The present invention provides a set of holding pattern entry algorithms used
to define flight segments for entry into holding patterns. These geometries preferably
describe the specific location and distance of various segments used in the holding
pattern and holding pattern racetrack, with each segment defined as a curved or
straight segment between endpoints. The algorithms also preferably include criteria
used to determine entry extension, maximum initial turn angle, and minimum distance
between a hold fix and an entry turn point. The geometry also preferably extends
entry distance to avoid excessive iterative calculations. The algorithms are preferably
utilized by a flight management system and method that determines segment sequencing
during entry into holding patterns and the holding patterns themselves. The flight
management system and method monitors the aircraft's progress along the active
segment of the flight plan to determine what is the appropriate next segment in
the algorithm and when to switch control from the active segment to the next segment.