AFOQT Practice Test 2025 - Free AFOQT Questions and Complete Study Guide

A biplane is defined as an airplane that has two pairs of wings stacked one above the other. This configuration provides enhanced lift and improved structural integrity, allowing for greater agility and maneuverability compared to monoplane designs, which have only one pair of wings. The design of biplanes was especially common in early aviation and remains in use for certain types of aircraft today, including some aerobatic planes and historical replicas.

The other options do not adequately capture the essence of what a biplane is. An airplane with one pair of wings refers to a monoplane, while an airplane with variable wing geometry pertains to designs that can alter the shape of their wings for different flight conditions, which is unrelated to the traditional definition of a biplane. An airplane with a horizontal stabilizer may define a common feature of many aircraft but does not specifically categorize it as a biplane, since stabilizers are present in many types of aircraft irrespective of wing configuration.