
Boulton and Paul P85.
Fairey P4/34 (developed as torepedo plane not as Fulmar) instead of Albicore
Hawker Henley (harricane wings as fleet fighter bomber instead of Skua)
I could go on and On

Boulton-Paul P.88a - indeed I think it a better navalised option than the Gloster, to compensate for only one seat, it gives a jump to 4 x 20mm cannon.

sonofpegasus · Jul 7, 2015

No arguement here, the Hercules engine version would have been a good option IMHO, I said I could go on and on

perfectgeneral · Jul 7, 2015

sonofpegasus said:
No arguement here, the Hercules engine version would have been a good option IMHO, I said I could go on and on

Well I'd read it. See you over on the dark side (ASB magic etc.).

phx1138 · Jul 7, 2015

Although the "Sea Defiant" was expected to be 85 mph (137 km/h) faster, the Roc was chosen.

And the Defiant was already in production...?

OK, it was a dog.

Removing the turret (but not the second seat) would have been dead easy & would have given FAA an aircraft plenty capable of intercept missions & more than capable of beating the Roc, not to mention it would have been available sooner...

It does have the problem of absorbing Merlin production, which (I continue to maintain) should have gone to Spitfires. Can a radial version (*Twin Mercury?

) have been developed?

Sior · Jul 7, 2015

Just Leo · Jul 7, 2015

Has anyone seen the structure and format of the Defiant wing? Has there been a Defiant wing with guns in it? Does the Hispano HS404 fit within the Defiant's two-spar jointed structure? Do the magazines fit? Does anyone want to try the engineering or is this just fantasy talk? Please keep in mind that the Beaufighter wing, converted from Beaufort, didn't bother to even relocate the landing light type and location, and installed assymetric (sic) weapons instead. Of course, the fuel tanks will be moved from the gun location and moved behind the pilot.

Sior · Jul 7, 2015

Just Leo said:
Has anyone seen the structure and format of the Defiant wing? Has there been a Defiant wing with guns in it? Does the Hispano HS404 fit within the Defiant's two-spar jointed structure? Do the magazines fit? Does anyone want to try the engineering or is this just fantasy talk? Please keep in mind that the Beaufighter wing, converted from Beaufort, didn't bother to even relocate the landing light type and location, and installed assymetric (sic) weapons instead. Of course, the fuel tanks will be moved from the gun location and moved behind the pilot.

Just Leo · Jul 7, 2015

I was thinking more of this one.

Zheng He · Jul 7, 2015

This is a good thread.

BTW, in all of the what ifs of FAA aircraft early in the war, was there ever a proposal for a mono-plane variant of the Gladiator? Kind of like the F4F Wildcat starting out as a bi-plane. I'm sure it would have been nothing special but it probably would have been a solid carrier fighter by 1939 standards.

Hammerbolt · Jul 7, 2015

Don't think they would have acepted, tbh. The FAA had a real mania for 2-seater fighters. Even after the war started they went on with the development of the sucessor of the Fulmar, the 2-seater Firefly. Besides, the US started supplying Wildcats, with the first (from french contracts) going into operation in August 1940.

For the FAA to have british-designed single-seater fighters, the whole program would have had to be started instead of the Fulmar, around 37-38. Which would only be possible of the RN Admiralty changed their minds on the whole stupid 2-seater idea...

sonofpegasus · Jul 8, 2015

Just Leo said:
Has anyone seen the structure and format of the Defiant wing? Has there been a Defiant wing with guns in it? Does the Hispano HS404 fit within the Defiant's two-spar jointed structure? Do the magazines fit? Does anyone want to try the engineering or is this just fantasy talk? Please keep in mind that the Beaufighter wing, converted from Beaufort, didn't bother to even relocate the landing light type and location, and installed assymetric (sic) weapons instead. Of course, the fuel tanks will be moved from the gun location and moved behind the pilot.

The single seat Fighter variant was a 1940 proposal by the aircrafts manufacturer and designers and was intended as a quick fix if Hurricane or Spitfire production was interupped by dammage to the aircraft factories building them. Therfore I think it is safe to say thet the design of the Defiant wing was such that fitting guns was not a problem. Now folding said wing for aircraft carrier use might be more problematical.
For the single or two seat version of the Hawker Hotsper it's just a case of fitting Hurricane outer wings.

Just Leo · Jul 8, 2015

sonofpegasus said:
The single seat Fighter variant was a 1940 proposal by the aircrafts manufacturer and designers and was intended as a quick fix if Hurricane or Spitfire production was interupped by dammage to the aircraft factories building them. Therfore I think it is safe to say thet the design of the Defiant wing was such that fitting guns was not a problem. Now folding said wing for aircraft carrier use might be more problematical.
For the single or two seat version of the Hawker Hotsper it's just a case of fitting Hurricane outer wings.

I was just wondering how the guns would be fitted, since there is no evidence that it was ever done, and talk is cheap. Also, fitting guns in the wing means relocating the fuel tanks, which means the back seater isn't an option without some pretty gross modifications. The wing structure, specifically the joint between center-section and outer panel, doesn't seem to be conveniently located for weapons installation. It would also probably be the location of the wing fold. The undercarriage sure takes up a lot of room. I'm not saying that a Defiant wing can't hold cannons. I am saying that the original wing can't hold 4 cannons. The original Hurricane wing couldn't either. The subsequent metal wing could.

Driftless · Jul 8, 2015

Just Leo said:
I was just wondering how the guns would be fitted, since there is no evidence that it was ever done, and talk is cheap. Also, fitting guns in the wing means relocating the fuel tanks, which means the back seater isn't an option without some pretty gross modifications. The wing structure, specifically the joint between center-section and outer panel, doesn't seem to be conveniently located for weapons installation. It would also probably be the location of the wing fold. The undercarriage sure takes up a lot of room. I'm not saying that a Defiant wing can't hold cannons. I am saying that the original wing can't hold 4 cannons. The original Hurricane wing couldn't either. The subsequent metal wing could.

So, you're saying there's a chance.......

In the end, to get the Defiant to the state we're all longing for

, the turret goes, and the wing (and other structures) get rebuilt. Wouldn't removing the turret and moving the gas tanks, adding the folding wing appartus, and adding cannons to the wings would alter the COG too?

Basically, you wind up with a completely different plane, that just kinda looks like the old Defiant.

Just Leo · Jul 8, 2015

Driftless said:
So, you're saying there's a chance.......

In the end, to get the Defiant to the state we're all longing for , the turret goes, and the wing (and other structures) get rebuilt. Wouldn't removing the turret and moving the gas tanks, adding the folding wing appartus, and adding cannons to the wings would alter the COG too?

Basically, you wind up with a completely different plane, that just kinda looks like the old Defiant.

The Defiant has kinda neat nose contours. We keep that. Nothing wrong with the tail. The cockpit canopy has the Bf-109 shape to it, and it's kinda narrow, with no rear visibility, and the windscreen could be sleeker. The air intake is too bulbous. The mainwheel legs are coarse and the mechanism cumbersome. The rad is no worse than the usual worst. We could save it.

But what are we saving? Pilots loved the Hurri and Spit. Did they like flying the Defiant? It didn't and couldn't out-perform either, and it was never designed to be a single seater, meaning that some steps to conversion would be a shameless compromise. Unlike the Beaufighter, I did relocate the landing light.

yulzari · Jul 8, 2015

Hammerbolt said:
Don't think they would have acepted, tbh. The FAA had a real mania for 2-seater fighters.

They had a reason for the second seat. They wanted to be able to operate in the poor visibility of the North Atlantic in winter and had a secret method for the fighter to find the carrier. This was a form of radio beacon and needed an operator. The back seater was not an observer(officer) but a telegraphist(rating). In the context of the weight of contemporary aeroplanes the extra weight was not that much (maybe 400lb). In the meantime shipboard radar had moved on and let the carrier keep track of it's fighters who only had to find the area of the shipboard radar range. Even so their lordships wanted a sea Spitfire but couldn't get it so the P4/34 used the existing back seat space to this purpose. Also allowed a navigator for the longer flights but that was not a requirement.

For the Firefly one has to look at contemporary strike peers. US strike aeroplanes at the time had 2 seats. Later they, and the FAA, found that you could use the fleet fighters for strike if the range was limited. The Firefly was a light strike aeroplane not a heavy fleet fighter even though, with the Youngman flaps lowered, it could out turn most opponents and outgun many and a back seater to observe the rear and shout directions was no bad thing.

The FAA and the RAF had both thought vary deeply and carefully about doctrines pre war and chosen designs to suit. The base line was that France would stand and would be an active ally. Thus the FAA would largely sail out of range of the Luftwaffe. The French Navy would dominate the Mediterranean and the Royal Navy the North Atlantic. Land based aeroplanes from France and North Africa could provide air cover in the Mediterannean and the FAA fleet fighter could deal with German maritime recce over the North Atlantic and the Skua had the endurance to fly CAP. Never meant to cope with 109s or 110s. It would have all worked well except for the fall of France and the unforseen need to support land forces in Norway.

In the light of the existing doctrine a Defiant cannon naval fighter was a solution in search of a problem. Until well into 1941 all Defiant production was allocated to the air defence of Britain. By the time the need for Defiants to be night fighters had gone away their Lordships were getting access to Sea Hurricanes and the desired Seafire was on the horizon. Boulton Paul had other things to make and Defiant production ended. The earliest beginnings of a cannon armed Sea Defiant would be one following the BoF and would have to be a successor to the Defiant which was in RAF demand. That puts it into the late 1942 timeslot for a beginning. By the time production had delivered a useful amount and the squadrons had worked up for active sea service you would be looking into mid 1943 at best by which time the Seafire was the alternative.

Essentially a cannon armed Defiant would have been very useful 1940 to 1944 but could only come about with a change to the planning doctrines of the early 1930's. Remember that the Defiant was only entering service in mid 1940 as it was. One could postulate that a Sea Defiant instead of an RAF Defiant would allow Hawkers to shift Glosters into Hurricane production instead of Gladiator production but, at that time, Gladiators were jam today and hurricanes were jam tomorrow.