Hi likair,
For the alternative procedure in EGTC, you should extend the outbound leg for 2'30'' in nil winds condition like you said (if you are Cat. A aircraft as I would imagine).
Once you are cleared for the procedure, you turn to the outbound, start the timer when you have the wings level or at the abeam point whichever comes later. You should be flying the first minute of the 2.5 minutes as a normal hold i.e. 2x drift or 3x drift according to winds. Once you've flown that first minute, you should reduce the correction to only single drift for the rest of the 2.5 minutes. But bear in mind that you will most likely need to adjust the total time according to winds. Let's assume that the proportion of wind you are flying at is 10 knots of tailwind while you are in the outbound leg. This means that you have to fly 10 seconds less for each minute in the extended outbound leg.
So out of the 2'30'':
1st minute would be adjusted to 50 seconds. (with 2x or 3x the drift)
2nd minute would be adjusted to 50 seconds as well. (back to single drift)
the final 30 seconds would be adjusted to 25 seconds. (Single drift)
Now as you do this, you should be already descending from the hold level to the platform altitude.
This would give you a total flying time of 2'05'', and then you commence the base turn.
I hope this answers your question.
Cheers mate.
