The Miles M52

The world-beater that didn't quite get there...

I write this as an extension to my previous piece on the subject of experimental aircraft, in particular the Gloster Pioneer. I was reminded whilst writing that brief history of the unfortunate tale of the Miles M52.

As you will know, I have built several experimental aircraft now and am looking at the possibility of scratch building this aircraft. In terms of what I understand as “scratch building” this would be something of a departure in the sense that every component would be made from polystyrene sheet, rod or bar rather than my more usual method of finding a pre made kit and creating enhancements that add some visual interest to the model. Such a project I suspect would be quite an undertaking and I wonder if using a resin 3D printer for some of the parts might be a good route to take.

Accordingly I have decided to take a look at the range of available printers and I have come up with some options which I am going to investigate and see how I can use this new (ish) product to build and enhance my projects. Perhaps I may be able to make something unique reasonably easily and at a cost that might not be too astronomical. The key area that I want to explore is the software that these devices use. I want to see how easy or intuitive the interfaces are. If the software is as easy to use as the Cricut package, then 3d printing may be a very good way to upgrade the more common pre moulded models that we all buy and build. This may take some time, but you will hear from me on this again…

In the meantime, I think that a brief history of the M52 might be in order. Perhaps some of you may be vaguely familiar with this aircraft. In the early forties, activity to develop jet aircraft was well under way with the Gloster Pioneer already flying and the war office looking hard at the benefits of developing jet flight. This interest extended also to looking at civilian aircraft and to the future requirement to develop these to maintain a leading edge position in the fledgling air transport industry after the war was concluded.

Miles’ one and only jet aircraft was the result of the RAE specification E24/43 which was quite short and simple. It requested a research aircraft built around the second Whittle engine- W2-700 with number 4 augmentor, (a reheat unit) capable of 1,000 mph at 36,000 feet. It should take off and land under its own propulsion, (no auxiliary aircraft launch vehicle or rocket assistance should be used), and also travel at 800 MPH at 18,000 feet. To suggest that this was ambitious is understating things a little. Most propeller driven aircraft of the time were travelling at speeds of less than half this and beginning to experience severe problems operating at what might be described as “at the edge of the envelope.” What was understood at the time about compressibility and trans sonic travel was, at best, sketchy. The maximum speed recorded by a propeller driven aircraft was Mach 0.92 by a Spitfire PR Mk9 and travelling at this speed, the controls were rendered almost unusable owning to compression effects.

Indeed, it was surmised in some quarters that the sound barrier was exactly that- an impenetrable wall. The RAE suspected, (and I use this term deliberately) that the effects of drag would be very significant, perhaps as much as 10 to 20 times as large at mach 1.1 compared to mach 0.9.

However, it was known that projectiles from weapons travelled at very high mach numbers and experiments were done to assess the drag characteristics of such projectiles which gave some confidence to researchers that the sound barrier may be an attainable velocity and that the drag characteristics between mach 0.9 and mach 1.1 would in fact be perhaps a factor of two to four. This led somewhat to the design of the M52 following the shape that it did which is rather like a bullet.

As it happens, the appointment of Miles Aircraft to the role of contractor for the development of the specification was seen by some as surprising. Miles had hitherto not been involved in advanced combat aircraft, instead having gained a reputation for elementary and advanced trainers. The reasons for the appointment (amongst others) appear to have been that Miles was situated in Reading, not far from the RAE, so liaison would be easy and also that Miles had spare capacity to develop an aircraft of this kind. Another key point was that Miles would have easy access to supersonic wind tunnels which would certainly be required to evaluate the performance of a small model of the design that Miles were to produce. Also, at that stage, all of the other manufacturers who could be considered were fully engaged in producing aircraft for the war effort. So one might say that Hobson’s choice seems to have been the order of the day.

Miles wasted no time in producing a design and settled on an unswept biconvex wing and an innovative cockpit in the form of a capsule which could be detached in the event of a catastrophic failure of the aircraft. The air intake ducting formed an annular ring around the rear side of this cockpit assembly and lent the whole aircraft a very streamlined look.

A test pilot was appointed at a quite early stage and was none other than Eric “Winkle” Brown whose reputation survives to this day and whose capability as a test pilot was nothing short of legendary. He is reported as being excited to undertake the test program and took a keen interest in the development of the project from a very early stage.

There were a number of practical issues to overcome in flying an aircraft from a standing start to supersonic velocities, not the least of which is that the wing sections required in each regime are somewhat different- high lift at low speeds and balanced characteristics in the trans and supersonic areas. Miles designed a very slim wing section with very sharp edges for the mainplane and tail section and deployed the specified “all flying tail.” It was necessary to test the wing section to ensure that it was suitable and, to this end, the proposed design wings were fitted to a Miles Falcon trainer in order to fully establish their properties. It was noted that they performed well at low speed which was most encouraging despite their very sharp leading and trailing edges which caused injury to ground handlers earning the aircraft the name “Gillette Falcon.” Covers were quickly made to prevent further cuts and scrapes to those moving the aeroplane around.

It should be noted that it was clearly seen that the development of jet aircraft had the potential to open a door to trans-sonic and supersonic travel. Development of such aircraft was going on simultaneously across the world amongst both allies and axis powers. The USAAF was working hard to develop a rocket powered mach 1 capable craft and had encountered problems of their own. Even though the designs of the Bell X1 and the Miles M52 were similar, the X1 required to be launched from the belly of a larger aircraft which considerably limited its potential as a viable interceptor or fighter, so the Americans were considerably interested in the M52.

This led to a what has been described as a “fateful meeting” in 1944 where the developing prototype was shown to a party from America and the “all flying tail” principle was disclosed to the visitors. The knowledge that the new elevator configuration would assist flying at trans-sonic and supersonic speeds considerably advanced the development of the Bell X1 and within a short period (in development terms) it was able, under the control of Chuck Yeager, to surpass the sound barrier for the first time in history.

The fate of the M52 was not as fortunate however. There have been occasions in history when politics and politicians have interfered with experiment and development of jet aircraft- the TSR2 was another example with which you may be familiar. Various excuses are proffered for this cancellation which with the benefit of hindsight seem weak, but there is perhaps some reason to think that foreign interests had something to do with the end of the E24/43 project.

The Miles M52 was an example of a test bed that it seems likely would have surpassed the sound barrier during the Second World War and, not only that, would quite likely have been a test bed for the development of further engines and probably swept wings amongst other things. A scale model that was launched from a Mosquito (just off the Isles of Scilly in fact) shortly after the war (1947) reached a speed of 938mph in level flight. My own view is that this certainly proves the case for the full sized M52 as the model operated well in all three key areas (sub sonic, trans sonic and supersonic) with the measured drag characteristics being significantly less than the suggested Miles estimates made some years beforehand.

As is usual when development is ceased under these circumstances, the design jigs were destroyed in addition to the aircraft themselves. The reason for this is clearly to ensure that the project cannot be reinstated at a later date. It is of note that the 1,000mph barrier was not finally surpassed until 1956 when Peter Twiss flew a Fairey Delta 2 to a speed of 1132 MPH. This extended the previous speed record by 300 miles per hour. Imagine for a second what might have been had the 1,000 mph barrier been breached some fourteen years earlier.

An opportunity missed.