Definition
A logbook carried aboard an aircraft that records its flight hours, mechanical condition, defects reported by the flight crew, and the corrective maintenance actions taken in response. It provides a continuous, traceable record linking flight operations to maintenance status.
Plain English
A book kept on the aircraft that tracks how many hours it has flown, anything the crew found wrong with it, and what mechanics did to fix those issues.
Context Anchor
A pilot may check or complete the Technical Log before flight, after flight, or when reporting an aircraft problem to maintenance.
Derivation
Technical' here refers to the engineering and mechanical condition of the aircraft, not flight operations. The 'log' is the running record. Together it distinguishes this book from the pilot's flight logbook, which tracks the pilot rather than the machine.
Why Pilots Care
Pilots are legally required to confirm the aircraft is airworthy by checking the technical log before every flight; an incomplete or unsigned entry can ground the aircraft.
Analogy
Think of it as the aircraft’s daily notebook: what it did, what was found, what was fixed, and whether it is ready to go again.
Intuition Check
A Technical Log is not just a notebook for technical comments. In aviation, it is an official aircraft record that can affect whether the aircraft may be flown.
Example Sentence 1
After landing, the captain entered a note in the technical log about a flickering fuel quantity indicator so the engineers could investigate before the next flight.
Example Sentence 2
After replacing the alternator, the mechanic entered the part number, serial number, and his certificate number in the technical log.