Magari diṛ una banalità, ma tutte le regole a cui gli operatori di voli commerciali devono attenersi (e sulle quali basare i propri manuali) sono riportate nel documento JAR-OPS 1, liberamente scaricabile qui:
http://www.jaat.eu/publications/publications.html#
Per il caso in particolare credo che abbia ragione airdolomiten. (Vedere il punto (iii))
Appendix 1 to JAR-OPS 1.430
Aerodrome Operating Minima
(See IEM to Appendix 1 to JAR-OPS 1.430
(a) Take-off Minima
(1) General
(i) Take-off minima established by
the operator must be expressed as visibility
or RVR limits, taking into account all
relevant factors for each aerodrome
planned to be used and the aeroplane
characteristics. Where there is a specific
need to see and avoid obstacles on
departure and/or for a forced landing,
additional conditions (e.g. ceiling) must be
specified.
(ii) The commander shall not
commence take-off unless the weather
conditions at the aerodrome of departure
are equal to or better than applicable
minima for landing at that aerodrome
unless a suitable take-off alternate
aerodrome is available.
(iii) When the reported
meteorological visibility is below that
required for take-off and RVR is not
reported, a take-off may only be
commenced if the commander can
determine that the RVR/visibility along the
take-off runway is equal to or better than
the required minimum.
(iv) When no reported
meteorological visibility or RVR is
available, a take-off may only be
commenced if the commander can
determine that the RVR/visibility along the
take-off runway is equal to or better than
the required minimum.
(2) Visual reference. The take-off
minima must be selected to ensure sufficient
guidance to control the aeroplane in the event of
both a discontinued take-off in adverse
circumstances and a continued take-off after
failure of the critical power unit.