Alternate Aerodrome

Alternate Aerodrome is an airport designated in the flight plan to which a flight may proceed when landing at the intended destination is inadvisable or impossible — due to weather, runway closure, or other factors. Fuel planning must include sufficient reserves to reach the alternate.

• Takeoff alternate: used if the departure airport becomes unavailable shortly after takeoff
• Destination alternate: used if the destination cannot accept the aircraft
• En-route alternate: used in ETOPS operations over remote areas
• Weather minima at the alternate must be above published alternate minimums at the ETA