Operations in Class A airspace

In plain English

Class A airspace (18,000 ft MSL up to FL600) is IFR-only. You must have an ATC clearance before entering, maintain two-way radio communication, be transponder/ADS-B equipped, and navigate per your clearance. VFR is not permitted, and in the RVSM band (FL290–FL410) you need RVSM equipment and authorization.

Key points

• All operations under IFR, with an ATC clearance obtained before entry.
• Maintain two-way radio communication with ATC throughout.
• Transponder + ADS-B Out required; RVSM authorization between FL290 and FL410.
• VFR is not allowed in Class A.

Common pitfalls

• Forgetting Class A begins at 18,000 ft MSL and requires IFR plus a clearance.
• Operating in the RVSM band without RVSM authorization.

Summary: Class A airspace (FL180–FL600) is IFR-only, requiring an ATC clearance, two-way communication, transponder/ADS-B, and RVSM authorization in the FL290–FL410 band.