Definition
The temperature of the exhaust gases as they leave the turbine section of a turbine engine. TOT is one of several engine temperature measurements (along with EGT, ITT, and TIT) used to monitor turbine engine health and to ensure the engine is operated within its certified temperature limits.
Plain English
How hot the gases are right after they pass through the turbine and exit on their way out of the engine. Pilots watch this number to make sure the engine is not running too hot.
Context Anchor
Seen on turbine-engine cockpit gauges, engine start procedures, takeoff power checks, and engine limitation charts.
Derivation
Turbine comes from the Latin turbo, meaning a spinning or whirling thing. The turbine is the spinning wheel that hot gases drive on their way out of the engine. Outlet simply means where the gases come out. So TOT is literally the temperature at the place where the gases leave the spinning wheel.
Why Pilots Care
Staying within published TOT limits prevents damage to turbine blades and other hot-section components; exceeding limits can lead to reduced engine life or in-flight failure.
Grounding Statement
During engine start or high-power operation, the pilot watches TOT to make sure the engine stays within its safe heat limit.
Intuition Check
Outlet does not mean an electrical socket here. It means the exit area being measured: the hot gas leaving the turbine section.
Example Sentence 1
During the engine start, the pilot kept a close eye on TOT to make sure it stayed below the starting limit.
Example Sentence 2
In cruise a gradual rise in TOT with no change in power setting prompted the pilot to check for a possible bleed-air leak.