Take-off minima are generally expressed as VIS or RVR Limits. Where there is a specific need to see and avoid obstacles, a ceiling, or climb gradient will be specified.
a) According to the information available to the Commander, the weather at the aerodrome and the condition of the intended runway to be used should not prevent a safe takeoff and departure.
b) Take-off shall not be commenced unless weather conditions at the airport of departure are equal to or better than applicable minima for landing at that airport, unless a suitable take-off alternate aerodrome is available.
c) When the reported visibility VIS 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/VIS along the take-off runway is equal to or better than the required minimum.
d) When no report of VIS or RVR is available, a take-off may only be commenced if the commander can determine that the RVR/VIS along the take-off runway is equal to or better than the required minima.