Tustin Marine Pilot Among Helicopter Crash Victims : Accident: Three others presumed dead off African coast are identified as members of a unit based at Camp Pendleton.

One of four Marines missing and presumed dead after a weekend helicopter crash off the coast of East Africa was identified Tuesday as Capt. Mark D. Derickson of Irvine, pilot of the ill-fated aircraft.

Fourteen other Marines were rescued after the CH-46E Sea Knight went down Saturday night. Five of them suffered serious burns and were immediately flown to a U.S. military hospital in Germany.

The three other missing Marines in the fiery crash were from the 1st Battalion, 1st Marine Regiment at Camp Pendleton. They were identified as Sgt. James L. Hagger, 29, of Spartanburg, S.C.; Cpl. Clarence E. Jenkins Jr., 26, of Greenville, N.C.; and Lance Cpl. Rodney N. Hudson, 22, of Garden City, Mich.

Derickson, 28, whose wife, Denise, and two daughters, Cassandra, 2, and Kimberley, 2 months, live on base housing in Irvine, joined the Marine Corps as an aviator in 1985. He transferred to the Tustin-based Marine Medium Helicopter Squadron 161 in August, 1991, and went to the Persian Gulf War as a helicopter pilot. It was his second tour of duty at the Tustin Marine Corps Air Station.

When the accident occurred, the helicopter was attached to the 13th Marine Expeditionary Unit, which is made up of personnel from Camp Pendleton and the Tustin helicopter base. The expeditionary force was on a six-month deployment at sea and was headed from the Gulf of Arabia to Mombasa, Kenya.

Although the military refused to say what the expeditionary unit was doing in the area, Gen. Carl E. Mundy Jr., Marine Corps commandant, said in a recent interview in The Times that Marines were involved in the evacuation of U.S. civilians and diplomats from intertribal strife in Liberia and in Somalia. The helicopter accident occurred 60 miles off the Somalia coast while the helicopter was on a routine flight, the military said.

The accident is still under investigation, Marine Corps officials said Tuesday, and the cause of the crash is still unknown.

Other than indications that there was fire aboard the aircraft, little is known about what happened before the helicopter plunged into the ocean.

A search for the four missing Marines was called off Monday. Their remains have not been recovered.

The crash has rekindled debate concerning the age of the 1960s vintage CH-46. Its replacement, the V-22 Osprey tilt-rotor plane, is stalled in Congress, one of many victims of Pentagon cutbacks.