What is the maximum allowable difference in RPM drop?

The maximum allowable difference in RPM drop during an engine failure check, specifically in a multi-engine aircraft, is 50 RPM. This standard helps ensure that both engines are performing consistently and that there is not a significant discrepancy that could indicate a potential issue with one of the engines.

Having a maximum RPM drop threshold is critical for maintaining safety and performance, as a larger difference in RPM could suggest that one engine is not developing power as it should, which could lead to an imbalance during flight.

While other options suggest various RPM thresholds, they do not align with the established standards for multi-engine aircraft checks, which have set this limit to 50 RPM to promote safety and operational reliability during critical engine performance evaluations.