Navy investigators have been unable to determine what caused a twin-engine radar plane to crash off North Carolina's coast last August, killing three aviators.

A report released Monday indicates the E2-C Hawkeye experienced
problems with a cockpit indicator during flight the preceding day.
It also notes the most recent maintenance records were onboard when
the plane crashed.

Thirty-year-old Lieutenant Cameron Hall of Natchitoches,
Louisiana; 31-year-old Lieutenant Ryan Betton of Collinsville,
Virginia; and 25-year-old Lieutenant Junior Grade Jerry Smith of
Greenville, Maine, died in the crash.

The plane went down just after takeoff from the Norfolk-based
aircraft carrier USS Harry S. Truman during exercises that involve
taking off and landing on a carrier deck.

The report said there was no evidence of maintenance issues
causing the crash.