Weight & Balance Terminology

Question 1

Reference Datum

Answer 1

An imaginary vertical plane from which all horizontal distances are measured for balance purposes.

Question 2

Station

Answer 2

A location along the airplane fuselage usually given in terms of the distance from the reference datum.

Question 3

Arm

Answer 3

Distance from the Reference Datum to the Center of Gravity of an item

Question 4

Moment

Answer 4

Weight of an item (like a suitcase or a box) multiplied by its arm.

Question 5

Center of Gravity (C.G.)

Answer 5

The point at which an airplane would balance if suspended. Its expressed in a distance from the reference datum.

Question 6

CG Limits

Answer 6

The extreme center of gravity locations with which the airplane must be operated (it can change as weight changes)

Question 7

CG Arm

Answer 7

obtained by adding individual moments and dividing by the total weight.

Question 8

Usable Fuel

Answer 8

Fuel available for flight planning

Question 9

Unusable fuel

Answer 9

Fuel remaining after a runout test has been completed in flight tests by the manufacturer. (Fuel in the tank that cannot be used)

Question 10

Standard Empty Weight

Answer 10

Weight of the airplane including Unusable Fuel, Full operating Fluids and Full Oil.

Question 11

Basic Empty Weight

Answer 11

Standard Empty Weight PLUS optional equipment

Question 12

Payload

Answer 12

Weight of Occupants, Cargo and Baggage

Question 13

Useful Load

Answer 13

Difference between takeoff weight and basic empty weight. (it is the Payload + Fuel)

Question 14

Maximum Ramp Weight

Answer 14

Maximum Weight approved to start taxiing.

Question 15

Maximum Takeoff Weight

Answer 15

Maximum Weight approved for the start of the takeoff roll

Question 16

Maximum Landing Weight

Answer 16

Maximum Weight Approved for landing

Question 17

Maximum Zero Fuel Weight

Answer 17

Maximum Weight of the aircraft before useable fuel is added.