The private pilot, who was the builder of the experimental, amateur-built airplane, reported that the Zodiac 601XL was in cruise flight when the engine experienced a total loss of power.
He noted that the right fuel tank was empty and that the fuel selector handle was on the left tank.
He attempted a restart, however this was unsuccessful, and he performed a forced landing in a field near Sanford, North Carolina.
The nose landing gear collapsed during the landing roll, resulting in structural damage to the lower fuselage and engine firewall.
Examination of the wreckage revealed that the fuel tank selector handle was on the left tank, but the fuel valve remained on the empty right tank.
Further examination of the hardware revealed that a threaded metal rod that the pilot installed to connect the tank selector handle to the fuel valve “twisted like bubble gum” when rotated and would not turn the fuel valve.
The pilot, who was the airplane builder, used a thinner rod than specified due to an interference problem. This rod was not part of the airplane kit and was improvised by the pilot. The pilot reported that the handle/valve assembly had operated normally during initial testing.
Probable cause: The pilot’s selection of a threaded metal rod of insufficient strength to connect the fuel tank selector handle to the fuel valve, which resulted in his inability to switch fuel tanks and a subsequent total loss of engine power due to fuel starvation.
NTSB Identification: ERA17TA196
This May 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
This raises the question as to why it had worked initially but not now. Was there any check done to see if the fuel tank selector valve was in someway binding and now required greater force to turn? This builder should have checked with the designer/kit supplier to see if that change in material was suitable for its function before making an arbitrary change to what is otherwise a safe and successful design.
Unbelievable. Second guess the designers? Unbelievable.