Engineers who design and manage government operated transportation networks estimate the volume of traffic each system must accommodate. Underspecifying capacity leaves the network vulnerable to congestion that can impede commerce; over‑engineering wastes public funds. Even with careful forecasting, exceptional situations sometimes push demand beyond a system’s limits. On a highway, vehicles can simply slow or stop. Aircraft, however, cannot safely halt their forward motion in mid‑air.

To manage airborne surges, the Federal Aviation Administration employs holding patterns—standardized oval flight paths anchored to a reference point on the ground. By directing aircraft to “hold,” air traffic control temporarily stores excess traffic aloft, easing workload and preventing bottlenecks downstream. Most holding patterns are published on FAA charts, but controllers may also issue unpublished, ad‑hoc holds when conditions warrant.

Holding Pattern Entries