January 1917. World War I combat service No. 4 Squadron arrived in England in March 1917 to undergo training in preparation for service on the Western Front. Equipped with Sopwith Camels, the unit was sent to France in December. Cobby later admitted to being so nervous about the prospect of going into battle that "if anything could have been done by me to delay that hour, I would have left nothing undone to bring it about". When he did see combat against the German Luftstreitkräfte for the first time, he had only twelve hours solo flying experience. Cobby claimed an early victory, over a DFW reconnaissance plane, in February 1918, but this was credited only as "driven down" and not confirmed. Based in the Pas-de-Calais area, No. 4 Squadron supported Allied forces during the German spring offensive that commenced the following month. Cobby's aerial opponents included members of Baron von Richthofen's "Flying Circus". On 21 March he shot down two of the formation's Albatros D.Vs, which were confirmed as his first official victories. Having proved himself a talented and aggressive pilot, Cobby's leadership abilities were recognised with his appointment as a flight commander on 14 May 1918, and promotion to captain on 25 May. Described as "an imp of mischief", he personalised his Sopwith Camel by fitting it with aluminium cutouts of comic actor Charlie Chaplin. Cobby again scored two kills in one day on 30 May near Estaires, when he destroyed an Albatros and an observation balloon, and repeated this feat the next day in the same area. He had been responsible for downing No. 4 Squadron's first balloon at Merville earlier in May; although vulnerable to attack with incendiary bullets, these large observation platforms, nicknamed Drachen (Dragons), were generally well protected by enemy fighters and anti-aircraft defences, and were thus considered a dangerous but valuable target. Cobby was recommended for the Military Cross on 3 June 1918 in recognition of his combat success and for being a "bold and skilful Patrol Leader, who is setting a fine example to his Squadron". The award was changed to a Distinguished Flying Cross (DFC), appearing in the London Gazette on 2 July. Cobby shot down three German aircraft on 28 June and was recommended for a bar to his DFC, highlighting his then-current tally of 15 victories. On 15 July 1918, he and another pilot dived on five Pfalz scouts near