I believe I've read someplace, that the French came up with a jet in 1910, and it flew, taking off without the pilot during an engine runup, but with the fabric and wood aircraft, it just wasn't feasible at the time. A Frenchman named Coanda designed it and built it. He wasn't a pilot, and it scared him, so it went no further.
Henri Coanda was a Romanian born in Bucharest who invented the Coanda effect that is used on NOTAR helicopters etc.
He also worked, after WW-1, for NACA (now NASA) and designed the aircooled cylinders used on Pratt Whitney and Wright aero engines
There is much debate about whether his 1910 aircraft flew but he claimed that the Coanda effect was discovered during the aircrafts one and only test flight where, once in flight, the firey jet exhaust (which was "aimed" away from the fuselage) actually followed the fuselage contour. The fuselage being covered with highly combustable nitrate dope this quite naturally terrified everyone involved
At the very least this aircraft was the first ducted fan aircraft and it predated the better known Caproni Campini aircraft by 30 years
Wikipedia reports "The most remarkable feature of the aircraft was its powerplant. Instead of a propeller, a 50 hp (37 kW) in-line water-cooled internal combustion engine built by Pierre Clerget at the Clément-Bayard workshop with funding from L'Aero-Club de France,[24] placed in the forward section of the fuselage drove a rotary compressor through a 1:4 gearbox (1,000 rpm on the Clerget turned the compressor at 4,000 rpm), which drew air in from the front and expelled it rearward under compression and with added heat.[25] The compressor, with a diameter of 50 centimetres (20 in), was located within a cowling at the front of the fuselage. According to later Coandă descriptions, cast aluminium components were also made by Clerget to create a powerplant with a weight of 2.8 pounds (1.3 kg) per horsepower (equivalent to a power-to-weight ratio of 0.36 hp/lb), a considerable achievement at the time"
Interestingly an American, Stanford Moss, was building Whittle style jet engines as turbocharger test rigs by the end of WW-1 but when people suggested they had a practlcal use his reply was basicly "been there, done that, does not work" and he refused to listen until the 1940s when he was tasked with taking the Whittle engine design (supplied under reverse lend-lease) to create the engine for the P-59 Airacomet. I will try and find my notes on him again later, along with a Frenchman who patented what was, apart from the starter, the first viable axial flow jet engine, such as used by the Germans. The Whittle type engines were, like the 1903 Stanford Moss engines, grossly inferior centrifigal flow engines
Moss's intellectual blindness originated pre WW-1 when he spent from 1903 on trying to make a usable (what is now called turboshaft) engine for power generation