The pilot of a Marine reconnaissance plane missing since Thursday on a flight from Camp Pendleton was identified Monday by the Marine Corps as Capt. Sergio R. Vivaldi, 29, of Port Chester, N.Y.
Vivaldi and observer 1st Lt. Joel H. Piehl, 31, of Bismarck, N.D., have been missing since their OV-10A Bronco aircraft failed to return to the San Diego County base at 2:30 p.m. Thursday after a training mission.
As many as 28 aircraft from the Marine helicopter base in Tustin and from Camp Pendleton have been searching for the craft in the desert and mountains as far east as Phoenix and as far north as Las Vegas. The plane is an olive drab-colored, twin-engine turboprop.
Searchers spent another unsuccessful day Monday looking for the plane.
Lt. Gene C. Browne, spokesman for El Toro Marine Corps Air Station in Orange County, said the military is relying on civilian reports to direct the search.
"We're concentrating search efforts based on valid sightings," Browne said.
As of Monday, the Marines had received 19 calls from people who recalled seeing the plane as it flew overhead, Browne said. The sightings were concentrated in the Southern California mountain ranges, including the Big Bear, San Gorgonio and San Jacinto areas.
Browne said the disappearance of a military plane for this long in Southern California is unprecedented for the Marines.
"We usually find them after a couple of hours," he said. "It's still a complete unknown."
Piehl's sister, Linda Wolski, said Monday that the family is hopeful that the craft will be found. She said Piehl is an expert at desert survival who has trained infantry troops on what to do if lost in the desert.
"We have a lot of hope he'll be found soon," Wolski said.
Efforts to reach Vivaldi's family were unsuccessful Monday.
Civilians who may have seen the observation plane between 11:30 a.m. and 2:30 p.m. Thursday are asked to call the El Toro Marine base at (714) 726-2512.