in front of the plane は勿論のことながら、in front of が熟語で「飛行機の前に」という意味で、飛行機の機体の外部の前方にという意味を表します。
(1) "It was pretty amazing," said
Hoffman, who remembers the moment in snippets: Seeing former President Jimmy
Carter; standing mere feet in front of the
plane that carried Ford's remains; walking away with a Ford
funeral card; playing the alma mater as one of the university's most beloved
alumni got his final salute. -- Daily Herald (Arlington Heights, IL), January
7, 2007
ところが、 in the front of the plane となると、the front of … が「…の前部」という意味になり、「飛行機の前部で」という意味になり、飛行機の内部のことを表します。
(2) The flight had been pleasant enough--they
were in the front of the plane--but the
stewardesses seemed disorganized, the meals coming at odd times. Emily had
turned down dinner because Tim was asleep, and she couldn't eat with Sarah
sleeping in her lap.
-- Michael Crichton, Airframe, p.3
