IFR departure procedure[PDF]
- 1 Introduction
- 2 Standard instrument departures - SID
- 3 Omnidirectional departures
- 4 Additional points for departure
- 5 See also
- 6 Reference
- 7 Author
The design of an instrument departure procedure is, in general, dictated by the terrain surrounding the aerodrome. It may also be required to provide for air traffic control (ATC) requirements in the case of SID routes. These factors in turn influence the type and siting of navigation aids in relation to the departure route. Airspace restrictions may also affect the routing and siting of navigation aids.
Departure procedures may be developed to procedurally separate air traffic. The procedure may be accompanied with altitude/flight level restrictions that are not associated with any obstacle clearance requirements but are developed to separate arriving and departing aircraft procedurally.
Non-prescribed departure routes
At many aerodromes, a prescribed departure route is not required for ATC purposes. Nevertheless, there may be obstacles in the vicinity of some aerodromes that have to be considered in determining whether restrictions to departures are to be prescribed. In such cases, departure procedures may be restricted to a given sector(s) or may be published with a procedure design gradient in the sector containing the obstacle.
Where no suitable navigation aid is available, the criteria for omnidirectional departures are applied. Omnidirectional departures may specify sectors to be avoided.
DER = departure end of the runway which is the end of the area declared suitable for take-off (i.e. the end of the runway including clearway as appropriate).
PDG = procedure design gradient = published climbing rate
Standard instrument departures - SID
- Aircraft identification
- Clearance limit, normally destination aerodrome
- Designator of the assigned SID (if applicable) and the applicable runway
- Initial level (except when this element is included in the SID description)
- Allocated SSR code
- Other necessary instructions or information not contained in the SID description (example frequency change)
The following information is also promulgated:
- Significant, highest and closest obstacles in the departure area (position and height)
- Procedure design gradients (PDG) greater than 3.3%
- Altitude/height at which a gradient is specified.
- Altitude to be achieved during the departure when over heading significant points
- All navigation facilities (navaids), fixes or waypoints, radials and DME distances.
- Straight departure
- Turning departure
When obstacles exist, procedure design gradients (PDG), greater than 3.3%, may be specified.
When such a gradient is specified, the altitude height to which it extends shall be promulgated.
Procedure turns are normally initiated at a point 600m from the beginning or the runway. However, in some cases, turns may not be initiated before the departure end of the runway (DER), and this information will be noted on the departure chart.
- An altitude or a height
- A fix or a facility
- Final missed approach speed increased by 10% to account for increased aircraft mass in departure
- Intermediate missed approach speed increased by 10% where acceptable terrain clearances cannot be provided. In such cases the procedure is annotated on charts.
The procedure must be constructed for all conditions of flight. The table below gives the maximum turn speed in function of aircraft category:
|Aircraft category||Maximum speed km/h||Maximum speed KT|
The wind conditions are maximum 95% of probability wind on an omnidirectional basis, where statistical wind data are available or omnidirectional 56 km/h (30kt).
The pilot reaction time taken is 3 seconds and the bank establishment time is 3 seconds.
- Sector to be avoided
- Sector having minimum procedure design gradient and/or minimum altitude
Since the point of lift-off will vary, the departure procedure assumes that a turn at 120m (194ft) above the elevation of the airfield is not initiated sooner than 600m from the beginning of the runway. However, in some cases turns may not be initiated before the DER or a specified point (this information will be noted on the departure chart).
Procedure design gradient
The omnidirectional departure procedure is designed using any one of a combination of the following:
|Procedure||Minimum PDG||Straight Climbing altitude|
before initiate a turn in any direction
|Standard with 90m (295ft) of obstacle clearance||3.3%||120m (394ft)|
|Specified turn altitude height||3.3%||Published altitude|
|Specified procedure design gradient||Published PDG||Published altitude|
Where obstacle exists
(the procedure may identify the concerned allowed sectors)
|Published PDG||Published altitude|
Specific omnidirectional departure
The pilot shall respect the standard procedure gradient and altitude.
Example: “BAW1133, cleared to destination airfield, after take-off, turn right heading 110°, climb flight level 180, squawk 6373”
Example: “BAW1133, cleared to destination airfield, after take-off, climb straight ahead. At 2000ft turn right heading 020° and intercept radial 210° of NKT VOR outbound and continue climb to FL100. At 23NM DME NKT, turn direct OMLET, squawk 6373”
Additional points for departure
Reduced power take-off
- Adversely affected runway conditions
- Horizontal visibility is less than 1.9km (1NM)
- Crosswind component of the wind including gusts greater than 28km/h (15kt)
- Tailwind component of the wind including gusts greater than 9km/h (5kt)
- Reported or forecasted wind shear
- Thunderstorms presence during approach or departure routes
Climb clearance above level specified in SID
When traffic conditions permit it, ATC may clear aircraft above the levels specified in SID given in the initial clearance.
- ICAO Documentation 8168 - Aircraft Operations - Volume I - Flight Procedures - 6th Edition 2010 - Section 3
- VID 150259 - Author
- VID 531824 - Wiki integration
DATE OF SUBMISSION
- 00:58, 14 May 2021
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