Malcolm Charles (Mac) McGregor, who was to achieve fame as a First World War air ace and later helped to establish civil aviation in New Zealand, was born on 4 March 1896 at Mangamako, near Hunterville. He was the youngest of three children of sheepfarmer Ewen McGregor and his wife, Matilda Chubbin. Little is known of his early life and education. Refused parental permission to enlist in the army during the First World War, he was allowed to train as a pilot instead. In March 1916 he entered Leo and Vivian Walsh's New Zealand Flying School at Mission Bay, Auckland, qualifying on 9 September.
In October 1916 McGregor sailed for England aboard the Willochra. After three months of advanced training with the Royal Flying Corps, he was posted as a fighter pilot to No 54 Squadron in France. On 29 June 1917, however, his operational flying was interrupted by injuries sustained in an emergency crash landing. After recovering in England, he served as a flying instructor. He found these duties frustrating, however, and in March 1918 he was reprimanded for allegedly performing stunts.
He returned to France in May that year, now with No 85 Squadron of the recently established Royal Air Force. Flying SE5a fighters throughout the final offensives of the war, McGregor was promoted to captain in June, and given command of his own flight. A recommendation for the Distinguished Flying Cross in August 1918 described him as 'a pilot of exceptional, even extraordinary skill' and 'a clever leader, full of resource and dash'. He was awarded the DFC and bar, and was credited with downing 10 enemy aircraft and an observation balloon. McGregor featured prominently in the celebrated American memoir War birds (1926).
The war over, McGregor returned to New Zealand in August 1919 aboard the Bremen. He worked initially on his parents' Waikato property, before purchasing a dairy farm at Taupiri. It proved difficult to sustain in the harsh economic conditions of the early 1920s, however, and he reluctantly disposed of it in 1925. He then managed his father's new farm at Rukuhia, near Hamilton. While there, McGregor married Isabel Dora Postgate, a law clerk, on 29 July 1925 at Frankton Junction; they were to have two sons and two daughters. The farm was sold in 1927 and he worked as a drover for the next two years.
Flying, however, remained McGregor's passion. He was a founding member of the New Zealand Air Force (Territorial) in 1923 and regularly attended its refresher courses over the following years. In September 1930 he was promoted to squadron leader and appointed commanding officer of No 2 (Bomber) Squadron. He was granted a commercial pilot's licence in April 1929, and formed Hamilton Airways with one de Havilland Gipsy Moth, which toured the country the following year; two other Moths were acquired later. Many New Zealanders gained their first experience of flying through a joyride with the company.
During the difficult years of the depression McGregor was involved in several false starts in the commercial sphere. In 1930 alone he was technical director of the short-lived National Airways (NZ), operated the 'Chocolate Plane' (a brown-painted Gipsy Moth) for Cadbury Fry Hudson Limited and, in partnership with F. Maurice Clarke, formed Air Travel. This company briefly operated a regular Christchurch–Dunedin service, but its survival, until mid 1932, was achieved chiefly through a combination of joyriding, carrying aloft well-known parachutists (such as Haakon Qviller and 'Scotty' Fraser) and undertaking experimental airmail flights.
In late 1932 McGregor secured regular employment as chief flying instructor to the Manawatu Aero Club. This was interrupted, however, by lengthy hospitalisation following a flying accident in December that year; he crashed during a competition in which pilots had to burst hydrogen balloons with their propellers. After his recovery he participated in the 1934 London–Melbourne centenary air race. With navigator H. C. Walker, McGregor flew a standard, single-engined Miles Hawk Major, named Manawatu, into a creditable fifth place and in the process broke two light-plane records.
Shortly afterwards McGregor became service manager with the newly formed Union Airways of New Zealand. He travelled to the United States and Britain in 1935 to investigate airline operations and equipment, and recommended that the company order de Havilland DH86 airliners. Union Airways commenced services from its Palmerston North base in January 1936, but McGregor was destined to enjoy little of its subsequent success.
On the afternoon of 19 February that year, while approaching Wellington's Rongotai aerodrome in wretched weather conditions, McGregor's Miles Falcon Major monoplane collided with the anemometer mast and crashed. He died of his injuries at Wellington Hospital two hours later. His sole passenger, C. W. F. (Bill) Hamilton (who later achieved international recognition for developing the jet boat), survived with minor abrasions.
Six feet three inches tall, of lean build, with fair hair and blue eyes, Mac McGregor was perhaps the best-known display pilot of his time; he also possessed an exceptional technical knowledge of aviation. His popularity was demonstrated by the extraordinary response to a national appeal launched immediately after his death, which raised over £5,000 to support his widow and their four young children.