On July 4, 2023, about 1407 central daylight time, a Grumman American Aviation AA-5A, N26387, was substantially damaged when it was involved in an accident near Redstone Arsenal, Alabama. The private pilot and pilot-rated passenger were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot stated that earlier that day he departed from the airplane’s home base, flew to Huntsville International Airport, Huntsville, Alabama, performed a RNAV approach, and then climbed to 3,500 ft mean sea level. While at that altitude en route to Guntersville Municipal Airport – Joe Starnes Field, Guntersville, Alabama, and while adjusting the engine power settings, the engine power decreased. He further described that the engine power was at high idle and would not respond to throttle control inputs. At that time, he declared an emergency and descended at slightly above best glide airspeed in an attempt to land at Redstone Arsenal, which he believed was the nearest airfield. When it was apparent that the airplane would be unable to reach the runway, he selected a nearby field with a paved road. After landing on the road, he applied maximum braking; however, the left wing impacted a metal pole, resulting in damage to the leading edge of the wing measuring 39 inches; the total wingspan was 31 ft 6 inches. Postaccident inspection of the engine compartment by an FAA inspector revealed the throttle control cable assembly remained attached to the throttle control lever of the fuel injection servo, but the outer cable assembly was not secured in the engine compartment. Thus, movement of the throttle control in the cockpit did not result in movement of the throttle control lever. A clamp, shim, two screws, and two metal self-locking nuts that secured the outer cable assembly were not located, but a washer was found loose in the engine compartment. A review of the maintenance records revealed the throttle cable was replaced at the airplane’s last annual inspection, which was completed on November 13, 2022. The airplane had been operated for about 15 hours since the annual inspection was completed.