Which of the following are categories of aircraft for the certification of airmen?

The correct choice highlights the recognized categories of aircraft for the certification of airmen, which are relevant in establishing the different operational environments and types of pilots. The categories listed—airplane, rotorcraft, glider, and lighter-than-air—cover a wide spectrum of aircraft types, each of which requires specific training and certification.

Airplanes encompass fixed-wing aircraft designed for various purposes. Rotorcraft includes any aircraft that uses rotor systems for lift, such as helicopters and gyroplanes. Gliders refer to unpowered aircraft that use aerodynamic lift to stay aloft. Lighter-than-air aircraft, like airships and balloons, float in the atmosphere relying on buoyancy. Understanding these categories is essential for pilot certification, as each type has distinct regulatory requirements and operational characteristics.

Other choices might include valid aircraft types but do not encompass the broader recognized categories essential for airmen certification as defined by aviation regulations. The answer emphasizing airplane, rotorcraft, glider, and lighter-than-air offers a comprehensive overview aligned with regulatory classifications used by aviation authorities.