ZENITH STOL CH750

Full Narrative

On May 2, 2023, about 2013 central daylight time, a Zenith STOL CH750 airplane, N750TK, sustained substantial damage when it was involved in an accident near Udall, Kansas. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
The pilot reported that while en route to Cook Airfield (K50), Rose Hill, Kansas, he experienced an “engine stumble.” He descended toward open fields and the engine returned to normal operation. The pilot continued over open fields for about 12 more miles. During an attempted climbing turn, the engine sustained a “prolonged stumble” and a loss of power that did not improve. The pilot maneuvered the airplane for a forced landing to a road. During the landing attempt the airplane struck a power line. The pilot aborted the landing attempt, engine power was restored, and he flew about 10 miles to K50 for an uneventful landing.
A witness reported seeing the airplane flying low towards his house. He provided a photo of the airplane in flight, right before it struck the power line (see Figure 1). He stated that he saw the airplane fly under power lines, heard a noise, and then saw the power lines moving. He stated that he heard engine noise and that there was no indication of a rough running engine. After striking the power lines, the airplane climbed and flew to the northwest at “treetop height.”

Figure 1. A witness photo that shows the accident airplane right before it struck the power line. The airplane is circled in red and the power lines are labeled in yellow.
Postaccident examination of the airplane revealed substantial damage to the vertical stabilizer. The engine’s right carburetor exhibited fuel staining around the choke housing and in the drip pan. The left carburetor had fuel staining around one screw on the choke housing. The throttle cable exhibited chafing where it passed through the firewall. The engine started and was run up to full rpm and no discrepancies were noted. The carburetors were removed and an examination revealed no indication of malfunction or failure that would have precluded normal operation. The throttle cable chafing did not inhibit carburetor operation.
A review of the airplane’s logbooks revealed that the engine was installed on August 27, 2016. The last condition inspection was completed on January 4, 2023. At that time the engine had accumulated 591.76 hours.
A review of ADS-B data showed the airplane departed Ponca City Regional Airport (PNC), Ponca City, Oklahoma, about 1939 and climbed to an altitude of about 1,000 ft agl. About 14 miles north of PNC, the airplane descended and remained at altitudes below 300 ft agl until the area of the power line collision. Then, the airplane climbed and ultimately reached the maximum altitude of the entire flight, about 1100 ft agl, before it descended to land on runway 35 at K50.