Aircraft are classified in several ways:
i. With respect to certification, rating, privileges, and information of fliers, there is a broad classification of aircraft. Examples include airplane, rotorcraft, glider, and lighter-than-air aircraft.
ii. With respect to certification, aircraft are grouped based upon intended use or operating limitations. Examples include transport, normal, utility, acrobatic, limited, restricted, and provisional.
iii. With respect to certification by weight, aircraft are classified as small—weighing 12,500 lb or less (5700 kg)—or large—weighing more than 12,500 lb.
iv. By their approach speed, which itself is 1.3 times the stalling speed at maximum gross landing weight, or VSO. These are categorized from A to E as shown in the illustration.
v. By wake turbulence separation (i.e., heavy, large, and small). Heavy aircraft have takeoff weights of more than 25,500 lb (116,000 kg); large aircraft have a certificated takeoff weight of more than 41,000 lb (18,600 kg) up to 25,500 lb; and small aircraft have a certificated takeoff weight of less than 41,000 lb. This is irrespective of whether they are at these weights at that particular phase of flight. This classification is by FAA. ICAO classifies aircraft for this purpose as heavy, medium, and light. Heavy aircraft have a maximum certificated takeoff weight (MCTOW) of 136,000 kg or more (300,000 lb); medium aircraft have a MCTOW of more than 7000 kg (15,750 lb) and less than 136,000 kg; and light aircraft are the ones with MCTOW of less than 7000 kg. This is irrespective of whether they are at these weights at that particular phase of flight.