First Article Inspection: What It Proves, and Why So Many Fail

First article inspection is one of the most common reasons an aerospace supplier gets a finding, loses time on a new part, or has a package returned by a customer. It is also one of the most commonly misunderstood requirements in the standard, and the misunderstanding is always the same.

An FAI is not a good part with paperwork attached. It is objective evidence that your production process produces conforming parts.

Everything that goes wrong with first article inspection follows from missing that distinction.

What that means in practice

If the requirement were "make one good part and measure it", you could machine it carefully on a quiet Friday, have your best setter run it, measure it twice and submit the results. People do exactly that, and it is why their second batch fails.

Because the point is the process, the article you submit has to be made:

• by production methods, not a one-off approach
• on production tooling and equipment
• by production personnel, working to the released instructions
• from production material, with the traceability intact

A part made any other way proves something — just not the thing the customer is asking you to prove.

The three forms, and what each is really for

AS9102 structures the report into three forms, and each answers a different question.

Form 1 — part number accountability. What the part is, which drawing and revision, where it sits in the assembly. Dull, and the place where the most avoidable errors happen: wrong revision, missing sub-assembly accountability, a part number that does not match the purchase order.

Form 2 — product accountability. Materials, special processes and functional testing. This is where traceability gets tested: the raw material certification, the approval status of every special process, and whether the processor you used is actually on the customer's approved list. A beautifully measured part with a plating process from an unapproved source is a failed FAI.

Form 3 — characteristic accountability. Every characteristic on the drawing, numbered, with the actual result and how it was verified. Not a sample. Every one.

Where they actually come apart

In order of how often I see them:

Characteristics missed during ballooning. Notes on the drawing are characteristics too. So are tolerances carried in the title block, surface finish callouts and flagged requirements in the specification the drawing invokes. A reviewer counts the balloons against the drawing, and a missing one is a finding before anyone looks at a measurement.

Special process approvals not evidenced. Heat treatment, plating, NDT, welding. The approval has to be current, the source has to be approved for that customer and that process, and the evidence has to be in the package rather than in a folder somewhere.

Material traceability broken at the sub-tier. You can trace to your supplier; your supplier cannot trace to the mill. The chain has to reach the beginning.

The article was not made the production way. Covered above, and the hardest one to admit to after the event.

Forms completed retrospectively. Assembled from records weeks later, with dates that do not reconcile. An auditor reads dates.

No re-FAI after a change. This is the one that bites established suppliers rather than new ones, and it is worth its own section.

When you need to do it again

A full or partial first article is triggered by change, and the list is wider than most suppliers apply:

• a change in design affecting form, fit or function
• a change in manufacturing process, method or tooling
• a change in location of manufacture
• a change of supplier — including a sub-tier special processor
• a lapse in production, commonly two years, though check your customer's requirement
• natural or man-made events that may have affected the process

A partial — often called a delta FAI — covers only the characteristics affected by the change, with the earlier report referenced. You do not re-measure everything because you moved one operation. But you do have to make the judgement deliberately and record it, rather than deciding informally that nothing has really changed.

Moving a machine across the shop floor is a change of process. Replacing a retiring setter is not, by itself. The grey ground between those is where the judgement sits, and where a customer may take a different view from you — which is a conversation worth having before you ship, not after.

Who should do it

Not the person who made the part, where you can avoid it. The same independence principle that applies to internal auditing applies here: someone verifying their own work is testing whether they did what they intended, not whether the drawing was met.

In a small team that is not always possible, and a declared, sensible compromise is better than a pretence of independence nobody believes.

Frequently asked questions

Is an FAI required if the customer has not asked for one?

If you are working to AS9100, first article inspection is a requirement of your own system, not a favour to the customer. The customer may specify their own format or additional requirements on top — and plenty flow down their own forms — but the obligation does not depend on them asking.

How long should an FAI take?

Longer than people plan for, and the measurement is rarely the slow part. Assembling special process approvals and material certification usually is. Starting the package when the part is finished is the most common scheduling mistake.

Do we need a full FAI for every change?

No — a partial covering the affected characteristics is normally appropriate, referencing the original report. The discipline is deciding deliberately which characteristics are affected and recording that reasoning.

Can you review our FAI packages before we submit them?

Yes. We carry out internal and second-party audits for clients and review first article packages as part of that. We are not a certification body, and nothing we do replaces your customer's acceptance of the package.

We train teams in first article inspection, APQP and PPAP against your own drawings and records rather than generic examples. See our training services, our quality management work, or get in touch.