FAA Flight Instructor Airplane (FIA)Navigation and AirspaceEasy
A flight instructor explains to an instrument student that Class A airspace requires an IFR clearance and specific vertical limits. Which range correctly describes Class A airspace in the contiguous United States?
- A18,000 feet MSL up to and including FL600, IFR operations only
- BSurface up to 18,000 feet MSL
- C12,500 feet MSL up to FL600, IFR operations only
- DFL180 up to FL450, VFR or IFR permitted
Show answer & explanationAnswer & explanation
Correct answer: A. 18,000 feet MSL up to and including FL600, IFR operations only
Class A airspace extends from 18,000 feet MSL up to and including FL600 across the contiguous U.S., and all operations must be conducted under IFR with an ATC clearance; VFR flight is not permitted.
Why the other options are wrong
- B. This describes airspace below Class A, not Class A itself.
- C. Incorrect lower limit; Class A begins at 18,000 MSL, not 12,500.
- D. Wrong lower/upper limits and incorrectly allows VFR.
Class A Airspace
Airspace from 18,000 ft MSL up to and including FL600 where all flights must operate under IFR with an ATC clearance.
- No VFR flight allowed
- Requires an instrument rating and clearance
- Extends over the entire contiguous U.S. and Alaska
Memory trick: 'A' is for Always IFR above 18,000!