What does 'useful load' include?

The concept of 'useful load' is essential in aviation as it represents the total weight that an aircraft can carry in addition to its empty weight. Specifically, useful load includes the weight of passengers, baggage, usable fuel, and drainable oil. This definition is crucial for flight planning and ensuring that the aircraft operates well within its weight limits for safety and performance.

Passengers contribute directly to the useful load, as their weight affects how much cargo or fuel the aircraft can safely carry. Baggage also adds to the payload the pilot needs to account for when calculating the total weight. Usable fuel means the fuel that can be used during the flight, as opposed to the maximum fuel capacity, which may include weight that isn’t usable. Lastly, drainable oil is included because while not all oil is utilized for propulsion, the weight of the oil can impact the aircraft's overall weight.

Understanding that passengers, luggage, usable fuel, and drainable oil together form the useful load helps pilots make informed decisions about weight and balance, ensuring safety and efficiency during the flight. This knowledge safeguards against exceeding weight limits, which can lead to performance issues or even accidents.