William Wallace Burn (later known as William Wallace Allison Burn) was the first New Zealand army officer to qualify as a military aviator. He was born on 17 July 1891 at Melbourne, Australia, where his parents, Forbes Burn, a station manager, and his wife, Isabel Ayers, had emigrated soon after their marriage at Christchurch in 1885. The family moved to Canterbury, New Zealand, where Burn was educated at Christchurch Boys' High School. He showed a keen interest in cadet force training, eventually reaching the rank of cadet captain.
In August 1911 Burn joined the New Zealand Staff Corps as a probationary second lieutenant. He was posted to the Canterbury Military District on 21 February 1912, where he was appointed acting adjutant, 1st (Canterbury) Regiment. A report on his performance in May 1912 indicated that he was 'tactful, energetic, resourceful, likely to make a good officer'.
On 8 August Burn departed, along with three other junior officers, for England for a course of study with the Imperial Forces. He undertook instruction with the military aeronautical directorate and obtained the necessary certificates to qualify as a pilot. Burn returned to New Zealand in September 1914 and was appointed area officer, Auckland, with the rank of lieutenant.
In February 1915 the Indian government called on the other dominions to provide trained pilots for service in the Tigris valley during the Mesopotamian campaign. Burn was seconded to the Royal Flying Corps for service as a flying officer, attached to the Indian Expeditionary Force.
Burn joined a Royal Flying Corps unit at Basra on 26 May 1915 as one of five pilots. The unit took over three aircraft that had already seen service in Egypt and were in poor shape. Operations commenced on 31 May 1915, with a reconnaissance flight over Turkish positions near Kurna. Two Caudron aircraft joined the unit on 4 July 1915. They were used for reconnaissance in the battle for An Nāşirīyah. Burn flew on a number of these sorties. The Caudrons were unreliable, being prone to frequent engine failure. On 30 July 1915 the two Caudrons were returning in loose formation from the Nāşirīyah area to Basra when they lost sight of each other. One suffered an engine failure and landed near a village; the villagers were, fortunately, friendly. The other machine, piloted by an Australian, Lieutenant G. P. Merz, with Burn as observer, went missing.
According to reports of eyewitnesses, the machine landed in the desert about 20 miles from the refilling station at Abu Salibiq. Burn and Merz were immediately attacked by a number of well-armed Arabs, and, recognising that they could not defend their machine, they retreated in the direction of Abu Salibiq. Armed only with revolvers, the two airmen carried out a running fight, during which they killed one and wounded five of their adversaries. Then one of them was wounded, and his comrade died fighting beside him. Search parties were sent out from Abu Salibiq and Basra, but no trace of the missing airmen was ever found. The aeroplane was found several days later, hacked to matchwood.
The loss of Burn and Merz was a severe blow to the unit. Both were capable pilots, Burn being described as a laughing and likeable fellow. Because William Burn served with an RFC unit his death is not recorded in the official New Zealand roll of honour. He was the first New Zealand pilot to be killed in action.