Point of No Return (PNR):

The Point of No Return (PNR) is the stage of flight up to which the aircraft can fly and still have enough fuel to return safely to the base within the given endurance.

• PNR in Nil Wind Conditions:
  In nil wind conditions, the distance to the PNR is maximum, as there are no wind components affecting fuel consumption.
• PNR in Wind Conditions:
  With headwind or tailwind conditions, the distance to the PNR reduces compared to nil wind conditions.
  • As the wind component increases (either headwind or tailwind), the distance to the PNR further reduces.

The PNR is fundamentally a fuel management problem, as it directly relates to the endurance and fuel available for the flight