Instrument Departure Procedures (Doc 8168): Omnidirectional, Straight, and Turning Departures
Instrument departure procedures are designed to ensure safety and separation from obstacles after takeoff.
Types of Departure
1. Omnidirectional Departure
Used when no track guidance exists.
- Design: It is assumed that the aircraft maintains runway heading until reaching a specified height and then may turn in any direction.
- Restrictions: Sectors to be avoided (defined by bearings and distances) or minimum climb gradients/minimum altitudes to overfly obstacles may be specified.
- It is a flexible and simple method when no specific navigation aids are available.
2. Straight Departure
- One in which the initial track is within 15° of the runway centerline alignment.
3. Turning Departure
- Termed as such when the procedure requires a turn of more than 15°.
- Turn initiation: Normally straight flight is assumed until reaching at least 120 m (394 ft) height (90 m for helicopters) and 600 m from the beginning of the runway.
General Criteria
- Pilot Responsibility: Nothing in the procedures prevents the pilot-in-command from exercising their authority for safe operation, including noise abatement maneuvers.
- Wind Effect:
- In radar-vectored departures, wind is not compensated (assigned heading is flown).
- In track-based departures, known wind must be compensated to maintain the track.
Noise Abatement
Departure procedures often incorporate noise abatement techniques. However, aircraft safety (commander's authority) always prevails over these restrictions.