Sec. 125.373 - Original flight release or amendment of flight
(a) A certificate holder may specify any airport authorized for the type of airplane as a destination for the purpose of original release.
(b) No person may allow a flight to continue to an airport to which it has been released unless the weather conditions at an alternate airport that was specified in the flight release are forecast to be at or above the alternate minimums specified in the operations specifications for that airport at the time the airplane would arrive at the alternate airport. However, the flight release may be amended en route to include any alternate airport that is within the fuel range of the airplane as specified in §125.375 or §125.377.
(c) No person may change an original destination or alternate airport that is specified in the original flight release to another airport while the airplane is en route unless the other airport is authorized for that type of airplane.
(d) Each person who amends a flight release en route shall record that amendment.