train to Milan. On 29 November he downed an Austrian Albatros D.III flown by Lt. Haertl of Jasta 1 near Pieve di Soligo. A Jasta 39 pilot was shot down and killed and a balloon of BK 10 destroyed on 3 December. One of his most successful, and also most controversial raids – fictionalized by Ernest Hemingway in the short story "The Snows of Kilimanjaro" – was on 25 December 1917. Catching the Germans off guard, he and Lt. Harold B. Hudson, his wingman, shot up the airfield of Fliegerabteilung (A) 204, setting fire to one hangar and damaging four German aircraft before dropping a placard wishing their opponents a "Happy Christmas." Lt. Lang of Jasta 1 was killed by Barker on 1 January 1918, and two balloons, two Albatros fighters (one flown by Feldwebel Karl Semmelrock of Flik 51J) and a pair of two-seaters fell to Barker during February. Awarded the Distinguished Service Order (DSO) in March, he also claimed three more Albatroses and an observation balloon. Owing to his tendency to ignore orders by flying many unofficial patrols, Barker was passed over when the post of Commanding Officer of 28 Squadron became vacant. Dissatisfied, he applied for a posting and joined 66 Squadron in April 1918, where he claimed a further 16 kills by mid-July. On 17 April, he shot down Oblt. Gassner-Norden of Flik 41J, flying an Albatros D.III (OEF), over Vittorio. He then became Squadron Commander of 139 Squadron, flying the Bristol Fighter. Barker however took his Sopwith Camel with him and continued to fly fighter operations. He carried out an unusual sortie on the night of 9 August when he flew a Savoia-Pomilio SP.4 bomber to land a spy behind enemy lines. By this time, his personal Sopwith Camel (serial no. B6313) had become the most successful fighter aircraft in the history of the RAF, Barker having used it to shoot down 46 aircraft and balloons from September 1917 to September 1918, for a total of 404 operational flying hours. It was dismantled in October 1918, Barker keeping the clock as a memento, although he was asked to return it the following day. During this time, Barker trialed a series of modifications to B6313, to improve its combat performance. The Clerget rotary engine's cooling efficiency was poorer in the hotter Italian climate, so several supplementary cooling slots were cut into the cowling. The poor upward