CAT.POL.A.230 Landing – dry runways

FACTORING OF AUTOMATIC LANDING DISTANCE PERFORMANCE DATA In those cases where the landing requires the use of an automatic landing system, and the distance published in the AFM includes safety margins equivalent to those contained in CAT.POL.A.230(a)(1) and CAT.POL.A.230(a)(2), the landing mass of the aeroplane should be the lesser of:

(a)the landing mass determined in accordance with CAT.POL.A.230(a)(1) and CAT.POL.A.230(a)(2); or

(b)the landing mass determined for the automatic landing distance for the appropriate surface condition, as given in the AFM or equivalent document. Increments due to system features such as beam location or elevations, or procedures such as use of overspeed, should also be included.

FACTORING OF LANDING DISTANCE PERFORMANCE DATA WHEN USING A HEAD-UP DISPLAY (HUD) OR AN EQUIVALENT DISPLAY WITH FLARE CUE In those cases where the landing requires the use of a HUD or an equivalent display with flare cue, and the landing distance published in the AFM includes safety factors, the landing mass of the aeroplane should be the lesser of:

(a)the landing mass determined in accordance with CAT.POL.A.230(a)(1); or

(b)the landing mass determined, when using a HUD or an equivalent display with flare cue for the appropriate surface condition, as given in the AFM or equivalent document.

LANDING MASS CAT.POL.A.230 establishes two considerations in determining the maximum permissible landing mass at the destination and alternate aerodromes:

(a)Firstly, the aeroplane mass will be such that on arrival the aeroplane can be landed within 60 %, 70 %, or 80 % (as applicable) of the landing distance available (LDA) on the most favourable (normally the longest) runway in still air. Regardless of the wind conditions, the maximum landing mass for an aerodrome/aeroplane configuration at a particular aerodrome cannot be exceeded.

(b)Secondly, consideration should be given to anticipated conditions and circumstances. The expected wind, or ATC and noise abatement procedures, may indicate the use of a different runway. These factors may result in a lower landing mass than that permitted under (a), in which case dispatch should be based on this lesser mass.

(c)The expected wind referred to in (b) is the wind expected to exist at the time of arrival.

WORKFLOW OF THE LANDING DISTANCE ASSESSMENT AT THE TIME OF DISPATCH — GENERAL [Figure or form omitted from this preview — available in the Avioverse workspace library.]

WORKFLOW OF THE LANDING DISTANCE ASSESSMENT AT THE TIME OF DISPATCH — RUNWAY SUITABILITY CHECK [Figure or form omitted from this preview — available in the Avioverse workspace library.]

WORKFLOW OF THE LANDING DISTANCE ASSESSMENT AT THE TIME OF DISPATCH — DRY RUNWAYS [Figure or form omitted from this preview — available in the Avioverse workspace library.]

WORKFLOW OF THE LANDING DISTANCE ASSESSMENT AT THE TIME OF DISPATCH — WET RUNWAYS [Figure or form omitted from this preview — available in the Avioverse workspace library.]

WORKFLOW OF THE LANDING DISTANCE ASSESSMENT AT THE TIME OF DISPATCH — CONTAMINATED RUNWAYS [Figure or form omitted from this preview — available in the Avioverse workspace library.]

LANDING DISTANCES AND CORRECTIVE FACTORS The AFM provides performance data for landing distance under conditions defined in the applicable certification standards. This distance, commonly referred to as the actual landing distance (ALD), is the distance from the position on the runway of the screen height to the point where the aeroplane comes to a full stop on a dry runway. The determination of the ALD is based on the assumption that the landing is performed in accordance with the conditions and the procedures set out in the AFM on the basis of the applicable certification standards. As a matter of fact, any particular landing may be different from the landing technique that is assumed in the AFM for certification purposes. The aircraft may approach the runway faster and/or higher than assumed; the aircraft may touch down further along the runway than the optimum point; the actual winds and other weather factors may be different from those assumed in the calculation of the ALD; and maximum braking may not be always achievable. For this reason, the LDA is required by CAT.POL.A.230 and CAT.POL.A.235 to be longer than the ALD. The margins by which the LDA shall exceed the ALD on dry runways, in accordance with CAT.POL.A.230, are shown in the following Table 1.

Table 1: Corrective factors for dry runways

If the runway is wet and the AFM does not provide specific performance data for dispatch on wet runways, a further increase of 15 % of the landing distance on dry runways has to be applied, in accordance with CAT.POL.A.235, as shown in the following Table 2.

Table 2: Corrective factors for wet runways

However, for aeroplanes that are approved under CAT.POL.A.255, when landing on wet runways, CAT.POL.A.255 further requires the flight crew to apply the longer of the landing distance resulting from the above table and the landing distance resulting from the application of CAT.OP.MPA.303(a) or (b) as applicable. If performance information for the assessment of LDTA is not available as per CAT.OP.MPA.303(b)(2), the required landing distance on wet runways should be at least: 1.15 x 1.67 x ALD for turbojet-powered aircraft and 1.15 x 1.43 x ALD for turbopropeller-powered aircraft.

ALTERNATE AERODROMES The alternate aerodromes for which the landing mass is required to be determined in accordance with CAT.POL.A.230 are:

(a)destination alternate aerodromes;

(b)fuel ERA aerodromes; and

(c)re-dispatch or re-clearance aerodromes.

AFM LANDING PERFORMANCE CORRECTIONS Landing performance data is provided in the AFM at least for the certified range of pressure altitudes. AFM data may include other influence parameters such as, but not limited to, runway slope and temperature. The effect of speed increments over threshold should also be accounted for when these increments are required by the applicable AFM procedures, such as autoland or steep approach.