Basic Empty Mass (BEM), sometimes referred to as Basic Empty Weight (BEW), is a critical parameter in aircraft design and operation. It represents the weight of the aircraft when it is in a completely empty or non-operational condition, excluding all usable fuel, payload (such as passengers and cargo), and operational fluids (like engine oil and hydraulic fluid). Here’s the formula, definition, and SI unit for Basic Empty Mass:
Basic Empty Mass Formula: The formula for calculating the Basic Empty Mass (BEM) is relatively straightforward:
- BEM: Basic Empty Mass, measured in kilograms (kg) or pounds (lbs), depending on regional conventions.
- EOW: Empty Operating Weight, which includes the structural weight of the aircraft, standard equipment, and furnishings, measured in kilograms (kg) or pounds (lbs).
- Operational Fluids Weight: The combined weight of operational fluids required for aircraft operation, such as engine oil, hydraulic fluid, and other fluids, measured in kilograms (kg) or pounds (lbs).