The exploits of the Australian aviator Charles Kingsford Smith inspired Clouston to learn to fly at the Marlborough Aero Club at Omaka Aerodrome, near Blenheim.

[3][6][7] When he arrived in the United Kingdom, Clouston found work at the Fairey Aviation Company while awaiting the processing of his application to the RAF.

In October 1930, once some initial concerns over his blood pressure were resolved, Clouston was granted a short service commission in the RAF as a pilot officer.

This was declined and, dissatisfied with the compromise offer of an extension of his short service commission, in October 1935 he ended his commitment to the RAF and transferred to the Royal Air Force Volunteer Reserve.

[6] On returning to life as a civilian, Clouston applied to the Air Ministry for a job as a test pilot at the Royal Aircraft Establishment, based at Farnborough.

On 30 May 1936, he flew his Aeronca C-3 from Hanworth Aerodrome in the London to Isle of Man Race, but missed the final turning point in fog.

[14] In June 1937, he learned that the DH.88 Comet (G-ACSS), that won the 1934 MacRobertson Race, was for sale by a scrap dealer, after it had been damaged in Air Ministry testing.

He persuaded architect Fred Tasker to purchase the Comet, and then arranged for it to be repaired with upgraded engines and propellers, by Jack Cross of Essex Aero at Gravesend Aerodrome.

On 20 August 1937, accompanied by Flt Lt George Nelson as co-pilot of the Comet, Clouston took off from Istres as one of 13 entrants, of which all the others were more powerful, and all heavily sponsored by European governments.

Betty Kirby-Green was relatively new to flying, with an appetite for adventure, and agreed to help raise money for an attempt on the Cape record set by Amy Johnson in 1936.

[7] In December 1937, Daily Express air correspondent Victor Ricketts proposed to Clouston that they should attempt to break the England to Australia flight record.

The first scheduled stop was to be Aleppo in Syria, but bad storms forced Clouston to land at a flooded airfield at Adana in Turkey.

Engineer Jack Cross, plus the financier and some equipment, was flown to Cyprus by Alex Henshaw in a Vega Gull borrowed from Charles Gardner.

He flew via Cairo, Basra, Allahabad, Penang and Singapore to Darwin, but without beating the 1934 record set by C. W. A. Scott and Tom Campbell Black in the same aircraft.

Although the unit operated some high speed fighters, it was forbidden to arm them, but Clouston reportedly on one occasion, shortly after the death of his brother, also a pilot in the RAF, over Dunkirk, chased an intruding German aircraft with the intention of ramming it.

Increasing Luftwaffe incursions led to orders to arm the fighters, and their pilots were authorised to fly patrols over the airfield in the event of detection of approaching German aircraft.

[17][5] He carried out many flight tests using both tethered and untethered flares launched from a Handley Page Hampden flying behind a Whitley bomber, in experiments to illuminate target aircraft at night.

There he carried out testing of the Turbinlite concept of an aerial searchlight mounted on a Havoc night fighter, in collaboration with Group Captain William Helmore and with aeronautical engineer L.E.

Clouston conducted another trial instigated by Helmore, involving radio control of a full-size motor launch boat from a high-flying aircraft, using a Douglas DB-7 Havoc.

He was also involved in testing the Leigh Light, an aerial searchlight designed to illuminate submarines and surface vessels, and trialled on a Vickers Wellington.

[12] In May 1945, Clouston was posted as CO of German airstrip B151 that was being developed into the headquarters of BAFO (British Air Forces of Occupation), and named RAF Bückeburg.

Instead of being released by the RAF, he was promoted to group captain, and given a two-year posting on exchange to the Royal New Zealand Air Force as commanding officer of RNZAF Base Ohakea.

[23][24] Returning to service with the RAF after concluding his appointment at Ohakea, he was commandant of the Empire Test Pilots' School at Farnborough in 1949.