How the considerable help given to the R.A.F. by United States manufacturers of aircraft and aircraft equipment
HUDSON OVER DUNKIRK. The Lockheed Hudson, the military version of the Lockheed Fourteen commercial aeroplane, has done considerable duty with Coastal Command as a long range reconnaissance bomber. It has a range of 2,000 miles and has a rotating gun turret fitted to the upper part of the fuselage. The Hudson shown here is on patrol duty over Dunkirk at the time of the evacuation.
TODAY the United States is still providing Britain with aircraft, though she has her own services to equip. For certain classes of work the R.A.F. relies entirely on American machines, while American pilots likewise fly British types. The Spitfire, with which some American fighter squadrons are equipped, is perhaps the outstanding example. The two countries are fighting as one. Their production of aircraft, engines and equipment is organized as a whole. But when the war began it was not so and this is the story of how American help started, developed and finally became one of the dominating factors in turning the tide of the air operations.
When the United States first set out to supply aeroplanes to the R.A.F., Britain had to take what could be spared. At that time the purchaser had both “to pay on the nail” for everything he chose and to do the transporting himself. Britain placed quite large orders under that arrangement, but in March 1941 the Lease and Lend Act was passed by the United States Legislature. That meant that the R.A.F. could have more aeroplanes than it could pay for.
At the end of May President Roosevelt pledged the United States to see that the weapons of war from America should reach the democracies; and that meant that American ships could carry some of the goods and that, if necessary, American warships would convoy them. To British self-help had been added the promise of the generous help America could give.
These stages are worth considering as a prelude to estimating the American contribution to Britain’s war effort, not only because they explain the growing momentum of the American aid but also because they are significant of British influence in guiding that aid along paths parallel with those which were being followed in Great Britain. Mere numbers alone would not necessarily have assured the R.A.F. of air superiority. In the Battle of Britain, an enormous advantage in numbers availed the Germans little. Superior quality in men and machines enabled the R.A.F. to throw back the German hordes with tremendous losses. If America had simply flooded the R.A.F. with aircraft of inferior performance and armament, Britain might equally have found herself in the unhappy position of having the numbers but not the strength.
HARVARD ADVANCED TRAINERS. North American Harvards play a leading part in the training of fighter pilots for the R.A.F. They are easily recognized by the fully tapered leading edges of their wings, and their distinctive and harsh engine note which sounds somewhat like a two-stroke motor cycle.
Some such situation might have arisen if, from the start, the U.S.A. had been handing out largesse to the British. The easy way would have been to go full speed ahead with the types which were already in production. Up to a point the British had to accept that method because of the urgency of their need, but the important point was that they were paying for what they got and were therefore in a position to require modifications here, more armour there, and guns in different positions. Furthermore, within the limits set by considerations of early delivery, Britain could pick this type and reject that. The result was that she began to direct American development along particular lines and stimulated the production of certain types.
The independence that Britain gained in those early months was well worth the huge sums she undertook to pay the American manufacturers, since it meant that her specifications were accepted and her views on the types of aeroplane best suited to modem warfare became established.
A trend was established by the British requirements in the early days that influenced American fashions. As an example of this one need only recall that arrangements were made for the Rolls Royce Merlin engine to be built in America. Production and delivery are now in full swing. Already a water-cooled engine, the Allison, had been produced there, and so a nation which had previously relied on air-cooled engines began to think in terms of the slimmer lines and higher speeds which the small frontal area of the liquid-cooled engine permits.
Pre-War Purchases
Even before the war the British had been buying Lockheed Hudsons for reconnaissance work and Harvards for advanced training. Both aircraft, in improved forms are still being delivered for use by the R.A.F. The Hudson was the commercial aeroplane known as the Lockheed Fourteen, so modified that a rotating gun turret could be fitted on the upper part of the fuselage just forward of the tail. The North American Harvard was a fast, single-engined trainer.
For a long time the British asked for nothing more, but the French, whose aircraft industry had been shamefully neglected, had been buying much more freely. They had taken delivery of a good many Curtiss Hawk fighters. They were hoping, when the German advance crushed them, to receive aircraft of at least four other types from America. These were the Vought-Sikorsky 156 dive bomber, the Martin 167 twin-engined bomber, the Douglas DB-7 twin-engined bomber and the great Consolidated Model 32, which is a four-engined bomber of a loaded weight of more than eighteen tons and a top speed of 335 miles per hour. It is known in the R.A.F. as the “Liberator” bomber.
MARYLANDS IN THE MIDDLE EAST. Martin Maryland twin-engine bombers first proved their worth in the Middle East where they were first in service in November, 1940. They also took photographs which led to the Fleet Air Arm attack at Taranto. Above, two machines of a Maryland squadron are seen on active service in the desert. They have a top speed in the neighbourhood of 320 m.p.h.
When Great Britain found herself standing alone against the Germans in June, 1940, she was able to arrange to take over these orders and so to profit by the time which had already been devoted to them. The Hawk passed into the R.A.F. in slightly modified form as the Mohawk. The others were named the Martin Maryland, the Douglas Boston and the Consolidated Liberator. The Vought-Sikorsky was named the Chesapeake and passed into service with the Fleet Air Arm.
During the succeeding six months the British Purchasing Commission worked so hard that more than thirty different types of American aeroplanes were being built for the R.A.F. Among them were ten fighters, seven bombers, six reconnaissance types including flying-boats and three types suitable for service in aircraft carriers with the Fleet Air Arm. By the beginning of 1941 many were flowing in large numbers into R.A.F. units in Britain and overseas. The Marylands, for instance, were in service in the Middle East as early as November, 1940. They took the photographs which led to the great Fleet Air Arm attack on ships of the Italian Navy in Taranto harbour and returned afterwards to get pictures of the damage done by torpedo bombers of the Fleet Air Arm. Tomahawk fighters were first reported in action during attacks on German aeroplanes using aerodromes in Syria in the latter part of May, 1941. Before that, Bostons had taken part in bombing raids from Great Britain and the Havoc, the night fighter version of the Boston, had begun to destroy German bombers.
Operational and technical advice was invited by American manufacturers. In response, Air Chief Marshal Sir Hugh Dowding, who had formerly commanded Fighter Command, led a mission which remained for many months in the United States. British technical men were admitted to the works of the principal aircraft firms. The rapid results of all these forms of contact were almost startling and they quickly became apparent.
Firms which had previously given the scantiest attention to protecting the vital parts of their aeroplanes from damage by machine gun and anti-aircraft fire now produced in remarkably short time bombers and fighters which had better protection for fuel tanks and pilots than was to be found even in the aeroplanes with which Britain entered the war.
TOMAHAWK AND KITTYHAWK. The Curtiss Tomahawk fighter (top), like the Maryland, was first used operationally in the Middle East. It is extremely fast and manoeuvrable and is the American counterpart of the Hurricane, which it closely resembles. The Kittyhawk (below), is an improved version of the Tomahawk, and it has a maximum speed of about 380 m.p.h.
They were typical of the advantages which accrued to the R.A.F. from the readiness of Great Britain to “pay the piper”, and of the consequent willingness of most American manufacturers to allow the British, up to a point, to “call the tune”. The British for their part were only too happy to give all the help they could. A Messerschmitt 110 twin-engined fighter was even shipped across to the United States for examination by American aeronautical engineers so that the best available examples of modern practice on both sides of the war front might be at the disposal of those who had undertaken to build for the R.A.F. out of range of the enemy’s bombers.
Lockheed Lightning
The Lockheed Company promptly set itself to produce the P.38 twin-engined fighter. It is known as the Lightning, and its speed, according to manufacturers’ reports, is just over 400 miles per hour. It did not see service with the R.A.F. however, as the United States entered the war before it was fully in production. It is now being used by the U.S. Army Air Force. The Douglas Company, for its part, set out to produce a more capacious bomber than anybody had yet contemplated using in war. It designed a huge machine of a loaded weight of seventy-three tons.
LOCKHEED LIGHTNING. The Lockheed P-38 fighter, shown above, is a high speed twin-engine aircraft of unusual design. The tail unit is carried on two booms and the central nacelle accommodates the pilot and the armament. The P-38E is a two-seat version of the same machine.
Before the war, the Boeing Company was engaged in producing what it called the Stratoliner, a commercial aeroplane with a hermetically sealed cabin in which the air pressure was to be kept much higher than that in which the aeroplane was flying. The intention was to obtain the speed advantages which come from flying in the thin air at great heights without causing the discomfort which passengers normally suffer from reduced pressure and shortage of oxygen. The Stratoliner was not really supposed to fly in the stratosphere. It was to cruise at heights between 20,000 and 30,000 feet, but to preserve in the passenger cabin an air pressure roughly corresponding to that at 10,000 feet.
The Wright Corporation having provided the supercharged Cyclone engines for the Stratoliner continued its experiments with still more efficient superchargers. For some years engine designers have been examining the possibility of harnessing the wasted energy from engine exhausts to the task of driving superchargers. The gases, as they emerge from the exhausts, possess a large store of energy. This, it had been hoped to apply on the ordinary turbine principle to a piece of special apparatus which in turn would drive the impeller or fan attached to the supercharger.
One awkward matter had been to find a metallic substance for the turbine blades which could withstand the extremely high temperatures of the exhaust gases. At last the Wright engineers met with success, for the engine which was used originally in the Stratoliner has now appeared for use in military aeroplanes with a turbo-supercharger. This permits the Cyclone engine to give unusually high power at heights where ordinarily supercharged engines are giving only a fraction of their “rated” output. The Boeing Company, having stimulated work in this direction, was the first firm of aircraft constructors to reap the benefit of this new supercharger.
PRINCIPLE OF THE TURBO-SUPERCHARGER. Diagram illustrating how the exhaust gases from the engine can be used to drive the supercharger. Turbo-superchargers are embodied in Wright Cyclone engines such as are fitted to Boeing Flying Fortress bombers, and permit the engine to give unusually high power at heights where ordinarily supercharged engines are giving only a fraction of their rated output.
Out of the Boeing Company’s works in 1935 had come the big four-engined bomber described by the United States Army Air Corps as the B. 17, and popularly known as the Flying Fortress. In its early form the Flying Fortress, operating at a loaded weight of twenty-two tons, developed a top speed of 250 miles per hour at a height of 13,000 feet. It has undergone various modifications since war broke out. By far the most important of them was the fitting of the new Cyclone engines. With this type of engine, the new Flying Fortress, or B. 17C, as it is officially known, can carry the same load and develop a top speed of 325 miles per hour at a height of 20,000 feet, and is rated for cruising at a speed of 245 miles per hour at 30,000 feet. Bombers of this kind have made many daylight raids with outstanding success on enemy objectives from great heights.
No other aeroplane in the world has such a high “rated height”. Many aeroplanes of course can fly at heights above 30,000 feet, but the “rated height” of most military aeroplanes is somewhere between 15,000 and 20,000 feet. The “rated height” is that at which the best combination of speed and load can be obtained. It depends almost wholly on the degree of supercharging which can be given to the engine or engines. The “rated height” of the Spitfire fighter, for instance, is 17,000 feet, whereas its “service ceiling” — the height at which it is still capable of climbing at the rate of 100 feet per minute — is well over 30,000 feet.
The benefit to be derived from increasing the height at which the bombers can fly is obvious to all who examine the question of interception by enemy fighters. If the fighters have to climb to great heights to cut off the bombers, there is a fair chance that the raiders may have reached their targets before they can be attacked. Flying high, the bombers may be out of range of the anti-aircraft guns. In certain circumstances they may escape detection altogether. They may get above the “smoke-trail” forming layer of the atmosphere. Also, of course, as sound takes time to travel, great height causes confusion to the ground defences. Aircraft flying fast at a great height will be well in advance of the apparent location of the noise they make. Height indeed is one of the most valuable attributes in air warfare, and in these days of highly accurate bomb sights, it may be no serious deterrent to accurate bombing either in daylight or clear weather.
Tricycle Undercarriage
There was another form of aeronautical advance in which the United States had “taken a chance.” It had pushed on with the application of the tricycle undercarriage. Some experiments had been made with the new combination of wheels in Great Britain, but whereas the British came slowly and cautiously to this development, the aircraft industry in the United States took its courage in both hands and applied the new idea to quite massive aeroplanes. The Boston twin-engined bomber, weighing some seven and a half tons fully loaded, had a front wheel instead of a tail wheel, from the start. The Liberator, the big four-engined bomber of a loaded weight of eighteen tons, was born, so to speak, with a tricycle undercarriage. The Liberator, by the way, in addition to being used by the U.S. Army for daylight raids, is doing valiant service with the British Coastal Command in the Battle of the Atlantic.
In the end this improvement may prove to have been a good thing. In the early stages, R.A.F. pilots had a certain amount of trouble with the nose wheel. It did not behave well on soft, muddy surfaces, and there was a period at which the front wheel developed the form of wobble known as “shimmying”. A certain amount of modification had to be done, and during the interval, British pilots acquired the habit of landing on the two main wheels and of using the front wheel simply as a safeguard against “nosing over”, when the brakes were firmly applied. The device has thus come to serve one of the principal purposes for which it was intended, and it is well on the way towards fulfilling all the other hopes that were reposed on it.
The arguments in favour of the nose wheel are that it helps the take-off by enabling the pilot to start his run with the aeroplane in the flying attitude, that it makes control on the ground easier if there is a steerable wheel in the front, and that landings are simpler because the aeroplane need not be stalled on to the ground and the landing rim shorter because the brakes can be put on hard as soon as the wheels touch down. These are important matters with fast landing speeds and heavy overloads at take-off.
One of the most useful of the night fighters, the Havoc, is fitted with a tricycle undercarriage. This machine is the fighter variant of the Boston and has been operating successfully as a night fighter since the early part of 1941. Another United States fighter which also uses the nose wheel embodies various other novel ideas besides. This is the Bell Airacobra, a single-engined machine of a top speed of about 400 miles per hour. It is fitted with the new Allison liquid-cooled engine. This is set behind the pilot and drives the airscrew by means of a long shaft which passes between the pilot’s feet to a set of gears arranged to transmit the power to a shorter shaft driving the airscrew. By way of final complication, a 37-mm. cannon is placed to fire through the airscrew hub. A British fighter squadron engaged in low level attacks on targets in Northern France and Channel shipping was equipped with the Airacobra towards the end of 1941, but the machine was later superseded by another type.
Bearing in mind the fact that the R.A.F. began the war without enough machines in any category, those who look into the matter will realize how valuable some of the American help proved. One of the first machines to be delivered to the R.A.F. from the United States was the Catalina flying-boat (see the chapter “Coastal Command”), the military version of the Guba civil flying-boat which made a survey flight just before the war across the Indian Ocean from Australia to Africa, calling at small islands on the way. That flying-boat is supposed to have a range of 4,000 miles. During the week in which the German battleship Bismarck was shadowed in May, 1941, one Catalina remained on patrol for twenty-seven hours and must have flown 3,500 miles in the course of that tour of duty.
The R.A.F. had no other flying-boat capable of such endurance. The normal range of the Short Sunderland, the four-engined British flying-boat is 1,780 miles. The two craft are not strictly comparable of course. The Sunderland is faster, is better armed for self-defence and better armoured for protection. It has much greater capacity. In brief, it was built for an entirely different class of work in the relatively narrow seas, whereas the Catalina, or PBY 5 as the United States Navy calls it, was built for ocean work. A Catalina could fly 1,000 miles westwards over the Atlantic to meet a convoy, could remain cruising protectively in its vicinity for ten hours, and then could fly back to its base without having exhausted its supply of fuel. That was the sort of thing the Coastal Command badly needed when German occupation of France and Norway enabled her to spread her submarine operations over a coastline which was too long for the Navy to watch closely. The Catalinas came at the right time and fitted admirably into a vacant place.
CONSOLIDATED LIBERATOR BOMBER. The Liberator, illustrated here, was the first of the big bombers to be flown direct to Britain. It has a range of 3,000 miles and an exceptional top speed of 335 miles per hour.
America’s chief advance in aircraft technique concerned the production of long range, weight-carrying machines, the day bombers such as the Fortresses, Liberators, the transports and the flying boats. Britain, having begun the war on the defensive, had to rely to a great extent on fighters. She therefore developed the fighter more rapidly and then concentrated on the night bomber such as the Halifax and Lancaster.
But there was one type of aircraft to which America paid attention almost alone, the dive-bomber. Britain left dive-bombers out of her early calculations for the simple reason that their use by the Germans had proved that they were ineffective except where there was complete air dominance and that they only had a tactical advantage, not a strategic. Britain, first of all, had to get air dominance by means of fighters and she then found that fighter-bombers, such as the Hurricane and Whirlwind, could be used in many cases more effectively than dive-bombers. Today, however, two dive bombers are being produced by the United States for the R.A.F., the Bermuda and Vengeance, but how or where they are being used cannot yet be disclosed.
The old Curtis “Helldiver” of 1937 will be remembered, for it received a good deal of publicity. It is an obsolete model, though its performance was nearly as good as that of the Junkers 87 (the Stuka) which the Germans used largely in Poland and France. Great Britain produced one dive bomber, the Blackburn Skua, especially for the Fleet Air Arm. The Vengeance, in particular is a vast improvement on either the “Helldiver” or the Skua and is now reported to have overcome its various “teething” troubles most satisfactorily.
Several large firms in the United States agreed to share with one another the task of turning out quantities of the types the R.A.F. particularly needed quickly or in great numbers. As one outstanding example there was the agreement of the Boeing, Douglas and Lockheed concerns to co-operate in the building of Fortresses, the high flying bombers. A joint effort on a rather smaller scale was that of the Vultee and the Northrop Companies to turn out the Vultee Vengeance at a high rate. In addition, sections of the motor car industry were turned on to aeronautical work, and huge new factories were set up and equipped with machinery at an amazing rate. The famous Packard firm is manufacturing the Rolls Royce Merlin engine and Ford’s have erected the world’s largest aeroplane plant at Willow Run for the production of Liberators.
On the industrial side, the expansion of manufacturing capacity was great and rapid. One of the best signs of the rate at which aeroplanes were being turned out was to be found in engine production. Before the United States began building for the R.A.F. the average monthly output of aero-engines stood at 200 to 300 a month. By the end of May, 1942, the rate of production had risen to 15,000 a month, and this has advanced steadily ever since. That represented a total of more than 5,000 aeroplanes, some of which were wanted by the United States for her own air services, but reports showed that the R.A.F. received something exceeding half up to the time when help was extended to Russia.
Delivery of the goods has naturally been as important as making them, and in this respect too the United States gave help in an ascending scale. When the Lease and Lend Act had been passed, British crews were allowed to collect aeroplanes from the makers’ works and to fly them to Newfoundland and Canada on their way to the European front. Until Japan entered the war others were flown from the Pacific coast to Hong Kong and Malaya.
The United States, as a measure of self-defence, established air and naval patrols over the western waters of the Atlantic. When enemy vessels were sighted, she broadcast the information for the benefit of all shipping in the vicinity. Later, after German attacks on several U.S. ships, she announced that her navy would protect all Lease-Lend cargoes between America and Iceland.
Another important factor was the decision of President Roosevelt that, after the defeat of the Italians in Eritrea and Somaliland, the Red Sea need no longer be regarded as a theatre of war, and American ships need no longer be excluded from it. Many fighters from the United States were thereafter delivered by American ships to the R.A.F. in the Middle East. They began to arrive in time for the big operations over Libya.
THE EAGLE SQUADRON. Many citizens of the U.S. enlisted in the R.A.F. and in the summer of 1941 an American squadron, the Eagle squadron, went into action. Some of its flying members are seen above.
As American opinion hardened against the Germans throughout the summer of 1941, there was a shrewd suspicion in Great Britain that more would soon be done by the United States to accelerate and to ensure the delivery of war material to the R.A.F. That this suspicion was justified was proved in September, 1941, when the United States decided to protect Lease-Lend cargoes. One slight token of the spirit of the United States Government was the decision to put some of its own Fortresses on a passenger and goods service between America and Great Britain. Another, of greater significance, was the agreement to train 8,000 R.A.F. pilot pupils at flying schools in the United States during the year 1941-1942.
Before war between the U.S. and Japan broke out a great many citizens of the United States had crossed into Canada to enlist, with or without subterfuge in the R.A.F. One purely American squadron of the R.A.F., the Eagle Squadron, first went into action in the summer of 1941. Later two more Eagle squadrons operated with the R.A.F. until the entry of the United States into the war resulted in all the pilots transferring to the U.S. Army Air Corps. Those pilots now wear two “wings”, the R.A.F. and the U.S.
Out of the United States, therefore, we have received in a variety of ways support of good quality and a measure of encouragement which may truly have emerged from the realist outlook declared by many American writers to be the mainspring of American actions, or may have been mixed with a sentimental regard for Great Britain when she stood alone to face the full power of an over-armed, ruthless and fully regimented nation of gangsters. Great Britain began well by placing orders and financing the expansion of the United States Aircraft Industry to the value of £500,000,000. She received good value in return, and received it much sooner than she could possibly have done had she waited for the passing of the Lease and Lend Act.
American aid brought greater striking power to the R.A.F., and greatly strengthened that force in the Battle of the Atlantic. In short, it helped Britain to progress from the defensive to the offensive in air warfare, and gave promise of contributing effectively to the most massive air offensive that the world has ever seen.
THUNDERBOLT FIGHTER. The Thunderbolt single-seater American fighter in service with the U.S. Army Air Force in Britain. It is powered by a Pratt and Whitney 2,000 h.p. engine which will carry it to 40,000 feet and gives a top speed of more than 400 miles per hour. Its powerful armament consists of eight 0.5 machine guns with a combined rate of fire of 6,400 rounds a minute.
