Pilot Transmitted “Mayday” Several Times And Advised The Controller That The Airplane Was Experiencing A Rough Running Engine

Location: Kellyton, AL Accident Number: ERA23FA087
Date & Time: December 13, 2022, 09:25 Local Registration: N74586
Aircraft: Mooney M20B Injuries: 1 Fatal
Flight Conducted Under: Part 91: General aviation - Executive/Corporate 

On December 13, 2022, at 0925 central standard time, a Mooney M20B, N74586, was substantially damaged when it was involved in an accident in Kellyton, Alabama. The pilot was fatally injured. The airplane was operated by the pilot as a corporate flight conducted under the provisions of Title 14 Code of Federal Regulations Part 91.

The airplane owner reported that the pilot worked for him flying various airplanes that the owner managed, and that the accident flight was the pilot’s second flight in the owner’s personal airplane. The first flight was the day before the accident, and the owner stated that he provided “at least an hour” of ground instruction to the pilot before the flight. 

Review of Federal Aviation Administration preliminary air traffic control and Automatic Dependent Surveillance Broadcast-Data revealed that the airplane departed runway 36 at the Perry-Houston County Airport (PXE), in Perry, Georgia, at 0825 on an instrument flight rules (IFR) flight plan to Bessemer Airport (EKY), Bessemer, Alabama. The airplane turned toward the west and climbed to an altitude of 6,000 ft mean sea level (msl). At 0918, the pilot transmitted “Mayday” several times and advised the controller that the airplane was experiencing a rough running engine. The pilot requested to divert to the nearest airport and the controller provided course guidance to the Thomas C Russell Field Airport (ALX), Alexander City, Alabama. Shortly after the pilot initiated the left turn to ALX, he reported that the engine was once again producing power; however, he wanted to continue the diversion. The controller provided the pilot course guidance until radio and radar contact were lost at 0925 about 5.8 nautical miles (nm) north-northeast of the airport.

A witness near the accident site reported that he heard tree branches breaking and looked up to see the airplane “clipping the trees.” He indicated that the airplane appeared to be level and upright and stated that there was no engine noise.

Video obtained from the property owner showed the airplane impacting trees before rolling inverted and descending nose first to the ground. The wreckage was located 5.5 nm north of ALX and about 1.41 nm west of the last radar data.

Examination at the accident site revealed that the airplane came to rest in a pasture, inverted and folded over the engine and propeller. All portions of the airplane were intact, except for the outermost portion of the left wing, including the left aileron, which was located at the base of some large trees about 68 ft from the main wreckage. The fractured outermost portion of the left wing exhibited leading edge damage consistent with tree impact while in a left turn. Equipment was brought to the accident site and the airplane was positioned upright and further examined. The propeller hub with propeller blades attached was impact separated from the engine and embedded at the ground impact point. Examination of the propeller revealed that both blades exhibited minimal chordwise rotational scoring on the face sides and no remarkable twisting. One of the blades exhibited aft bending. The engine compartment and cockpit area were impact crushed aft and the fuselage and empennage were substantially damaged. The engine control levers were in their full forward position. The fuel selector was positioned to the right wing fuel bladder. Control continuity was established from the rudder and elevator cockpit flight controls to the flight control surfaces; however, aileron control continuity could not be established due to impact damage at both wing roots. Examination of the wing fuel bladders revealed significant fuel in the left bladder and no fuel in the right bladder. There was no evidence of fire.

The engine was removed from its engine mounts and hoisted to facilitate examination. Examination revealed that the sparkplug electrodes showed coloration and wear consistent with normal operation when compared to a Champion Check-A-Plug chart. Thumb suction and compression were attained on all cylinders when the crankshaft was rotated manually. Crankshaft and camshaft continuity were confirmed from the front to the rear of the engine. A visual inspection of the cylinders revealed normal coloration and condition of the piston faces. The magnetos produced sparks on all leads when removed and rotated by hand. The carburetor was disassembled, and its inlet screen removed. The fuel screen was free from debris and unobstructed. No fluid or sediment was present in the float bowl. The floats were of the black plastic style and moved freely throughout their travel range. Suction and compression were noted at the respective ports on the engine driven fuel pump when rotated using an electric drill. No fuel was found in the fuel lines during the examination. 

The airplane was retained for further examination.

FMI: www.ntsb.gov