How do aerospace manufacturers handle out-of-tolerance results detected during FAI?

Out-of-tolerance results detected during First Article Inspection are normally handled as nonconformances, not as values to be corrected in the FAI package. The manufacturer should contain the affected part or lot, verify that the measurement is valid, document the actual result, open the required nonconformance process, and obtain disposition through the approved quality system before shipment or further use. FAI does not make an out-of-tolerance condition acceptable by itself.

Typical handling sequence

The exact workflow depends on the customer contract, internal QMS procedures, delegated authority, and whether the organization is the design holder, build-to-print supplier, or sub-tier supplier. Commonly, the process includes:

• Containment: The affected part, serial number, batch, or associated work order is placed on hold so it cannot be shipped, installed, or consumed without disposition.
• Measurement verification: Quality or metrology confirms the result, including gage calibration status, setup, datum scheme, GD&T interpretation, environmental conditions, inspection method, and operator or CMM program factors.
• FAI documentation: The actual measured value is recorded in the FAI record. If a characteristic is nonconforming, the FAI package should reference the nonconformance record rather than hiding or overwriting the result.
• NCR or discrepancy process: A nonconformance report is opened according to the site’s QMS. This may trigger material review board activity, engineering review, supplier notification, or customer notification.
• Disposition: The part may be reworked, repaired, scrapped, accepted by approved concession or use-as-is authority, or held pending design or process clarification. Authority limits matter; many suppliers cannot self-approve use-as-is conditions without customer or design authority involvement.
• Corrective action: If the issue indicates a process failure, planning error, tooling problem, programming issue, drawing interpretation problem, or systemic inspection gap, RCCA or CAPA may be required.
• FAI completion or repeat activity: After correction, the organization may need to complete, update, or repeat all or part of the FAI, depending on AS9102 requirements, customer flow-downs, and the nature of the change.

What should not happen

An out-of-tolerance FAI result should not be averaged away, rounded into tolerance, replaced with a later value without traceability, or accepted informally because the part is “functionally fine.” If the drawing, model, specification, or inspection plan is wrong or ambiguous, that is normally handled through change control or formal clarification, not by editing the inspection result to fit the expected answer.

Similarly, FAI is not a substitute for MRB, engineering disposition, or customer approval where those are required. A completed FAI package with an unresolved nonconformance is not evidence that the product is acceptable for delivery.

How AS9102 affects the record

AS9102 focuses on documenting that the production process can produce characteristics that meet engineering requirements. When a characteristic is out of tolerance, the FAI record should show the actual result and identify the related nonconformance. Whether the FAI can be considered complete, conditionally submitted, rejected, or resubmitted is usually driven by customer requirements and the organization’s approved procedures.

In many aerospace supply chains, the customer may require submission through a portal or specific FAI workflow. That does not change the basic control principle: the measurement, disposition, approval, and any follow-up action need to remain traceable.

System implications in brownfield plants

In mature aerospace operations, this workflow often crosses several systems. The FAI tool may hold the AS9102 forms, the QMS may manage the NCR and CAPA, the MES may place the traveler or serial number on hold, ERP may block inventory movement or shipment, PLM may control drawing and model revisions, and calibration or metrology systems may support measurement validity.

Failures often occur at the handoff points. A nonconformance may be documented in the QMS but not reflected in the MES traveler. A part may be physically segregated but not blocked in ERP. A drawing clarification may be captured in email but not incorporated into PLM or controlled work instructions. These gaps matter because FAI evidence is only as reliable as the traceability between the result, the part, the revision, the disposition, and the approval authority.

When rework or redesign is involved

If the part is reworked back into tolerance using an approved process, the corrected characteristic is typically reinspected and documented. The organization still needs traceability to the original nonconformance and the rework authorization. If the requirement itself changes, the FAI impact depends on revision control, customer requirements, and whether the change affects fit, form, function, manufacturing source, process, tooling, or inspection method.

Full process replacement or broad system change is rarely the immediate answer to an FAI nonconformance in a regulated aerospace environment. The practical priority is controlled containment, valid measurement, documented disposition, and traceable closure. Broader system improvements may be justified if repeated FAI failures reveal integration debt, poor planning controls, weak characteristic management, or inadequate inspection governance.