How long is the required final fuel reserve for air transport piston flights?

The requirement for the final fuel reserve for air transport piston flights is set at 45 minutes of fuel. This regulation is in place to ensure that pilots have enough fuel to return to the departure airport or safely divert to an alternate airport in the event of unforeseen circumstances, such as adverse weather or air traffic control delays. Having a reserve of 45 minutes allows for a reasonable buffer that enhances safety and provides pilots with options in an emergency. This time frame is considered adequate for most scenarios encountered in general aviation while still maintaining sufficient safety margins. While different types of flights or aircraft might have varying reserve requirements, for air transport piston flights, the standard is 45 minutes.