Definition
A cockpit instrument that displays the temperature of the exhaust gases as they pass through the turbine section of a turbine engine. The reading is taken by thermocouples positioned in the gas stream and is used to monitor that the turbine is operating within its certified temperature limits during start, acceleration, climb, and cruise.
Plain English
A gauge that shows how hot the gases are inside the turbine part of the engine, so the pilot can make sure the engine isn't getting too hot.
Context Anchor
Seen on turbine-engine aircraft instrument panels, especially during engine start and power changes.
Derivation
Turbine comes from the Latin turbo, meaning a spinning thing or whirlwind, which fits a wheel driven by fast-moving gas. Gas temperature simply names what is being measured. The label tells you exactly what the gauge reads: how hot the gas is as it drives the turbine.
Why Pilots Care
Exceeding TGT limits can quickly damage turbine blades and other hot-section parts, so the gauge is watched to keep the engine inside safe operating temperatures.
Grounding Statement
When a turbine engine is started or power is increased, the TGT gauge shows whether the hot gas inside the engine is staying within safe limits.
Intuition Check
Do not think of this as outside air temperature or general engine warmth. It is a specific engine instrument showing the temperature of hot gases in the turbine area.
Example Sentence 1
During engine start, the pilot watched the TGT gauge closely to make sure the temperature stayed below the starting limit.
Example Sentence 2
A sudden rise on the TGT gauge after starting the engine prompted the pilot to shut down and inspect for a problem.