Take off alternate - Landing distance req
We all agree that prior to departure, a pilot need to confirm that for the destination and alternate aerodromes is he able to meet the regulatory requirement, which means lands within 60% of the LDA.
What about a take off alternate? do we need to comply with the certified data (regulatory req) or can we use the operational (advisory) data?
Looking at EASA, it is said all alternate so it includes the take off alternate.
But for a take off alternate I would guess you would look at the One engine out performance which is by definition an advisory data. But if we need to look at a dispatch calculation for the take off alternate we would then have to multiply this by 1,67 in dry condition ?
thanks for your thought.