Both Airplane Pilot Friedrich Karl and his observer, Senior Patrol Agent John S. Blue, were stationed at Yuma, Arizona, when they were killed in an airplane crash.
The agents were on a signcutting and aircraft patrol assignment, having departed from the Yuma County Airport at approximately 6:00 a.m., on October 4, 1973. The flight also served to acquaint Senior Patrol Agent Blue with portions of the Yuma Sector since he had transferred there a short time before.
After some five hours of flight, the officers landed at the Stoker Company airport at Tacna, Arizona, for a rest stop and to communicate with units from the Tacna Station relative to patrol plans and operations. At approximately 12:00 noon, shortly after take-off from Tacna, the airplane struck a static line near the top of 52-foot poles of the Wellton Irrigation District power line. Contact of the landing gear with the static line caused the plane to flip, invert, and fall to the ground in an upside-down position. Both of the agents were killed instantly upon impact.