A Northwest airlines flight has apparently been damaged by some unknown object while flying at 18,000 feet:
"An FAA spokeswoman in Chicago said officials haven't determined what caused the dent yet, but there is "definitely no evidence of a bird strike." Bergen said the crew aboard Flight 478 from Detroit reported a loud bang Monday and then the aircraft's radar became inoperative. The aircraft landed safely."
Link to full article here.
Despite what the article says, a bird strike is not out of the question at the altitude mentioned. (However, I believe a bird strike would be obvious during a visual inspection.)
"An FAA spokeswoman in Chicago said officials haven't determined what caused the dent yet, but there is "definitely no evidence of a bird strike." Bergen said the crew aboard Flight 478 from Detroit reported a loud bang Monday and then the aircraft's radar became inoperative. The aircraft landed safely."
Link to full article here.
Despite what the article says, a bird strike is not out of the question at the altitude mentioned. (However, I believe a bird strike would be obvious during a visual inspection.)