Updated 17 June 2018
Part history, part fantasy. These are my might-have-beens, my "What-ifs".
“The MacRobertson Interceptor” According to an American contemporary, the British Government will seriously consider the adoption of the winning machine in the England-Australia race for modification as an interceptor fighter. – Flight, 7 June 1934, p.560.
The MacRobertson Air Race was won by de Havilland Comet G-ACSS Grosvenor House. The Air Ministry did indeed buy the aircraft afterwards, gave it military registration K5084 and had it painted standard silver with RAF markings. It ws then flown to Martlesham Heath for evaluation. The fighter idea was dropped because by now two new monoplane interceptors were taking shape, powered by the equally new and far more powerful Rolls-Royce PV-12 engine - to become familiar as the Merlin-powered Hurricane and Spitfire. De Havilland proposed a fast bomber version, which was also turned down at the time but would eventually resurface as the famous Mosquito of World War II.
But I knew nothing of the Comet's history beyond the original race, when I was walking past my local model shop one day and spotted an Airfix kit of one in the window. It occurred to me just how similar in size it was to the Hurricane and Spitfire, which had been under development at the time of the race. Both of those fighters were to be powered by the Rolls-Royce PV-12 engine, also in development and soon to be renamed the Merlin. And it was obvious from the kit artwork that the Merlin would fit the Comet like a glove. I wondered "What if?", went in and bought the kit.
So here is K5084 after undergoing "modification as an interceptor fighter" to become the prototype de Havilland DH.88A Meteor:
Its two Gipsy Sixes and the forward fuel tank have been replaced by a single Merlin. The wing is modified with the middle spar moved forward, not only to accommodate the now inward-retracting undercarriage, but also to slip through past the engine firewall without positioning the engine off-balance. The original undercarriage attachment points on the inboard side are re-used but reinforced for the single-leg design. Behind them the landing flaps have been extended outboard. Note the "proto-Mossie" style wing-mounted glycol radiators, re-using the attachment points for the engine firewall and mounting frame, and the faired-over rear seating position.
Note also the de Havilland-style chin intake for carburettor and oil cooler. The small underside bulge in front of the wheel wells is the engine air intake duct, showing how snug the fit of the Merlin had to be. The offset rectangular vent in front of that is the oil cooler air outlet; similar outlets under the wing-mounted radiators mirror the Comet's arrangement on top, to double the airflow capacity of the radiator exit ducting.
Top speed was almost doubled, to slightly above that of the contemporary Spitfire prototype K5054 with the equivalent development Merlin. This was due in part to the ruthless reduction of frontal area being carried through from the racer to the interceptor. Manoeuvrability was less due to the higher wing loading and greater span. The propeller seen here is an early flying prototype of de Havilland's variable-pitch type. It is perhaps the main reason why K5084 beat K5054 in the speed stakes, as at the time the RAF still had the mindset of the fixed-pitch era and the Spits and Hurries would not receive the benefits of variable pitch, in three-bladed form, until some years later.
In the event, the Meteor came just too late and the early success of the Hurri and Spit meant that a third option was not needed and it was canned. Changes planned for the production version at the time of cancellation included eight Browning .303 gun positions (three in each wing and two below the engine on either side of the air intake), further repositioned landing flaps and modified wing outer sections to address the Comet's appalling stall characteristcs.
The model inspired a historical novel, as yet only half-written, and it was while researching the history of the Comet that I stumbled not only on K5084 but even on the MacRobertson Interceptor, discovering how astonishingly close to the truth I had come.
The de Havilland Aircraft Company was in a privileged position at the start of WWII, making both aircraft and engines. Geoffrey de Havilland and his engine designer Major Frank Halford were invited to watch a flight of Britain's first jet aeroplane, the Gloster "Whittle", and were then asked to design their own jet fighter and engine. Halford's H-1 engine proved a winner and was borrowed by both Gloster and the Americans to get their prototype fighters into the air, even before de Havilland's odd little twin-boom fighter was ready to receive it.
In the middle of all this, the DH.99 designation got patched onto several designs including the first, all-metal stab at the fighter which later became the part-wooden DH.100 Spider Crab and then the DH.100 Vampire.
Meanwhile de Havilland's old pioneer colleague and predecessor in his first job at Farnborough, J. W. Dunne, got back in touch to lobby for a tailless, swept-wing fighter of the type he had once made his own and which had been further developed by G.T.R. Hill with his Pterodactyl series until work was stopped in 1934. It was known that Germany was working on just such a project, which would emerge as the operational Messeschmitt Me163 Komet rocket fighter. DH would respond to the Komet with their own tailless jet, the DH.108 Swallow, after the war was over.
What if DH had followed up on Dunne's initiative and launched a tailless jet project some four years before they actually did so, updating Hill's work and in the middle of all the naming muddle designating it as yet another DH.99 hopeful? The result might well have looked something like this, its small twin fins earning the nickname "vampire claws" and making it even more obviously a Vampire than the competing design which won the day and stole the name:
The model won me the odd prize and even found its way to the IPMS national competition finals in 1981.
Meanwhile NASA had commissioned Rockwell to create their HiMAT - Highly Maneuvrable Aircraft Technology - unmanned research aircraft. When the design was released, to my astonishment it was effectively a small-scale prototype of my XF-28!
More backstory at http://www.whatifmodellers.com/index.php/topic,39605.html
Much to my surprise yet again, the HOTOL Project and Technical
Burns, took the idea seriously enough to write a letter in reply, which
was published in Issue No.25,
March 1987, Page 31. He questioned in particular the high capital
cost of developing a purpose-designed carrier aircraft – probably quite
rightly at this stage of the concept lifecycle. I have other
correspondence which shows that this was no off-the-cuff response but
B.Ae had already given the idea serious thought before I came on the
Meanwhile I had revised my design to use some of the more powerful
jet engines that were becoming available. This study is published here
for the first time:
At that time, Boeing were developing a stretched variant of their 747 jumbo jet. I reckoned it would just about be able to heft a HOTOL – in fact I had stolen its engines for my redesigned carrier. So in response to Burns' letter I dropped my purpose-designed carrier and started to plan a 747 conversion. I soon found that others closer to the project had already had much the same idea, so I gave up.
B.Ae's attention was later drawn to the Antonov An-225 Mriya (Dream), built to ferry the Russian Buran space shuttle around. It was huge, bigger even than the stretched 747. When British government interest in the military potential of HOTOL waned, it allowed B.Ae and Antonov to join forces. Sadly, nothing more than a design study and a few models (not mine) ever came of it.
For more about all this, see http://www.secretprojects.co.uk/forum/index.php/topic,277.msg234984.html#msg234984