How a signature gets made.
A signed entry has to mean something — to the owner, to a buyer, and to an inspector. Here is every step, why it's there, and the FAA Advisory Circular 120-78B practice it follows.
Six steps, in order
Nothing here is skipped for convenience. Each step answers a question somebody will ask about the entry later.
Draft the entry
The mechanic (or the owner, for owner-performed work) writes the entry, starting from a template if it's routine. The fields 14 CFR 43.9 and 43.11 call for are prompted, not remembered.
Why: a signature should land on a complete record, not a half-written one.
AC 120-78B practice: the record is complete before it is signedReview the exact version
Before signing, the signer reads exactly the text they're about to sign — not a summary, and not what it said five minutes ago.
Why: a signer should only ever be bound to words they actually saw.
AC 120-78B practice: the signer knowingly signs the specific contentRe-authenticate
The signer proves it's them again, at the moment of signing. A session that's already open isn't enough.
Why: an unattended laptop in the hangar shouldn't be able to sign for anyone.
AC 120-78B practice: signer identification at the time of signingSign
The signature records the signer's name and certificate number against that exact version of the entry, as they stood when they signed.
Why: years later, the record still says who signed and what they held, even if their details change.
AC 120-78B practice: the signature is attributable to one identified signerSeal
The entry is hashed and becomes append-only. From here on, it is never overwritten, and a change to it would be detectable.
Why: anyone checking the record later can tell whether it still matches what was signed.
AC 120-78B practice: the signed record's integrity can be checked after signingCorrect, don't erase
If something needs fixing later, the signer creates a new version linked to the original. Owners can request a correction; only the signer makes it. Both versions stay visible.
Why: on paper you'd draw a line through it and initial it, not tear out the page. Same here.
AC 120-78B practice: changes after signing are traceable, and the original stays availableHashed, append-only, tamper-evident.
The hash
When an entry is sealed, we compute a fingerprint of its exact contents — the record hash. If even one character of the stored entry changed afterward, it would no longer match its hash, and verification would say so. That's what tamper-evident means: a change is detectable. It doesn't mean nobody could ever try; it means a change would show up the moment the record is checked.
Append-only
Signed entries are never overwritten. New information is added alongside, never written over the top.
Corrections are linked versions
A correction is a new version of the entry, signed by the original signer and linked to the one it corrects. The original stays in the book, visible, with its own signature and hash. Anyone reading the record sees both, and which came first.
Entry 0483 — 100-hour inspection
- Aircraft
- N1234S · Cessna 172M
- Signed by
- R. Alvarez, A&P/IA 3417609
- Signed
- Sep 16, 2026, 9:14 AM
- Record hash
- 8f3a1c…e02e
- Status
- version 1 · still visible
Entry 0483, version 2 — correction
- Corrects
- Entry 0483, version 1
- Change
- tach time at inspection
- Signed by
- R. Alvarez, A&P/IA 3417609
- Signed
- Sep 18, 2026, 4:02 PM
- Record hash
- 2c71d9…a4b8
For the life of the aircraft.
Maintenance records follow the airplane, not the subscription. We keep them for the life of the aircraft — and you can export the complete record as PDF, CSV, or a JSON package whenever you like.
Sell the airplane and the records and their signatures transfer with it. Leave Aero Logworks and your records leave with you.
- Retained for the life of the aircraft, not the life of a plan.
- Ownership transfer keeps every record and every signature.
- A departing user takes their records with them.
The paper logbook still works.
If Aero Logworks is unreachable when the work is done, sign the paper logbook the way you always could. Nothing about going digital takes that away.
When the service is back, record the entry digitally, then print its label and paste it beside the paper sign-off. The label ties the two together, so anyone reading the paper book can scan through to the digital record.
Scan to verify at aerologworks.com/verify
What we claim, and what we don't.
There is no FAA approval for logbook software, and we don't claim one. Signing follows the electronic-signature practices in AC 120-78B, and entries are prompted for the content 14 CFR 43.9 and 43.11 require. Whether a record is acceptable rests with the operator and the mechanic, exactly as it does on paper.
A QR scan tells you whether the record matches what was signed. It is not an airworthiness determination.
Put a signature in the book that holds up.
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