While neither the first reaction powered aircraft, nor combustion turbined aircraft to fly, Whittle's Gloster jet flew for the first time today, about a month after Heinkel's twin jet fighter.
Note that Henri Coanda, in 1910, had already designed and had one lfighit in a reaction aircraft, where the compressor was driven by a petrol engine. Other than than, it had the basic features of a reaction aircraft... thrust was entirely from the mixing of air/pertrol with the flame, as there was no propeller.