Manufacturer's Weight Empty (MWE) (also known as Manufacturer's Empty Weight (MEW) is the weight of the aircraft "as built" and includes the weight of the structure, power plant, furnishings, installations, systems and other equipment that are considered an integral part of an aircraft before additional operator items are added for operation.

Basic aircraft empty weight is essentially the same and excludes any baggage, passengers, or usable fuel

Fuel

Fuel is any material that stores energy that can later be extracted to perform mechanical work in a controlled manner. Most fuels used by humans undergo combustion, a redox reaction in which a combustible substance releases energy after it ignites and reacts with the oxygen in the air...

. Some manufacturers define this empty weight as including optional equipment, i.e. GPS units, cargo baskets, or spotlights.

Specification MEW

This is the MEW quoted in the manufacturer's standard specification documents and is the aircraft standard basic dry weight upon which all other standard specifications and aircraft performance are based by the manufacturer.

The Specification MEW includes the weight of:

• Airframe
  Airframe
  The airframe of an aircraft is its mechanical structure. It is typically considered to include fuselage, wings and undercarriage and exclude the propulsion system...
  
   structure - primary and secondary structures (fuselage
  Fuselage
  The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...
  
  , wing
  Wing
  A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...
  
  , tail, control surfaces, nacelle
  Nacelle
  The nacelle is a cover housing that holds engines, fuel, or equipment on an aircraft. In some cases—for instance in the typical "Farman" type "pusher" aircraft, or the World War II-era P-38 Lightning—an aircraft's cockpit may also be housed in a nacelle, which essentially fills the...
  
  s, landing gear
  Landing Gear
  Landing Gear is Devin the Dude's fifth studio album. It was released on October 7, 2008. It was his first studio album since signing with the label Razor & Tie. It features a high-profile guest appearance from Snoop Dogg. As of October 30, 2008, the album has sold 18,906 copies.-Track...
  
  ).
• Powerplant
  PowerPlant
  PowerPlant is an object-oriented GUI toolkit, application framework and set of class libraries for Mac OS, created by Metrowerks. The framework was fairly popular at the height of the Classic Mac OS era, and was primarily used with CodeWarrior...
  
  .
• Auxiliary Power Unit
  Auxiliary power unit
  An auxiliary power unit is a device on a vehicle that provides energy for functions other than propulsion. They are commonly found on large aircraft, as well as some large land vehicles.-Function:...
  
  (APU).
• Systems (instruments, navigation, hydraulics, pneumatics, fuel systems (but not fuel itself), electrical system, electronics, fixed furnishings (but not operator specific), air conditioning, anti-ice system, etc.).
• Fixed equipment and services considered an integral part of the aircraft.
• Fixed ballast (if present).
• Closed system fluids (such as hydraulic fluids).

For small aircraft, the MEW may include unusable fuel and oil.

The Specification MEW excludes the weight of:

• All fuel (both usable and unusable).
• Potable water, anti-ice, and chemicals in toilets.
• Engine oil and APU oil.
• All specification items, selections, and installations which are non-basic (i.e. optional selections).
• Customer specific selections, installations, and options.
• Operator/Operating items.
• Removable equipment and services.
• Payload.

For small aircraft, the Specification MEW is known as the Standard Weight Empty (or Standard Empty Weight).

External links

• Aircraft weight and balance