What signifies that the engines are prepared for startup?

The phrase "Ready to Start Engine" signifies that the engines are prepared for startup because it indicates that all necessary pre-start checks have been completed and the crew has confirmed that the aircraft is in the right condition for beginning engine operations. This includes ensuring that systems within the aircraft are functioning properly, fuel is available, and there are no mechanical issues that would impede engine startup.

This phrase is a clear communication tool that directly reflects readiness for engine operation, making it a critical step in the pre-flight checklist and operational protocols for ramp operations. Other options, although important in their context, do not specifically indicate engine readiness. For instance, "Chocks Inserted" refers to the physical safety measures taken to secure the aircraft in place, "Power On" indicates that electrical systems have been activated, and "Flight Clearance Granted" pertains to air traffic control permissions to operate. While all these elements are essential to flight safety and operational readiness, none specifically denote that the engines are primed and ready for startup as effectively as "Ready to Start Engine."