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Reference · Traceability and documentation

Return to service

Approval for return to service is a regulatory act by an authorized person, recorded in the maintenance record. It is not the moment the technician puts the unit down — and the gap between those two events is where a great deal of turn time quietly goes.

Definition

Approval for return to service is the act by which an authorized person or organization certifies that an aircraft, engine, propeller, appliance or component part may be returned to service following maintenance, preventive maintenance, rebuilding or alteration.

It is a regulatory act performed by a specific authorized party and recorded in the maintenance record. It is not the same thing as the physical work being finished.

Who may approve return to service

In the United States this is set out in 14 CFR 43.7. The general rule is that no person other than the Administrator may approve an article for return to service after maintenance, except for the categories the regulation names. Those include:

  • the holder of a mechanic certificate or an inspection authorization, as provided in Part 65;
  • the holder of a repair station certificate, as provided in Part 145;
  • the holder of an air carrier operating certificate or an operating certificate issued under Part 121 or Part 135, as provided in those parts;
  • a manufacturer, for articles it has worked on under the relevant provision of Part 43.

The practical consequence is that the authority sits with a person or an organization, within a defined scope — not with a job being complete, a system status, or a customer's expectation. A repair station may only release work within the ratings and limitations of its certificate.

Jurisdiction and context

The framework above is the US one. Equivalent concepts exist elsewhere under different regulations — a certificate of release to service issued by appropriately approved personnel, for example. The details, the titles and the recording requirements differ by jurisdiction and by the type of operation. Treat this page as an orientation to the concept, not as a compliance reference for a particular operation.

Work complete is not return to service

This distinction is the single most useful thing on the page, because it is where commercial and technical expectations diverge.

Work complete, approved for return to service, and shippable are three different states Three sequential states shown left to right. First, the physical work is complete. Second, an authorized person approves the article for return to service and the record is made. Third, the documentation package is assembled and the unit can ship. Notes explain that a unit can sit at the first or second state for a long time and that the customer only experiences the third. THREE DIFFERENT STATES — OFTEN TREATED AS ONE 1 · Work complete The technical task is finished on the bench 2 · Approved for RTS An authorized person certifies and records it 3 · Shippable Release document and package complete waiting on inspection or authorized signatory waiting on paperwork, certifications for material fitted The customer only ever experiences state three. A unit that has been "finished" for a week and cannot ship is, to them, not finished.
Work complete, approved for return to service, and shippable are three distinct states with real time between them. Most disputes about turn time are actually disagreements about which state "done" refers to.

What has to be in place

  • The work itself — performed using acceptable or approved data, as applicable to the task.
  • Inspection — required in-process and final inspections completed and any discrepancies dispositioned.
  • Authority — an appropriately authorized person or organization, acting within its scope, willing to sign.
  • The record — the maintenance record entry required by the applicable regulation. In the US, the recording requirements sit in 14 CFR 43.9 and related provisions.
  • Supporting documentation — certifications for material fitted, and any additional documents the contract requires.

Why RTS readiness is cross-functional

A unit cannot be released while any one of those elements is missing, and they are owned by different parts of the organization. The bench owns the work. Quality owns the inspection and, usually, the signature. Purchasing and stores own the material and its certifications. Whoever handles the customer owns the approvals that authorized any additional findings.

That is why release readiness is rarely a single team's problem, and why units so often stall at the last step for reasons that have nothing to do with the technical work. The aviation MRO software page covers this coordination question in more depth.

Common misunderstandings

"It's done" usually means state one

When a shop says a unit is finished, that is frequently a statement about the bench. Ask which of the three states it is in.

A tag is the record of the approval, not the approval itself

The approval is the act of an authorized person. The document — an 8130-3 or an equivalent record — evidences it. Producing the document without the underlying authority and record is not a shortcut; it is a serious problem.

Return to service is not the same as airworthy in every context

Approval for return to service addresses the article following the maintenance performed. Whether a given article is eligible for installation on a particular aircraft is a separate determination made by the installer against approved data.

Scope limits are real

An organization can only release work within the ratings and limitations it holds. Being technically capable of doing a job is not the same as being authorized to release it.