Arm

Definitions

• See moment arm.
• (GAMA) The horizontal distance from the reference
  datum to the CG of an item. The algebraic sign is plus (+) if measured aft of the datum or to the right side of the center line when considering a lateral calculation. The algebraic sign is minus (–) if measured forward of the datum or the left side of the center line when considering a lateral calculation.
• The horizontal distance in inches from the reference datum line to the center of gravity of an item. Used in weight and loading calculations.

References

• Pilot's Handbook of Aeronautical Knowledge, Federal Aviation Administration, 2023
• Powered Parachute Flying Handbook, Federal Aviation Administration, 2007
• Weight and Balance Handbook, Federal Aviation Administration, 2016
• Weight-Shift Control Aircraft Flying Handbook, Federal Aviation Administration, 2008