CEN21LA175

The pilot was performing a practice instrument approach with a safety pilot onboard when the accident occurred. Upon crossing the final approach fix inbound, he reduced engine power to initiate a descent. Shortly afterward, he attempted to increase engine power slightly; however, there was no response. He subsequently applied full throttle without any corresponding increase in engine power. Attempts to restore adequate engine power were not successful and the pilot executed a forced landing to a field during which the airplane sustained substantial damage. A postaccident examination revealed that the throttle cable had become disconnected from the carburetor throttle arm. The attachment hardware was not located. The airplane parts catalog specified that a castellated nut and cotter pin be used to secure the throttle cable rod end bearing to the carburetor. No other anomalies with respect to the engine, carburetor, or throttle cable were observed. The airplane maintenance records indicated that the carburetor was replaced about 23 flight hours before the accident. An annual inspection was completed about 11 flight hours before the accident. Based on the available information, it is likely that the throttle cable was not properly secured to the carburetor throttle arm when the carburetor was replaced; specifically, the cotter pin was not installed. The missing cotter pin was not detected during the annual inspection. The engine power available at the time the cable became disconnected was not sufficient to maintain altitude, resulting in a descent and forced landing.

On April 1, 2021, about 1600 central daylight time, a Piper PA-28-140, N7274F, was substantially damaged when it was involved in an accident near Augusta, Kansas. The pilot and safety pilot were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that he was performing a practice VOR/DME-A instrument approach into Augusta Municipal Airport (3AU) with a safety pilot onboard. Shortly after passing the final approach fix inbound, he reduced engine power. He then attempted to increase engine power slightly; however, there was no response. He subsequently increased to full throttle without any corresponding increase in engine power. The pilot’s efforts to restore engine power were not successful and he executed a forced landing to a field. The safety pilot reported that the pilot reduced engine power and initiated a descent upon crossing the final approach fix inbound. About 30 seconds later, the pilot informed him that the engine was not responding. The safety pilot recalled that the engine tachometer was at an idle rpm indication. He noted that there was about 3 hours fuel onboard at the time of the accident. A postaccident examination was conducted by a Federal Aviation Administration inspector. The right wing struck a trailer and a fence post during the landing rollout and separated from the fuselage. The airplane came to rest adjacent to an outbuilding. The left wing remained attached to the fuselage. The fuselage, both wings, engine mount and propeller were damaged. An undetermined amount of fuel remained in the left fuel tank, the right fuel tank had been compromised, and a strong fuel odor was present at the accident site. The examination revealed that the throttle cable rod end bearing was not connected to the carburetor throttle arm. The attachment hardware was not located. The mixture cable remained attached to the carburetor. Both the throttle and mixture control cables were continuous from the cockpit controls to the engine compartment. The carburetor appeared undamaged and was securely mounted to the engine. The engine assembly appeared intact. The airplane maintenance records indicated that the carburetor had been replaced on January 17, 2021, at a recording tachometer time of 8,244 hours. An annual inspection was completed on March 4, 2021, at 8,256 hours. The tachometer indicated 8,267 hours at the time of the examination. Review of the airplane parts catalog noted that the throttle cable was to be secured to the carburetor throttle arm rod end bearing using a hex-head bolt with a drilled shank (AN3-7), a castellated nut (AN310-3), and a cotter pin (MS24665-132).