For on-demand flight operations, how many hours are required in a consecutive calendar quarter?

For on-demand flight operations under Part 135, operators are required to achieve a minimum of 500 hours of flight time in a consecutive calendar quarter to maintain operational currency and ensure sufficient experience levels for safety and compliance. This requirement is part of the regulations that pertain to the operational capabilities of the flight crew and the overall operational reliability of the air carrier.

Flying a minimum of 500 hours ensures that pilots are actively engaged in operations, maintaining their skills and familiarizing themselves with various flight conditions and scenarios. This is critical in an on-demand operation, where pilots must be prepared for diverse and often rapidly changing flight environments.

The other choices reflect higher hour requirements that do not align with the regulations for on-demand flight operations, thus making them incorrect options. A thorough understanding of these requirements is vital for compliance and safety in Part 135 operations.