N4143P

On November 15, 2024, at 1639 central standard time, a Piper PA-23-160, N4143P, was substantially damaged when it was involved in an accident near Manvel, Texas. The flight instructor and pilot receiving instruction were not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 instructional flight.

The pilots stated that the airplane had flown multiple flights that day with no issues reported. They completed a preflight inspection and an engine runup before departing on the accident flight. During the initial climb, about 100 ft agl, the left engine lost total power. Unable to maintain altitude, the pilots maneuvered for a forced landing in a pasture off the left side of the runway. During the landing roll, the nose landing gear collapsed. The pilots secured the airplane and egressed without further incident.

The airplane sustained substantial damage to the forward fuselage. The fuel tanks remained intact and were mostly full of fuel. The left engine oil dipstick indicated adequate oil, and the exterior of the engine did not reveal any signs of catastrophic failure.

An engine data monitor was removed from the airplane, and the data was extracted. The unit recorded exhaust gas temperatures, cylinder head temperatures, and fuel flow for both engines during the accident flight. A review of the data indicated a sudden reduction in fuel flow to the left engine shortly before the end of the data. Shortly after, there was a subsequent reduction in fuel flow to the right engine, consistent with the pilot’s statements that they reduced power on the right engine in preparation for landing in the field. There were no other anomalies noted in the data.

Postaccident examination of the fuel system revealed that the left fuel selector lever was difficult to move from the Off position to either the Auxiliary or Main positions. When the lever was moved full forward from the Off position to the Main position, there was significant resistance to the movement. If the lever was released, it would spring back (aft) towards the Off position with notable force. The fuel control support arm rotated slowly toward the outboard position after the selector lever was actuated. The support arm continued to move for about 10 to 12 seconds following the movement of the selector lever only if the lever was held in the forward (Main) position. The airplane owner stated that the left fuel quantity display was consistently delayed when switching between tanks. The delay matched the slow movement of the fuel control support arm, which actuates the electrical switches and controls the source for the fuel quantity gauge.

The fuel control cable from the selector lever and the fuel control cable to the shut off valve were disconnected from the fuel control support arm. The left fuel control selector lever was then manipulated and moved without restriction or resistance, like before. The fuel control support arm was able to rotate easily and smoothly with normal contact noted on the fuel quantity electrical switches. The fuel control cable to the shutoff valve could not be pushed or pulled manually. This cable was disconnected from the fuel shutoff valve in the left engine nacelle to determine whether it was the cable or the valves that were resistant to movement. Each of the fuel valves were able to move freely and smoothly. The fuel control cable between the fuel control support arm and the fuel shutoff valves exhibited binding and was unable to move manually once disconnected from the support arm and shutoff valve.

A functional test run of left engine was completed. The left main fuel shutoff valve, which had been disconnected from the auxiliary fuel shutoff valve and control cable, was manually placed in the On position. The engine started and the engine speed was kept below 1,200 rpm due to vibration from the bent propeller. The engine ran for about 1½ minutes with no anomalies noted.

The most recent inspection in the maintenance logbook was completed on October 14, 2024. The logbook entry noted that FAA airworthiness directives (AD) for the fuel control cable inspection (AD 60-03-08R3) and the fuel selector valve inspection (AD 80-18-10) were completed with no defects noted on any of the inspections.

AD 60-03-08R3 required the following:

Check rigging and clamping of control cable and rigging of valve control linkage to eliminate bowing and to ensure proper valve operation.

AD 80-18-10 required the following:

In accordance with Piper Service Bulletin No. 507 and appropriate Piper Service Manual, inspect all fuel valves and control cables through all detent positions by having someone operate the fuel controls in the cockpit while inspecting for the following:

· Rigging and adjustment.

· Unrestricted motion of cable wires, swivel fitting and valve actuating levers.

· Proper lubrication of fuel valve attachments and controls. Correct unsatisfactory conditions in accordance with the appropriate aforementioned Piper Service documents.