On Monday, 14 October 1912, between about 6.30pm and 7pm, many people in Sheerness and in Queenborough, two miles to the south, heard a sound like an aeroplane engine coming from the skies overhead. Sunset was shortly after 6pm, and so it was rapidly getting dark. Some witnesses — including a Royal Navy lieutenant — believed they could also make out a red light, and possibly a searchlight, passing to and fro over the town. It was assumed by some townsfolk that the pilot was from the Royal Naval Aerial Service station at nearby Eastchurch, where there was a flight training school; perhaps the pilot was in trouble. The aerodrome was alerted by telephone, and flares were lit in an effort to guide the aircraft in. But although the engine sounds were also heard at Eastchurch, nothing was seen. By about 7pm the sound, and the light, was no longer detectable.

Where did the sounds come from? Eastchurch had no aircraft up that night, so it wasn’t from there. In fact, night flying was relatively rare at the time:Claude Grahame-Wright was the first to do it successfully in an aeroplane, in 1910. The world of British aviation in 1912 was a small one, and if a pilot had successfully undertaken a hazardous cross-country night flight it seems unlikely that it would have remained a secret. (An unsuccessful flight, of course, would have been even harder to miss!) Newspapers no longer reported on each and every flight, but weekly aviation magazines seem to have had notices of many of them. For example, Flight reported on flights at Eastchurch by nine different pilots during the week in question, though for 14 October itself only noted that ‘Lieut. Briggs was out with passenger on Monday’ So it seems unlikely that any British pilot was flying that night over the Isle of Sheppey.

The next most obvious explanation was that a German airship was responsible, and most press speculation focused on this possibility. Hence the question asked by William Joynson-Hicks in the House of Commons on 18 November 1912: whether J. E. B. Seely, the Minister for War, had any information concerning a Zeppelin dirigible passing over Sheerness on the night of October 14, about 8 p.m’. Seely did not, and neither did Winston Churchill, the First Lord of the Admiralty. But Churchill promised to make inquiries. In fact, the Air Department of the Admiralty was already on the case, having ordered the commander of HMS Actaeon to prepare a report on the incident as early as 25 October. On 21 and 27 November, Churchill reported to Commons on the results: he could not say whether it was an airship or an aeroplane, nor could he identify its nationality; he could only say that it was ‘not one of our own airships’ But that was only what Churchill felt it prudent to say in public. Privately, in a meeting of the Committee of Imperial Defence, he said that ‘there was very little doubt that the airship reported recently to have passed over Sheerness was a German vessel’. In fact, this was of course was implicit in Joynson-Hicks’s use of the word "Zeppelin”. In its giant Zeppelins, Germany had the means to carry out such a long-distance flight. And due to the Anglo-German antagonism, it presumably had the motive. Airminded nationalists in Germany thought that a big fleet of Zeppelins was just the thing to counter British naval superiority, so it seemed plausible — to airminded nationalists in Britain, at least — that the Germans might want to practice flying to a British naval base and back.

There was even a candidate. The German press had reported that the new German naval Zeppelin, L1, had undertaken a proving flight north from Friedrichshafen (in Bavaria), out over the North Sea on 13 and 14 October. But the problem was that, according to those same reports, the L1 had ended its flight at Johannistal, near Berlin, at 3.30pm, 3 hours before the engine sounds were heard at Sheerness. But perhaps it was the case, as naval officers at Sheerness and Portsmouth suggested to the Daily Mail’s correspondent, that the reported times of the L.1’s flight were intentionally altered by 24 hours. The Germans — including Count Zeppelin himself — publicly denied any involvement, but then they would, wouldn’t they?

Another, much later suggestion is that the Sheerness Incident was hoaxed by Grahame-White and Churchill in order to demonstrate Britain’s vulnerability to German air attack. This has a superficial plausibility. As I noted above, Grahame-White was an experienced night flier. He was also very concerned about Britain’s lack of aerial defences. And he was Britain’s greatest aerial propagandist. On 26 September 1912, all of these aspects of Grahame-White came together when he held his first “Illuminated Night Flying Display” at Hendon. Accompanied by a fireworks display, and watched by ten thousand spectators, five aeroplanes carrying searchlights “bombed” a dummy battleship. As for Churchill, he was certainly interested in aviation and worried about the aerial threat to Britain. So perhaps they concocted this stunt to highlight Britain’s vulnerability to air attack.

And the Sheerness Incident certainly did that. The conservative press read between the lines of Churchill’s non-committal statement about the identity of the aircraft, and henceforth used the incident as proof that Germany had the capability and the intention to attack Britain from the air. This lent plausibility to further reports of phantom airships seen in British skies early in 1913, which in turn reinforced the calls from the conservative press for the government to spend a million pounds on air defence. As an anonymous Royal Flying Corps pilot told the Standard:

We are helpless. We have neither aeroplane nor dirigible capable of coping with these vessels [the phantom airships] in the air [...] The fact is that we have been hopelessly left behind in military aeronautics, and there seems very little prospect of any advance being made as long as responsible Ministers give public utterances of their being content to wait to pick the brains of foreigners.

The government didn’t rush to expand its air forces, but it did rush through Parliament legislation banning the overflight of, among other things, naval bases. Although the bill was in preparation before Sheerness, the incident was mentioned in CID discussions as further justification (along with a much less dubious overflight by the Hansa of a British cruiser squadron at Copenhagen).

So what really happened at Sheerness? It’s hard to say. It seems pretty clear that something was definitely heard. There were many witnesses — we have names for some of them — and the press accounts were corroborated by the Admiralty’s investigation. And given that the people of Sheerness knew what an aero engine sounded like, it also seems likely there was an aircraft aloft that night. I don’t buy the theory that it was a conspiracy by Grahame-White and Churchill. Partly because such subterfuge seems out of character for such relentless publicity-seekers as these two were (I can imagine Grahame-White taking part in such a stunt but he would have soon enough revealed his part in it), but mostly because no actual evidence has ever surfaced, despite the vast amount of research done on Churchill since then. And if Churchill was in on it, why wait for a month before drawing attention to the incident? It’s more likely that a German airship was involved, but again, if so then it’s strange that no evidence for this surfaced in the last 95 years. It’s the sort of thing that would turn up in post-war memoirs, even if the original records had been lost or destroyed. Really, I have nothing better to offer than the possibility that it was in fact some British airman who went out for a jaunt over the Isle of Sheppey one autumn evening, and for some reason the investigators never got wind of the flight. That’s admittedly rather lame, but then I’m more interested in how the incident was interpreted and the conclusions drawn from it, than in what really happened that night over Sheerness …