Last reviewed July 14, 2026 by Noah Lencki, CFI.
Solo Endorsements Under Part 61: What Every Student Pilot Needs
A student pilot's first solo is a major milestone — and it's also one of the most heavily regulated moments in primary training. Before a student can legally fly an airplane alone, 14 CFR 61.87 requires a specific sequence of knowledge testing, flight training, and instructor endorsements. Here's what that actually means in practice, for both students and the CFIs signing them off.
Before the First Solo: What a CFI Must Verify
Section 61.87 splits the pre-solo requirements into two pieces: aeronautical knowledge and flight proficiency.
Aeronautical knowledge. The student must pass a knowledge test — written and administered by the authorizing instructor, not a third party — covering the applicable flight rules, the specific airspace the student will operate in, and the operating limitations of the make and model to be flown. The instructor reviews every incorrect answer with the student before signing off; this test isn't scored pass/fail against a curve, it's a teaching tool the instructor uses to confirm real understanding.
Flight proficiency. The student must have received and logged flight training on the maneuvers and procedures relevant to the make and model, and the instructor must find that training satisfactory before authorizing solo flight. This is a judgment call the regulation deliberately leaves to the instructor — there's no fixed number of hours that guarantees solo readiness.
What this means for you
In practice, this is two separate sign-offs a CFI tracks for every pre-solo student: a pre-solo aeronautical knowledge endorsement and a pre-solo flight training endorsement (AC 61-65K endorsements A.3 and A.4). Both have to be in place — and current — before the first solo, and the flight-training endorsement is what actually starts the 90-day clock described below.
The 90-Day Solo Endorsement Cycle
Getting cleared to solo once isn't the end of it. Every solo flight requires a current endorsement, and that endorsement expires on a rolling 90-day cycle tied to when the training was given — not to a school's semester calendar or the student's flying schedule.
Limitations on student pilots operating an aircraft in solo flight. A student pilot may not operate an aircraft in solo flight unless that student pilot has received an endorsement in the student's logbook for the specific make and model aircraft to be flown by an authorized instructor who gave the training within the 90 days preceding the date of the flight.
That 90-day window resets every time a new solo endorsement is issued, so an active student who flies regularly and gets re-endorsed each cycle can stay current indefinitely. A student who takes an extended break, though, comes back to an expired endorsement — and needs a fresh one, with the instructor's own current judgment of proficiency, before soloing again. The endorsement is also make-and-model specific: switching training aircraft mid-course means a new pre-solo knowledge test and a new endorsement, even if the student already has hundreds of solo hours in a different airplane.
Frequently asked questions
90 days from the date the endorsing instructor gave the training. After that, the student needs a fresh endorsement — a new logbook entry, not just a renewed old one — before flying solo again in that make and model.
One specific make and model. A student endorsed to solo a Cessna 172 is not automatically covered to solo a Piper PA-28 — a new pre-solo knowledge test and a new endorsement are required for the different make and model.
No. Solo flight after night — one hour after sunset to one hour before sunrise — requires a separate pre-solo night endorsement under 14 CFR 61.87(o), on top of the standard solo endorsement in this article. It has its own training requirements and its own 90-day clock.
The authorizing flight instructor, and only that instructor. There's no fixed hour requirement in the regulation — readiness is judged on demonstrated proficiency in the required maneuvers and a passing score (with all wrong answers reviewed) on the pre-solo knowledge test.
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