I've read all the previous threads on PPRuNe and elsewhere regarding landing distance performance and Performance A factors; yet even the most in depth thread I found on this site is still very subjective as to whether
CAT.POL.A.230 f) applies when carrying out an inflight, pre-landing assessment of the destination airfield with the latest weather.
For this question I am referring to commercial operations on a Performance A aircraft. The situation I am referring to is pre-landing performance assessment of the planned destination, under normal circumstances, using the actual conditions. Abnormal, Emergency, or other "RE-planning" diversions are not considered.
Here's the section from IR-OPS Annex IV:
CAT.POL.A.230 Landing — dry runways
a) The landing mass of the aeroplane determined in accordance with CAT.POL.A.105(a) for the estimated time of landing at the destination aerodrome and at any alternate aerodrome shall allow a full stop landing from 50 ft above the threshold:
1) for turbo-jet powered aeroplanes, within 60 % of the landing distance available (LDA); and
2) for turbo-propeller powered aeroplanes, within 70 % of the LDA.
b) For steep approach operations, the operator shall use the landing distance data factored in accordance with (a), based on a screen height of less than 60 ft, but not less than 35 ft, and shall comply with CAT.POL.A.245.
c) For short landing operations, the operator shall use the landing distance data factored in accordance with (a) and shall comply with CAT.POL.A.250.
d) When determining the landing mass, the operator shall take the following into account:
1) the altitude at the aerodrome;
2) not more than 50% of the headwind component or not less than 150 % of the tailwind component; and
3) the runway slope in the direction of landing if greater than ± 2 %.
e) For dispatching the aeroplane it shall be assumed that:
1) the aeroplane will land on the most favourable runway, in still air; and
2) the aeroplane will land on the runway most likely to be assigned, considering the probable wind speed and direction, the ground handling characteristics of the aeroplane and other conditions such as landing aids and terrain.
f) If the operator is unable to comply with (e)(1) for a destination aerodrome having a single runway where a landing depends upon a specified wind component, the aeroplane may be dispatched if two alternate aerodromes are designated that permit full compliance with (a) to (e). Before commencing an approach to land at the destination aerodrome, the commander shall check that a landing can be made in full compliance with (a) to (d) and CAT.POL.A.225.
g) If the operator is unable to comply with (e)(2) for the destination aerodrome, the aeroplane shall be only dispatched if an alternate aerodrome is designated that allows full compliance with (a) to (e).
CAT.POL.A.235 Landing — wet and contaminated runways
a) When the appropriate weather reports and/or forecasts indicate that the runway at the estimated time of arrival may be wet, the LDA shall be at least 115 % of the required landing distance, determined in accordance with CAT.POL.A.230.
As I have understood all the threads I've found on this subject, some believe the requirements of
a) -
d) do not need to be applied once enroute to your planned destination and only the relevant AFM landing performance is applicable. I interpret the above regulation to mean that we are required to ensure our landing performance calculation complies with these Performance A factors.
I could be entirely wrong.
Our AFM landing performance figures, and our performance calculations created via our briefing software, allow me to calculate operational dispatch planning via a supplement and then AFM landing performance, which is factored as per
CAT.POL.A.230 a) 1) and
CAT.POL.A.235 a). For my aircraft, the operational dispatch planning figure seem reasonable and the AFM Supplement it is derived from does state it complies with the EASA requirements to land within 60% of the LDA and we can further factor the landing distances for wet runways. (i.e. it complies with
CAT.POL.A.230 a) 1) and
CAT.POL.A.235 a)) The supplement specifically states that it is a requirement to calculate the landing performance prior to approach, and to use the main AFM landing performance section and the prevailing weather at the destination airfield to calculate this
actual landing performance. Using the applicable Performance A factors with the main AFM landing performance figures results in severely restricted landing performance, in particular for wet runways.
The aircraft manufacturer has been very helpful responding to my enquiries seeking clarification. They have advised that the requirement to factor the landing distance to land with 60% of the LDA is not applicable once enroute. (They don't mention
CAT.POL.A.230 a) 1) specifically.) In practice, we currently apply these factors via the FMS and crosscheck the FMS performance against our briefing performance with
CAT.POL.A.230 a) 1) factor (x1.67), or the
CAT.POL.A.235 a) factor (x1.92), applied.
Operational Dispatch Planning does state compliance with these two factors. AFM landing performance section does not state any factor, although clearly one is already applied otherwise there would not be such a large reduction in landing performance when comparing the operational dispatch planning to the AFM landing performance with either the 1.67 or 1.92 factors applied. AFM landing performance without these factors applies is significantly less restrictive than operational dispatch planning figures. It is not stated by what factor the landing performance calculated directly from the AFM is factored by. I presume it has some factor to avoid the risk of runway overrun excursions. Assuming
CAT.POL.A.230 a) 1) is applicable, we are therefore unable to show the standard AFM landing performance complies with this.
I know this subject is raised a few times a year, but I haven't seen a decisive consensus in any of the threads I've read regarding the application of
CAT.POL.A.230 a) 1) and
CAT.POL.A.235 a) during inflight assessment of the planned landing. I intended to set this up as a simple "they apply" or "they don't apply" poll but haven't figured out how to do it here on PPRuNe. I've been pouring over IR-OPS, AFM Sections, AFM Supplements and back and forth with the manufacturer and I'm afraid I'm struggling to see the wood for the trees… Your collective advice is much appreciated!
