R101 would generate favourable publicity for the airship programme. The final trial flight of R101 was originally scheduled for 26 September 1930, but high winds delayed the move from the shed until 1 October. That evening, R101 slipped the mast for its only trial flight before setting off for India. This lasted 16 hours 51 minutes and was undertaken under near-ideal weather conditions; because of the failure of the oil cooler in one engine, it was not possible to carry out full speed trials. The flight was curtailed because of the need to prepare the airship for the flight to India.
R101 new course was set to bring R101 over Orly, based on an estimated wind direction of 245 degrees and speed of . The intended course would have taken R101 four miles west of Beauvais, but the estimated wind speed and direction were inaccurate, as a result of which the 101's track was to the east of its intended course. This error would have become apparent when, at about 01:00, R101 passed over Poix-de-Picardie, a distinctive hilltop town that would have been readily recognisable to the navigation officer, Squadron Leader E.L. Johnston. Accordingly, R101 changed course: the new course would take