Hi OPEN DES,
The explanation notes in Performance, Go Around, General, Procedure say:
"According to airport pressure altitude and temperature determine if the slats/flaps setting must be restricted as a function of the landing weight, in order to meet the go around gradient requirement of 2.1 %.
Establish the final approach configuration with one more step of flaps. If the approach is interrupted, retract the flaps by one step during the go-around.
In case of category II approach, JAR-OPS requires a regulatory approach climb gradient of 2.5 % to be maintained.
Use the tables for CAT II approach to determine the maximum approach climb limiting weight according to airport pressure altitude and temperature."
I have always assumed the published gradient must be valid from airport level an an AA of 1500ft (the default AA before amendment).
If you look at the published tables in: Go Around, ACG-Approach Climb limiting for various gradients, weights and airfield Altitudes - one can see that in order to maintain the gradient, the weight must be reduced by about 1 ton per 1,000 ft increase in airport Altitude. (for A320)
Therefore to answer
the LPC says the a/c can achieve 4,01% but can it still guarantee 4% at 5000ft???
- then no it can't.
I guess you would have to enter the LPC calculation with an assumed weight of about 1 ton heavier for every thousand feet your AA is above 1500ft AAL. (for A320)