After only eighteen months of service two aircraft disappeared within three months of each other. The Secretary of State for Civil Aviation ordered a full investigation into the causes of the disappearances. This was carried out by the Royal Aircraft Establishment (RAE) at Farnborough and a court of enquiry was established.

G-ALYU in tank
One part of the investigation examined cabin pressurisation.
This used water to produce cabin loading and hydraulic rams to generate
wing loading. BOAC Comet, Yoke Uncle, was placed inside a water tank with
the wings protruding through seals in the walls of the tank. The loads
which were applied simulated a three hour flight in ten minutes.