John C. Stuelpnagel, a retired Northrop Grumman software analyst and world traveler, died of heart failure May 23 at Symphony Manor in Roland Park. He was 79.

The son of Daniel Stuelpnagel, an egg dealer, and Elva Triggs Stuelpnagel, a homemaker, John Clay Stuelpnagel was born in Houston and spent his youth in Yankton, S.D.

After graduating from the Cranbrook School, a private school in Bloomfield Hills, Mich., he earned a bachelor's degree from Yankton College in Yankton.

As a graduate student he came to Baltimore and entered the Johns Hopkins University, from which he obtained a doctorate in mathematics in 1962.

While in graduate school, he met and fell in love with Dinny Linville, who was a librarian at Johns Hopkins. The couple married in 1959.

After completing a three-year postdoctoral fellowship at the Research Institute for Advanced Studies in Baltimore, he joined the Defense Electronics Group at Westinghouse Electric Corp. in 1965. There his work in software and signal processing led to a distinguished career in radar development.

In 1985, Dr. Stuelpnagel was named manager of the F-16 Radar Programs. In order to evaluate military use of Westinghouse radar systems, he flew several missions in a Navy F-4 Phantom jet as a radar operator. He also spent time aboard the aircraft carrier USS John F. Kennedy, observing flight and ship movements.

He was promoted to director of research and development for Westinghouse Electronic Systems Group.

From 1996 until retiring in 2012, he was a software analyst in Northrop Grumman's Defense Travel System in Arlington, Va.

The longtime Homeland resident enjoyed vacationing at North Carolina's Outer Banks, where he liked to play tennis and relax on the beach. He also traveled to Europe and the Galapagos Islands. He was a member of the L'Hirondelle Club and the Country Club of Maryland.

He was a communicant and vestryman at St. David's Episcopal Church, 4700 Roland Ave., where services will be held at 11 a.m. today.

In addition to his wife of 56 years, Dr. Stuelpnagel is survived by a son, Daniel Stuelpnagel of Baltimore; two daughters, Jenny Hovermill of Roland Park and Vicky Murray of Ruxton; a sister, Jean Britton of Slinger, Wis.; and four granddaughters.

—?Frederick N. Rasmussen