Definition
The temperature of the exhaust gases as they leave the last stage of the turbine in a gas turbine engine. It is measured by thermocouples positioned in the exhaust stream just aft of the turbine section and is used as an indirect indication of turbine inlet temperature, which is too high to measure directly with reliable instruments.
Plain English
How hot the gases are right after they finish passing through the turbine wheels and leave the engine. Pilots watch this number because it tells them, indirectly, how hot the engine is running internally.
Context Anchor
Seen on turbine-engine instruments, engine-start checks, takeoff power checks, and aircraft operating limits.
Derivation
Turbine comes from a Latin word meaning a spinning or whirling thing. Outlet means the place where something flows out. Together, the term points to the temperature measured where the hot gas flows out of the spinning turbine section.
Why Pilots Care
Exceeding limits can damage turbine blades and reduce engine life; pilots use it to manage power safely.
Grounding Statement
Picture the engine making power by sending very hot gas through a spinning turbine; this term tells you how hot that gas is as it leaves that section.
Intuition Check
Outlet does not simply mean the end of the exhaust pipe here. It means the point where gases leave the turbine section, which is the temperature the engine limit is based on.
Example Sentence 1
During engine start, the pilot watched the turbine outlet temperature carefully to make sure it stayed below the published start limit.
Example Sentence 2
A sudden rise in turbine outlet temperature prompted the pilot to reduce power and check for a problem.