Winter Park resident Gene Witt was really high last week when he proposed marriage to Kathy Bernich. Witt, 25, was in the air at the time in a Cessna 172 at an elevation of 1,500 feet, and on the air for WKIS (740). He's the radio station's Eye-in- the-Sky traffic reporter, in addition to working as a flight instructor at Orlando Executive Airport. On the air he asked Bernich, 29, a pilot for Florida Express, to be his wife, and, if her answer was yes, to cover the top of her car outside her Winter Park residence with a pink blanket. ''I was listening to Gene,'' she said, ''but I was in my car and thought, 'Oh, my gosh.' I had to drive like crazy to get home.'' Her answer was yes, the pink blanket was sighted from the air, listeners heard all about it on the airwaves, and on Saturday of last week, in a private ceremony in Winter Park, they were married.