John Patrick Callahan was working as a researcher and engineer for a defense contractor in New York City in the early 1950s when he noticed from his office window overlooking Flushing Bay that airplanes sometimes overshot the runway at LaGuardia Airport and ended up in the water.
He went home to his basement to puzzle out a solution. Three weeks later, with a colleague at EDO Corp. in College Point, N.Y., he had invented the timing device used in the Loran system that assists pilots in judging their landing distance.
Mr. Callahan, 71, died Thursday at Johns Hopkins Hospital after a long battle with cancer. Even in his illness, said his wife, Barbara Callahan, the Gambrills resident continued to consult with defense industry colleagues who wanted to discuss ideas.
"He gave a lot of his time to his country and to the Boy Scouts and just to people," Mrs. Callahan said.
Mr. Callahan spent more than 50 years in the military and then the defense industry, retiring in February from Northrop Grumman Corp.
An engineering graduate of Cornell University, he served in the Army Signal Corps during World War II. Then he began a 37-year career with EDO, working with sonar and acoustics.
Often, Mrs. Callahan recalled, her husband would leave on short notice to board a submarine to check systems and trouble-shoot. "He was a very interesting man to live with," she said. "I never knew where he was, but I knew he was somewhere doing his job."
He retired from EDO in 1985, and moved to Gambrills to join Westinghouse Electric Corp.'s Oceanic Division, where he worked on a team that developed an anti-submarine warfare system. He was working for Westinghouse when it was purchased by Northrop Grumman.
He received many honors for his work, including the Order of the Decibel, a rarity for a civilian, from the Naval Undersea Warfare Center in recognition of his 10 years as chairman of the National Security Industrial Association Detection and Classification Subcommittee. He also was awarded two meritorious public service awards from the chief of Naval Operations and Warfare Center.
An avid hiker and amateur radio buff and photographer, Mr. Callahan was active in the Boy Scouts of America for many years.
He was a member of St. Stephen's Episcopal Church in Crownsville, where services will be held at 2 p.m. tomorrow.
In addition to his wife, he is survived by three sons, David Callahan of Eldersburg, William Callahan of Richmond, Va., and Richard Callahan of Gambrills; and a brother, Edward Callahan of New York City. His first wife, Joyce McCormick Callahan, died in 1975.
A trust fund with the Boy Scouts of America has been established in Mr. Callahan's honor. Contributions may be sent to T. J. Furlong, 822 Birch Trail, Crownsville 21032. Donations may be made also to the Johns Hopkins Department of Otolaryngology Head and Neck Cancer Center, 601 N. Caroline St., No. 6260 B, Baltimore 21287-0881.
Pub Date: 5/25/98