Definition
The degree to which a measured or indicated value matches the true value. In aviation, accuracy describes how close an instrument reading, navigation fix, or measurement is to what is actually correct in the real world.
Plain English
How close a reading is to the real value. If an altimeter says 5,000 feet and you really are at 5,000 feet, the reading is accurate.
Context Anchor
Seen in discussions of aircraft instruments, navigation equipment, performance data, and maintenance checks.
Derivation
From Latin accuratus, meaning 'done with care.' The original sense was about the carefulness of the work; over time it came to describe the result of that careful work — being correct or close to the truth.
Why Pilots Care
Inaccurate instruments or navigation data can produce altitude or position errors that directly affect safety and decision making.
Intuition Check
Accuracy does not mean the reading is neat, steady, or easy to read. In aviation, it means the reading is close to the true value.
Example Sentence 1
The accuracy of the altimeter must be checked before flying under instrument flight rules.