The airship was to be given a curtailed series of tests before being handed over to the U.S. Navy, who were to fly it across the Atlantic.
J. E. M. Pritchard, the officer in charge of flight testing, proposed to carry out 100 hours of flight testing, including flights in rough weather, followed by 50 more flown by an American crew before crossing the Atlantic. The commander of the Howden Detachment Commander Maxfield disagreed and urged that the test of R.38 be completed in one day. Air Commodore Edward Maitland as the man most responsible for testing the R.38 was appalled and disagreed. He protested the abbreviated test schedule. He was told to not provide advice unless asked. The Air Ministry ruled that 50 hours would be sufficient. The decision had been made in ignorance by officials unfamiliar with airships as well as the knowledgeable officers who were reluctant to release an airship of unproven strength, egged on by an eagerness to return to America by Commander Maxfield. The
R.38 made its first flight on 23–24 June 1921, when it flew registered as R.38 but bearing the US designation ZR-2; the seven-hour flight revealed problems with over-balance of the control surfaces. With the balance area of the top rudder reduced, a second test flight was carried out on 17–18 July. The control balance problem remained, and, on return to Cardington, all the control surfaces were reduced in area. On 17–18 July, a third flight was made, during which the airship was flown from Cardington to Howden and then out over the North Sea, where the speed was increased to , causing the ship to begin
hunting over a range of around . The highly experienced Pritchard took over the controls from the American coxswain and reduced the oscillation, but several girders in the vicinity of the midship engine cars had already failed. The control surfaces were still over balanced. More importantly girders of intermediate frame 7b as well as longitudinal Girder F had failed in one place, while frame 7a and longitudinal F' each had failed in two locations. R.38 returned to
Howden at reduced speed. Work on reinforcing the buckled girders was carried out and completed by 30 July at Howden. There were increasing doubts being expressed about the design, including some made by
Air Commodore E. M. Maitland, the very experienced commander of the Howden base. Maitland urged that all future speed trials be conducted at higher altitude as was the practice of the Germans while testing the fragile Zeppelins upon which the R.38 design was based. There was considerable concern expressed by Admiral Griffen, the chief of the Bureau of Steam Engineering. Burgess at the Bureau of Construction and Repair was also concerned. Starr Truscott of the Bureau of Construction and Repairs believed that the negative endorsements of Admirals Griffin and Taylor would suffice to extend trials for the ZR-2 (R.38) but he was soon proven wrong. Admiral Taylor endorsed Commander Maxfield's optimistic report of July 20.
Fatal crash Following a spell of bad weather, the airship was walked out on 23 August and, in the early morning, took off for its fourth flight, which had an intended destination of
RNAS Pulham in Norfolk, where it could be moored to a mast (a facility unavailable at Howden). The mooring, however, proved impossible because of low cloud, so the airship returned to sea for the night. Lieutenant Richard Byrd was unable to join the crew as he had mistakenly missed his train and the British thought he had skipped out. Byrd later rose to Rear Admiral and explored the North and South poles . The next day, after a brief speed trial (during which a speed of was reached), a series of turning trials was started at a speed of and an altitude of . Passing over Hull, a series of control reversals were started which the Germans would never have attempted at such a low altitude. Wann, who was in the control gondola, stated that the controls were never put beyond 15 degrees, while Bateman, from the National Physical Laboratory who was recording pressures upon the vertical fins, stated clearly that the rudders were being driven rapidly from hard over to hard over which would have been 25 degrees from one side to 25 degrees to the other. At 17:37, while close offshore near
Hull and watched by thousands of spectators, the structure failed amidships. Eyewitnesses reported seeing creases diagonally along the hull towards the stern. Both ends drooped. The R.38 then cracked open with men and objects dropping from the rupture. The two sections separated with the forward section catching fire followed by two colossal explosions. The two explosions broke windows over a large area with the flaming fore section falling rapidly followed by the aft section descending slowly. The remains fell into the shallow waters of the
Humber Estuary. 16 of the 17 Americans, and 28 of the 32 Britons, in the crew were killed, including both Maitland and Pritchard. The only American to survive was Rigger Norman Otto Walker. Four of those who survived were in the tail section, Flight Lieutenant Archibald Herbert Wann, R.38's British Commanding Officer, was in the control gondola and survived.
Aftermath The loss of the R.38, which represented the hope of airship men in Britain, resulted in three official enquiries into the disaster. The first, chaired by Air Vice-Marshal
Sir John Salmond and composed mainly of RAF personnel, was convened on 27 August. Its remit was to consider the general circumstances of the accident, and, although it came to the conclusion that the structure had failed while extreme control forces were being exerted, it was considered necessary to carry out a more detailed technical inquiry into the airship's design. The report also criticized the system by which a single authority was responsible both for the airship's construction and for inspection of the work, and, given the great differences between R.38 and previous British designs, held that the design should have been subjected to a more thorough scrutiny. The Admiralty held a second inquiry into the history of the design of the airship, and into its construction up to the point where it was taken over from the Admiralty by the Air Ministry. In contrast to the previous inquiry, this one concluded that the design did not incorporate any new features which affected the airship's strength, and further maintained that "there was at the time no body in existence which could have been called in to advise on the structural strength of R.38." The technical Committee of Enquiry, chaired by
Mervyn O'Gorman, concluded that no allowance had been made for aerodynamic
stresses in the design, and that while no loads had been placed on the structure during testing that would not have been met in normal use, the effects of the manoeuvres made had weakened the hull. No blame was attached to anyone, as this was not part of the committee's remit. The R.38 disaster led to a rigorous investigation of the structure of airships preceding the design of the next two airships built in Britain, the
R.100 and the more radical
R.101. What is curious is that the practice of having responsibility for design and ultimately judging the airworthiness of that design remained in the same hands. Nevil Shute Norway (who was the novelist
Nevil Shute) worked on the design of the R.100 airship for
Vickers Ltd. from 1924. When he researched previous airship calculations and read the reports of the 1921 R.38 crash he was "unable to believe the words he was reading" that "the civil servants concerned had made no attempt to calculate the aerodynamic forces ... " and he asked one of his chiefs "if this could possibly be true. Not only did he confirm it but he pointed out that no one had been sacked over it or even suffered any censure." For the men who built the R.38 its sale to the US Navy represented a last chance to salvage something from the Royal Navy's rigid airship program and its takeover and abandonment by the RAF. The demands of the Exchequer and the US Navy's commander Maxwell converged to cause risks to be taken which were questioned at the time and ignored with fatal consequences. , Hull ==Specifications (
R.38/ZR-2)==