Final answer:
A large aircraft is considered to be 12,500 lbs or heavier at MCTOW, which affects piloting, maintenance, and operational regulations.
Step-by-step explanation:
A large aircraft is considered to be 12,500 lbs or heavier at maximum certified takeoff weight (MCTOW). This classification is used for regulatory and operational purposes and can include various types of aircraft, from passenger jets to cargo planes. Whether a particular aircraft exceeds the 12,500 lbs threshold can be critical for determining the category it falls into for pilot licensing, maintenance requirements, and operational considerations.