BCal was so pleased with the DC-10's performance that it decided to convert both of the options it had taken when placing the original order for two aircraft during 1976 into firm orders for delivery in autumn 1978 and spring 1979 respectively. However, a subsequent strike at the manufacturer's plant meant that McDonnell Douglas could not honour its delivery schedules. This necessitated the temporary lease of a Boeing 747-100 from Aer Lingus, and the use of BA flightdeck crews to operate the aircraft. The aircraft, which wore a slightly modified BCal livery, was operating the Gatwick—Houston schedule during the 1978/79 winter timetable period to cover for the late delivery of the airline's third DC-10.