IFR Visual manoeuvring (circling)[PDF]
- 1 Introduction
- 2 Visual manoeuvring or Circling
- 3 Visual manoeuvring using predefined prescribed tracks
- 4 See also
- 5 Reference
- 6 Author
Descent below the MDA/H should not be made until:
- Visual reference has been established and can be maintained
- The pilot has the landing threshold in sight
- The required obstacle clearance can be maintained
- The aircraft is in a position to carry out a landing
Visual manoeuvring or Circling
Visual manoeuvring area
The radius (R) of the arc is related to:
- Category of aircraft
- Wind speed 25kt
- Bank angle 20° average or 3° per second, whichever requires less bank
|Category of aircraft||A||B||C||D||E|
|Maximum speed (kt)||100||135||180||205||240|
|Maximum true air speed with wind +25kt at 1000ft||131||168||215||242||279|
|Radius (r) of turn (NM)||0.69||1.13||1.85||2.34||3.12|
|Straight segment (NM)||0.30||0.40||0.50||0.60||0.70|
|Radius (R) from threshold (NM)||1.68||2.66||4.20||5.28||6.94|
When the visual manoeuvring (circling) has been established, the obstacle clearance altitude/height (OCA/H) is determined for each category of aircraft.
|Aircraft category||Obstacle clearance m (ft)||Lowest OCH above airfield elevation m (ft)||Minimum visibility km (NM)|
|A||90 (295)||120 (394)||1.9 (1.0)|
|B||90 (295)||150 (492)||2.8 (1.5)|
|C||120 (394)||180 (591)||3.7 (2.0)|
|D||120 (394)||210 (689)||4.6 (2.5)|
|E||150 (492)||240 (787)||6.5 (3.5)|
Each circling situation is different because of:
- Runway layout
- Final approach track
- Wind speed
- Meteorological conditions
- Landmarks and obstacles in environment
- A track to join the downwind leg
- A downwind leg, except if the aircraft can join and is cleared to join a base leg directly
- A half turn in order to join the final leg, if a downwind leg has been performed
Below we present several track configurations that can be used when performing visual manoeuvring:
However, the pilot can choose a higher altitude if the weather conditions so permit. But, the visual manoeuvring and timing must be executed conform to the aircraft specification manual (FCOM) with the aircraft remaining within the visual manoeuvring area. The pilot can choose the normal altitude circuit to perform its visual approach.
Use of Autopilot
Missed approach procedure
Visual manoeuvring using predefined prescribed tracks
The missed approach for the normal instrument procedure applies, but the prescribed tracks provide for manoeuvring to allow for go around and to achieve a safe altitude/height thereafter – joining the downwind leg of the prescribed track procedure or the instrument missed approach trajectory.
The figure below shows one type of a standard track.
Common cases of tracks
The common cases of prescribed tracks that you may face are
Examples in charts
Due to specific runway configuration or terrain layout, airports can provide other configurations than the standard track.
Example of a special visual manoeuvring using predefined prescribed tracks after an ILS approach:
Example of a visual manoeuvring using predefined prescribed tracks directly after IAF:
Minimum obstacle clearance (MOC)
The OCA/H for visual manoeuvring on prescribed tracks provides the minimum obstacle clearance (MOC) over the highest obstacle within the prescribed track area.
It also conforms to the limit presented in the table under 'OBSTACLE CLEARANCE' and is not less than the OCA/H calculated for the instrument procedure approach which leads the visual manoeuvre.
Missed approach procedure
- ICAO Documentation 8168 - Aircraft Operations - Volume II - 6th Edition 2014 - Appendix to Chapter 7
- ICAO Documentation 8168 - Aircraft Operations - Volume I - Flight Procedures - 6th Edition 2010 - Section 4 - Chapter 7
- VID 150259 - Creation
- VID 531824 - Wiki Integration
- VID 150259 - Update September 2019
DATE OF SUBMISSION
- 19:20, 11 November 2019
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