The National Transportation Safety Board has issued two Aviation Safety Alerts — one for pilots and one for mechanics — warning of fuel starvation and loss of engine power from worn fuel selectors.
The safety alerts come after the NTSB investigated several recent accidents where worn fuel selectors contributed to the cause of the accident.
A companion video (below), featuring aircraft investigators discussing the safety issue, has been posted on the agency’s YouTube Channel.

Part of every 100 hour and / or annual inspection should be a check of the fuel selector valve during engine run-up. Ensure that the engine will continue to run and accelerate during the selection of each tank (left, right, aux, both), and that the engine will quit when “off” is selected. Ensure that the selector moves smoothly with no binding and that the detent can be felt with each position selection.
This all takes less than 5 minutes, and may save a life.