Definition
An informal category of multiengine airplane having two reciprocating engines and a maximum certificated takeoff weight of 12,500 pounds or less. Light-twins are the smallest and most common class of multiengine airplane and are the type most pilots encounter when first transitioning to multiengine flying.
Plain English
A small two-engine airplane that weighs no more than 12,500 pounds at takeoff. It is the entry-level size of twin-engine aircraft, used for personal flying, training, and light business travel.
Context Anchor
Seen in multiengine training, especially when discussing the handling and performance of small two-engine airplanes.
Derivation
“Light” comes from an older English sense meaning not heavy. “Twin” means two of the same kind. Together, the term points to a smaller airplane with two engines, not to an airplane that is necessarily easy to fly.
Why Pilots Care
Light-twins have distinct handling qualities, lower inertia, and specific engine-out performance that pilots must master before moving to larger twins.
Intuition Check
Do not read “light” as “simple” or “low-risk.” In this term, “light” means relatively small; the airplane still has two engines and needs proper multiengine skill.
Example Sentence 1
She earned her multiengine rating in a light-twin before moving on to larger corporate aircraft.
Example Sentence 2
Flight schools commonly use light-twins such as the Seminole to introduce students to asymmetric thrust.