The endorsements most CFIs forget (and when the FAA asks for them)
There are 21 endorsements in AC 61-65K. You use maybe 6 regularly. The other 15 sit there until the day a DPE, an inspector, or a logbook audit makes their absence your problem. Here are the ones that trip people up.
Most CFIs have the pre-solo endorsement memorized. The cross-country endorsement, the flight-review sign-off, the knowledge-test preparation — those are muscle memory. But AC 61-65K has 21 endorsements, and the ones that trip people up are the ones you encounter once a year or less.
The ones that get missed
§A.72 — High-performance airplane (14 CFR §61.31(f)):If your student transitions to an airplane with more than 200 HP, they need this endorsement before acting as PIC. It's not part of a checkride — it's standalone. Most CFIs forget it exists until the student asks "can I rent the 182RG?"
§A.74 — Tailwheel (14 CFR §61.31(i)):Same pattern. The student finishes their private in a 172 and later wants to fly a Citabria. No checkride — just the endorsement after demonstrated proficiency. If you didn't log the training and sign the endorsement, the student is technically not legal.
§A.68 — Solo in Class B airspace (14 CFR §61.95(a)):Pre-solo students flying within Class B need a specific endorsement beyond the standard solo sign-off. I've seen flight schools near Class B airports forget this one for months.
§A.1 vs §A.2 — Ground training for the knowledge test: There are TWO endorsements for knowledge-test preparation. §A.1 is for applicants who received instruction from a ground instructor or CFI. §A.2 is for self-study applicants. Different wording, different attestation. Using the wrong one is a paperwork error that the testing center can flag.
§A.46 — Retesting after failure (14 CFR §61.49): A student who fails a practical test or knowledge test needs a specific endorsement certifying additional training before retaking. This one exists to prevent send-it-again-and-hope-it-works. The DPE will ask for it.
When the FAA asks
The FAA doesn't routinely audit CFI endorsements — until they do. A ramp check, an incident investigation, an insurance claim, or a DPE who reads logbooks carefully. The endorsement either exists or it doesn't. If it doesn't, the CFI is on the hook: "did you provide the required training and sign the required endorsement?"
The endorsement protects the CFI as much as the student. It's the receipt that says "I verified this; here's my signature."
Look them up
We built a free Endorsement Lookup with all 21 endorsements from AC 61-65K, filterable by category (pre-solo, cross-country, additional aircraft, reviews, tests, instructor track). It tells you which endorsement you need and which paragraph in the AC it comes from — the verbatim text always stays on the FAA document per our data-only rule.
If you're tracking endorsements for multiple students, Trim logs which ones each student has, which ones they still need, and surfaces the gaps — so nothing is missing on checkride day.