Unit 8 Landing, Takeoff and En Route Procedures
Air terminal ATC involves aircraft departures and arrivals. Its procedures include issuing instrument flight rules route clearances and communicating departure runways, taxi instructions, and definition of climb and altitude routes. These operations assure passengers of safe, speedy air traffic patterns.
A departing aircraft enters the taxiway as instructed by the ground controller and the pilot waits being fitted into the pattern of incoming and outgoing flights. ATC controllers allocate available departure runways to enable safe aircraft separation. Once the aircraft climbs to its initial altitude on an ATC-instructed heading, departure control makes sure that radio contact with the departing pilot is established before allowing a new takeoff. More instructions clear the aircraft for its final climb to the en route segment of the flight and for transferring the pilot to the next control facility.
Air traffic controllers relay descent instructions to incoming aircraft to keep them separated by five-mile intervals. As the aircraft approaches an airport, its speed is adjusted and its flight path altered to maintain an aircraft separation of over three miles within airport boundaries.
ATC controllers determine aircraft landing sequences, stacking plans, and takeoff adjustments to handle aircraft flow. To simplify this flow, all commercial aircraft remain at their origin airport until it is confirmed that a landing site will be available at their destination airport at the planned arrival time. Travelers often become frustrated when a pilot cannot obtain a landing slot after leaving the gate at the origin airport, but the practice maximizes safety since flight delays are safer when spent on the ground than in the air.
The last part of descent control transfers the aircraft to the approach controller. Data from radar surveillance determine the final landing directions. Radar monitors optimize landing, and once on a runway, the pilot and the ground controller interact to prevent aircraft movement conflicts on the field. This controller also tells the pilot how to reach the craft’s apron or parking position at the airport.
En route ATC includes monitoring the routes between terminals granted to individual pilots. A flight follows a predetermined path in a defined airway corridor. Effective en route ATC instructs pilots when and how to avoid nearby aircraft. During most flights, a given ATC facility periodically transfers control of each flight within its jurisdiction to the next facility on a flight plan. For this reason, ATC gives pilots radio-frequency changes that occur as they are passed on to the next controller along their flight paths.
The availability of inertial navigation units for commercial aircraft has reduced the need for this communication. In an inertial navigation unit, a computer and gyroscope are oriented to true north, while speed sensors track the aircraft’s direction and the distance to its destination. Although inertial navigational units can fly virtually automatically until the aircraft reaches an airport, en route information is provided for safety and to warn of impending delays or other dangers. As a result, all IFR aircraft are monitored continuously throughout each flight. In addition, pilots must get ATC approval before making any flight path alterations.
The main rule systems governing flights are instrument flight rules (IFR) and visual flight rules (VFR). The minimum instruments needed for VFR are an airspeed indicator, an altimeter, and a magnetic direction indicator. In VFR, pilots fly using visual ground references and a “see and be seen” rule. The minimum requirements for VFR vary, but often include cloud ceilings of 1,000 feet and visibility of three miles.
IFR are used if aircraft operate above 18,000 feet, an area known as Class A airspace. Outside this airspace, any aircraft may use VFR, although only slow-moving, low flying aircraft or small jets on short flights routinely do so.
Exercises
1. You should check the pronunciation of key words. Transcribe the words:
Procedures, issuing, departure, en route, surveillance, jurisdiction, ceilings, routinely, visual
2. Find in the texts the English equivalents for the following expressions:
(1) departure runways, (2) the en route segment of the flight, (3) descent instructions, (4) aircraft landing sequences, (5) to handle aircraft flow, (6) obtain a landing slot, (7) a defined airway corridor, (8) instrument flight rules, (9) visual flight rules, (10) a magnetic direction indicator