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 Royal Airship Works, and the
R100 from the private-sector Airship Guarantee Company, a subsidiary of
Vickers-Armstrongs. Irwin was involved in the programme in two capacities, first 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 Royal Airship Works at
Cardington, Bedfordshire on 1 December 1924. There he took command of the R33, which had been recommissioned as part of the programme after four years in mothballs, on 2 April 1925. Under his command, the ship flew to
Pulham in Norfolk 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 to over-ride the Cardington mooring mast. Irwin and Atherstone were "thoroughly upset" by the episode. Other incidents took place on the ship's third flight on 1 November when Scott released ballast during the landing without Irwin's knowledge and on the subsequent flight, when Scott took charge while landing at Cardington on 3 November and caused damage to one of the ship's reefing booms.
The endurance flight and afterwards On 17 and 18 November 1929, the R101 made an "endurance" flight of over 30 hours' duration (in fact, this flight was to be the longest the ship ever completed), taking the airship over England, Scotland, Ireland and Wales. According to Atherstone's diary, as the R101 approached
Dublin Bay at 08:00 on 18 November, Irwin "took over for the Forenoon Watch and flew the ship in majestic sweeps over his native land and city"; the R101 then passed down the coast to
Bray and "gave the
Kingstown–
Holyhead mail boat a good start and then hooshed past her headed for the same place." In
Anglesey, the ship overflew
Rhosneigr, where Irwin's mother lived. According to the report of the subsequent inquiry into the R101 disaster, the R101's performance on this flight "gave much satisfaction" to both Irwin and Major Scott. At this point, the ship had still not been formally handed over to Irwin. According to Atherstone's diary entry for 2 December, Irwin was "fed [up] to the teeth about the way promises made to him by Colmore [the Director of Airship Development] and Scott have not been kept." Irwin had been "definitely assured" that the R101 would be handed over to him before entering its shed for a refit that began on 1 December, but he was left in what Atherstone called the "unenviable position of being unofficial captain of the ship."
Modifications and preparations for the India flight Lord Thomson, the
Secretary of State for Air, expressed his interest in making a flight to India after travelling as a passenger on the new airship's second flight. However, the R101, as originally built, had insufficient disposable lift to make the flight. Weight-saving measures and efforts to improve lift were initiated and completed in early 1930. R101 made three flights in late June 1930 and, in a report to Scott on 1 July, Irwin expressed concerns over "flapping" of the ship's outer cover, possible malfunctioning of gas valves and "an abundance of holes" in the gas cells due to chafing against girders. In a previous conversation with Squadron Leader Ralph Booth, captain of the
R100, on 27 June, Irwin had expressed the opinion that "most of the losses were from the gas valves", due to "excessive pulsing and flapping" of the envelope fabric. The R101 then returned to its shed for rebuilding with an added section. It came out of the shed on 1 October and departed later that day on what would be its only test flight before departure for India. However, the flight, planned to last 24 hours, was cut short to 16 hours 51 minutes. At the inquiry following the crash, Irwin and the other officers were described as "undoubtedly well satisfied with the performance of the ship" but Squadron Leader Booth told the inquiry that he had no reason to think that Irwin had changed his previous view that "more elaborate trials in bad weather would be expedient", and the inquiry report stated that it was "impossible to avoid agreeing" with Booth's opinion. It was eventually decided that the flight from Cardington to
Karachi (then northern British India, now
Pakistan) and back, with a stop at
Ismaïlia, Egypt, in both directions, would set out on 4 October 1930. Lord Thomson, Director of Civil Aviation
Sefton Brancker and other dignitaries would be aboard. Major Scott was in charge of the flight. He had travelled on the R100's trip to
Montreal and back in July and August 1930. As he explained his position to a
Flight correspondent, he was "officer in command of the flight" and decided "all such points as when the ship would sail, her course, her speed, her altitude." Irwin was the airship's captain, in charge of the crew and discipline." As
James Leasor phrased it in his book
The Millionth Chance, "Scott was in the position of an
Admiral in his
flagship; Irwin was the flagship captain and responsible for [crew] discipline." Sources differ on the degree to which Irwin expressed concern as the India flight neared. Leasor quoted Elsie O'Neill, the widow of one of the passengers, to the effect that Irwin "kept on saying 'They're rushing us. We're not ready, we're just not ready'" when she and her husband visited the ship prior to the flight. Moreover, according to the airship historian Giles Camplin, it was "often said" that Irwin "considered stepping down" but was dissuaded from this by "the certain knowledge that others would step forward to take his place." However, Sir
Peter Masefield, another historian of the R101, believed that "Colmore, Scott,
Richmond [the ship's designer] and Irwin were all satisfied that the airship was sound and airworthy and that the flight...could be mounted in confidence". Notwithstanding this, both Masefield and the inquiry report observed that the programme of trial flights that Irwin himself drew up in 1929 had not been completed at the time of departure. == Personal life ==