How do you weigh a 747?

Answer 1

How it's actually done:

Weight and balance need to be calculated before every flight. This includes the total weight.

Large aircraft use load sensors in each gear strut to calculate the suspended weight (the weight below the sensors doesn't change with loading: rims,tires, brakes, etc)

During maintenance and inspection, load sensors are calibrated to ensure they're correct.

Small aircraft are weighed on scales that are put under each wheel and the weights are combined. Once the empty weight is known for that particular aircraft, adjustments can be made when equipment is installed or removed, passengers and luggage loaded or unloaded, and fuel weight for each flight by using the as-measured empty weight.

Answer 2

A 747 is weighed using scales specifically designed to accommodate aircraft. The airplane is typically positioned on these scales so that each landing gear is supported independently, allowing the weight of the aircraft to be measured accurately. This information is important for determining fuel load, cargo capacity, and adherence to weight limits for safe operation.