SEATTLE (Reuters)- A Boeing Co. spokesman said Monday that the engine lost from a 747 cargo plane on its approach to Luxembourg airport had apparently fallen off by design to prevent greater damage to the wing. 

The plane, belonging to the Luxembourg freight carrier Cargolux, landed safely Sunday, and none of the four crew members was hurt, the police said. Bill Curry, the Boeing spokesman, said that a strut attaching the engine to the wing is believed to have snapped and allowed the engine to fall off, as it is designed to do in some cases to prevent greater damage to the wing, which holds the jet’s fuel tanks. The strut could snap in the event of an engine failure or other problem, such as hitting something. Mr. Curry said. 

The same type of jumbo jet, belonging to the Israeli airline El Al, lost two of its four engines last month before plunging into an apartment building in Amsterdam, killing up to 70 people.