GM1 CAT.POL.A.430
& CAT.POL.A.435 Landing — dry runways & Landing — wet and
contaminated runways
ED Decision 2021/005/R
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
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.430 and CAT.POL.A.435 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.430, are shown in the following Table 1.
Table 1:
— Corrective factors for dry runways
|
Aeroplane category |
Required Margin (dry runway) |
Resulting factor (dry runway) |
|
All aeroplanes |
ALD < 70 % of the LDA |
LDA = at least 1.43 x ALD |
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.435, as shown in the
following Table 2.
Table 2:
Corrective factors for wet runways
|
Aeroplane category |
Resulting factor (dry runway) |
|
All aeroplanes |
LDA = at least 1.15 x 1.43 x ALD =
1.64 x ALD |
EASA regulations mandate sufficient runway length for safe aircraft landings. The available landing distance (LDA) must exceed the actual landing distance (ALD) specified in the aircraft flight manual. Dry runways require LDA to be at least 1.43 times the ALD. Wet runways, lacking specific AFM data, necessitate a further 15% increase, resulting in an LDA of 1.64 times the ALD.
* Summary by Aviation.Bot - Always consult the original document for the most accurate information.
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