How Competitive Flying has Advanced the Design of Civil and Military Aircraft
WAITING FOR THE STARTER’S FLAG in the King’s Cup Air Race in 1937. The King’s Cup Air Races are arranged on handicap lines. In the foreground is the Short Scion Senior four-engined liner, with its engines running ready to start. The aircraft which compete in these races are of all types and sizes, ranging down to the smallest of single-seater machines.
AN important part in aeronautical progress has been played by air racing. The biggest advances in performance have almost always followed racing events. It is frequently said that the war of 1914-18 was the biggest influence in advancing aeronautical science, but an examination of progress in performance throws doubt on this view. A well-known designer, in a paper read some years ago before the Royal Aeronautical Society, expressed the opinion that the war had done little or nothing to speed up aeronautical progress; and that, on the contrary, during the times of peace progress in speed, rate of climb, load carried and height attained, was far more rapid than in times of war. In peace, progress is certainly rapid, and normally its most sensational advances follow closely on important air races.
Perhaps the outstanding machines of the war of 1914-18 were the Avro 504 and its derivatives; for single-seater fighters the Sopwith Pup and its derivative the Sopwith Camel probably deserve first place. Both these types were the outcome of work done in air racing. It was in the Aerial Derby of 1913 that the Avro 504 first flew in a race. F. P. Raynham was the pilot, and its performance at once established the position of A. V. Roe (later Sir Alliott Verdon-Roe) among pre-eminent designers.
The Avro took fourth place in that race, but its performance had been noteworthy, and the race had really been a struggle between Hawker in the Sopwith biplane and Raynham in the Avro. For a distance of 100 miles the difference in their times amounted to only 37 seconds. So it may be said that the two most important war aeroplanes built in England appeared in the 1913 Aerial Derby and did well in that event.
The machines were developed when, some time later, they went into war service; but they were not fundamentally altered nor was their performance increased. On the contrary, the Avro flown by Raynham in the Aerial Derby averaged 67 miles an hour, yet the Avro which went to war had, according to the official figures, a top speed of only 62 miles an hour. That was with the Gnome engine. Later, when the Monosoupape engine came into use, the speed was put up to 82 miles an hour.
The Sopwith set the pace for the single-seater fighters. Its speed in the Aerial Derby of 1913 was about the same as the Avro’s speed, but, when the machine reappeared in the form of the Sopwith Tabloid, it showed remarkable qualities and laid the foundations for its success as a single-seater in the war of 1914-18. First, however, it went through a metamorphosis in the form of the Sopwith Baby, and it was with this machine that Howard Pixton won the 1914 Schneider Trophy contest at an average speed of 86·8 miles an hour. The Sopwith Baby did a great deal of useful work with the Royal Naval Air Service and the Royal Flying Corps. It gave rise to the excellent Sopwith Pup which helped to restore the air-fighting balance when the Fokker had given an advantage to Germany.
So the influence of racing on military machines during the war period is clear. In the later periods some developments are outstanding. These include the change in commercial machines from the biplane to the monoplane, from the fixed pitch to the variable pitch airscrew, and from the fixed undercarriage to the retractable undercarriage; and the change in military machines from the low landing speed built-up biplane to the higher landing speed stressed-skin monoplane.
Since the war period there have been two great races - the England-Australia Race for the MacRobertson Trophy, in 1934, and the Schneider Trophy series of races. The development in both military and commercial aeroplanes of the post-war period is closely bound up with these two events.
Before the England-Australia Race, Great Britain had taken little notice of the work that had been done in America with monoplane commercial machines having retractable undercarriages and variable pitch airscrews. Some time before that event the Air Ministry did not appear to be greatly interested in variable pitch airscrews and work which had been going on in Great Britain with the Hele-Shaw was not advanced in the way that later events show would have been desirable. As soon as it was known that the England-Australia Air Race was to be held and that unprecedentedly high prize money might be won in it, designers realized that the whole basic idea of the commercial machine as it had been conceived in Great Britain would have to be discarded and a new principle adopted. The De Havilland Aircraft Company undertook a careful research which yielded the De Havilland Comet. The K.L.M. (Royal Dutch Air Lines Company) determined to enter one of its new Douglas air liners, such as were in service in America but about which little was known in Great Britain.
The race excited worldwide attention. The progress of C. W. A. Scott and Captain T. Campbell Black in their Comet was watched with anxiety and intense interest wherever civilization existed. In addition the flying of the Dutch pilots, K. D. Parmentier and J. J. Moll, in the Douglas D.C2. air liner, drew universal admiration, for the Douglas was a standard commercial type. It was beating special racing machines and at one moment looked as if it might beat the specially designed and built De Havilland Comet. The result is recorded in aeronautical history. Scott and Black won in their Comet at 176·8 miles an hour flying time, or 160 miles an hour elapsed time, and the Dutch pilots in their Douglas obtained second place at 156 miles an hour flying time.
WINNER OF THE HANDICAP PRIZE in the MacRobertson race in 1934 from England to Australia, this Douglas air liner was of a standard commercial type. It was entered by the Dutch firm of K.L.M. and flown by Parmentier and Moll. Apart from winning the handicap prize, these two pilots made the second fastest time in the race. The winners were Scott and Black on a De Havilland Comet aeroplane.
From that day it was accepted that the retractable, undercarriage and the variable pitch airscrew were essential to all commercial types of the future. The development of the new type of machine was stimulated in Great Britain. The race proved to aircraft makers and to air line operators that, when they again turned to building up their fleets, they would have to provide machines of higher speed and more advanced design.
In contrast to the marked effects which racing has on commercial design, complicated competitions appear to have relatively little influence. The Lympne (Kent) Light Aeroplane Competition of 1923 did not influence to any apparent extent the light aeroplanes which were brought into use afterwards. The Martlesham Air Ministry Competition for commercial aircraft of 1922, for instance, was won by the Handley Page W 8. Although it gave this aeroplane an admirable send-off and was no doubt partly responsible for its being used by Imperial Airways, it had little effect on the world development of commercial machines.
Military machines, no one can deny, owe much to the Schneider Trophy series of races. The stressed skin type of monoplane for military purposes is an outcome of the Schneider Trophy seaplanes; and the fast R.A.F. single-seater fighter, the Supermarine Spitfire, is a direct development of the Supermarine which won the last Schneider Trophy contest.
Full British participation in the Schneider Trophy contest began in 1927, although a British win was recorded in 1914 and again in 1922, with a flying boat. British attempts to win the race had been made several times. In 1927, however, the British entry received Government backing. Flight Lieutenant S. N. Webster, in a Napier-engined Supermarine, flying round a course laid out over the Adriatic, won at 281·68 miles an hour. In 1929, when the next race was held, the place was the Solent, for the winning country had to organize the next contest. Again there was Government backing and this time Flight Lieut. H. R. D. Waghorn in a Rolls-Royce-engined Supermarine won the race at 328·63 miles an hour.
For 1931 the Government announced that it would no longer back the race. The cost, it was said, was too high. It could scarcely have foreseen that the later Royal Air Force expansion programme in the years to come would be based upon the results of the races. At any rate, it was a strong probability that there would be no British participation in the 1931 event. This would have been doubly unfortunate - first because the research work that had been done for 1927 and 1929 would not have been completed and brought to full fruition, and secondly because Great Britain, having won the contest two years running, had a good chance of winning it outright; for the rules laid down that three consecutive wins by any nation gave that nation the Schneider Trophy in perpetuity.
Support of £100,000
It was at this moment that Lady Houston, widow of a shipping magnate who had left her his fortune, first wrote her name in aeronautical history. She consented to defray personally the entire expenses of the research, building and participation in the 1931 event.
Lady Houston’s cheque for £100,000 was no sooner paid than preparations began for the 1931 contest. The Italian, German and American challenge fell through and Flight Lieutenant J. N. Boothman in the Vickers Supermarine S6B with a Rolls-Royce engine flew over the course to win at 340·08 miles an hour. Because its objective was speed, this race aroused greater interest even than the England-Australia event was to do. There were few limiting clauses in the rules and the essential point was to cover a course of reasonable length with corners in the shortest possible time. The Schneider Trophy designers were stimulated to aim for the highest possibilities of speed, and the fastest man-carrying vehicles so far built were designed for that contest.
ROUNDING A PYLON in the 1936 King's Cup Air Race. The machine is a special Miles Hawk, with a Gipsy Six engine, piloted by Flight Lieutenant T. Rose. The form of this race and the course over which it is flown are continually being changed. Generally the machines taking part fly low to avoid using time in climbing. The race is confined to pilots of British nationality and to British-built aircraft.
In Great Britain the speeds of the ordinary fighting aeroplanes are creeping gradually up towards the Schneider Trophy figures, but the pioneer work was done in racing.
These races, more than any others, have affected progress in aviation, but there have been many other air races which have not had such an appreciable influence on design. Chief among these races is the King’s Cup Air Race, which is flown annually.
The first race for the King’s Cup was flown in 1922. The winner was Captain F. L. Barnard, who flew Sir Samuel Instone’sD.H.4a (with Rolls-Royce engine), and averaged 120 miles an hour. Few outstanding speeds were recorded during the first ten years of the races, but the table below shows the high speeds achieved in recent years.
The Aerial Derby, in which, before 1914, the Avro and Sopwith machines made their first appearances, was revived after the war of 1914-18, but it was found difficult to maintain the entries. The race was round London, and it provided some good racing. It also induced people to build special machines. Some of these did have a useful influence on future design, and the Gloster Bamel, a design of Mr. Folland’s, was one of the first high-performance machines to be built after the war.
Officially this aeroplane was called the Mars I. Its planes were slightly staggered, and the wing tips of the upper plane were rounded. The wing tips of the lower plane were rounded only in front. The machine was designed with a honeycomb radiator retractable into the fuselage, a first practical essay in racing of the form of retractable radiator which was later to be used extensively in commercial and in Service aviation. The engine was the Napier Lion.
Three times the Gloster Bamel won the Aerial Derby, in 1921, 1922 and 1923, at speeds of 163·34, 177·85 and 192·4 miles an hour respectively. In the final event it attained 220 miles an hour on the straights. The machine had a span of 23 feet, later reduced to 20 feet to increase the speed. The loading went up correspondingly from 12·2 lb. per square foot to 16 lb. per square foot - another indication of the way in which racing was leading designers towards higher loadings and showing that there was nothing impossible in handling machines with them.
In 1935 a cross-country event was organized. It was designed to test not so much the speed of the aeroplanes as the navigating ability of the pilots. Each pilot had to fly solo. The machines, of which there were about forty for the first race and about thirty-five for the second, were lined up on the aerodrome. The course was kept secret.
It was marked on a number of maps by the organizers but no competitors were permitted to see these maps. The machines were handicapped on performance and, when the starting signal was given for each individual, he was allowed to open his map, see where the course ran, prepare his course and set off. Rapidity in working out a course and accuracy in keeping to it were the essentials to victory. The same pilot, Mr. Walker, won both events, and so won the trophy outright.
After the England Australia race came the England-South Africa race, which was won by C. W. A. Scott and G. Guthrie. The England-South Africa event did not produce results commensurate with the risks involved, and no special machines were designed for it. For a race of such length it is essential that the prize money should be high enough to tempt manufacturers to build special machines.
The Coupe Deutsch de la Meurthe has had a marked effect in improving French aircraft design. It is a formula race in which the engine size is limited. Thus, the machines taking part are small; but they have a refinement of design not known outside this class, and components such as retractable undercarriages and wing flaps are carefully studied with the object of causing the least possible resistance.
In America there are the national air races held every year, and these occasionally produce new types of machine. On the whole, however, they have not had so much effect as might have been expected. The reason is probably that the regulations were not drawn up with sufficient regard to the stimulus afforded by this kind of contest.
The great events of the past have faded away - though they have left their mark deeply on design. There seems to be nothing now to take their place. In 1937 it was proposed to run a race across the Atlantic Ocean from Paris to New York, but the Americans declined to participate. The Istres-Damascus-Paris Race was substituted, and was won by an Italian Savoia 79, flown by Cupini and Paradisi.
THE SCENE AT MELBOURNE on the arrival of Scott and Black, winners of the 1934 England to Australia race. Their De Havilland Comet machine was one of a type specially built for this race, and focused the attention of designers of commercial machines in Great Britain on to the importance of retractable undercarriages, controllable-pitch propellers and monoplane design. The race also showed the need for air liners of greater speed to replace those in general use at the time.