14 work orders. Zero unsigned entries. One annual inspection — finally done right.

Jake Morrison has been a certificated A&P mechanic for eleven years. For most of that time, his logbook system was a three-ring binder with ruled notebook paper, a stack of work order carbons, and a habit of photographing entries with his phone before handing them back to aircraft owners.

"The photos were for me," he said. "If a record ever went missing during a sale, I wanted proof I did the work and signed it. It's not a great system."

N99TEST is a 1978 Cessna 172N that Jake maintains for a private owner based at a small GA field in the southeast. The aircraft is low-hours — less than 4,200 total time — but had accumulated a backlog of deferred squawks going into the annual inspection.

The problem with paper annuals

Annual inspections generate a lot of paper. Fourteen separate work items — spark plug replacement, mag timing check, oil change, transponder check, prop strike review, avionics inspection, airframe inspection by zone, fuel system inspection, brake inspection, landing gear, flight control rigging, engine compression, exhaust system, and ELT battery replacement — each with its own FAR 43.9 fields to complete.

"On paper, you fill out a work order, do the work, sign the logbook page, and that's it," Jake said. "But there's no connection between the work order and the logbook entry except proximity in a binder. If someone removes a page or the binder gets wet, that connection is gone."

How the pipeline worked

Before starting the annual, Jake created an aircraft record for N99TEST in myAviationTools and logged the existing total airframe time. He then created squawks for each known discrepancy from the previous inspection — five items carried forward — plus the standard annual items.

Each squawk became a work order when the work began. Work orders expanded into individual work items with description, method of compliance, parts used, and reference to the applicable maintenance manual section. When the work was complete, he sealed the work item — the system required his FAA certificate number, which it cross-referenced against the Airmen registry in real time.

"The certificate check surprised me the first time," he said. "It confirmed my certificate was current and my A&P and IA ratings were active. That confirmation is now attached to every record I signed. That's the kind of audit trail I've always wanted but had no way to create with paper."

Sealed work items rolled up into a logbook page — the final FAR 43.9-compliant entry — which was then sealed as a unit. The seal produced a SHA-256 hash, an Ed25519 server signature, and a Merkle inclusion proof. The Merkle root was anchored to Ethereum Sepolia that night in the daily batch.

What changed

Jake completed the annual in seven days — slightly longer than his usual five, because he was learning the system on a real inspection. He expects future inspections to take the same time or less.

The owner can now look up N99TEST's complete maintenance history in the blockchain explorer without contacting Jake, without asking for the binder, and without trusting that any specific entry hasn't been altered. The Merkle proof is publicly verifiable.

"The owner sent me a message after I finished," Jake said. "First thing he said was, 'I can see the whole thing on the blockchain.' He was more excited about that than the actual work. But honestly? So was I."