Boone, IA Two Civil Air Patrol Officers Die in Crash of a Beech A45 Doing Flood Surveillance, Mar 1971
On March 13th, 1971, Civil Air Patrol Iowa Wing Commander Lt Col Robert A. Graybill was killed in the crash of N9716Z, a Beech A45, during a flight to conduct flood surveillance. The airplane clipped a powerline near Boone, Iowa and was completely destroyed in the crash. A passenger serving as an observer/scanner was also killed.
The ensuing investigation found that the Pilot in Command attempted operation with known deficiencies in equipment. The aircraft windshield had a heavily crazed windshield.
National Transportation and Safety Board - https://www.ntsb.gov/_layouts/ntsb.aviation/brief.aspx?ev_id=58945&key=0
Robert Graybill Find a Grave site - https://www.findagrave.com/memorial/179284831/robert-graybill#add-to-vc