Larkhill, Salisbury Plain, between 1926 and 1928. He was granted a permanent commission as Flight Lieutenant on 1 January 1926. Although on secondment to the RAW, Irwin was studying in his spare time for his RAF promotional examination at the time of his death. (However, he was the intended commander of the R101's proposed successor, R102; Atherstone would then have taken command of the R101.) The Imperial Airship Scheme Proposals for an airship network linking Britain to its colonies and dominions emerged in the early 1920s but, due to economic and political factors, only bore fruit with the 1929 launch of two large prototype passenger airships from competing manufacturers, the R101 from the state-owned RAW and the R100 from the private-sector Airship Guarantee Company, a subsidiary of Vickers-Armstrongs. Irwin was involved in the programme in two capacities: initially commanding the R33 on experimental flights to aid the design of the new ships and later as captain of the R101. R33 Irwin was transferred to the RAW on 1 December 1924. He took command of the R33, which had been recommissioned as part of the programme after four years in mothballs, at Cardington on 2 April 1925. Under his command, the ship flew to Pulham for aerodynamic testing. However, the R33 broke away from its mast, at a time when Irwin was not aboard, during a gale on the night of 16–17 April and—after being blown backwards to the Netherlands, then making a safe return to Pulham—spent six months in its hangar, undergoing repairs that included the complete replacement of the nose section. The R33 returned to service in October, then was mothballed again in the spring of 1926 and resurrected in October of that year before its final withdrawal in November; it was eventually broken up in 1928. Irwin transferred back to the RAF in 1926. R101 Early flights and incidents In 1929, Irwin returned to the Royal Airship Works to command the newly completed R101, which first flew on 14 October. However, the ship's second flight on 18 October ended in an unfortunate incident, reminiscent of the one that had ended the R36's career and again involving Scott, who by now was Officer in Charge of Flying and Training at the Works. Scott "not only insisted on taking over for the landing from [Irwin] but also made a mess of the job," upsetting the ship's trim and permitting it