DEFINITION OF TERMS

Question 1

The point about which an airplane would balance if it were possible to suspend it at that point

Answer 1

Center of gravity (CG)

Question 2

The horizontal distance in inches from the reference datum line to the center of gravity of an item

Answer 2

Arm (Moment Arm)

Question 3

The specified forward and aft points within which the CG must be located during flight

Answer 3

Center-of-Gravity Limits

Question 4

The distance between the forward and aft CG limits indicated on pertinent airplane specifications

Answer 4

Center-of-Gravity Range

Question 5

An imaginary vertical plane or line from which all measurements of arm are taken

Answer 5

Datum (Reference Datum)

Question 6

The maximum weight the floor can
sustain per square inch/foot as provided by the manufacturer

Answer 6

Floor Load Limit

Question 7

The average distance from the leading edge to the trailing edge of the wing

Answer 7

Mean Aerodynamic Chord (MAC)

Question 8

The product of the weight of an item multiplied by its arm

Answer 8

Moment

Question 9

A moment divided by a constant such as 100, 1,000, or 10,000

Answer 9

Moment Index (or Index)

Question 10

A location in the airplane that is identified by a number designating its distance in inches from the datum

Answer 10

Station

Question 11

Normally used with smaller aircraft

With this type of scale, aircraft are
typically lifted off the floor with jacks and
then lowered onto platform scales that are placed under each wheel

Answer 11

Platform Scales

Question 12

Used in large aircrafts placed between
the jack and the jack pad of the aircraft

Strain-gauge capsules whose resistance changes proportionally to the amount of
load imposed on them

Answer 12

Load Cells

Question 13

Permanently installed in an aircraft and must not be removed

Answer 13

Permanent Ballast

Question 14

Typically installed to bring the CG within its range for a specific flight condition

Answer 14

Temporary Ballast