4 ms·

Any flight above 17999 ft in class A airspace requires an IFR flight plan. IFR requires controllers for the clearance, release, and approach clearance. Probab

Any flight above 17999 ft in class A airspace requires an IFR flight plan. IFR requires controllers for the clearance, release, and approach clearance. Probably what he means.... Most Jets and planes people have experience with would be flying at those altitudes.

Casseres 8y ago
FYI: Civilian flights in Class A airspace (at or above 18,000ft in most places) require an IFR clearance. State flights can fly "due regard" (VFR) in Class A airspace. In Hawaii, there is no Class A airspace, and I once controlled a civilian aircraft flying VFR at FL210 (21,000ft).