Early flight pioneers: Identify who designed the first successful hang gliders. Full question: The first hang glider was designed by which aviation pioneer noted for systematic gliding experiments? Choose the correct option.

Given data

• Pioneer of practical, controlled gliding flight.

Concept / Approach
Otto Lilienthal (1890s Germany) designed and flew the first widely recognized successful hang gliders, conducting hundreds of flights and publishing aerodynamic data.

Notes on options
George Cayley — Early visionary; built a man-carrying glider (1853) but not the hallmark hang gliders of the 1890s. Wright brothers — Later, powered controlled flight (1903). Montgomery — Early U.S. gliding experiments (also notable but after Lilienthal's foundational work).

Final Answer
Otto Lilienthal.