gallois wrote:
However, you don’t always have to fly the airways to fly IFR
Exactly. The lower limit of an ATS route is frequently determined by ATC considerations and not by obstacle clearance or even controlled airspace limits. E.g. the MVA maybe lower than the lower limit of the ATS route.
So you could fly the exact same route IFR lower than the lower limit of the “airway”. Of course, if you want to flight plan that, you would have to file DCT.
