Definition
A system that sprays a mixture of water and methanol into the induction system of a reciprocating engine (or into the compressor section of some turbine engines) during high-power operations such as takeoff. The water cools the charge, allowing the engine to produce more power without detonation, and the methanol acts as an antifreeze and adds a small amount of fuel value to the mixture.
Plain English
A boost system that injects a water-and-methanol mix into the engine to let it safely produce extra power for short periods, usually during takeoff. The water cools things down so the engine doesn't damage itself, and the methanol keeps the water from freezing.
Context Anchor
Seen in aircraft engine systems, especially in procedures for takeoff, heavy-load operation, hot-day operation, or emergency power on aircraft equipped with the system.
Derivation
Methanol is the simplest alcohol, named from the Greek 'methy' (wine) and 'hyle' (wood), because it was originally produced by distilling wood. Adding it to water lowers the freezing point and provides a bit of extra fuel energy when the mixture enters the engine.
Why Pilots Care
It prevents engine damage from detonation while delivering extra power for short periods such as takeoff.
Grounding Statement
Picture the system as a short-duration helper: when the engine needs extra power, it adds a cooling mixture so that power can be made safely for a limited time.
Intuition Check
Do not think of water/methanol injection as ordinary engine fuel or as a cleaning spray. It is a controlled cooling and power-boost mixture used only on engines designed for it.
Example Sentence 1
The takeoff checklist required the crew to confirm the water/methanol tank was full before applying full power.
Example Sentence 2
After the climb, the crew shut off the water/methanol injection once the engine returned to normal power settings.