Flight testing the Titanic: re-visiting the loss of the R101 airship

Guy Gratton, Visiting Senior Research Fellow, School of Engineering and Design, Brunel University, London & Head, Facility for Airborne Atmospheric Measurements (FAAM)

Abstract

His Majesty’s Airship R101 was a British airship built between 1926 and 1929; requiring a crew of 48 of whom an absolute minimum of 15 were required to be on duty at any time, and at 267m with a gas capacity over 5 million cubic feet long it remains the third largest aircraft ever flown –3.6 times the length of an A380. R101 also incorporated many points of new and under-development technology, including recovery of water ballast, semi-rigid construction, steel framework, wire cage gasbag retention, high rate of climb relief valves, multiple control rooms and aircraft Diesel engines. Following some major modifications, HMA R101 was scheduled for a 74 hour multi-sector endurance demonstration in October 1930, from England to India. Despite adverse weather, lack of testing of some recent design changes and two out of five engines having failed the flight was continued out of England and into France. Early in the morning of the second day of the flight the aircraft entered an uncontrollable descent, striking the ground at about 15 knots and 20° nose down. The initial impact appears to have been survivable, but the subsequent hydrogen fire killed 48 of the 54 persons on board, and destroyed the aircraft – also effectively ending all large airship development in the United Kingdom, despite a parallel “sister” project, the R100, being well into its own flight test programme without significant problems.

This paper will briefly describe the history of the R101, but concentrate upon comparing the R101 programme with both the more successful R100 programme, and modern best practice in large flight test programmes. It will show that modern good practice, if followed: including the “no-vote”, modern CRM, realism about failing technologies, consideration of ergonomics, and use of instrumented airframes: should have prevented many of the mistakes which led to the world’s worst flight test accident. There are still however lessons to be learned from the loss of the R101 for both flight test and overall aircraft programme management. This includes preventing political pressure from overriding good safety practice, ensuring that aircraft changes are properly evaluated before resuming a pre-planned flight test programme, not permitting safety critical programme decisions to be made by staff without the right knowledge base, and understanding and learning from other organisations’ flight test and development lessons as well as your own.