Standard Instrument Departure
Encyclopedia
Standard instrument departure (SID) routes, also known as departure procedures (DP) are published flight procedures followed by aircraft on an IFR
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....

 flight plan
Flight plan
Flight plans are documents filed by pilots or a Flight Dispatcher with the local Civil Aviation Authority prior to departure...

 immediately after take-off from an airport
Airport
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...

.

Introduction

A SID is an air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...

 coded departure procedure that has been established at certain airports to simplify clearance delivery procedures. SIDs are supposed to be easy to understand and if possible limited to one page.

Although a SID will keep aircraft away from terrain, it is optimized for ATC route of flight and will not always provide the lowest climb gradient. It strikes a balance between terrain and obstacle avoidance, noise abatement (if necessary) and airspace management considerations. In order to legally fly a SID the pilot must possess at least the current version of the SID's textual description . SIDs in the USA are created either by the military (USAF or USN) or by the FAA (which includes US Army Fields). The main difference between US military and civilian SIDs is that military SIDs depict obstacles, ATC climb gradients, and obstacle climb gradients while civilian SIDs depict only minimum obstacle climb gradients.

Types of SIDs

There are two main types of SIDs: Pilot-Nav SIDs and Vector SIDs.

A Pilot-Nav SID is a SID where the pilot is primarily responsible for navigation along the SID route. They are established for airports where terrain and related safety factors dictate a specific ground track be flown.

A Vector SID is used where ATC can provide radar navigational guidance to a filed/assigned route or to a fix depicted on a SID. Flying a Vector SID may require flying an ODP (Obstacle Departure Procedure) first. This is usually annotated in the ODP section stating, "Fly runway heading to xxx prior to making any turns." Vector SIDs give ATC more control over air traffic routing than do Pilot-Nav SIDs.

Assignment procedure

Air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...

 clearance must be received prior to flying a SID. A SID clearance is issued to the pilot based on a combination of the destination, the first waypoint
Waypoint
A waypoint is a reference point in physical space used for purposes of navigation.-Concept:Waypoints are sets of coordinates that identify a point in physical space. Coordinates used can vary depending on the application. For terrestrial navigation these coordinates can include longitude and...

 in the flight plan
Flight plan
Flight plans are documents filed by pilots or a Flight Dispatcher with the local Civil Aviation Authority prior to departure...

, and the take-off runway used.

A standard instrument departure procedure consists of a number of waypoints or fixes, which may either be given by their geographical coordinates, or which may be defined by radio beacons such as VOR
VHF omnidirectional range
VOR, short for VHF omnidirectional radio range, is a type of radio navigation system for aircraft. A VOR ground station broadcasts a VHF radio composite signal including the station's identifier, voice , and navigation signal. The identifier is typically a two- or three-letter string in Morse code...

 or NDB
Non-directional beacon
A non-directional beacon is a radio transmitter at a known location, used as an aviation or marine navigational aid. As the name implies, the signal transmitted does not include inherent directional information, in contrast to other navigational aids such as low frequency radio range, VHF...

 and radial headings, or a radial heading with a DME
Distance Measuring Equipment
Distance measuring equipment is a transponder-based radio navigation technology that measures distance by timing the propagation delay of VHF or UHF radio signals....

 distance.
It also includes a climb
Climb
thumb|right|An [[Embraer ERJ 145]] climbingIn aviation, the term climb refers both to the actual operation of increasing the altitude of an aircraft and to the logical phase of a typical flight following take-off and preceding the cruise, during which an increase in altitude to a predetermined...

 profile, instructing the pilot to cross certain points at or above a certain altitude
Altitude
Altitude or height is defined based on the context in which it is used . As a general definition, altitude is a distance measurement, usually in the vertical or "up" direction, between a reference datum and a point or object. The reference datum also often varies according to the context...

.
A SID procedure ends at a waypoint lying on an airway
Airway (aviation)
In aviation, an airway is a designated route in the air. Airways are laid out between navigational aids such as VORs, NDBs and Intersections ....

 which the pilot will follow from there.

SID procedures are defined by the local authorities (government
Government
Government refers to the legislators, administrators, and arbitrators in the administrative bureaucracy who control a state at a given time, and to the system of government by which they are organized...

s, airport
Airport
An airport is a location where aircraft such as fixed-wing aircraft, helicopters, and blimps take off and land. Aircraft may be stored or maintained at an airport...

s and air traffic control
Air traffic control
Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...

 organizations) to ensure safety and expedite handling of departing traffic and - when possible - to minimize the amount of noise over inhabited areas such as cities.

Naming of SID procedures

Naming conventions for SID procedures vary by region.

In most of Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

, SID procedures are usually named after the final waypoint (fix) of the procedure, which often lies on an airway, followed optionally by a version number and often a single letter. The version number starts at 1 and is increased each time the procedure is altered. The letter designates the runway (the route to be flown to a particular fix depends on the take-off runway).
For example, at Amsterdam
Amsterdam
Amsterdam is the largest city and the capital of the Netherlands. The current position of Amsterdam as capital city of the Kingdom of the Netherlands is governed by the constitution of August 24, 1815 and its successors. Amsterdam has a population of 783,364 within city limits, an urban population...

 airport Schiphol, there are several published departure procedures to reach the GORLO waypoint
Waypoint
A waypoint is a reference point in physical space used for purposes of navigation.-Concept:Waypoints are sets of coordinates that identify a point in physical space. Coordinates used can vary depending on the application. For terrestrial navigation these coordinates can include longitude and...

 (which is an intersection from where the (U)L980 or (U)P20 airways can be joined):
  • The SID to GORLO from runway
    Runway
    According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...

     09 is named GORLO2N (pronounce GORLO Two November).
  • Aircraft departing to GORLO from runway 36L will fly the GORLO3V departure (GORLO Three Victor) instead.
  • All names of SIDs from runway 09, whatever their final waypoint, will end in the letter N.


In the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, SID procedure names are less rigidly formatted, and may simply refer to some notable characteristic of the procedure, a waypoint, or its geographical situation, along with a single digit that is incremented with each revision of the procedure. Thus, the LOOP5 SID at Los Angeles International Airport
Los Angeles International Airport
Los Angeles International Airport is the primary airport serving the Greater Los Angeles Area, the second-most populated metropolitan area in the United States. It is most often referred to by its IATA airport code LAX, with the letters pronounced individually...

 was so called because it was the fifth revision of a procedure that required aircraft to take off towards the west, over the ocean, and then make a roughly 180-degree turn back towards the mainland (a loop, in other words).

Deviations and separation

Though SID procedures are primarily designed for IFR
Instrument flight rules
Instrument flight rules are one of two sets of regulations governing all aspects of civil aviation aircraft operations; the other are visual flight rules ....

 traffic to join airways, air traffic control at busy airports can request that VFR
Visual flight rules
Visual flight rules are a set of regulations which allow a pilot to operate an aircraft in weather conditions generally clear enough to allow the pilot to see where the aircraft is going. Specifically, the weather must be better than basic VFR weather minimums, as specified in the rules of the...

 traffic also follows such a procedure so that aircraft separation
Separation (air traffic control)
In air traffic control, separation is the name for the concept of keeping an aircraft outside a minimum distance from another aircraft to reduce the risk of those aircraft colliding, as well as prevent accidents due to wake turbulence....

 can be more easily maintained. Usually VFR pilots will be given radar vectors corresponding to the SID lateral
Lateral
Lateral may refer to:*Lateral , an anatomical direction*Lateral canal, a canal built beside another stream*Lateral consonant, an ℓ-like consonant in which air flows along the sides of the tongue...

 route with different altitude restrictions.

Pilots must follow the published SID route. Small deviations are allowed (usually there are flight paths of some kilometers wide) but bigger deviations may cause separation conflicts. Pilots can be fined for too large deviations from the prescribed path.

The precision of SIDs also varies by region. In some countries and regions, every detail of the lateral and vertical flight path to be followed is specified exactly in the SID; in other areas, the SID may be much more general, with details being left either to pilot discretion or to ATC. In general, however, SIDs are quite detailed.

Example of a SID at a major airport in Europe

As of 21 October 2010, there were 7 published SIDs from runway
Runway
According to ICAO a runway is a "defined rectangular area on a land aerodrome prepared for the landing and take-off of aircraft." Runways may be a man-made surface or a natural surface .- Orientation and dimensions :Runways are named by a number between 01 and 36, which is generally one tenth...

 22 at Amsterdam
Amsterdam
Amsterdam is the largest city and the capital of the Netherlands. The current position of Amsterdam as capital city of the Kingdom of the Netherlands is governed by the constitution of August 24, 1815 and its successors. Amsterdam has a population of 783,364 within city limits, an urban population...

 airport Schiphol, The Netherlands (see chart AD 2.EHAM-SID-22).

Among them, the ANDIK2G Standard Instrument Departure for reaching the ANDIK waypoint
Waypoint
A waypoint is a reference point in physical space used for purposes of navigation.-Concept:Waypoints are sets of coordinates that identify a point in physical space. Coordinates used can vary depending on the application. For terrestrial navigation these coordinates can include longitude and...

 northeast of Amsterdam read as follows: The textual description of the SID is much easier to understand by following its graphical description on the chart.
  • Lateral route: Track 222° MAG. At 500 ft AMSL turn left (turn MAX 220 KT IAS
    Indicated airspeed
    Indicated airspeed is the airspeed read directly from the airspeed indicator on an aircraft, driven by the pitot-static system. IAS is directly related to calibrated airspeed , which is the IAS corrected for instrument and installation errors....

    ) to track 093° MAG
    Bearing (navigation)
    In marine navigation, a bearing is the direction one object is from another object, usually, the direction of an object from one's own vessel. In aircraft navigation, a bearing is the actual compass direction of the forward course of the aircraft...

    . At PAM 223
    VHF omnidirectional range
    VOR, short for VHF omnidirectional radio range, is a type of radio navigation system for aircraft. A VOR ground station broadcasts a VHF radio composite signal including the station's identifier, voice , and navigation signal. The identifier is typically a two- or three-letter string in Morse code...

     turn left to intercept PAM 207 inbound PAM VOR to intercept PAM 016 to ANDIK (25.2 PAM).
  • RNAV (sequence of relevant waypoints): THR 22 / At 500 ft AMSL turn left / EH023 (MAX 220 KT IAS) / EH027 / PAM / ANDIK The RNAV data describes here a route which shall be considered overlaying the conventional Lateral route. It is only provided in order to be inserted in a flight management system
    Flight management system
    A flight management system is a fundamental part of a modern airliner's avionics. An FMS is a specialized computer system that automates a wide variety of in-flight tasks, reducing the workload on the flight crew to the point that modern aircraft no longer carry flight engineers or navigators. A...

    's navigation database.
  • Vertical: Cross ANDIK at FL
    Flight level
    A Flight Level is a standard nominal altitude of an aircraft, in hundreds of feet. This altitude is calculated from the International standard pressure datum of 1013.25 hPa , the average sea-level pressure, and therefore is not necessarily the same as the aircraft's true altitude either...

     060 (or above if instructed by ATC
    Air traffic control
    Air traffic control is a service provided by ground-based controllers who direct aircraft on the ground and in the air. The primary purpose of ATC systems worldwide is to separate aircraft to prevent collisions, to organize and expedite the flow of traffic, and to provide information and other...

    )
  • After departure: Contact Schiphol Departure
    Departure
    Departure may refer to:Aviation* A "departure" from controlled flight* Taxiing and takeoffNavigationIn navigation, departure is the distance made good in an east––west direction when going from one place to another ....

    119.050 MHz when passing 2000 ft AMSL. Climb to maintain: FL 060


Notes
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