Empty weight (EW) is the sum of the ‘as built’
manufacturer's empty weight
In aviation, manufacturer's empty weight (MEW) (also known as manufacturer's weight empty (MWE)) is the weight of the aircraft "as built" and includes the weight of the structure, power plant, furnishings, installations, systems, and other equipmen ...
(MEW), plus any standard items (SI) plus any operator items (OI), EW = MEW + SI + OI. The EW is calculated for each aircraft series and each unique configuration of an aircraft and is confirmed by periodically weighing it.
The "Operating empty weight" (OEW) is the sum of the empty weight and the crew plus their baggage.
Standard items include all structural modification or configuration orders that may have altered the MEW, including all fluids necessary for operation such as
engine oil
Motor oil, engine oil, or engine lubricant is any one of various substances used for the lubrication of internal combustion engines. They typically consist of base oils enhanced with various additives, particularly antiwear additives, detergen ...
,
engine coolant,
water
Water (chemical formula ) is an Inorganic compound, inorganic, transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living ...
,
hydraulic fluid and
unusable fuel.
Operator items include fixed, optional equipment added by the operator for service reasons.
The weight added to the aircraft above its OEW for a given flight is variable and includes fuel for the flight and the
cargo
Cargo consists of bulk goods conveyed by water, air, or land. In economics, freight is cargo that is transported at a freight rate for commercial gain. ''Cargo'' was originally a shipload but now covers all types of freight, including trans ...
. Cargo depends upon the type of aircraft; i.e., passengers plus baggage for a transport or commuter airplane, materiel for a cargo airplane, stores for fighters/bombers and service loads such as meals and beverages. Fuel and cargo weights may alter the centre of gravity and flight performance, and require careful calculation before each flight.
Aircraft purchase price by type is a close
linear function
In mathematics, the term linear function refers to two distinct but related notions:
* In calculus and related areas, a linear function is a function whose graph is a straight line, that is, a polynomial function of degree zero or one. For dist ...
of EW.
See also
*
Maximum takeoff weight
The maximum takeoff weight (MTOW) or maximum gross takeoff weight (MGTOW) or maximum takeoff mass (MTOM) of an aircraft is the maximum weight at which the pilot is allowed to attempt to take off, due to structural or other limits. The analogous ...
*
Aircraft gross weight
*
Zero-fuel weight The zero-fuel weight (ZFW) of an aircraft is the total weight of the airplane and all its contents, minus the total weight of the usable fuel on board. Unusable fuel is included in ZFW.
For many types of airplane, the airworthiness limitations incl ...
References
Aircraft weight measurements
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