The first effective airplane was the result of the designs of which inventors?

• A. The Wright brothers
• B. Leonardo da Vinci
• C. Samuel P. Langley
• D. Glenn Curtiss

Answer: (A)

The question tests who first achieved controlled, powered flight. The Wright brothers are credited with the first airplane to fly with sustained, controllable power. In 1903 at Kitty Hawk, they flew a heavier-than-air machine that could take off under its own power, maintain controlled flight, and land safely. Their key breakthrough was practical three-axis control: adjusting the wings for roll (wing-warping), using a movable elevator for pitch, and coordinating the rudder for yaw. They combined this with systematic experimentation—including wind-tunnel work to refine shapes and propulsion—to produce a stable, repeatable flight. This combination of powered propulsion and real control defines the first effective airplane.

Earlier efforts, like Leonardo da Vinci’s sketches, never built a functioning aircraft; Samuel Langley’s machine failed to achieve sustained flight despite prior funding; Glenn Curtiss contributed significant improvements after, but did not achieve the first successful controlled flight.