My first-ever trip on an aircraft was in VT-DJX, Rani of Madurai, which later became BG-579.
The trip was behind a tug, from the Air India hangar on the south side, to the then 'Passnger Terminal' on the north side at LHR, courtesy of the AI Station Engineer. Must have been late '59 or early '60.
A small step for mankind, but as much of a thrill to an eleven-year-old as a flight round the world!