The MEDEVAC reference article from the English Wikipedia on 24-Apr-2004
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MEDEVAC

A MEDEVAC is a military acronym for "medical evacuation."

A MEDEVAC is also a helicopter used as an ambulance (sometimes called an "air ambulance"). This permits the rapid transport of seriously injured persons, particularly trauma patients, from the scene of the accident to the hospital. The US military pioneered this lifesaving technique during the Korean War.

News accounts of such transportation typically use the term "airlifted".

Many patients transported by MEDEVAC are taken to a specialized hospital known as a trauma center.