David said: > SVFR means something entirely different in North America. [...]
His was a good summary. It did not address the pilot qualifications and currencies needed to use SVFR, which exist in part because SVFR is often used for scud running ... which is extremely dangerous. The reason for SVFR as a third set of flight rules is that it basically permits very near to clouds visual navigation under conditions which preclude see and avoid separation from other traffic. Unusual situation. Whereas IFR traffic could share airspace with VFR, because the ordinary VFR keeps far enough away from clouds to allow aircraft to avoid each other, no IFR is possible in a block of airspace that is being used for SVFR. Of course, you cannot have two SVFR operations in the same airspace block. Because SVFR shuts down IFR, it has to be granted by whoever owns the right to grant IFR clearances through all airspace being approved for SVFR use. For as long as the SVFR use is authorized, all IFR traffic is turned away. All airlines are required to operate all scheduled flights under IFR, and KLAX cannot accept the schedule disruption associated with _any_ SVFR because the backlog of waiting aircraft would build up far too quickly. Technically, there is no reason to specify the "No SVFR" because they can simply always say no. However, making the statement on charts saves them having to say that often, and deal with the subsequent pilot complaints. Not all SVFR uses are for scud running. If the visibility drops very low, as it often does in the Los Angeles basin, the airports can go below VFR minimums and all VFR traffic is blocked on the ground or is above the inversion layer a couple of thousand feet above the airport runways. Pilots then need an IFR clearance to fly the one mile of climb/descent that gets them through the smog. Alternatively, they can use SVFR. Note that there are cases that are safe to fly and where it is illegal to land at an airport under VFR or under IFR but still legal under SVFR. I have never needed to request an SVFR ... yet ... _______________________________________________ Flightgear-devel mailing list [EMAIL PROTECTED] http://mail.flightgear.org/mailman/listinfo/flightgear-devel
