GM1 CAT.POL.A.355(b)(7) Approval of reduced required landing distance operations

CAA ORS9 Decision No. 15

AERODROME LANDING ANALYSIS PROGRAMME (ALAP)

The intent of an ALAP is to ensure that the aerodrome critical data related to landing performance in reduced required landing distance operations is known and taken into account in order to avoid any further increase of the landing distance. Two important aerodrome-related variables largely contribute to increasing the landing distance: landing (ground) speed and deceleration capability. Related factors to consider should include at least the following elements:

(a) Topography

Terrain around the aerodrome should be considered. High, fast-rising terrain may require special approach or decision points, missed approach or balked landing procedures and may affect landing performance. Aerodromes located on top of hilly terrain or downwind of mountainous terrain may occasionally experience conditions of wind shear and gusts. Such conditions are particularly relevant during the landing manoeuvre, particularly during the flare, and may increase landing distance.

(b) Runway conditions

Runway characteristics, such as unknown slope and surface composition, can cause the actual landing distance to be longer than the calculated landing distance. Braking action always impacts the landing distance required as it deteriorates. To this regard, consideration should be given to, and information obtained on, the maintenance status of the runway, as a wet runway surface may be significantly degraded due to poor aerodrome maintenance.

Some aerodromes may not have current weather reports and forecast available for flight planning. Others may have automated observations for operational use. Others may depend on the weather forecast of a nearby aerodrome. Area forecasts are also valuable in evaluating weather conditions for a particular operation. Comparing forecasted conditions to current conditions provides insight on upcoming changes as weather systems move and forecasts are updated. Longer flight segments may lean more heavily on the forecast for the ETA, as current conditions may change significantly as weather systems move. The most important factors that should be considered are contained in AMC1 CAT.OP.MPA.300(a), AMC1 CAT.OP.MPA.311, GM1 CAT.OP.MPA.311, GM1 CAT.OP.MPA.303 and GM2 CAT.OP.MPA.303.

(d) Adverse weather

Adverse weather conditions include, but are not restricted to, thunderstorms, showers, downbursts, squall lines, tornadoes, moderate or severe turbulence on approach, heavy precipitation, wind shear and icing conditions. In general, all weather phenomena having the potential to increase the landing distance should be carefully assessed. Among these, tailwind is particularly relevant.

Wind variations should be carefully monitored as they may lead to variations in the reported and/or actual wind at the touchdown zone. Due consideration should be given also to the crosswind perpendicular to the landing runway as a slight variation in the direction of the crosswind may result in a considerable tailwind component.

(e) Runway safety margins

Displaced thresholds, aerodrome construction, and temporary obstacles (such as cranes and drawbridges) may impact the runway length available for landing. NOTAMs must be consulted during the flight preparation. Another safety margin is the size and adequacy of the runway strip and the RESA. A well-designed and well-maintained runway strip and RESA decrease the risk of damaging