Hi,
I've been trawling for a reference for manoeuvring from an Instrument Approach to a longer straight-in final when visual. Specifically a GNSS approach (although any straight-in will do.)
Scenario is:
-At what point can you visually manoeuvre to a longer final approach if visual before the Mapt, day or night. However, the straight-in approach is 15 deg offset from the runway centreline for a Cat C aircraft and the straight-in approach takes you through a 'no-circling' area depicted. Argyle (YARG) Rwy 01 GNSS.
The current interpretation with-in our company is that you can't manoeuvre because you're in a no-circling area, however others interpret that you can manoeuvre the aircraft because you aren't actually circling.
Our Oz Jepps (Terminal p25 - 4.15)
Visual Manoeuvring (non-circling) Subsequent to Non-Precision Approaches (NPA) and Approaches with Vertical Guidance (APV)
Alignment with the Runway Centreline. Manoeuvring to align the aircraft with the runway centreline can be undertaken when:
- Within the circling area
- Visual reference can be maintained
- Continuously in sight of ground and water
Note 1: Procedures with offset angles greater than 5deg are designed such that the aircraft crosses the runway centreline no closer than 1400m to the threshold.
I've read the Pans Ops 4 (ICAO 8168 Vol 2) design criteria, plenty to learn from in there.
5.2.2.3.1 Maximum angle. For a straight-in approach, the angle formed by the final approach track and the runway
centre line shall not exceed:
a) 30° for procedures restricted to Cat A and B aircraft ; and
b) 15° for other aircraft categories.
5.2.2.3.2 Minimum distance. The distance between the runway threshold and the point at which the final approach
track intersects the runway centre line shall not be less than 1 400 m
5.2.3 Circling approach
The circling approach contains the visual phase of flight after completing an instrument approach, to bring an aircraft
into position for landing on a runway that for operational reasons is not suitably located for straight-in approach.
Appendix to Chapter 5
CALCULATIONS FOR OCA/H IN NON-ALIGNED
STRAIGHT-IN APPROACHES
....Maximum turn angle (max) = 15 degrees (for 5 < 15) or 30 degrees (for 15 < 30)
9.4.3 Final approach segment
9.4.3.2 A straight-in OCA/H shall not be published where final approach alignment or descent gradient criteria
are not met. In this case, only circling OCA/H shall be published.
This all implies (and common-sense says) that you can manoeuvre visually within the 'no-circling' area, day or night, if conducting a straight-in instrument approach because:
1) You're not circling, but instead conducting a straight-in approach, and
2) The 1400m (0.8nm) MAPt to which you "can" fly to is a "design criteria," not an "operational criteria."
There is also a CASA CAAP 178-1(2) that provides some great extra info, namely:
5.3.1 - In order for the aircraft to be able to safely land straight-in, the pilot needs to be able, at or before reaching the MDA, to sight the runway, align the aircraft with the centreline, and continue descent without significant changes to the descent rate, while visually avoiding any terrain in the runway approach area.
Any thing I'm missing?
Cheers!
