It's in the definition of 'clearance' a clearance must always be read back btw.
Take off at your discretion
Is not a 'clearance'
It is distinct from an ATCO saying 'Cleared to take-off 07' which is a 'clearance'
CLEARED ‡ Authorised to proceed under the conditions specified
A FISO cannot do that, they can only say 'Take off at your discretion'
Take off at your discretion certainly doesn't say you are 'cleared to take off', it says take off WHEN YOU have confirmed it is clear and safe to do so. Remember a FISO cannot issue instructions only information most of the time:
C
AP 413 2.2.2
Whilst the RTF procedures used by air traffic controllers form the main content of this
publication it should be noted that the phraseology used by FISOs at aerodromes is
different from that used by controllers. A FISO at an aerodrome provides a service to
give information useful for the safe and efficient conduct of flights in the Aerodrome
Traffic Zone. From the information received pilots will be able to decide the
appropriate course of action to be taken to ensure the safety of flight. Generally, the
FISO is not permitted to issue instructions or advice to pilots of his own volition.
However, in granting or refusing permission under Rule 40 and 41 of the Rules of the
Air, FISOs at aerodromes are permitted to pass instructions to vehicles and personnel
operating on the manoeuvring area and information and instructions to aircraft moving
on the apron and specific parts of the manoeuvring area. Elsewhere on the
manoeuvring area and at all times in the air, information only shall be passed to pilots.
Further details on the passing of instructions by FISOs at aerodromes are contained
in CAP 410 Manual of Flight Information Services - Part B Aerodrome.
I cannot find any reference to a FISO being able to use the term 'cleared' i.e. to issue a 'clearance' in CAP 413 - but I'm more than happy to be corrected too, the point of the exercise is to learn after all, not prove one is always right.
