Unconventional aircraft designs do not often succeed in war. The amazing invention which appears so often in fiction and which in fiction wins so many wars seems to have no counterpart in real life. In aviation especially it is usually the orthodox well-developed aeroplane that proves the best in service. An example is the Armstrong-Whitworth Whitley, a bombing aeroplane of perfectly normal conventional design built by conventional methods. At the outbreak of war in September 1939, the Whitley was looked upon by many people as obsolescent if not obsolete. Yet a year later it was one of the mainstays of the British bombing fleet.
The Whitley was given a fresh lease of life by being slightly modified and re-engined and in this form it proved completely successful and showed itself capable of operating under difficult conditions.
But although a conventional aeroplane appropriately developed and modified seems usually to play the leading part in war there are occasions when unorthodox designs or constructional methods or novel equipment comes into service with surprisingly successful results.
If the operations of the Royal Air Force are studied, it will be seen that they owe their successes mainly to steady development of aircraft and aircraft equipment, but also to some extent to strikingly original thinking and to the introduction of unorthodox features.
The power-operated gun turret, which has been since the beginning, a feature of the big British aircraft, and which is fitted to not only the heavy bombers but also to the medium bombers, is an example of a bold unconventional piece of design work.
No other country in the world thought it possible to introduce a power-operated turret. But British designers went forward with this component, developed it both for electrical operation and for hydraulic operation, and finally brought it to the stage of full efficiency.
At first many different theories were held about the method of operating such turrets, and one of the early Boulton Paul turrets was so arranged that the entire working of the rotatable part was brought about simply by the action of the gunner in aiming his gun. Thus, by swinging the gun to the right, power would be clutched in to the turret and the turret would turn to the right.
Other methods employed the twist grip similar to that found in some motorcycles. But all these methods were quickly sorted out under stress of war and the power-operated gun turret is now incorporated in vast numbers of British aircraft and has been responsible more than anything else for enabling Britain's biggest machines to beat off fighter attack.
Here then is one example of original unconventional thinking brought to a highly successful conclusion in war. It is matched, so far as the structural side is concerned, by the geodetic construction of the Vickers-Armstrong Wellington. This form of construction has frequently been described and it is not necessary here to repeat the details. In essentials it consists of a basketwork of criss-crossing metal members which themselves give the aircraft not only its strength but also its shape. In other words, the geodetic construction places the strength of the machine where it is needed near the surfaces of the aerodynamic shapes. In this it contrasts with more conventional construction wherein the strength is imparted through girders and struts which are inside the wings or fuselage and which do nothing to impart to them their aerodynamic shape. The Wellington, has a right claim to be one of the most successful heavy bombing aircraft of the whole war. It has worked in many theaters and under difficult conditions. It has been employed on most of the very long range attacks that the RAF has made and it has invariably given the fullest satisfaction. Constructionally it is probably the most outstanding case of all.
In armament the success achieved by the RAF fighters must be attributed more to the unorthodox tactical thinking than to any special design novelties. It was decided some time before the war that British fighters would be given the power of hitting harder than any other fighters in the world. The consequence was that guns were packed into them to an extent never before thought possible. One other point is worth noting, that these guns were packed in such a way as to enable them to be used without any synchronizing or interrupter gear. In other words, they were so disposed as to be clear of the disk swept by the airscrew blades.
The Vickers-Armstrong * Spitfire had eight guns mounted in its wings all fixed to fire forward in the line of flight and all outside the disk swept by the airscrew. Similarly, the Hawker Hurricane had eight guns mounted in its wings. The latter version of the Hurricane has no fewer than twelve machine guns, or, alternatively, four 20-mm cannon.
This tremendously heavy armament for single-seat fighters must be looked upon as unorthodox. It was not matched by anything in Germany or in any other country and it gave RAF fighter pilots a notable and lasting advantage over the enemy. The plan has been pushed even farther in the Bristol Beaufighter which carries four 20-mm cannon and six machine guns.
When we turn to other classes of aircraft we find some notable unorthodox types, chief among them the Westland Lysander Army Cooperation machine. This aeroplane has had a long lease of useful life and has earned extremely high opinions from the pilots who have flown it. It has been used for innumerable different tasks, though most of them not of the kind that will see much publicity. It is still regarded as one of the best Army Cooperation aircraft in service today.
Its design is a brilliant piece of specialized work. For Army Cooperation purposes an aircraft must be able to take off from and land in a comparatively small area. Consequently the wing loading and the general wing arrangement of the Lysander is adapted to give a wide speed range. The aeroplane is capable of slow flying under full control yet it has a reasonably high top speed to enable it to meet all conditions under which it may be used. Partly this result is achieved by fitting the wings with Handley-Page slots. These devices, by controlling the air flow over the wings, enable lift to be generated at lower speeds than would otherwise be possible.
The Lysander is also a masterpiece of internal planning. It packs into its fuselage a vast quantity of equipment. High wing arrangement has the obvious purpose of allowing the pilot to get a clear view downwards. Lysanders have been used for an enormous variety of different tasks including message dropping and picking up and the dropping of containers for revictualling troops in isolated places.
These aircraft are instances of successful departures from orthodox design. They have played a vital part in RAF operations from the start of the war and they show that although the scope is restricted there still is scope for the novelty and for unconventional feature. More recently the RAF has taken into service the United States single-seat fighter of extremely unorthodox design, the Bell Airacobra. This will be watched with especial interest for many people believe that it may point the way for useful future developments. Its engine installation behind the pilot, extension drive shaft to a hollow-hub propeller through which an automatic cannon is fired, and tricycle landing gear are all features now undergoing the rigorous trials of actual service conditions.
This article was originally printed in the June, 1942, issue of Aviation magazine, vol 41, no 6, pp 76-77.
The original article includes 3 photos.
Photos credited to Air Ministry, Wide World, Flight.