Plain English Meaning
An airplane that the FAA classifies as 'large' because it can take off weighing more than 12,500 pounds. Once an airplane crosses that weight line, extra rules apply to how it is built, how it is flown, and what qualifications the pilot must hold.
Full Definition
For FAA certification and operating purposes, an airplane with a maximum certificated takeoff weight of more than 12,500 pounds. Large airplanes are subject to specific airworthiness, operational, and pilot certification requirements that do not apply to smaller airplanes, including type ratings for the pilot in command.
Context Anchor
Seen in instrument flying, aircraft certification, , and training discussions when the FAA separates airplanes by weight .