Holding (aeronautics)

[3] The primary use of a holding pattern is to delay aircraft that have arrived at their destination but cannot land yet because of traffic congestion, poor weather, or runway unavailability (for instance, during snow removal or emergencies).

[4] Normally, when no delay is anticipated, ATC issues holding instructions at least 5 minutes before the estimated arrival at the fix.

One airport may have several holding patterns; depending on where aircraft arrive from or which runway is in use, or because of vertical airspace limitations.

Since an aircraft with an emergency has priority over all other air traffic, it will always be allowed to bypass the holding pattern and go directly to the airport (if possible).

For civil aircraft (not military) in the United States and Canada, these airspeeds are:[1][8] The ICAO Maximum holding speeds:[9] With their higher performance characteristics, military aircraft have higher holding speed limits.