What is the normal operation limit for engine indicating during flight?

The normal operation limit for engine indications during flight is represented by the green arc. This green arc signifies the parameters within which the engine operates safely and efficiently. Maintaining engine indications within this range ensures optimal performance, reliability, and safety of the aircraft operations during flight.

The other arcs represent warning or caution zones. The red arc typically indicates limits that should not be exceeded, as operating in this range can result in severe damage or failure. The yellow arc is often associated with cautionary limits, where operations may be safe but require extra vigilance. The blue arc, depending on the specific system, might indicate certain operating or configuration parameters that are not related to normal operating range for engine performance.

Understanding these limitations is crucial for pilots to avert potential engine malfunctions and maintain safe flight conditions. Hence, operating within the green arc is essential for effective engine management during flight.