A missing tool is a class of FOD
Foreign object debris (FOD) is any object left where it should not be — and a tool left inside an aircraft after maintenance is a textbook case. The risk is not abstract: a torque wrench, a socket, or a piece of a tool left in a bay can damage systems or injure personnel the next time the aircraft operates.
The reason tool control matters at the point of return to service is precisely this. Part-145's tooling obligations exist to keep the right tools available and to keep them from becoming hazards. A tool you cannot account for is a risk you cannot close out.
Reconciliation before return to service
The controlling moment is reconciliation: before the aircraft returns to service, every tool that was issued must be accounted for. This is the operational discipline behind the control register and serviceability monitoring — the loop is only closed when what was taken out is confirmed back.
Reconciliation is not a hope that the count is right. It is a verifiable fact that every issued item has a known state. When a tool is missing, the process must surface it immediately, so the search and the FOD prevention response happen before the aircraft moves, not after.
Custody and reconciliation are the evidence
This is where custody tracking earns its value. If a tool can have only one active custody record, then 'who holds it' is always an answerable question. Issue, handoff, and return are transactional state changes, and a missing-tool investigation is far more efficient when the system shows the last known holder, location, and timing.
A token board can indicate intent — it cannot reliably show the aircraft, work order, bay, expected return, or transfer history. For reconciliation, the accounting has to be complete and trustworthy, which is what an auditable custody record provides.
What Aviamatic tracks — and what it does not sign
Aviamatic tracks custody and supports tool reconciliation: one active custody record per tool, transactional issue and return, audit evidence for missing-tool investigations, and a single coherent view across line stations, hangars, and workshops.
The honest boundary is important. Aviamatic reconciles and records the accounting; it does not make the airworthiness decision. Release to service, and the determination that the aircraft is fit to return, remain with the certifying staff and the approved maintenance data. We provide the reliable, auditable evidence that supports that decision — we do not replace it.