Definition
The aircraft-specific information used to calculate how much the airplane weighs and where its center of gravity is located for a given flight. It includes the empty weight, empty weight center of gravity, useful load, maximum allowable weights, and the moment arms for each loading station (such as seats, baggage compartments, and fuel tanks). This data is found in the airplane's weight and balance records and the Pilot's Operating Handbook (POH) or Aircraft Flight Manual (AFM).
Plain English
The numbers and limits the pilot needs to work out whether the airplane is loaded within safe weight limits and whether that weight is distributed correctly from nose to tail.
Context Anchor
Seen during preflight planning, especially before carrying passengers, baggage, or a fuel load that could affect how the airplane handles.
Derivation
Weight comes from an old word meaning heaviness. Balance comes through French from a word for scales used to weigh things. Data comes from Latin and means things given. Together, the phrase means the given figures used to check both how heavy the airplane is and how that heaviness is distributed.
Why Pilots Care
Incorrect weight or balance can cause loss of control, reduced climb performance, longer takeoff rolls, or structural damage.
Intuition Check
Do not read this as just the airplane’s weight. Weight and balance data covers both how heavy the airplane is and where the load is placed.
Example Sentence 1
Before loading the passengers and bags, the pilot pulled the weight and balance data from the POH and ran the numbers for the planned trip.
Example Sentence 2
Updated weight and balance data must be used after any equipment change or repair that alters the aircraft's empty weight.