Plain English Meaning

Reading between the lines of a chart. If the chart gives you a number for 2,000 feet and another for 3,000 feet, but you need the value for 2,500 feet, you split the difference to estimate it.

Full Definition

A method of estimating an unknown value that falls between two known values in a table or chart by assuming the change between them is proportional. In aviation performance work, interpolation is used when the actual conditions (such as temperature, pressure altitude, or weight) sit between the rows or columns printed in a performance chart.

Context Anchor

Pilots encounter interpolation when using aircraft performance charts and tables, especially for takeoff distance, landing distance, , and weight-related calculations.