Airspeed AS.31

[kampfflieger]

Airspeed AS.31 aka Airspeed F.35/35. Does anybody know more about it?

 

[borovik]

"The British specification 35/35 was for an experimental high-speed aircraft with the option of turning it in to an 8-gun fighter, as in the Hurricane & Spitfire. There were four firms who replied to this specification the most un-conventional was the Airspeed A.S.31 which was a tractor monoplane in which the tailplane, on twin metal booms, carried the pilot in an eggshaped nacelle. No rudder or fin surface was indicated on the general arrangement drawing. Split flaps were fitted across the trailing edge of the wing between the booms, with wide-span ailerons outboard of the booms. A widetrack undercarriage was depicted . The aircraft was to be powered by a Rolls-Royce Merlin E engine. No details of its potential performance are recorded. Its wing span was 33 ft. and its length 29.5 ft.
The other contenders were the Bristol 151 single seat monoplane, powered by a Bristol Hercules engine. Its speed, with 100-octane fuel, was estimated to be 440mph. The General Aircraft GAL.28 was a single-seat aircraft , powered by a single Hercules engine, with a wing of variable area. The Hawker design was a Hurricane variant.
The Specification not proceeded with."
excerpt from:http://unusual british aircraft.htm/
Drawing I.SHESTAKOVA from Unicraft Models ?

 

[kampfflieger]

Thank you for information. Yes, it's a Shestakov's drawings

Could you tell a right URL? http://unusual british aircraft.htm does not work

 

[dan_inbox]

[quote author=kampfflieger]
Could you tell a right URL? http://unusual british aircraft.htm does not work
[/quote]
http://www.geocities.com/Heartland/Village/4082/brit/odd_air.htm

 

[kampfflieger]

Thank you!

 

[Apophenia]

Just came another artist's impression of the Airspeed AS.31 while purging my files. This painting was done by Ken Steacy who also wrote the background article for Canadian Aviation, September 1981.

The dimensions agree with those from John Clarke's site. Other specs are a weight of about 1900 lbs [865 kg[, top speed of 305 kts [350 mph, 563 km/h], range 435 nm [500 miles, 805 km].

According to Steacy, the point of the odd, tail-mounted capsule was to ensure an excellent view for the pilot in both level flight and while landing (for which the seat was lowered).

For a Merlin (listed as 880 hp), the exhaust arrangement seems odd.

 

[burunduk]

Thank you for nice pictures.

I'm too doubt that empty mass may be 865 kg. Merlin 61 weights 744 kg. Of course, earlier version are lighter, but probably more 600 kg. 8 Brownings weights about 120 kg (without ammo)

So, construction is less 150 kg? Impossible.

 

[Apophenia]

Agreed on weight. Steacy does say "Weight approx. 1,900 Lbs". But both Hurricane I and Spitfire I weighed over 4500 lbs empty.

 

[Maveric]

...some new details...

 

[Maveric]

Source: Luftfahrt International Nr-26

 

[cluttonfred]

It's very surprising to me that, if the AS.31 was really meant to be taken seriously a contender for F.35/35 or any other specification, Airspeed did not gin up some sort of proof of concept. An Airspeed Courier or a Miles or Percival monoplane of the time could have served as the basis for such a test vehicle to demonstrate whether or not the whole scheme had merit. Was something like that ever done?

 

[Arjen]

AS.31

Rarely has there been such a strange and ingeniously original aircraft project as the AS.31 fighter. This was a tractor monoplane, powered by an 880 hp Rolls-Royce Merlin E twelve-cylinder vee liquid-cooled engine, in which the tailplane, on twin tubular metal booms, carried the pilot in an egg-shaped streamlined nacelle. It was designed to meet Air Ministry specification F.35/35 and was the subject of Patent No. 470650 in the names of Airspeed and A.H. Tiltman. Amongst the advantages claimed for military purposes were a reduction in slipstream disturbance and drag in the area immediately behind the engine and propeller; a reduction in skin friction; and good fighting and flying view provided for the pilot, though this might in practice have been marginal in some circumstances.
Among the features of the AS.31 were a wide-track retractable main undercarriage (unusual still in 1936-era British military aircraft), a tailwheel retracting into the rear part of the pilot's nacelle, and the burying of fuel, oil, armament, coolant-radiators and such items as oxygen bottles in the thick-section cantilever wing. Eight Browning guns were to be buried in the outboard of the booms. Split flaps were fitted across the trailing edge of the wing between the booms, with wide-span ailerons outboard.
Curiously, no rudder or fin surface (apart from the nacelle itself) are indicated in the original prints from which the general arrangement, reproduced here, was developed. In level flight, the pilot's view, with his seat fully raised, was unrestricted above the wing and engine, and was restricted by little more than 9 degrees downwards on either side of the engine-nacelle cowling. With the seat in the lowest position the pilot's view under the wing and flap would probably have been adequate in the fully-flared tail-down attitude but questionable during the final approach and hold-off.

Span 33 ft (10.06 m); length 29 ft 6 in (8.99 m); wing area 195 sq ft (18.1 sq m).

"Airspeed Aircraft since 1931" by H.A. Taylor, Putnam, 1970, p.155.

35/35

High Speed Aircraft (Experimental)
See aircraft types below
File no. 460005/35/RDA.3 (S.36972)
Issued to Tender 7/12/35

This specification, in satisfying Operational Requirement OR.30, included the following statement:- "Since the time of the Schneider Trophy Race the problem of producing an aircraft in which all other qualities are sometimes sacrificed for speed has always been a matter of great importance." It appears that an aircraft armament of eight forward-firing machine guns may have also been a specification requirement.

Four firms responded with project designs to Specification 35/35. The best recorded design is that for the Airspeed AS.31.

The Airspeed A.S.31 was a tractor monoplane in which the tailplane, on twin metal booms, carried the pilot in an egg-shaped nacelle. No rudder or fin surface was indicated on the general arrangement drawing. Split flaps were fitted on the trailing edge of the wing between the booms, with wide-span ailerons outboard of the booms. A wide-track undercarriage was depicted. The aircraft was powered by a Rolls-Royce Merlin E engine. No details of its potential performance are recorded. Its wing span was 33 ft. and its length 29.5 ft.

The Bristol 151 project design is recorde as a high-speed single-seat monoplane, powered by a Bristol Hercules engine. Its speed, with 100 octane fuel, was estimated to be 440 mph.

The General Aircraft GAL.28 design was a single-seat high speed fighter project, powered by a single Hercules engine, with a wing of variable area.

The Hawker design was a Hurricane variant, with its engine coolant radiator duct in line with the leading edge of the mainplane, was recorded as being tendered on 21/2/36/.

-- Specification not proceeded with --

"The British Aircraft Specification File" by KJ Meekcoms & EB Morgan, Air-Britain, 1994, p.217.

 

[Maveric]

Anybody know more about the G.A.L.28? Drawings or technical data...

Thanks Maveric

 

[AeroFranz]

I was about to ask the same thing...
Thanks for the research, Arjen

 

[Arjen]

I'm digging...

 

[alfakilo]

The effect on the pilot when pulling g's would be interesting, given his location so far behind the wing.

 

[Stargazer]

A beautiful illustration scanned and cleaned up from Flypast, June 1987:

 

[hesham]

Hi,


the Airspeed AS.31,V.1,V.2 & V.3.


http://alternathistory.org.ua/taxonomy/term/889

 

[lark]

Is there any background for these AS.31 'variants'..

Alternate history always rings a bell to me...

 

[Jemiba]

If I understand the online-translation correctly, it states about those variants, that,
with regards to uncomfirmed information, they could have looked like this.
So it's source grade 1, at best I'm afraid and I would take them with a pinch of salt.

 

[lark]

Thanks Jens,

That confirms what I thought..

 

[hesham]

Via my dear Tophe.

 

[Schneiderman]

I don't know why the Putnam and others say that the AS31 was to be powered by a Merlin E, the drawings in the patent and company artwork clearly show four exhaust pipes for four banks of cylinders, so most likely intended to be powered by a Vulture. This make sense for an aircraft intended for high speed research

 

[hesham]

From L+K 22/1992.

 

[Grey Havoc]

I don't know why the Putnam and others say that the AS31 was to be powered by a Merlin E, the drawings in the patent and company artwork clearly show four exhaust pipes for four banks of cylinders, so most likely intended to be powered by a Vulture. This make sense for an aircraft intended for high speed research

Likely was intended for the main production version, if the go-ahead had been given.

 

[Schneiderman]

Likely not. The whole point of the specification was to come up with something superior to current fighters under development (Hurricane, Spitfire and the F.5/34 projects), top speed in excess of 400mph. Sticking a Merlin E in there just reduces it down to an also-ran

 

[Grey Havoc]

Wasn't the Merlin E originally supposed to have a higher horsepower rating than the 995hp standard (1,045hp maximum) it ended up with?

 

[Schneiderman]

Not that I was aware of. It was just one step along the road for the abortive ramp-head Merlins, 'C's with new heads and relocated plugs.

 

[PhR]

Design comparison between French Delanne 10 and English AS.31 concepts in 1938 magazines: Popular Mechanics and Modern Wonder.

 

[riggerrob]

Fantastic Plasctic will cheerfully sell you a 1/72 scale model kit of an AS.91. It was designed by Igor Shastekov's UKrainian-based Unicraft Company.

 

[Tonton-42]

Fantastic Plasctic will cheerfully sell you a 1/72 scale model kit of an AS.91. It was designed by Igor Shastekov's UKrainian-based Unicraft Company.

This one seems scratch built ...

 

[Schneiderman]

I don't know why the Putnam and others say that the AS31 was to be powered by a Merlin E, the drawings in the patent and company artwork clearly show four exhaust pipes for four banks of cylinders, so most likely intended to be powered by a Vulture. This make sense for an aircraft intended for high speed research

So........ignore what I said, the Airspeed GA blueprint clearly says Merlin E. I just overlaid drawings of the Vulture and Merlin on the blueprint and a Vulture will definitely not fit in the nose. Why the exhausts were led forward and then into four pipes is not at all clear (to me).