Air Force Lieutenant General Christopher Bogdan said officials would allow flights to resume when it was safe to do so. He said the programme remained fundamentally on track despite the incident given the margins planned in during a recent restructuring of the $398.6 billion (232.91 billion pounds) programme.

Bogdan said he was glad the incident happened on the ground, and that both the pilot and rescue crew were not injured.

He said it was also easier to deal with an issue early in the programme, when there are about 150 engines in production or already delivered, as opposed to later when thousands of engines will be in use.

(Reporting by Andrea Shalal; editing by Jason Neely)