Plain English Meaning
A signed note from your instructor that officially shows you've completed a required step in training, or that you're cleared to do something on your own.
Full Definition
A flight instructor's signature is the formal endorsement, written and signed by a certificated flight instructor (CFI) in a student's logbook or on a lesson plan, that confirms a specific training requirement has been met or that the student has been authorized to perform a particular activity, such as solo flight, a stage check, or a checkride.
Context Anchor
Seen on lesson plans, training records, logbooks, and endorsements where an instructor must show responsibility for a training action or approval.
Derivation
Signature comes from the Latin idea of making a sign or mark. That helps here because the signature is not just a name; it is the instructor’s identifying mark that attaches responsibility to the document.
Why Pilots Care
A valid flight instructor signature is legally required before a student may solo, apply for a certificate, or exercise certain privileges; missing or improper signatures invalidate training time and can prevent progression.
Intuition Check
Do not treat a flight instructor’s signature as just a formality or decoration. In aviation records, it usually means the instructor is confirming something specific and accepting responsibility for that confirmation.
Example Sentence 1
Before her first solo, the student needed her flight instructor's signature in her logbook endorsing her to operate the aircraft alone.
Example Sentence 2
Without the flight instructor’s signature on the pre-solo endorsement, the student could not legally fly solo.