Definition
The temperature of the exhaust gases as they leave the last stage of the turbine in a turbine engine, measured by probes at the turbine outlet and displayed on a cockpit gauge. TOT is one of several engine temperature parameters used to monitor turbine engine operation and protect the engine from overtemperature damage.
Plain English
How hot the gas is just after it has finished pushing on the turbine wheels and is heading out the back of the engine. Pilots watch this number to make sure the engine is not running too hot.
Context Anchor
Seen on turbine-engine aircraft engine gauges, especially during engine start, takeoff, climb, and high-power operation.
Derivation
Turbine comes from a Latin word meaning a spinning object. Outlet means an exit. Together, turbine outlet temperature points to the heat measured where the gases exit the spinning turbine section.
Why Pilots Care
Exceeding TOT limits can damage turbine blades and reduce engine life; pilots monitor it to stay within safe operating ranges.
Intuition Check
TOT is not the outside air temperature and not the temperature at the front of the engine. It is the temperature measured after the hot gases have gone through the turbine section.
Example Sentence 1
During the start sequence, the pilot watched the TOT closely to make sure it stayed below the published start limit.
Example Sentence 2
A rapid increase in TOT during cruise prompted the pilot to reduce power and troubleshoot the engine.