Commercial Pilot License (CPL) Practice Exam 2025 - Free Commercial Pilot License Practice Questions and Study Guide

The correct answer indicates that the pressure range in the green arc for the aircraft's oil system is between 60-90 psi. This range is designed to show the optimal operating conditions for the oil pressure within the aircraft's engine system. Maintaining oil pressure within this range is critical as it ensures proper lubrication of engine components, helping to prevent wear and overheating.

Oil pressure that falls within this range signifies that the oil system is functioning efficiently, providing necessary lubrication while maintaining engine performance. It is important for pilots to monitor oil pressure, and an indication within the green arc suggests that everything is operating normally.

If the oil pressure were to drop below or rise above this range, it could indicate potential issues with the oil system, leading to insufficient lubrication or possible engine damage. Understanding the significance of the green arc is crucial for pilots in ensuring the safety and efficiency of flight operations.