How many pounds under gross weight was the airplane in the scenario?

• A. 75 pounds
• B. 25 pounds
• C. 0 pounds
• D. 150 pounds

Answer: (A)

The key idea is that gross weight is the maximum allowable weight for the airplane. Being under gross weight means the aircraft is lighter than that limit, and the difference between the gross weight and the actual weight is how much weight you could still add before hitting the limit.

In this scenario, the calculations show the airplane weighed 75 pounds less than its maximum gross weight, so the margin is 75 pounds. That means you could add up to 75 pounds of ballast, fuel, or payload and still be within the permitted limit. The other numbers would imply different margins (exactly at the limit, or margins that don’t match the given weights) and wouldn’t fit the scenario’s data.