Sector Entry (Holding Patterns)
Overview
In aviation, sector entry refers to the specific method an aircraft uses to enter a holding pattern, which is a predetermined maneuver to delay aircraft while awaiting further clearance from air traffic control. The three main types of sector entries are direct, parallel, and teardrop.
Sector Entry Types
Direct Entry
The most straightforward entry, where the aircraft flies directly to the holding fix and then turns to join the outbound leg.
Parallel Entry
Involves overflying the holding fix and then turning to a heading parallel to the outbound course for one minute, before turning to join the inbound course.
Teardrop Entry
Starts by overflying the holding fix and then turning 30 degrees from the outbound leg, flying outbound for one minute, and then turning to intercept the inbound course.
Historical Context
Early Days
Holding patterns were initially simple, with pilots using basic maneuvers to delay aircraft.
Development
As air traffic grew, more standardized holding procedures and entry methods were developed to ensure efficiency and safety.
Modern Practice
Today, holding patterns and sector entry methods are well-defined and regulated, with specific procedures for different aircraft types and airspace conditions.
Purpose
Holding patterns are used to manage traffic congestion, delays due to weather, or runway unavailability.
Air Traffic Control
Air traffic controllers use holding patterns to ensure safe and efficient air traffic flow, and they are responsible for assigning holding patterns to aircraft.
