miles m.52

1943 miles got contract with air ministry to build turbojet supersonic research project

experimental

level supersonic flight

air ministry specification e.24 / 43

at least 1000 mph (1600 km/h)

super secret

feb 1946 programme terminated by new labour government of clement attlee

budget
ministry officials doubting practicality of supersonic aircraft

september 1946 announced to public and lots of criticism of decision to cancel

2 models using m.52 design

ministry of supply investigating design with different wing and control surfaces, rocket powered, 30% scale models. contract given to vickers and air launched from a modified havilland mosquito
same wing and control surface mach 1.38 in controlled transonic and supersonic, validating m52 design

w.b 2/700 turbojet also cancelled

shared to bell aircraft

bell xs-1 broke sound barrier 1946

belief before ww2 that supersonic flight was impossible

1930s few researches studying it

german research of a swept wing in drag reduction

became more believable they could do it after intercepted but misunderstood german speed performance

over 1000 mph level flight (at the time over twice the exisiting speed record)

36000 ft (11000m) in 1.5 mins

miles in charge of development and design whule frank whittle power jets company produced engine

miles cooperated and receieved assistance from royal aircraft establishment (RAE) and national physical laboratory

conical nose, very thin wings, sharp leading edges - contrasting with aircraft of the time

power operated stabilator / all moving tail / flying tail. different to elevators hinged on horizontal stabilisers cuz traditional design became ineffective or weekend at high subsonic speeds due to aerodynamic forces cause by shockwaves at the hinge and rearward movement of centre of pressure

control reversal when flight inputs (rudder, stick) switch direction at high speeds - huge issue at the time was cause of many / near accidents

all flying tail needed for non delta winged aircraft to pass subsonic without loss of control, m52 first example of this

augmentor fan directing excess airflow around the engine through a bypass duct and combustion of fuel in bypassair behind the fan. gave another 1600 lb of thrust

worry that bioconvex wing would not give sufficient altitude for testing diving aircraft. could be made thicker or have a section added to increase wing span, but then worry about more drag from weight and wing width

small undercarriage made it dangerous for landing speed but compromise they made

aircraft made of high tensile steel and light alloy covering

fuselage

cylindrical
5 ft diameter
annular fuel tank around engine
cg close to airframe
wings attached to main structure aft of engine
shock cone so conical shockwave from nose produced lower loss in ram pressure for engine than a supersonic aircraft pitot (way of measuring pressure) intake
retractable tricycle undercarriage used with folding out wheels at the tip of the plane (in cockpit)

biconvex wings, jakob ackeret low drag gillette

wing tips clipped to keep them clear of the conical shock wave generated by aircraft nose

wide chord ailerons split flaps

centrifugal flow jet engine

research aircraft so was gonna have flight instrumentation, instrument readings photographed automatically, structurals train gauge readings on an oscilloscope

simon whistler docu

miles reputation for reliable and cheap aircraft during wartime

innovation low tech aircraft during the 30s and wartime

created primarily trainers for raf such as master, magister, martinet

good cuz raf needed cheap cuz of money being spent during the war

handley page, avro, vickerarmstrong all approached to help design it but very shocking cuz miles got the contract

huge task for miles and the aircraft industry at the time

intended to match what they thought the german messerschmitt me 163 + 262 could do, but it was actually a mistranslation cuz intercepted german comms said kph and not mph which is what we use

no existing researach done on this

drag and speed most important, cuz needs strong thrust and aerodynamic

miles were pioneers cuz no prioir info on what they typically desiged so used to referring to other things for refence

study in 1943 on spitfire performance showed that thick flat surface (curved nose, thick wings, hinged elevators) caused lots of drag, so they knew they had to replace that

looked at bullets cuz they broke the sound barrier all the time specifically spitzer pointed bullets, 19th century which are faster and more stable that flat tipped bullets

pointed front on m52 allowed shock wave to form on apex and directed to lip of intake, ensuring airflow to engine and improving supersonic performance

pointed shape in front of intake called intake cone is used in high speed jets including fastest jet ever the lockhead

unique to m52 - cockpit in the tip so fuselage could be smooth and aerodynamic

detachable cockpit cuz of unpredicatable nature of the plane

explosive bolts and then parachute

wings

max lift, min drag
jakob ackeret swiss aeronautical engineer suggested biconvex wing design which would produce very thin but strong wings, minimising drag
lots of aircraft testing found the pefect wing
called gillette wings cuz of the razor brand
small aspect ratio, opposite to gliders
sharply angled at tips as pointed tip of plane created shockwave which affected air flow over typical wings

fuel tank

wings too small to put fuel tanks on
diameter of fuselage affected largely by initial low pressure fan and compressor and turbine exhaust casing, which was a lot broader than later high pressure compressor and combustion chamber
empty space around middle of engine that fuel tanks could be shoved next to

wind tunnel testing and spitfire study showed that hinged elevator / control surfaces proved inefficient in transonic speeds therefore awful for supersonic

force exerted on control surfaces by fast air generate more force than can be exerted by the pilot

control reversal - physical and pyschological phenomena which caused controls to either act differently or feel like they act differently in fast flights

miles invented ‘all moving tail’, added motor to control surface’s acutators to augment the force that could be exerted on the control surface by the pilot

power jets w.2

latest engine from legenddary from frank whittle
expansion of jets w1 the first british jet engine to fly
trailblazer for the time, eventually developed into rolls royce derwent
dated for the time
miles team knew the limitations of engine - unrefined and untested
did the math predeicted the w.2 would take it to transonic speeds but not supersonic but they had to prioritise costs and resources and time restraints
immediate focus was on getting engine fitted and getting airframe flight worthy. generating excess power for supersonic was a problem for later
planned to add a reheater to the engine at a later date. jet engine combusts with a surplus of air of which not all is combusted. reheated mixes fuel with excess oxygen downstream of the turbine power, then combusts and increases overall thrust produced
reheating invented beforehand on the italian caproni campini cc2 in 1941
miles did innovate using an augumenter fan driven from engine shaft to efficiently draw air into support the combustion of the reheated. tested in gloster meteor in late 1944 and showed promising results
eric brown historian of miles m52 believed this modified engine would take m52 to 1000 mph

not straightforward to make. m52 design changed many times due to uncertain nature of the task and having to seek help from so many different engineers and designers

e.g., wing team worried about the thin wings and wanted more traditional thicker wing design, while engine people worried that more drag and weight from the wing would mean more power output from an engine that is already being pushed to its limit. solutions proposed

launching from high altitude lancaster bomber
rocket assistance for takeoff and level supersonic run

never settled cuz project was cancelled

problem was high landing speed approx 160 - 200 mph

normal for high peromance jets but rlly bad for the time

spitfire landing speed only 110 - 120 mph

thin landing gear profile making aircraft very top heavy and unstable during landing

not solved because wings were so small and thin they couldn’t put landing gear on otherwise the wings wouldve widened landing gear profile and therefore making plane more stable. eventually realised they just had to deal with it

progressed well reached stage could be testedd

miles m3b falcon six modified with proposed wing shape and undercarriage, calaled the gilette falcon

august 1944 fly, during testing it went well. wing area reduced by 12% yet produced good lift in low and high altitude

not good cuz landing speed increased by 40 to 61 mph and also was unstable in landing cuz of undercarriage

still promising enough to keep testing

spitfire was fastest aircraft available to miles at the time. fitted with all movement tail and high speed testing from october to novemeber 1944, spitfire repeated high altitude high speed dives to test to test responsiveness of tail control surfaces at transonic speed

peaked at mach 0.86 (660 mph) huge success

all appeared to be good

end of 1944 design was 90% complete and air ministry gave go ahead for 3 full model prototypes to be build

prototypes never finished or fly

first one 82% complete and was set to fly in a few months time. proposed test programme, mach 1 by end of 1946 after series of subsonic test flights

m52 cancelled killed miles aircraft. no training aircrafts needed anymore so put all their money in m52 to hope to be a pioneer in high speed air travel. when government funding cut off miles sold their assests to handley page in 1947

director of scientificed research ben lockspeiser cancelled project in 1946

pilot safety
cost overuns
budget cuts
recent german research of swept wings being better for supersonic flight

other potential explanations, conspiracy

caused by american pressure as they wanted their bell xs-1 to be the first supersonic aircraft. rocket engine inside bell xs1 as opposed to m52. 1944 british government agred to exchange high speed research data, but britain sent off more than it ever recieved, xs1 started development after american delegation visited miles m52 being produced. no proof that they were given plans and the delegation did not work for bell, but after that bell also happened to create the same all movement tail
sabatogaed by barnes wallis who made bouncing bomb. theory - believed future of supersonic aviation to be in rockets and aerplanes was no longer gonna be used in combat cuz of that. aircraft was an issue after ww2. wallis used his influence to kill the m52 and take funding for his own ideas. given more funding for rocket testing after m52 cancelled, but still a conspiracy and maybe he was just lucky

global alliances shifting after ww2, post war politics

break mach 1 in level speed, faster than speed of sound

new frontier in high speed planes to outrun missiles

wondered if necessary to spend money on this when post war reconstructions were necessary

afterburning engine concept

frank whittle w 2 7000

centrifugal compressor design engine, made with strong cutting edge materials and high temperatuer resistant casing to withstand conditions of supersonic flight

w2700 2000 pounds of thrust, reheat (Afterburner), augmenter duct added (specifically designed fan) that would give an additional 1600 pounds of thrust, therefore 3600 total

air would successfuly go around the engine and fuel could be combust without overherating any components - working on this

aimed to produce sustained thrust allowing it to accelerate, maintain level mach 1 flight, and maneouver making it different to rocket powered designs which has short bursts of acceleration. steady power output miles

set benchmark for future jet designs

superstonic stability. people thought flying at mach 1 would rip plane apart or cause sever turbulence - soloution was all moving tailplane

shock waves can form on hinged elevators causing them to be ineffective or destructive. all moving tailplane allowed for full pivoting tailplane, maintaining control authority during subsonic speeds. same technology used by bell. bell was rocket powered not turbo jet

shock waves and boundary layers formed on fuselage so miles made m52 more curved to reduce drag

pilot ejection module cuz super risky going at mach 1

british people upset about it being gone because it wouldve been a testament to british science but instead documents probably taken to bell

x1 rocket powered

better to have turbo jet cuz you have enough thrust to constantly accelerate, maintain level speed, and even climb, which are different to rocket powered planes which struggle to sustain doing any of that

about sharing research, it was tough cuz england had way more research it was giving to america that it didnt seem fair. engineers were upset cuz all their hard work going to america meanwhile it was apparently to increase good relationships between america and england

Following the cancellation of the M.52, the Government instituted a new programme involving "no danger to test pilots and economy in purpose." This was another way of saying that it was planned to use expendable, pilotless, rocket-propelled missiles. The Royal Aircraft Establishment was responsible for the development of a suitable rocket motor and in charge of aircraft design was Barnes Wallis from Vickers Armstrong - the father of the "bouncing bomb" and the 12,000lb "Tallboy" earthquake bomb

The rockets were 3/10 scale replicas of the M.52 and the first launch took place on 8th October 1947

A light bomber took off from RAF St. Eval in Cornwall with a rocket strapped to its belly but the motor exploded shortly after launch. Following this, and the success of the XS-1 the Daily Express took up the cause for the restoration of the M.52 programme, but to no effect

In October 1948 a second rocket was launched. This was successful and a speed of Mach 1.5 was obtained. But, instead of diving into the sea as planned, the model ignored radio commands and was last observed (on radar) heading out into the Atlantic.

The final touch of irony came when even these rocket trials were suspended, the reason being, "the high cost for little return". The total dividend from this investment was the information that a small scale model of the Miles M.52 had successfully broken the sound barrier. But, the United Kingdom had already lost the chance of being the first nation to achieve piloted supersonic flight.

Crew: 1
Length: 28 ft 7 in (8.71 m)
Wingspan: 27 ft (8.2 m)
Diameter: 5 ft (1.5 m) fuselage
Wing area: 143 sq ft (13.3 m²)
Aspect ratio: 5:1
Airfoil: bi-convex – root : 7.5% thickness ; tip: 4.9% thickness
Gross weight: 7,710 lb (3,497 kg)
Fuel capacity: 200 imp gal (240 US gal; 910 L) / 1,600 lb (730 kg)
Powerplant: 1 × Power Jets W.2/700 turbojet engine with augmentor fan and afterburner, 2,000 lbf (8.9 kN) thrust at sea level dry

3,200 lbf (14 kN) with afterburner for take-off

4,100 lbf (18 kN) with afterburner at 1,000 mph (870 kn; 1,600 km/h) (M1.5) and 36,000 ft (11,000 m)

Performance

Maximum speed: 1,000 mph (1,600 km/h, 870 kn) at 36,000 ft (11,000 m) after a dive from 50,000 ft (15,000 m) (M1.5)

705 mph (613 kn; 1,135 km/h) with augmentor at sea level

585 mph (508 kn; 941 km/h) without augmentor at 30,000 ft (9,100 m)

Best climb speed: 600 mph (520 kn; 970 km/h)
Time to altitude: 36,000 ft (11,000 m) in 1 minute 30 seconds
Wing loading: 52 lb/sq ft (250 kg/m²)
Take-off run to 50 ft (15 m): 4,650 ft (1,420 m)

miles m.52

See also