Which of the following metrics is considered when planning a multi-engine flight?

When planning a multi-engine flight, operating weight is a critical metric to consider. It encompasses the total weight of the aircraft, including passengers, cargo, fuel, and any additional equipment. This total weight significantly affects various performance parameters of the aircraft, such as takeoff distance, climb rate, and fuel efficiency.

Managing the operating weight is crucial for safety and compliance with regulatory performance criteria, as exceeding weight limits may impair the aircraft's ability to take off, climb, or maneuver effectively. Additionally, understanding the operating weight helps in calculating the required fuel load and ensuring that the aircraft meets weight and balance requirements, which are vital for stable flight operations.

While engine fuel type is important for operational planning, and flight path length plays a role in navigation and fuel calculations, the operating weight directly impacts the aircraft's performance capabilities and is therefore a fundamental metric in the pre-flight planning process. The color of the aircraft is not a relevant factor in the technical aspects of flight planning.