Biplane Hurricane?

i do recall the ‘biplane’ hurricane was featured in a war comic back in the late 1950s – characters were depicted gazing skywards comment on same and uttering ‘strewth’ etc

i wonder if anyone can add to this comic recollection

A very interesting article, in fact the fullest account I’ve ever seen of this project and the most photos too. Coincidentally, The window where I’m typing this looks towards the former RAF Sealand and the very extensive Dee Marshes. I believe Sealand was chosen because the nearby marsh only floods with a very high tide and thus it would be fairly easy to recover the jettisoned wing for reuse. I have yet to confirm whether or not the wing was ever slipped on a test from Sealand. From the background terrain, one of the photos was almost certainly taken at Sealand.

Yep, that is the Hurricane with the slipping for long range ferry flights. Was tested in fixed configuration and the wing was supposed to be jettisoned if needed, like a long range tank. Jettison was never tried though, and the aircraft design and operational needs overtook this development.
Would have loved to see it fly though…
Chris

Johnny Skyrocket,s Vampire jetliner looks interesting too !!!

Ron

IIRC it was called the ‘Hillson slip wing Hurricane’ and was a second wing full of fuel for long range ferry flights to the Middle East…more pictures here I think it might even have been jettisonable, but wouldn’t fancy trying that myself!

Hi Warren,

No it is not a hoax.

Cheers,

Daniel.

It’s either CG or a Photoshop job. Difficult to say being so small.

In the 1920’s W S Gray put forward the idea of a ‘scrap-wing’, later termed ‘slip-wing’. An auxiliary airfoil would enhance lift on take-off and then be jettisoned. Gray talked of a mechanism to stow the wing. As the biplane prevailed at that time the idea was not developed.

From 1938 until late 1940, Blackburn investigated ‘lift augmentation devices’ which included the ‘scrap-wing’ theory. Under the guidance of J H Steiger (designer of the Monospar) Blackburn carried out trials on a converted Miles M.5 Sparrowhawk which flew briefly from February 1940.

F Hills and Son were a Manchester based woodworking company that dabbled in aeronautical matters under the name Hillson. The first venture was a Mignet HM Flying Flea which flew at Manchester Barton in October 1935. A small production under licence of the Czech Praga E.114 Air Baby was begun in 1936. 28 were completed with the name Hillson Praga. Two designs by Norman Sykes, the Pennine in 1937 and Helvellyn in 1939, did not progress from the prototypes.

At the outbreak of war, Hills and Son became a sub-contractor for its neighbour Avro for Anson Sub-assemblies. They were also kept busy with the manufacture of propellers. W R Chown, Managing Director, alongside Blackburn, became interested in the ‘scrap-wing’ theory. He advocated a simple-to-build, easy to maintain and store, fighter that could be produced in large numbers and operated from a wide range of fields. Augmented lift was the answer and Hills’ chief designer Norman Sykes was set the task. The AM was not convinced and would not back a full size prototype. Instead, a scaled down, flying test-bed was to be built, and if trials were successful, a production fighter would be modified. The Hurricane was chosen as the production fighter.

The scale test-bed, the Hillson Bi-Mono, has been described as not unlike shrunken Hurricane in appearance. How much official recognition it received is not clear as it was never allocated any kind of serial number or ‘B’ condition identity. Construction of the upper wing had to be to the same standards of airworthiness as the rest of the airframe which made it an expensive item to throw away. It was hoped that inter-plane struts would not be necessary to avoid complicating the separation. This proved too complex to achieve.

A model was tested at the RAE wind tunnel at Farnborough. These tests were successful proving that separation was simple and did not put the tail assembly at risk. A wide range of speeds were evaluated and it was found that this was not a major factor in deciding when to release the wing.

Flight testing commenced at Barton in early 1941, in both configurations. Wing dropping trials followed but these were carried out from Squires Gate as the wing was too large, and potentially lethal, to drop over land. Over the Irish Sea was safer. Flown by P H Richmond and followed by a Hudson full of observers the first live separation look place on 16th July 1941. During the process the aircraft dropped a couple of hundred feet.

Testing was also carried out by the A&AEE at Boscombe Down but by this time thoughts had faded away of a purpose-built, short-field fighter and the project was shelved. It was decided to develop the theme by adapting a Hurricane to see if there was a place for such a modification within RAF operations.

At the RAE, on 13th April 1942, a former RCAF Hurricane I, serial 341 (formerly L1884), was allocated to be used by Hills. It was taken to Barton where it was converted under the company designation FH.40. The second wing was essentially the same planform and airfoil sections as the Hurricane’s but without ailerons or other internal fittings. Including the release gear and struts the biplane weighted an extra 693 lbs. N type inter-plane struts supported the wing with extra support struts from the top inter-plane strut to a location just below the cockpit. Jettison gear was electrically actuated, with mechanical backup and warning circuit. On the ‘real’ mainplane, the ailerons were increased in area by 10% to impart better control when configured as a biplane.

Testing was successful, once again conducted over water, this time from Sealand. All trials were conducted under the charge of the A&AEE. The FH.40 was noted as being under repair after an unspecified accident in February 1944. It was ready for collection for the following May, but nothing else is known of its career, or fate.

As for Hills, its main contribution for most of the war was the construction of Percival Proctors, when Percival’s Luton production line was switched to Mosquitoes.

I believe the company Hillman is responsible for this, so also investigate the Hillman Bi-mono.

Close, it was the Hillson (Hills and Son) company that built the slip wing and Bi-mono.
The idea for these experiments came I believe from Noel Pemberton-Billing who proposed slip wings bombers, carrier wings and towing fighters as gliders to extend their range, and lets not forget his WW1 quadraplane Zeppelin fighters that couldclimb or fly as fast as a Zeppelin.
Pemberton-Billing may have come up with some odd ball ideas but calling his firm Supermarine was one of his better ones.

I believe the company Hillman is responsible for this, so also investigate the Hillman Bi-mono.

Yes, it was to extend the ferry range, I suspect with non-stop trips to Gibraltar in mind or perhaps Gib to Malta. It would be a supply nightmare getting lots of spare wingsets and struttery to every Hurricane operating base.

Slip wing Hurricane

I was under the impression that this idea was for increased range , and the top wing was in fact a fuel tank

For those who want a short cut version.. Slip wing Hurricane. basicaly trying to think ahead to if part of the airfield got destroyed and the aircraft require a shorter take off run.. the top wing would be detatched in flight although i dont think this part of the testing took place.. the top wing being a lift platform only with no controls being run through it as in a biplane

Did the picture “clearly” show it to be in flight? There was a lot that could be done to alter photos long before the day of PhotoShop.

That aside, might Henniker’s reference have had anything to do with the fact that the Hurricane was initially bruited about as “the monoplane Fury,” and that perhaps this was preceded by a retractable-gear Fury proposal?

Thanks for that but I still couldn’t find anything of substance about it one report said it was not flown but the picture clearly shows it in flight, I was wondering what became of it was it returned to service or scrapped?

Plenty of info to be found, under ‘slip-wing Hurricane’.

It followed on from this idea;
http://en.wikipedia.org/wiki/Hillson_Bi-mono

Here’s an interesting read about the general concept;
http://airminded.org/2007/04/18/a-sister-to-assist-er/

You can even build the kit!;
http://www.pmilona.cz/lang-en/modely-1-72/1279-hawker-hillson-slip-wing-hurricane.html

Cheers,
Matt