DH.99 Vampire prototype.

steelpillow · December 10, 2014, 03:20:31 AM

No, not the DH.100 Spider Crab, the one before that. DH actually submitted two parallel proposals for the "DH.99" single-engined jet interceptor, both all-metal. One was the well-known twin boom design that was re-engineered with a wooden fuselage as the DH.100 Spider Crab, later to be renamed the Vampire. The other was this little critter. It had much the same fuselage but a near-delta wing. It was in fact de Havilland's preferred design, and they had pressed ahead with it in order to parallel Halford's H.1 engine development and get something flying before the Ministry could get its act together. It was unofficially named the "Vampire" because its small twin fins were colloquially referred to in the design office as "vampire claws". After the Gloster "Whittle" it was only the second British jet to fly, providing Halford with valuable high-speed flight data that no other aircraft was able to. Despite all this, the Ministry's abiding mistrust of tailless types led to the selection of the twin-boom submission. They first named it the "Spider Crab". However, when this epithet was found to be a derogatory one dropped on it by a disgusted DH design office, they backtracked and stole the Vampire's name.

The design itself draws on the work of JW Dunne, GTR Hill and Alexander Lippisch. Turned-down wing tips and twin fins each have their advantages and disadvantages. The unique configuration of the original Vampire was designed to get the best of both worlds. The prototype had an unusually varied set of control surfaces. Internally, the control linkages could be adapted to vary the way in which they interconnected and synchronised during flight. The idea of this was to make comparative studies and discover the most effective arrangement for combat but, with the order passing to the other design, only the early engine test programme was ever carried out.

PR19_Kit · December 10, 2014, 04:48:49 AM

Oh YES!

I do like that, innovative thinking and well built too. How did you build it please, apart from the obvious Vampire nose that is?

Oh yes, love the serial's position too.

steelpillow · December 10, 2014, 05:36:12 AM

The front fuselage and some other bits of this 1:72 model come from a Frog Vampire. The rear fuselage and some of the wing structure come from a lousy rip-off of an Airmodel DH.108 Swallow vac-form that I was once conned into buying. Other bits are scratchbuilt. Essentially I built a supporting frame and covering skin to the wing, much like the real thing. There is a girder running right through the engine bay, behind the undercarriage. Used a mix of plastikard and hacked-about vac-form bits for most of all that. The paint job is a bit dodgy, my camera certainly bends the truth even if it doesn't lie! Most decals are home-printed, the P symbols sent to me by a very kind fellow modeller.

PR19_Kit · December 10, 2014, 06:21:53 AM

I'm even more impressed now.

Mixing vacform bits with injection moulded stuff isn't as straightforward as it seems, and I'm speaking as a veteran of many Airmodel 'conversions' here.

NARSES2 · December 10, 2014, 06:29:58 AM

Very nice

Tophe · December 10, 2014, 09:17:07 AM

Even if I love twin-boomers I am not jealous and I love your competitor on the drawing board turned solid!

steelpillow · December 10, 2014, 10:00:35 AM

Quote from: Tophe on December 10, 2014, 09:17:07 AM
Even if I love twin-boomers I am not jealous and I love your competitor on the drawing board turned solid!

Perhaps I should 'fess that the competitor on the drawing board is part of the whiff, though it was tempting to sit tight and wait for the meme to spread.

DogfighterZen · December 14, 2014, 06:09:31 PM

This looks great!!

IMHO it's just lacking GUNS!

But a fine piece of work anyway!!

Captain Canada · December 15, 2014, 09:20:24 AM

Oh yeah....there's a little beauty ! Love the shape and colours. Funny ( to me anyway ) how in the pics it looks like a totally different aeroplane from top and bottom views.

Off to look at the build thread......

kitnut617 · December 15, 2014, 10:05:35 AM

Um, the designation DH.99 was actually applied to the Sabre Mosquito before that designation got switched to DH.101. From what I've read, this was because it was an important spares pre-code number where all spare-part numbers started with - DH99 - and they didn't want any confusion (source: the Sharp/Bowyer book, Mosquito)

steelpillow · December 15, 2014, 12:09:46 PM

There is an original manufacturer's drawing of the DH.99, dating from 1941, in the National Archives. It shows the unmistakable twin-boom, single-engined Vampire configuration and is reproduced in: Martyn Chorlton and Tony Buttler, "De Havilland's 'First-Generation' Interceptor", Vampire:De Havilland's Twin-Boomed, Ground-Attack Jet Fighter, (Aeroplane Icons), Kelsey media (2004) Chorlton and Buttler give a good few details of the proposal's progress through the Ministry establishment. There can be no doubt that the meat of their story is true. But were all those Ministry documents indeed labelled "DH.99" or was that a historian's embellishment?

It would be most odd if a spares code was re-used, even odder if it was for two quite different aircraft projects. More likely, one or other source is at odds with what actually happened.

I would be interested to see the source acknowledgements for all these claims.

kitnut617 · December 15, 2014, 12:50:05 PM

Well, here's something else then to really confuse everything. Putman's De Havilland Aircraft since 1909 by A.J.Jackson, page 521, says DH.99 type number assigned to the Twin Sabre Bomber but in 1941 that was changed to DH.101 and that DH.99 was re-allotted to designs for a light twin-engine civil aircraft which J.P.Smith and the Moth Minor team had been working on at the beginning of the war. No mention of a previous Vampire project I'm afraid.

EDIT: I had a thought that maybe that jet project was actually a DH.109 (believe it or not, Tony Buttler has been known to make a mistake every now and then, one I found myself and quizzed him on it). So I did a google search, well this page seems to show you're right, but it also shows that there were three completely separate projects all which got allotted DH.99 but nothing about what the Sharp/Bowyers book says about DH99 (actually is says 99 was the parts pre-code number, not DH99)

http://en.wikipedia.org/wiki/List_of_de_Havilland_aircraft

zenrat · December 15, 2014, 02:58:03 PM

But that's in the real world.
Here in whiff world THIS is the DH-99.

It appears I neglected to say how much I like this.

I like this a lot.

PR19_Kit · December 15, 2014, 04:51:33 PM

Quote from: zenrat on December 15, 2014, 02:58:03 PM
Here in whiff world THIS is the DH-99.

steelpillow · December 16, 2014, 03:45:51 AM

Quote from: zenrat on December 15, 2014, 02:58:03 PM
But that's in the real world.
Here in whiff world THIS is the DH-99.

Yes indeed. In the real world the monicker seems to have got bandied around perhaps three different unbuilt projects in 1941. In the Whiff world, it finally landed on a fourth one that did get built. And I dare anybody in the real world to disprove that!