Also killed in the crash, which occurred about a half-mile west of the airfield, were Alan G. Spire, 59, of Clairemont and Lorne Groves, 40, of San Diego.
The three had returned from a project in Mexico and were headed from Brown Field to Montgomery Field in Kearny Mesa when their plane lost power and crashed in a craggy canyon.
A resident of Jamul, Mr. Akin settled in San Diego County 22 years ago. In addition to his work for San-Lo, he flew charter flights out of Montgomery Field for National Air College and survey flights, also out of Montgomery, for Gibbs Flite Center.
David Cowan of Spring Valley, a close friend of Mr. Akin, said, "Bob had a brilliant, analytical mind. He could solve the most difficult puzzles, spatial problems and brain teasers in seconds, leaving all his friends in the dust.
"He never stopped analyzing and perfecting his approach to a task, no matter how big or small."
In 1958, Mr. Akin left Dartmouth College after 2 1/2 years as a math major. He had questioned his goals in life and realized he had none at the time, he later would write in a brief autobiography.
Mr. Akin was commissioned as a naval aviator in February 1961 and assigned to flying A-4 attack planes for Marine Attack Squadron 331 in Beaufort, S.C.
Beginning in August 1967, he served for a year in Vietnam, where he provided air liaison to a battalion of the 9th Marines.
After his Vietnam tour, Mr. Akin earned a bachelor's degree in business administration at Oklahoma State University while in the Marines.
In the early 1970s, Mr. Akin completed an exchange tour with the Navy in a tactical air control squadron in Norfolk, Va. His final military assignment was with the Landing Force Training Command in Coronado, where he taught procedures in tactical air control and helped plan military operations.
As a civilian, Mr. Akin volunteered hundreds of hours as a San Diego Police Reserve from January 1984 to December 1995.
A native of Springfield, Mass., he was raised in New Bedford. He completed high school at a private boarding school in Windsor, Conn., where he played varsity football, wrestled and ran track.
While at Dartmouth, Mr. Akin wrestled on the freshman and later varsity teams and helped operate a campus radio station for the Dartmouth Radio Club.
He is survived by his wife, Terri; a daughter, Karen Erb, of Pensacola, Fla.; a son, Robert Akin, of Kadena Air Base, Okinawa, Japan; and his mother, Therese Akin, of Longmeadow, Mass.
Donations are suggested to Dartmouth College, in care of Bob Barr, 6068 Blunt Alumni Center, Hanover, N.H. 03755.
Robert M. Akin's 235 combat missions in Vietnam with a Marine Corps air attack squadron brought recognition in heroic proportions: two Distinguished Flying Crosses, 18 Air Medals and a Purple Heart.
Hoping to further his love of flying in private industry, he retired from active duty in the military in 1978.
"With my desire to travel and appreciation of diversity, I think that flying business jets in the corporate environment will provide me the most desirable career," he wrote in a brief resume of his life.
A free-lance pilot, Mr. Akin was on assignment for San-Lo Aerial Surveys of San Diego when he died in the crash of a twin-engine plane Friday near Brown Field in Otay Mesa. He was 59.
Services are scheduled for 10 a.m. tomorrow at the Marine Corps Recruit Depot Chapel in San Diego.
An investigation is under way by the Federal Aviation Administration and the National Transportation Safety Board to determine the cause of the crash.