The R.38 class was designed to meet an Admiralty requirement of June 1918 for an airship capable of patrolling for six days at ranges of up to 300 miles from home base and altitudes of up to 22,000 ft (6,700 m).

Design work was carried out by an Admiralty team led by Constructor-Commander C. I. R. Campbell, of the Royal Corps of Navy Constructors.

It was then re-ordered on 17 February: on the same day, Oswald Short was informed that the Cardington, Bedfordshire works, recently built as a specialised airship production facility, was to be nationalised.

It was intended to follow R.38 with orders for three airships of the same class: R.39, identical to R.38, to be built by Armstrong-Whitworth, and two others, R.40 and R.41, of a design variant with the length reduced to 690 ft (210.31 m) due to the limited size of existing manufacturing sheds.

[4] In a further round of cutbacks, the cancellation of the unfinished R.38 also appeared imminent, but, before this actually happened, the project was offered to the United States.

The 13-sided mainframes were 49 ft (15 m) apart, and were made up of diamond-shaped trusses connected by 13 main and 12 secondary longitudinal girders and a trapezoidal keel.

[10] The United States Navy had decided that it wanted to add rigid airships to its fleet and originally hoped to get two Zeppelins as part of war reparations, but these had been deliberately destroyed by their crews in 1919[11] in actions connected with the scuttling of the German fleet at Scapa Flow.

Following significant girder failures during testing Commander Jerome Hunsacker and Charles Burgess raised questions over the strength of R.38.

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 58 mph (93 km/h), causing the ship to begin hunting over a range of around 500 ft (150 m).

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.

[21] 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.

[23] 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.

"[24] 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,[25] which had an intended destination of RNAS Pulham in Norfolk, where it could be moored to a mast (a facility unavailable at Howden).

The first, chaired by Air Vice-Marshal Sir John Salmond and composed mainly of RAF personnel, was convened on 27 August.

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.

[41] Data from Flight 6 June 1921 :ZR.2 ("R.38")[42]General characteristics Performance Armament In December 1922, the Council of the Royal Aeronautical Society decided to offer an annual prize for technical papers on airships, open to international competition.

Burgess, Jerome Hunsacker, and Starr Truscott who presented their paper "The Strength of Rigid Airships.