Rudder failure was a likely factor in the crash of a Hawai'i Air National Guard F-15D fighter jet off O'ahu on Feb. 1, although an investigation could not find definitive evidence of the cause, Pacific Air Forces said yesterday.

The pilot ejected safely but the plane was destroyed upon impact.

An Accident Investigation Board convened by Pacific Air Forces determined that there "was no clear and convincing evidence" to determine a root cause for the crash, the Air Force said in a news release.

However, the board did find sufficient evidence to conclude that both rudders failed in a midrange position to the left, most likely due to a failure involving an aileron-rudder connection.

This failure induces a yawing, rolling motion to the left that the pilot was unable to correct, the Air Force said.

The twin-tailed fighter piloted by Lt. Col. Christopher "Frenchy" Faurot crashed in the ocean about 60 miles south of O'ahu.

Faurot, 41, had reported losing altitude and control before ejecting, officials said. The fighter sank in more than 2,000 feet of water.

The Damien Memorial School graduate, who lives in Lanikai, had been taken off flying status to assist with the Air Force investigation, officials said. Faurot suffered only minor injuries.

The financial loss of the aircraft was $43.8 million, the Air Force said.

The aircraft was assigned to the 199th Fighter Squadron, 154th Wing, and was part of a two-aircraft training mission, involving one-on-one offensive and defensive maneuvering.