Pans Ops 4 - Straight-in Manoeuvring Criteria

[Percy Prune]

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9.4.3.2 A straight-in OCA/H shall not be published where final approach alignment or descent gradient criteria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! :8:ok:

[AerocatS2A]

Where is the obstacle that is responsible for the no circling area? Why is the "straight in" approach, not in fact straight in? Could it be that the limiting obstacle is on the runway centreline? I would be wary of manoeuvring unless I knew the answers to those questions.

[Intruder]

Which specific airport/approach are you asking about?

At KJFK, for example, there are straight-in RNAV approaches to Rwy 22L and 22R, and a VOR approach to 22L with a 7 deg offset. It is clear from the charts and existence of the RNAV and ILS approaches that there are no obstacles to prevent maneuvering to final.

If there are no explicit restrictions on the chart, I would maneuver any time after the Final Approach Fix, so as to be on the runway centerline no later than the VDP (or constructive VDP of [MDH/300] miles, if not charted).

There is much discussion of straight-in approaches in Ch 5 of the FAA AIM, but no single, definitive answer.

[Percy Prune]

Hi guys, I've amended the above for clarity. Cheers

[Intruder]

It is a straight-in approach, so you are NOT circling.

From the depiction of the circling area, it appears to extend at some angle (15 deg?) from the end of the runway. If so, the final approach course is NOT in the circling area, but defines the western boundary of the circling area. If that is not the case, and the final approach course is inside the circling area, you can NEVER maneuver to align the airplane with the centerline, per strict interpretation of your Jepp citation.

Given the obstacle just outside the 2.0 NM from ARGSM fix, I'd start the alignment at 2.0 NM from ARGSM.

However, ARGSM appears to be on the extended runway centerline per the Note 1, so you should be able to start your final alignment turn as you approach ARGSM, using 15 deg AOB.

[Percy Prune]

Annex 14 of ICAO 8168 and MOS 139 in Australia detail requirements for airfields. Amongst many items, the no-circling areas are drawn with reference to the runway strip and the type of approach.

From reading these documents, it appears a no-circling area covers the limits to allow up to the greater of the runway splay or the inbound segment of the straight-in approach up to 15deg (for Cat C). If there were to be an obstacle infringing this area then only a Circling Approach would be specified. In this case the western edge of the no-circling limit. Therefore the approach may indeed coincide with the western edge of the no-circling limit. In which case this is all a moot point. Could someone confirm this?

I have also found an Airservices Australia (ASA) depiction of the chart, see here:
http://www.airservicesaustralia.com/aip/pending/dap/ARGGN01-135.pdf

It shows the 15deg offset. Not being familiar with these charts, there is also an arrow which I believe may be the approaching inbound track. Irrespective, even if (1) the ASA depiction is correct and (2) the assertions of some that you can't manoeuvre the aircraft because you're inside the no-circling area are correct, it can be seen that the inbound leg at some point will enter the no-circling area. Where though?..

I'm inclined to believe the Jepp and ASA circling area depictions are not truly to scale nor a perfect representation. This is perhaps what's causing confusion.

Intruder:
Given the obstacle just outside the 2.0 NM from ARGSM fix, I'd start the alignment at 2.0 NM from ARGSM.I completly agree. Practically and to mitigate any threats, 2nm to run ARGSM is an excellent position to begin altering the flight path to be stabilised whilst also giving a wide enough buffer for EGPWS. This position is also most likely outside the no-circling area for those that still believe you can't manoeuvre. This position gives you 2.8nm to run until the threshold. I'm still after a definitive reference for between 2.8nm and 4.2nm though...

At this stage, with this example, I'm inclined to believe manoeuvring to a longer straight-in final once within the circling area 'limit' (4.2nm from threshold) is allowed (as per above reference) even if it approaches through a no-circling area, simply because a straight-in approach has been designed as per the above regs quoted.
However, the edge of this no-circling area may in fact also be the inbound leg, therefore negating this particular query. Anyone have an answer for this?

[AerocatS2A]

I agree with Intruder. You are not in the circling area. That obstacle to the left of the final course is about 5NM from the threshold so once you are comfortably passed that obstacle there should be no issues with aligning yourself with the runway.

[Percy Prune]

Much appreciated from everyone so far. Can anyone else assist further?

[Intruder]

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.
So far you have found several documents that indicate the approach does NOT go through the no-circling area. Have those who believe differently show you their documentation.

If you can't maneuver, how can you land? What does the "no-circling, no maneuver" crowd do to land from that approach?

[Percy Prune]

So far you have found several documents that indicate the approach does NOT go through the no-circling area. Have those who believe differently shown you their documentation.Best not to go there.

If you can't maneuver, how can you land? What does the "no-circling, no maneuver" crowd do to land from that approach?Fly to the minima, then, turn.

[Intruder]

That is just as "illegal" as "maneuvering"! What makes a "turn" below minimums any more "legal" than "maneuvering" above minimums? By THEIR criteria, they are maneuvering INSIDE the no-circling zone, BELOW MINIMUMS! By YOUR criteria, you are maneuvering OUTSIDE the no-circling zone, ABOVE minimums! Who are these imbeciles?!?

"Best not to go there" REALLY means best not to be working for, or flying on, that company! The "I'm right because I say so, and I don't need substantiation" attitude is DANGEROUS!!! What company is it?