The Miles M-52 Research Aircraft was a truly stupendous
piece of design.
In 1943, the Ministry of Aviation asked Miles
Aircraft of Reading to design a research 'plane to a simple but very far-sighted
specification.
The 'plane should be able to fly at 1000mph after
diving from altitude to reach this speed.
Some say this was just a sop to Miles aircraft,
to make up for them not being given another more substantial contract,
but intelligence reports had convinced the authorities that the Germans
were working on research aircraft with this kind of performance, and the
choice of Miles to do the work had a lot to recommend it. For a start,
they had always produced aircraft that were 'a bit different' from the
norm, and quickly, too! Also, they were just down the road from the boffins
at the Royal Aircraft Establishment at Farnborough, and they knew more
about supersonics (at least, in theory) than anyone else in Britain.
So the M-52 was designed, in 1943, remember,
with the following far-sighted features:
1 An All-Flying Tail, to maintain pitch control
through and beyond the transonic region.
2 A true Supersonic Bi-Convex Wing Section, with
sharp leading edges, and very thin (for 1943) wings (I think 8% thickness/chord
ratio at the root and 4% at the tip).
3 Wing tips shaped to ensure that the nose shock
cone did not cut across the ailerons and disturb roll control.
4 A jettisonable nose section, to aid pilot escape
in the event of an emergency.
5 A Whittle designed jet engine with Reheat and
an Aft Fan (this is in 1943, remember).
Nowadays, no fighter would be seen without a
reheated fan jet engine, but in 1943, Whittle had foreseen the need for
greater mass flow and higher exhaust speeds without melting the turbines,
and had designed an engine to achieve these goals. I have seen films of
the engine undergoing testing, with very messy flames shooting out of the
tailpipe, so it was certainly nearing flight readiness on schedule, and
was no mere theoretical exercise.
At high speeds, the engine airflow was able to
bypass the turbine stages, becoming part turbojet, part ram jet, in much
the same way as, many tears later, the SR-71 engine achieved its high speed
thrust.
I am constantly amazed at Whittle's far-sightedness,
and, although he might be criticised for staying with a centrifugal compressor,
the Grumman Cougar and a development of the Lavochkin La-17 both flew supersonically
with essentially Whittle centrifugal compressor engines, so such an arrangement
was no fundamental hindrance to supersonic flight.
The tragedy of the M-52 was that it was cancelled, without warning, in early 1946, when construction was under way, with orders to break up the jigs and send all the design data to Bell Aircraft in the US. Since the 'plane would have been flying by the summer of 1946, and since later knowledge confirms that it would almost certainly have achieved its specified performance, I personally find it hard not to believe the British were 'Leaned on', to cancel the M-52, so that the US would be able to be the first 'through the barrier', which, indeed, they were in October 1947, thereby gaining not only the kudos of being the first through the barrier, but also gaining first hand knowledge of the aerodynamics of transonic and supersonic flight.
I am not, by nature, a 'conspiracy theorist', but there are many aspects of the cancellation which simply do not otherwise make sense, especially with regard to the 'official' reasons for the cancellation. It is as though word from 'on high' ordered it to be cancelled, and those involved with the cancellation (The 'Supersonic Committee', chaired by Ben Lockspeiser) had to think up vaguely plausible reasons for the cancellation.
Certainly, this hypothesis seems far more likely
than the 'official line', that we 'could not risk mens' lives' in this
venture, as we had already been risking them in high speed dives in Spitfires
for a considerable time, and the M-52 at least had a jettisonable nose
escape capsule, whereas the Bell X-1 simply had a 'side door', out of which
Yeager would have had to jump in an emergency, risking being sliced in
twain by the wing.
The other later-rumoured explanation for the
cancellation was said to be the discovery of German research showing the
advantages of swept wings in delaying compressibility effects, but, of
course, the drag coefficient of a straight wing actually drops below
that of a swept wing once the transonic region has been passed, and Miles
certainly knew this already, since the theory of wing sweep in delaying
the onset of compressibility effects, was already known.
Ackeret's work on the subject had been explained
by Taylor in a publicly available document published in 1932, and Dennis
Bancroft, Miles' chief aerodynamicist on the project, was well aware of
this work.
The RAE certainly should have known of
this work too, although it is not certain that the RAE representatives
on the 'Supersonic Committee' were actually aware of the work!
The design goal of the M-52 was 1000mph at altitude,
and so, being well and truly supersonic, Miles' decision to use a thin
straight wing was considered preferable to a swept wing if this design
goal was to be met, and it enabled the 'plane to be built without involving
still more unknowns with swept wings (which, incidentally, were
considered by Miles Aircraft at the design stage, and rejected for totally
sound reasons).
However, when the Supersonic Committee were discussing
cancelling the M-52 project, no-one appears to have gone back to Miles
to ask why they were not using swept wings, and, indeed, Miles' aerodynamicists
were not even aware that there was a Supersonic Committee!
Chuck Yeager has put on record that the
most useful contribution the Bell X-1 made was in establishing the need
for a 'Flying Tail' in order to maintain pitch control at transonic speeds.
Well, Miles Aircraft had already worked that
out, and had handed it on a plate to Bell Aircraft, who, 'In case the Limeys
were right', had duly beefed up their tailplane incidence trim system in
case it turned out to be needed for pitch control in transonic flight conditions,
which, indeed, proved to be the case!.
The M-52 saga is a tragedy of immense significance, and cost Britain the lead in practical first hand supersonic experience.
The two paintings are 'what might have been' paintings.
One of them shows the M-52 testing in a simple
cloudscape, and the other shows the 'plane beginning its descent from altitude
into what would have been 'The History Books', where the diminutive research
'plane might have been accompanied by two chase 'planes capable of following
it to altitude, namely the beautiful, but deadly (all three prototypes
crashed, killing their pilots) DeHavilland 108 'Swallow', and the Nene
powered Vampire, with its distinctive 'elephant ear' additional air intakes.
The pilot selected for the M-52 was Eric 'Winkle'
Brown, who fitted the bill as an outstanding pilot who was also 'compact'!
The top picture, entitled, "For Yeager, read Brown",
is now available as a very limited edition print of only 50 copies (if
I had been smarter, I'd have made it 52!), produced by the Giclee process,
and priced at £50 (plus p&p) for a 24"x20" print, with an image
size of 22"x14.5". The original painting is in oils, is 36"x24", and, to
my great pride, was sold to Captain Eric Brown, the designated test pilot
for the M-52. The lower picture is in oils on an
18"x14" canvas.