Definition
A signed and dated entry made by an authorized flight instructor in a pilot's logbook (or other approved record) certifying that the pilot has received specific training, met defined proficiency standards, or is authorized to perform a particular operation under the regulations.
Plain English
A written, signed note from a flight instructor in your logbook that says you have been trained to do something specific and are cleared to do it.
Context Anchor
Seen in pilot logbooks, training records, and FAA training requirements, especially when a student or sport pilot needs documented approval for a privilege.
Derivation
From the Latin 'in-' (on) and 'dorsum' (back) -- literally 'on the back.' Originally it meant signing the back of a document to confirm or approve it. In aviation, the instructor's signature serves the same purpose: a formal stamp of approval recorded in writing.
Why Pilots Care
Without the correct endorsement a pilot is not legally authorized to fly the aircraft or exercise the privilege, which can ground them or create regulatory violations.
Intuition Check
Do not read endorsement here as a casual recommendation or public support. In FAA use, it means a specific written approval or confirmation placed in an official training record.
Example Sentence 1
Before her first solo, the student received a logbook endorsement from her instructor certifying she was trained and proficient to fly the airplane alone.
Example Sentence 2
The pilot needed a new endorsement before acting as pilot in command of the different light-sport model.