by Colin Downes
In 1947 Miles Aircraft ran into financial difficulties and in 1948 the Woodley factory and airfield became part of the Handley Page Aircraft Company which was Britain’s oldest aircraft manufacturing company dating back to 1909. Handley Page produced the Hampden and Halifax bombers during the war. In the post-war years Handley Page produced the Victor ‘V’ bomber, the Hastings military and the Hermes civil transports and high speed research aircraft at its design and production facilities at Cricklewood and Radlett. The company had no experience in designing or producing small, civil aircraft, therefore, on taking over the Miles Aircraft facility at Woodley, Handley Page used the Miles Marathon to enter the medium civil-transport market and the aircraft , now called a Herald, became a fifty-passenger civil airliner and a military transport powered by two RR Dart turbo-props. My own view is that Handley Page, with its experience in the design of bomber and military transport aircraft, would have been more successful with its small eighteen passenger commuter or executive turbo-prop Jetstream had the Miles company been involved in the design and development of the aircraft. Of all the many Miles aircraft projects the most interesting for me was the Miles M-52 reheated jet-powered experimental aircraft intended to break the sound barrier in level flight with a speed of 1,000 mph at a height of 36,000 feet. The authorities at the time, no doubt influenced by the loss of Geoffrey de Havilland while flying the DH-108, favoured an unmanned aircraft to achieve this as it was considered to be too dangerous for the pilots involved. Subsequent test flights with air-launched rocket propelled scale models of the M-52 demonstrated the feasibility of the project by achieving speeds in the region of Mach 1.5. During 1946 a pusillanimous Labour government decided that budget restraints made the undertaking too costly. With this and the danger factor in mind they decided to cancel the piloted M-52 project. Miles had made provision for the safety of the pilot with the unique design of a detachable pressurized cockpit escape capsule for a safe parachute descent. This was later adopted by the USAF for the General Dynamics F-111. As a result of a British-US exchange agreement on high-speed research data (later to be reneged by the US) the Miles design and research data on the M-52 project passed to the Bell Aircraft Company who were researching a rocket propelled aircraft for supersonic flight. In 1947 a rocket propelled Bell X-1 aircraft piloted by Chuck Yeager became the first manned aircraft to fly supersonically in level flight and ‘break the sound barrier’. In all probability the success of this flight at the time was due to the Bell Aircraft Company being able to overcome the problem of control stability during transonic flight by the incorporation of an all-moving horizontal stabilizer taken from the design of the M-52. Interestingly, apart from a different means of propulsion, the design of the Bell X-1 closely resembled that of the Miles M-52 supersonic aircraft project with a similar bullet shaped fuselage and conical shaped nose housing the cockpit together with razor sharp straight leading-edge wings. In comparing the appearance of the two aircraft the impression given is that the Miles M-52, propelled by a similar rocket motor to the 6,000 lb static thrust motor installed in the Bell X-1, would have exceeded the speed obtained by the X-1 of 967 mph and achieved its design speed of 1,000 mph. A further spin-off from the design of the all-moving horizontal stabiliser on the M-52 would be seen later with the flying tail plane on the F-86, the succeeding F-100 and all the USAF Century Series of fighters. Influences from both the Miles-52 and the Bell X-1 aircraft are clearly seen in the design of the fuselage and wing of the supersonic Lockheed F-104 Starfighter.
Graduating from the course I started my tour of instructing with a flying school at Theale in the Kennet Valley of Berkshire, which was not far south of my home in Oxfordshire. It was a pleasant spot and the commissioned and non-commissioned flying instructors lived in a requisitioned manor house on a hill overlooking the airfield. This was by far the nicest and most comfortable mess with the best catering I ever experienced in the RAF; added to which was the provision of some excellent fly fishing in the River Kennet. The stables of the estate continued to function as a riding school providing some pleasant hacking. I enjoyed my time at Theale very much and after receiving my flight sergeant’s crowns and an ‘A’ category instructor’s rating, I attended a commissioning board and became a pilot officer. In changing from a non-commissioned officer to a commissioned one it was necessary for me to move. I continued my instructing a short distance north at Shellingford in the Vale of White Horse that was even closer to my home at the edge of the Cotswolds. The grass airfield at Shellingford with the wartime huts and the wood and fabric Tiger Moths resembled an RFC flying school of the First World War. As a relatively inexperienced flying instructor and newly commissioned pilot officer, my approach to teaching ab initio pilots to fly was more conciliatory than had been my own experience learning to fly with Sergeant Murphy at Cambridge and Mr O’Neil in Florida. It was certainly in marked contrast to the Polish flying instructors training the Polish pilots, who subjected their pupils to much lengthy haranguing and voluble tirades. A memorable example of the differing approach to the technique of teaching occurred when a Polish flying instructor sent his Polish pupil on his first solo flight. There are three simple rules for a smooth landing but unfortunately no one remembers what they are. The student made two unsuccessful attempts to land his aircraft with the engine surging as the pilot opened and closed his throttle while the aircraft bounded across the grass like a mechanical marsupial. This absorbing spectacle, if nothing else, demonstrated the robustness and resilience of the Tiger Moth’s undercarriage. At last on his third circuit and multiple attempts at a landing the pilot finally persuaded the Tiger Moth to stay on the ground just short of a hedge on the boundary of the airfield. As he taxied back to his dispersal his irate mentor met him as he parked the aircraft and switched off the engine. With the pilot still seated in the aircraft his instructor proceeded to berate him while all the time belabouring him about the head with his furled flying gauntlets.
I was fortunate to enjoy a comfortable existence during my time at Theale and Shellingford, insulated from the war and with easy access to my home near Oxford. My father assisted this by providing me with a second-hand Morris Minor motorcar and this enabled me to pursue my enthusiasm for game shooting and fly fishing. After the Morris failed to negotiate a sharp bend in the road one night returning to the mess, a Hillman Minx replaced it and there followed a succession of pre-war sports cars in an ascending order of potency. The first was an MG-TC, then a Riley Sprite and finally, just before the war ended, the forerunner of the Jaguar, an SS-100. Fortunately, I did not remain long at Shellingford before starting my progression to Fighter Command by means of an Advanced Flying Unit (AFU) and an Operational Training Unit (OTU), so perhaps the Assignment Board at Harrogate had been right after all. My lasting impressions from the Vale of White Horse were some wonderful walks along the Ridgeway of the Lambourn Downs with its ancient hill forts, and some parachute training at the nearby Army Parachute School at Watchfield. The course culminated in a live parachute jump from a basket suspended from a barrage balloon. This jump was to benefit me a few years later.
The AFU flying Masters and Harvards was at Tern Hill on the English side of Offer’s Dyke on the Welsh border and the OTU flying Spitfires was at Eshott on the English side of the Cheviot Hills on the Scottish border. Both were wild border areas and recognized graveyards for aircraft, where the desolate mountains wreathed in mists could reach out and grab erring pilots. By a happy coincidence an old friend from my Cambridge days and the flying school in Florida joined me at Eshott. He told me he had the misfortune to spend the intervening time towing targets at a Royal Navy gunnery school in the Isle of Man, which made me feel better disposed towards the assignment board at Harrogate. The OTU operated Spitfire IIs, and the Spitfire was the most respected and envied fighter of its time, having made its reputation during the Battle of Britain. Popular concepts gave it the credit for defeating the Luftwaffe over Britain, but in reality there were nearly twice as many Hurricanes fly
ing in the Battle and they accounted for nearly twice as many German aircraft destroyed. The Spitfire and the Hurricane were both powered by the Rolls Royce Merlin engine but the Spitfire was superior to the Hurricane in speed, climb and dive performance. However, the Hurricane was more manoeuvrable, it was a more stable gun platform and could absorb more battle damage and was more easily repaired than the Spitfire. In an ideal interception profile against the Luftwaffe, the Hurricanes would attack the German bombers and the Spitfires their escort fighters. Most of the instructor pilots at Eshott were battle-hardened Canadians on rest from Canadian Spitfire squadrons. The standard of discipline was somewhat more relaxed than was the case in the RAF. They were a wild bunch, causing the officer in charge of the WAAF much apprehension and many sleepless nights; not unlike that of the farmers of old for the raiding reivers across the border. However, they knew how to fly Spitfires in a fashion that brought our respect.
After a short period of familiarization, our RCAF instructors put us through the ringer with intense squadron formation and aerial dogfights. The Spitfire II had a Merlin 45 engine giving 1,175 hp, with a maximum speed of 357 mph, a service ceiling of 37,000 feet and a range of 500 miles. This was a considerable jump in performance to anything else we had flown. The Spitfire II, and its successor the Spitfire V, had a single radiator under the right wing, and one of the major problems associated with it were coolant leaks caused by the Merlin engine overheating. With the undercarriage down, the oleo leg partially obscured and deflected the airflow through the radiator causing the coolant temperature to rise. When the temperature of the glycol coolant reached boiling point, around 120°C, the cylinders would expand allowing the surrounding coolant to bleed into the cylinders. The first indication of trouble was a white puff of glycol smoke issuing from the engine exhaust. An attempt to take-off under those conditions would probably result in engine failure on or after take-off. Operating Spitfires in squadron strength exacerbated the problem as the taxiing time was considerably longer. In an attempt to reduce the effect of overheating after landing, some pilots adopted a dangerous procedure when landing by diving the aircraft into the circuit with power off and the radiator flap fully open to lower the radiator temperature. As the Spitfire crossed the start of the runway low level they pulled up in a steep climbing left turn to circuit height while turning through 180 degrees. The approach leg continued through a second 180 degree turn with full flap lowered and the selection of wheels down left to the last minute. The normal procedure was to lower the undercarriage before selecting landing flap, so this technique did not meet with approval for, in the excitement of a squadron landing, some pilots forgot to lower their wheels, despite the sound of a warning horn. One pilot, after an immaculate landing on the runway at Eshott with the landing gear retracted, explained why he disregarded the flying controller’s radio warning from the tower by saying he could not hear him for the sound of the horn blowing in his ears! Headquarters decided he was not Spitfire material and better suited to aircraft with fixed undercarriage. To avert similar incidences there was generally a duty controller in a caravan at the end of the runway to fire a red Very flare warning pilots attempting a landing with wheels retracted to overshoot.
The real joy of flying the Spitfire was in its incomparable handling in the air, but first one had to become used to the obstructed view forward by the big twelve-cylinder Merlin engine, which required the aircraft to swing from side to side while taxiing in order to see ahead. Then one became used to the swing to the left on take-off due to the strong propeller torque. Finally, one became accustomed to a tendency to swing on landing due to the narrow width undercarriage, especially in cross winds. After such acclimatization it was not a difficult aircraft to fly, being very responsive to the controls. It was also a very forgiving aircraft both in pitch and yaw, being able to turn tightly while flown to the limit without any unexpected and vicious stall characteristics, unlike many of the Allied and German fighters. It was also a very strong aircraft and stable in high-speed dives. Its main drawback while flying lay with the ailerons due to the fabric covering which resulted in a slower rate of roll than its rivals. The ailerons also became heavy at high speed in a dive. In the air the Spitfire was a delight but on the ground it was another story.
The Spitfire mated the largest possible engine with the smallest possible airframe, leaving little room for even the average size pilot. Larger pilots found that when wearing the traditional fleeced lined leather flying jacket it allowed very little movement in the cockpit. Sitting in the Spitfire the cockpit fitted one as a glove and its design did not incorporate the science of ergonomics. A tall and large pilot had problems even with the seat fully lowered. In the tight fit the sliding cockpit canopy did not provide a good view to the rear and even with a rear-view mirror attached to the windscreen the angle of view to the rear was small, requiring a continuous slight weave while flying to be able to see behind. This was a marked disadvantage considering that the majority of pilots shot down never saw their adversary. The hood opened by releasing a catch and sliding it back and it was extremely difficult to open at high speed; however, there was a cable release to jettison the hood. Although critical of the Spitfire’s restricted view, the Bf-109 pilot was worse off in this respect.
The quadrant containing throttle, propeller pitch and fuel mixture controls situated on the left side of the cockpit came readily to hand with the elevator and rudder trim wheels to its rear. A drawback with the Spitfire trim controls was the absence of any aileron trim that resulted in hands-on flying if the aircraft adopted a rolling moment. To correct a wing low attitude the only remedy was for the rigger to dope on a strip of cord along the trailing edge of the opposite aileron. This situation applied to both the Spitfire II and V with fabric covered ailerons. The Spitfire IX and onwards had metal ailerons and the rigger could adjust these by mechanical adjustment, but the Spitfire was still without pilot controlled trim for the ailerons. This feature was particularly irksome for photo-reconnaissance pilots on long high altitude flights. The wheel brakes were air operated by a brake lever on the spade handled grip of the control column through differential use of the rudder. This was a typical feature of British designed fighters up to and into the jet age. The American approach for wheel brakes was by hydraulic control operated by foot pedals on the rudder control bar. Another major inconvenience of the Spitfire was the control of the undercarriage selector lever. The operating lever positioned on the right side of the cockpit made it necessary to transfer control of the aircraft once airborne from the right hand to the left hand to select the wheels. Therefore, it was essential to ensure the throttle friction wheel was tight on take-off otherwise the throttle could vibrate rearwards with loss of power while retracting the wheels. Novice Spitfire pilots were easily discernible from the ground by their switch-back flight during the retraction of the wheels. This arrangement was unique to both the Spitfire and the Hurricane, the difference between the two being the Hurricane’s flap control was positioned with the undercarriage selector and the Spitfire’s flap control was an on-off selector switch located on the top left side of the instrument panel. The Spitfire’s flaps, like the wheel brakes, operated by air pressure with a single position operation, either up or down for landing. The landing flap was very effective with the full down position of 90 degrees, so it was not possible to use them to assist take-off or for turning in combat as was the case with the Mustang. This aircraft used hydraulic pressure to control a variable flap to provide take-off and combat settings as well as a landing position.
The normal maximum manifold boost of the Merlin engine was +12 lb or around 60 in. Certain modifications to the two-speed, two-stage supercharger could increase this to +18 lb. During take-off the torque from the propeller applied a gyroscopic force at 90 degrees and this resulted in a single-engine fighter swinging left or right depending on the direction of rotation of the propeller. The Spitfire accelerated rapidly on take-off and with the tail raised the aircraft required a
strong application of opposite rudder to maintain direction. For this reason a take-off power of +6 to +9 lb boost was sufficient until airborne before opening up to full power. All Merlin Spitfires swung to the left on take-off; but the propeller on the Griffon engine had an opposite rotation, making the Griffon Spitfires swing to the right. I never did find out a logical reason for the two Rolls Royce engines rotating in opposite directions: the last versions of the Griffon Spitfires, the naval Griffon Seafires and the final Spitfire variant, the Spiteful, resolved the torque problem by two contra-rotating propellers.
In the late 1930s the RAF standardized the instrument panel around the blind flying ‘Basic Six’. The centre of the panel carried an airspeed indicator in MPH, an artificial horizon, and a rate of climb or vertical speed indicator. Below these three instruments were positioned an altimeter in feet, a directional gyro compass or heading indicator, and a turn and bank or slip indicator. To the left of the flying instruments were gauges indicating oxygen contents, undercarriage lights, brake pressure, trim indicators and the voltmeter. The engine instruments indicating fuel contents and pressure, engine RPM and boost, radiator temperature, oil pressure and temperature were grouped to the right of the flying instruments. The control column had full fore-and-aft movement but was articulated above the pilot’s legs for full lateral movement due to the lack of leg room. The two-handed spade-grip incorporated the wheel brakes lever and the armament firing control button with a separate camera gun button. The two-position rudder pedals helped the pilot exert maximum rudder control with the feet in the upper position, and helped to raise his G threshold during high G manoeuvres with the seat lowered.
