Cole Black, a former Navy captain from Escondido, was aboard the twin-engine plane that crashed in an orange grove in a rural area near Delano, his wife, Karen Black, told The Associated Press in a telephone interview from her home.
Also aboard were Bruce Klein, who lives in Oregon and owns several pizza restaurants, and Sally S. Wilson, a retired school teacher from Oakland, the News-Review newspaper in Oregon reported.
The plane was being piloted by Klein, the paper reported.
Black, 74, was heading home after speaking to students in Oregon this week about his experience as a POW.
The Piper Aerostar 602P took off from Roseburg, Ore., about 75 miles southwest of Eugene, said Teresa Hitchcock, a spokeswoman for Meadows Field Airport in Bakersfield.
It was heading to McClellan Palomar Airport in north San Diego County to drop off Black, his wife said.
The crash was being investigated by the National Transportation Safety Board and the Federal Aviation Administration.
Black was flying an F-8 Crusader when he was shot down over North Vietnam in 1966. He was jailed in a torturous prisoner of war camp nicknamed the Hanoi Hilton for nearly seven years.
At a 1993 reunion marking the 20-year anniversary of the POWs' release, Black expressed regret over a flying maneuver that changed his life.
"If I had turned right instead of left, I wouldn't have got shot down. Everybody goes through life doing things you sometimes say, 'I shouldn't have done that.' The penalty isn't too bad in some cases but it was pretty bad in that case," Black was quoted saying in an AP story.
After the ordeal, Cole remained in the military and became executive officer of Marine Corps Air Station Miramar in San Diego, then a Naval attache for Mexico and Central America, Karen Black said.
After retiring from the military in 1986, Cole pursued a career in real estate. He spoke often to civic groups about his experience in Vietnam, and remained close with other POWs, said his wife.
"He was not bitter about what he went through," she said. "He was among a group of men who believed in honor and country."
Cole was to celebrate his 75th birthday Nov. 27, and his friends had been raising thousands of dollars to have his name painted on a plane he had flown on and is now displayed at the USS Midway Museum in San Diego.
"It would have been a nice tribute," she said.