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4.2. Go-Around Requirements
4.2.1. Normal Approach
During dispatch, only the approach climb gradient needs to be checked, as this is the limiting one.
The minimum required gradient is the one defined during aircraft certification
(C.f. 3.3.1 Approach Climb). Operators have a choice of go-around speed (from 1.23 VS1g to 1.41 VS1g), and configuration (3 or 2) to determine the Maximum weight limited by go-around gradient.
In the rare case of a go-around limitation during dispatch, operators can select CONF 2 and 1.4 VS1g for go-around calculation, and should no longer be limited. Nevertheless, even if the regulation authorizes such assumptions, it is important to warn pilots about the speed and configuration retained, as soon as they are not standard (CONF 3 and 1.23 VS1g).
In a normal approach, the required climb gradient is 2.1% for twin and 2.7% for four engine aircraft, independently of airport configuration and obstacles. During dispatch, operators can account for the gradient published in the airport approach chart.
4.2.2. CAT II or CAT III Approach
“JAR-OPS 1.510
(a) For instrument approaches with decision heights below 200 ft, an operator must verify that the approach mass of the aeroplane, taking into account the take-off mass and the fuel expected to be consumed in flight, allows a missed approach gradient of climb, with the critical engine failed and with the speed and configuration used for go-around of at least 2.5%, or the published gradient, whichever is the greater. The use of an alternative method must be approved by the Authority”.
In case of a CAT II/III approach, the gradient is 2.5% (all aircraft types) or more if the approach charts require a higher value for obstacle consideration.
4.3. Conclusion
. Landing weight must satisfy the structural constraints. So, the first limitation is:
LW ≤
maximum structural landing weight
. Landing weight is limited by aircraft performance (runway limitation and go-around limitation). Thus, the second condition is:
LW ≤
maximum performance landing weight
. Therefore, from these two conditions, it is possible to deduce the expression of the maximum allowed landing weight called maximum regulatorylanding weight (MLW):
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