On 6 September 1912, Captain Patrick Hamilton of 3 Squadron RFC was flying a Deperdussin Monoplane, serial number 258, over Graveley, near Hitchin, with Lt. Wyness-Stuart acting as his observer when there was a loud report; the machine was seen to wobble suddenly, then collapse and break into several pieces. Both officers fell to the ground and were killed instantly. At the inquest, Fritz Koolhoven, the machine’s designer, offered the opinion that the part of the Gnome rotary engine had come adrift, torn through the cowling, and caused damage to the bracing wires. This theory was supported by Major Robert Brooke-Popham, the squadron C.O., who had been flying nearby at the time of the accident. The accidents committee of the Royal Aero Club, which investigated the crash, concluded that the propeller had broken, causing damage to both the cowling and the bracing wires.
A Deperdussin monoplane similar to the one in which Captain Hamilton and Lt. Wyness-Stuart lost their lives. The Inquiry concluded that some part of the engine or propeller had broken off, flown upwards and damaged the bracing wires supporting the wings.
Four days later, on 10 September, the RFC suffered another double fatality when a Bristol Monoplane No 263, which was being flown from Larkhill to Cambridge by Lt. Edward Hotchkiss to take part in the annual manoeuvres crashed near Oxford, killing both Hotchkiss and his passenger, Lt. C. Bettington. The result of the Royal Aero Club enquiry was that a quick-release fitting, to which the bracing wires were attached, had failed in flight.
Both aeroplanes had been competitors in the recent Military Aeroplane competition and had only joined the RFC at the beginning of September.
Bristol Coanda monoplane No. 263 during the Military Aeroplane Competition with its competition number on the rudder. Taken over by the RFC, it crashed on 10 September when a bracing wire attachment failed.
That these two fatal accidents, occurring within a few days of each other, had both been caused by structural failure prompted a swift reaction and on 15 September, Col. J.E.B. Seeley, Secretary of State for War, issued an order banning RFC pilots from flying monoplanes of any kind.
A committee, chaired by R.T. Glazebrook, head of the National Physical Laboratory, was appointed “to enquire into and report upon the causes of recent accidents of the Royal Flying Corps and the steps, if any, that should be taken to minimise the risk of flying this class of aeroplane.” Other members included Major R. Brooke-Popham, C.O. of the squadron to which both aeroplanes had belonged, Lt. Spenser Grey RN, Brig.-Gen David Henderson, Mr F.W. Lanchester, Mervyn O’ Gorman, Superintendent of the Royal Aircraft Factory, and Major F.H. Sykes, commander of the RFC (Military Wing).
During their investigations, the committee interviewed eyewitnesses to the crash and expert witnesses, including Col. Holden, who had chaired the Royal Aero Club inquiry and representatives of the Bristol, Deperdussin and Gnome companies. Members also visited Larkhill to examine aeroplanes similar to those in which the four unfortunate airmen had met their deaths. An accident on 13 September when a Nieuport monoplane had suffered engine failure and made a forced landing, fortunately without injury to its pilot, was also examined.
The committee’s report was presented to the Government on December 3, 1912, and made public in February 1913. It concluded that “these accidents were not primarily due to causes dependant on the fact that the machines were monoplanes.”
The report also stated that; “Considerable attention has been given to consideration of the relative strength of the monoplane and the biplane. It will be generally agreed that the biplane possesses certain obvious advantages. The bridge girder construction possible in its main spars and struts admits of ample strength… The Committee are, however, of the opinion that it is quite possible to construct a monoplane so that it shall have adequate strength.” The report then went on to describe ways in which this strength could be achieved.
Regarding the monoplanes already in service, the Committee recommended that they be carefully inspected by a skilled engineer and, if necessary, modified to bring them within the report’s recommendations. This inspection was done, and the Royal Aircraft Factory made any necessary modifications before the machines returned to active service.
It has been stated by the eminent historian C.H. Gibbs-Smith that the ban on the use of monoplanes was not only “foolish” but that the development of the cantilever monoplane was significantly retarded. This allegation has since found support in the works of other writers. It has almost become an accepted tradition in British Aviation history. However, some of these writers appear confused over which crashes initially led to the ban, making it difficult to place any credence on their conclusions.
Some of the RFC’s monoplanes gave sterling service during the opening stages of the war, with, for example, the RFC’s first ever wartime reconnaissance mission, on 19 August 1914, being carried out by Capt. Phillip Joubert de la Ferte in a Bleriot XI, accompanied by Lt. G.W. Mapplebeck in a B.E.2a. However, the shape of the aeroplane’s immediate future had been set by such designs as the Royal Aircraft Factory’s B.S.1 and the Sopwith Tabloid which introduced single bay wing bracing, greatly reducing drag, and allowing the biplane to take over the role of fast scouts in which the monoplane had previously held sway.
Although most new designs were now biplanes, the monoplane continued in RFC service throughout the war, initially with Bleriots, then with Moranes. Although the Bristol M1 monoplane of 1917 was thought to have too high a landing speed for the airfields on the Western Front, the type saw service in the Middle East, where landing fields were larger.
Only with the development of thicker aerofoil sections, allowing the employment of deeper, stronger spars, did the cantilever monoplane become truly viable. If British aircraft designers were slow to embrace the layout, it owed more to the inertia that forms part of our national character than to a brief temporary ban in 1912.