Aerodrome Separation and Approach Procedures

Posted on Nov 8, 2024 in Other subjects

Aerodrome Separation

Adequate aerodrome separation can be achieved when:

  • All aircraft are constantly in view of the aerodrome controller.
  • In the case of two aircraft, each pilot has the other aircraft constantly in view and both report maintaining their own separation.
  • An overtaking aircraft pilot reports having the other aircraft in sight and can maintain separation. Note: These provisions primarily apply to arriving aircraft when operationally beneficial.

Simultaneous Takeoffs

Simultaneous takeoffs are permitted from parallel runways separated by 3,500 feet or more when aircraft deviate 45 degrees or more after takeoff.

  • 1 minute separation: Aircraft deviate 45 degrees or more immediately after takeoff.
  • 2 minutes separation: Aircraft diverge by 15 degrees or more within 5 minutes after takeoff.
  • 3 minutes separation: Leading aircraft has a true airspeed 40 knots or more greater than the following aircraft.
  • 5 minutes separation: Leading aircraft has a true airspeed 22 knots or more greater than the following aircraft (see fig. 4.6).
  • 5 minutes separation: Aircraft crossing cruise levels when one aircraft overtakes or overflies another on the same track (see fig. 4.7). Maintain or increase this separation.
  • 3 nautical miles separation: Aircraft diverge within 13 DME miles after takeoff, provided the leading aircraft has a true airspeed 22 knots or more greater than the following aircraft.
  • Departing aircraft may take off in any direction if the arriving aircraft is 5 minutes or more from the landing threshold.
  • Departing aircraft may take off in a direction differing by 45° or more from the arriving aircraft’s path if the latter is 3 minutes or more from the landing threshold.

IFR Arrivals Below Minimum Altitude

IFR arrivals below the established minimum altitude are not allowed unless:

  • The pilot reports having and maintaining the aerodrome in sight.
  • The aircraft is performing a visual approach.

Visual Descent

In VMC, pilots may request a visual descent, maintaining their own separation. The controller provides traffic information and alternate IFR instructions if separation cannot be maintained. Under radar conditions, the controller maintains surveillance and issues safety warnings.

Non-Radar Procedures and Instrument Approaches

Under non-radar procedures, if an aircraft is conducting an instrument approach on a specific track, departures on the same instrument approach are not authorized, even with initial separation and diverging paths. Note: In these conditions, the protected areas may overlap, creating uncertainty for the controller. A missed approach could place the departing aircraft on a similar path to the arriving aircraft.

Holding Points

  • Published in the IPA.
  • Specified by the controller using DME, radials, or QDM intersections. Aircraft altitude must be at or above Flight Level 200. Save on PBC.

Note: Holding patterns are generally 1-minute, non-standard (left) turns. For unpublished holding patterns, the controller specifies the turn direction and expected holding time.

Stepped Approach Sequence

Aircraft hold at the same or nearby radio aids with non-overlapping protected areas. The controller must:

  • Establish vertical separation at the Initial Approach Fix (IAF).
  • Allow aircraft to descend successively to altitudes vacated by preceding aircraft.
  • Assign each aircraft an Expected Approach Clearance (EAC) and an altitude to leave the IAF.
  • Authorize an aircraft to begin its IFR approach when the preceding aircraft:
    • Cancels its IFR flight plan or is approved for a visual approach.
    • Is in sight and the controller reasonably believes landing is assured.
    • Has landed.

Synchronized Approach Sequence

A time or distance interval separates aircraft. The controller must:

  • Assign IAF departure times to maintain the required interval.
  • Assign longitudinal separation with a minimum 2-minute interval (3 minutes if a heavy aircraft precedes a small one due to potential turbulence).
  • Monitor aircraft to ensure vertical and/or longitudinal separation is maintained or increased until the preceding aircraft:
    • Cancels its IFR flight plan or is approved for a visual approach.
    • Is in sight and the controller reasonably believes landing is assured.
    • Has landed.

Conditions for Synchronized Approach

A synchronized approach requires:

  • Aerodrome Control Service at the landing aerodrome.
  • Continuous direct communication between pilot and controller.
  • Navigation aids and procedures allowing aircraft to leave the IAF and proceed to the airfield, with missed approach paths not conflicting with the final approach path.
  • Ceiling and visibility at or above the prescribed IFR minimums.

Types of Approach

  • Circling approach
  • Side-Step approach
  • Visual approach
  • Contact approach
  • Practice instrument approach