Definition
A systematic inspection and verification of an aircraft and its systems performed before flight to confirm airworthiness, instrument accuracy, and proper configuration. In the context of pitot/static instruments, the preflight check includes verifying that the altimeter reads within acceptable tolerance when set to the current local altimeter setting, and that the static ports and pitot tube are unobstructed.
Plain English
The set of checks a pilot does on the ground before flying to make sure the aircraft and its instruments are working properly and safe to use.
Context Anchor
Seen during cockpit setup before flight, especially when checking the altimeter before relying on it for altitude information.
Derivation
"Pre-" means before, and "flight" is the act of flying. A "check" is a verification. Together: a verification done before flight. The plain meaning matches the aviation use closely, but in aviation the check is structured and follows a published checklist rather than being informal.
Why Pilots Care
Catches altimeter or pitot-static errors that could produce incorrect altitude or airspeed indications once airborne.
Intuition Check
Do not read preflight check as a casual glance before takeoff. In aviation, it means a deliberate before-flight inspection or test to confirm that something is safe and usable.
Example Sentence 1
During the preflight check, the pilot set the altimeter to the current local setting and confirmed it read within 75 feet of the known field elevation.
Example Sentence 2
The preflight check includes ensuring the pitot tube cover is removed so airspeed indications will be accurate after takeoff.