Twin-engined tricycle undercarriage WWII fighter

Supermarine Types 312 and 327

This design – Type 327 – was originally submitted as a tender to F.18/37 with 12 Brownings. 6 were mounted in each wing outboard of the nacelles. It was rejected as not offering any performance advantage over the Tornado/Typhoon that would justify using two Merlins, although it did get to mockup stage.

It was later, speculatively submitted as cannon fighter under Supermarine Spec. 460 dated 26/8/38. The 3-view posted by Mark 12 is from this Spec Document (i.e of the later, cannon armed version). The main changes were that 6 Hispanos were now mounted in the wing roots and the wing mounted airbrakes of the original version were deleted. The cannon were drum fed, but with the drums mounted somewhat remotely from the cannon, ammunition being fed from one to the other via duct made from some unspecified “flexible” material.

Basic Data for the cannon , Merlin powered version were given by Supermarine as:
Span: 40 ft
Gross wing area: 304 Sq ft
Length 33.5 ft
Fuel capacity 170 gallons
AUW: 11312 lbs (8769 lbs Tare)
Max Speed 465 at 22k and 423 at 15k
Service Ceiling 40k
Take off (zero wind) was given as 409 yds

Performance with optionanal Taurus power was slightly lower.

This design was also not much liked for much the same reasons, but with the additional one that the armament installation was seen as being impractical. There were also concerns about Supermarines ability to get it into production in a reasonable timeframe.

Type 327 shares some design features with the (earlier) Whirlwind: leading edge radiators (which may have looked pretty, but were almost certainly less aerodynamically effective than well designed conventional ones), full width Fowler flap and even the routing of the exhaust pipes through the nacelles to exit at the tail of the nacelle in the oil cooler outlet duct.

Type 327 is a very different beast to the Type 312 which was Supermarine’s tender to the F.37/35 Spec which led ultimately to the Whirlwind. 312 was Peregrine-powered twin and with a tailwheel undercarriage. (Supermarine also submitted a cannon-armed Sptfire) A prototype of the Type 312 (L6593) was ordered but later cancelled to allow Supermarine to concentrate on productionising the Spitfire and designing the B.12/36 Heavy Bomber for which the Supermarine Type 316-418 were seen as the most promising contenders (rather than the Stirling which ultimately won te production order)

NiallC

Just speculation, but I guess if it had been developed further they may have moved away from wing mounted cannon to fuselage mounted, as per the Beaufighter, Mosquito and Whirlwind. Possibly from the experience gained with the Spitfire which wasn’t a great gun platform.

There is something of the Mosquito about the aircraft and it’s profile.

That was the design weight and wing loading. I doubt if the project had been proceeded with it would have entered service at that weight.

From the GA drawing, it looks a very thick wing section considering the design speed.
I wonder what effect the props would have had on the cannon shells, they appear to pass very close to the airscrew disc.

What was the wing area then?

304 sq feet. Wing loading 37 lb/sq ft.

Best wishes
Steve P

To answer my own question, wing area was 12.5 per cent greater than that of the Spitfire and the tare weight was 8,769 lb.Steve P

What was the wing area then?
Looking at the thread on the Do335 that had a wing area of 414.411 sq ft and empty weight of 16,005 lbs.
Roger Smith.

What a beauty, If only…..

Shame about the ventral element of the tail fin, otherwise she’d have rivalled the DeH Albatross as one of the best looking aircraft designs ever….IMO anyway.

Paul F

To answer my own question, wing area was 12.5 per cent greater than that of the Spitfire and the tare weight was 8,769 lb. A top speed of 465 mph at 22,000 ft was claimed.

A version powered by Bristol Taurus engines was also considered.

Source: Interceptor Fighters For The Royal Air Force 1939-45
Michael J.F. Bowyer

Best wishes
Steve P

General Arrangement drawing of the Type 327.

Mark

Span aint everything though. What was the wing area?

Best wishes
SteveP

I too had the same thought when I first saw the drawing “small wings”. I guess Mitchell was going for maximum speed giving it enough to get it off the ground, I mean look at the likes of the F-104 or Lightning, their wing areas are not big but their thrust is (I’m no expert either, so i may be totally wrong). I guess the mock up must have been wind tunnel tested, I wonder what the results were like.

Thinking back to Dave’s original query about the Supermarine Type 327.

I am categorically NOT an aircraft designer and Supermarine had their fair share of extremely competent individuals, but… the wing doesn’t look big enough to me.

It’s 4 ft more span than a Spitfire, but 5 ft less than a Hornet and about 12 ft less than a Mossie, and still has to lift the airframe weight, 2 Merlins and six 20mm cannon.

Would have had an ‘interesting’ approach speed, I suspect.

English Electric Lightning?

Thanks for the info on the Supermarine fighter. What a shame it was never built and tested. Anyone fancy doing a replica? It had semi-eliptical wings too, so the Mitchell signature is there.

F37/35 was the Air Ministry Specification for the Whirlwind, it appears that R J Mitchell was working on a design for this specification in the last year of his life.

Also under this specification were the Bristol type 153 and 153a, the 153 was a single engined (Hercules) design and the 153a a twin engined design, Boulton Paul F.37/35, Hawker F.37/35, a Hurricane with four Oerlikon guns and the Spitfire type 312 also equipped with four Oerlikon cannons, no type 400.

Interestingly one of the last if not the last AM Specification issued that actually went into prodcution was F.23/49 anyone like to hazard a guess which famous aircraft this is/was ?

F37/35 was the Air Ministry Specification for the Whirlwind, it appears that R J Mitchell was working on a design for this specification in the last year of his life.

Wow. 4 foot more wingspan than a Spitfire and twice the power!

The book says two Merlins.

Mark

With only 40 ft wingspan I suspect a pair of Merlins would be a trifle excessive.

I didn’t cross-refer the specification number but I guess it was for the same requirement as the Whirlwind so Peregrines would be a good guess.

Thanks for that. Was a lovely looking design. Was it intended to have Merlins?

There’s nothing on google

Supermarine type 327. Mock up stage only. 40 ft wingspan, 6 x 20mm cannon.