SVFR is only available in a Control Zone. A Control Zone starts at the surface, an airway doesn't. Ergo SVFR is not available in airways.
1) No. Not without an IR anyway (bar being able to cross at the base level when said base is defined as a flight level, but you don't need to be talking to the mil for that. In fact you don't need to be talking to anybody).
2) No. Though where airways transit Terminal Control Areas they assume the airspace classification of the TMA. So if the TMA is a lower Class than A, any airways in the TMA assume the lower Class inside the TMA. Or, if the airway is Class D but goes through a Class A TMA, the airway changes from D to A in the TMA.
3) No. An aircraft that is not IFR equipped can cross an airway by day in VMC but the pilot still needs an IR and a clearance needs to be obtained from the controlling authority.
4) No. Not of a Class A airway, because you can't cross that VFR (or SVFR) anyway nor of any other en-route airspace that you may be able to transit VFR (e.g. anything Class D) either. A VFR FPL doesn't really do anything with regards airspace transits. You should however file a VFR flight plan on that route for S&R reasons if it takes you over the Irish Sea.
HTH.
Last edited by Roffa; 11th Apr 2010 at 23:11.