Originally Posted by
Barnaby the Bear
If a CTOT is given, and the pilot reports ready before the slot tollerance (5 ins prior, 10 mins after CTOT), then a ready message may be sent.
Slot tollerance is for ATC needs only

, the pilot is supposed to be ready as close as possible to CTOT
Originally Posted by
Barnaby the Bear
If it looks like you will be out of slot tollerance, a call to flow, can 'sometimes' buy an extra couple of mins.
If you give ATC a call to get an extra couple of mins, please make sure your handling agent does NOT sent a DLA message as well (at least wait for the ATC's answer

)
Same thing if you will be ready for T/O at CTOT+5. Please, pretty please, give us a call BEFORE sending the DLA message.
... that is, if you don't want a 3h delay