Definition
Electrical components that convert direct current (DC) from the aircraft battery or generator into alternating current (AC) needed to power certain instruments and systems, such as some attitude indicators, horizontal situation indicators, and radio equipment that require AC.
Plain English
A box that turns the aircraft's DC electricity into AC electricity, because some instruments only run on AC.
Context Anchor
Seen during the after-engine-start instrument and electrical checks, especially in aircraft where some flight or navigation instruments depend on inverter-supplied power.
Derivation
From Latin invertere, meaning 'to turn around' or 'to reverse.' An inverter reverses the form of the current — from DC (one-way flow) to AC (back-and-forth flow).
Why Pilots Care
Many gyroscopic instruments such as attitude and heading indicators depend on AC power; inverter failure can remove essential attitude and navigation information.
Analogy
An inverter is like a power adapter that lets a device use a kind of electricity it could not use directly. The airplane has power available, but the inverter changes it into the form certain equipment needs.
Intuition Check
Do not assume all aircraft electrical power is interchangeable. Some equipment needs power that changes direction back and forth; the inverter makes that from power that flows one way.
Example Sentence 1
After engine start, the pilot turned on the inverter and confirmed the attitude indicator powered up normally.
Example Sentence 2
Loss of the primary inverter in flight causes the standby inverter to supply AC power to the flight instruments.