91.411 Inadvertent change to flight plan

• Each pilot-in-command of an aircraft operating under IFR, shall in the event of an inadvertent departure from the current flight plan--
  • (1) advise an appropriate ATS unit of--
    • (i) any deviation from track; and
    • (ii) any variation of 5% or more of the true airspeed or any variation of ± 0.01 or more of the Mach number given in the flight plan; and
    • (iii) a revised ETA when the estimated ETA to the next reporting point notified to the ATS unit is found to be in error by more than two minutes; and
  • (2) regain track as soon as practicable.