11 TSG Courses
RTC – MOD-08 – Pt.03 – Visibility
Visibility is a measure of how far you can see directly in front of you and is measured in meters. In the US you will find it measured in Statute Miles, multiply by 1600 to get the value in meters (or by 1.6 then 1000).
Visibility will dictate whether your flight will conduct IFR or VFR ops, especially at the aerodrome or carrier.
Visibility in weather reports, or METARs, is 4 digits long. So 0300 is 300m, 1500 is 1,500m. This goes up to 9999m, any visibility 10km and above is reported as 9999m as it becomes no factor to flying IFR or VFR.
VFR, IFR, VMC and IMC
VFR and IFR stand for Visual Flight Rules and Instrument Flight Rules, they are the rules and conditions you must carry out your flight under. (Beyond the scope of this course)
VMC and IMC are Visual Meteorological Conditions and Instrument Meteorological Conditions, they are the physical conditions that are prevalent around you or in an area and are predefined all based on visibility and distance from clouds.
You can easily fly IFR in VMC or IMC, but not the other way around, you cannot fly VFR in IMC, only VMC.
IFR flight is much tougher and has much stricter tolerances on your flight. It is also highly advisable to fly IFR only with controller support or on pre-planned routes for reasons of concentration, SA, enhanced navigation, and terrain avoidance.