Where are VFR-on-top operations prohibited?

VFR-on-top operations are prohibited in Class A airspace because Class A airspace is designed for instrument flight rules (IFR) operations only. This airspace extends from 18,000 feet MSL to 60,000 feet MSL and all aircraft must operate under IFR. Pilots cannot operate VFR in this airspace to maintain the safety and operational standards required for instrument flying since it is above the cloud layer where visibility can be compromised.

In contrast, VFR-on-top operations can be conducted in Class B, Class C, and restricted airspace under certain conditions, provided that the pilot is cleared to operate in those areas and can maintain visual separation from other aircraft. Therefore, the prohibition of VFR-on-top specifically applies to Class A airspace due to the stringent regulations governing all flights within that altitude range.