I've timed myself as 2 minutes from leaving the office door to being ready to lift. (902)
So, in addition to getting to the 100m to the a/c
....
I do not leave switches in the 'ON' position ready.
The IIDS bite takes a few secs.
Listening to & noting ATIS .
SAS tests take a few more secs.
Challenge/Response pre-take off checks.
Clearance from ATC.
However, from callout!!
Got to go for a visit to the little boys room, finish off brew and biccies, logoff computer, turn off curry which is simmering on the cooker hob and remember to record big brother!
So, yes cc, probably 20mins is a bit more realistic.
ATB
SS