GM1 CAT.POL.A.330
& CAT.POL.A.335 Landing — dry runways & Landing — wet and
contaminated runways
ED Decision 2021/005/R
LANDING
DISTANCES AND CORRECTIVE FACTORS
The AFM
provides performance data for the 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.330 and CAT.POL.A.335 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.330, 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 |
|
Aeroplanes approved under CAT.POL.A.355 |
ALD < 80 % of the LDA |
LDA = at least 1.25 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.335,
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 |
|
Aeroplanes approved under CAT.POL.A.355 |
LDA = at least 1.15 x 1.25 X ALD =
1.44 x ALD |
However,
for aeroplanes approved under CAT.POL.A.355, when landing on wet runways,
CAT.POL.A.355 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(b).). 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.
EASA regulations mandate increased landing distance (LDA) compared to the Aircraft Landing Distance (ALD) in the flight manual. Dry runways require LDA to be at least 1.43x ALD (or 1.25x for CAT.POL.A.355 approved aircraft). Wet runways necessitate a further 15% increase, resulting in LDA of 1.64x ALD (or 1.44x for CAT.POL.A.355 approved aircraft), with additional considerations for CAT.OP.MPA.303(b).
* Summary by Aviation.Bot - Always consult the original document for the most accurate information.
Loading collections...