Monday, 6 July 2009

The R101 Airship Disaster


The R101 was a British rigid airship completed in 1929 as part of the Imperial Airship Scheme. After initial flights, and two enlargements to the lifting volume, it crashed on 5 October 1930 in France during its maiden overseas voyage, killing 48 people. Amongst airship accidents of the 1930s, the loss of life surpassed the Hindenburg disaster of 1937 ans was second only to that of the USS Akron crash of 1933. The demise of R101 effectively ended British employment of rigid airships.

R101 was the result of a British government initiative to develop airships. In 1924 the Imperial Airship Scheme was proposed as a way to carry 200 troops or five fighter aircraft. Two airships were built by two separate teams. One under the direction of the Government Air Ministry (R101), the other by a private company, Vickers, (R100), under contract for a fixed price. Among Vicker's engineers were the designer Barnes Wallis, later famous for the bouncing bomb and, as Chief Calculator (that is, Stress Engineer), Nevil Shute Norway, later well known as a novelist.

The 101 project was hampered by serious mismanagement and meddling by the Air Ministry that threatened the whole project from the beginning. Weight problems caused by excessive safety concerns, and the failure to develop proposed hydrogen burning engines, were two of the major obstacles. At the time opinion about the R101, varies from the best airship ever designed to an appalling bad piece of engineering. As the project progressed more problems emerged; the wiring of gasbags, unsatisfactory valves, and an outer cover prone to deterioration, and unsatisfactory dynamics causing instability.

The building of the R101 began in 1926 at the Royal Airship Works at Cardington in Bedfordshire. Due to the many problems encountered the completion was delayed from 1927 to 1929. The R101 was meant to have a useful lift of 60 long tons but ended up only able to carry 35 tons.

During its flight at the Hendon air show in 1030, it almost plunged to the ground, as well as repeatedly going into a dive on the return flight. The airship operated under a 'Permit to Fly'. restricted to experimental craft operating only in British airspace. Further modifications were carried out,after which only one test flight was carried out. The safety inspector, McWade, refused to issue a a Certificate of Airworthiness. However, the records show that despite McWades objections a Certificate of Airworthiness was issued on 2 October.

At completion, she was the largest flying aircraft ever built. The passenger accommodation was spread over two decks,included 50 passenger cabins, a dining room for 60 people, two promenade decks and an asbestos-lined smoking room for 24 people. The upper deck contained a spacious lounge, together with passenger and crew space, kitchens and washrooms.

The final trial flight, originally scheduled for 26 Septeber 1930 was delayed by unfavourable wind until October 1. She returned to Cardington after a flight of 17 hours.

The R101 departed on October 4 for its intended destination Karachi (then part of British India). On release from its tether mast, the nose of the R101 dipped alarmingly, forcing the airship to drop 4 tons of water ballast to bring her back to true. The reduction in forward ballast reduced usable lift by almost half. In contravention of reports received from the airship about cruising height, observers across both the UK and France were amazed and alarmed to see the airship flying so low. Even though it was foul weather, observers reported seeing people at the windows of the airship. In France observers feared the airship was so low it was in danger of hitting rooftops. Over France, R101 close to Beauvais ridge at a height of 88 feet went into a dive from which she slowly recovered. Almost immediately the airship went into another dive and hit the ground. She caught fire almost at once and burned fiercely, taking 24 hours to burn out. 46 of the 54 passengers and crew were killed immediately. Two men who survived the crash died later in hospital bringing the total to forty-eight dead.

The Court of Inquiry concluded that there was evidence there had been a failure of the outer cover of the upper nose, leading to the destruction of a gas bag, loss of hydrogen lifting gas, and caused the nose to drop. The R101 was the end of British attempt to create a lighter-than-air aircraft. Its competitor, R100, despite a more successful development programme, and a safe transatlantic trial flight, was mothballed immediately after R101 crashed and sold for scrap in 1931.