# Weight defenitions & limitations.

Weights:
In order to make the weighing, centre of gravity calculations and operation of the aircraft simpler, international agreements have been made regarding the definition of aircraft weight.
These definitions simply define what should or should not be done when weighing an aircraft. The weight definition therefore simply defines the configuration of the aircraft in relation to a certain weight. All documentation that has anything to do with the weighing of aircraft, centre of gravity definitions and/or aircraft operation (thus not only Fokker documentation) refers to these definitions.
Nearly all documentation with regard to these definitions is in the English language.

Manufacturers Empty Weight (MEW)

This is the weight of structure, powerplant, furnishings, systems and other items of equipment that are an integral part of a particular aircraft configuration (It is essentially a "dry" weight, including only those fluids contained in closed systems).

Standard Basic Empty Weight (SBEW)
This is the MEW plus standard items.
Standard items are:

‑ Unusable fuel and other unusable fluids

- Engine oil

- Toilet fluid and chemicals

- Fire extinguishers, pyrotechnics, portable oxygen equipment

- Structure in galley, buffet, bar

- Supplementary equipment

Basic Empty Weight (BEW)

This is the SBEW plus or minus weights of standard variations. Standard item variations are items that the operator adds, deducts or changes.

Operational Empty Weight (OEW)

The OEW is the BEW plus operational items. Operational items are personnel, equipment and supplies necessary for a particular operation but not included in BEW. These items may vary for a particular aircraft and may include, but are not limited to, the following:

‑ Crew and baggage

‑ Manuals and navigational equipment

‑ Removable service equipment for cabin, galley, and bar

‑ Food and beverages, including liquor
- Usable fluids, other than those is useful load
- Life rafts, life vests and emergency transmitters
- Aircraft cargo handling systems and cargo containers

Delivery Empty Weight (DEW)
The DEW is the MEW, minus any shortages, plus those standard items and operational items at the time of delivery.
Actual Zero Fuel Weight (ZFW)
The ZFW is the OEW plus traffic-load.
Traffic-load
The traffic-load is the weight of passengers, cargo and baggage. (These may be revenue and/or non-revenue).
Useful load
The useful load is the difference between Operational Take-off Weight and OEW. It includes traffic-load, usable fuel and other usable fluid not included as operational items.

Weight limitations:

There are a number of structural weight limitations which are based on the strength of an aircraft and/or the components used. These limitations are included in the chapter. Any other operation weight limitations are excluded from this course (Performance calculations). These limitations can lie considerably lower depending upon the runway and meteorological conditions.
Maximum Design Taxi Weight (MTW)
Maximum weight for ground manoeuvring as limited by aircraft strength and airworthiness requirements. It includes weight of tax and run-up fuel.
Maximum Design Take-Off Weight (MTOW)
The MTOW is the maximum weight for take-off as limited by aircraft strength and airworthiness requirements. It is the maximum allowed weight at the start of the take-off run.
Maximum Design Landing Weight (MLW)
The MLW is the maximum weight for landing as limited by aircraft strength and airworthiness requirements.

Maximum Design Zero Fuel Weight (MZFW)
The MZFW is the maximum weight allowed before usable fuel and other specified usable agents must be loaded in defined sections of the aircraft as limited by strength and airworthiness requirements.
Limiting Design Weight
The aircraft shall be certified for operation at the following gross weights*:

Datum

A vertical plane or line to which the Centre of Gravity position and all Lever Arm measurements relate.