"The trouble of In-Flight Shut-Down" is a most fact to influence aircraft, especially the civil aircraft.

Trouble with the gearboxes of the Rolls-Royce engines caused some in - flight engine shutdowns, prompting the carrier to take the aircraft out of service for immediate modifications.

With the increasing effects of corrosive environment on the aircraft structures, calendar life has become a severe trouble of the air force at present and in the future.