First Article Inspection: What It Proves
First article inspection is the cheapest mistake-detection mechanism available in manufacturing: one part, measured thoroughly, before the rest of the order is made. Its value depends almost entirely on whether the drawing was correctly interpreted and whether anyone reads the report rather than filing it.
First article inspection measures the first part produced against every dimensioned requirement on the drawing, and records the results in a report issued before the balance of the batch runs. It is a checkpoint on the process, not a quality guarantee for the batch.
What happens during an FAI
The first part off the line is measured against every ballooned requirement. The drawing has each dimension, note and tolerance numbered; the report lists each balloon number with its nominal, the tolerance, the actual measured value and a pass or fail. Material certificates are attached, and where the drawing specifies them, surface finish and coating thickness results are included.
The point of ballooning is coverage. Measuring the dimensions an inspector finds convenient, rather than the whole drawing, is how a discrepancy survives to the thousandth part.
What it proves, and what it does not
The distinction matters commercially. An approved FAI is not a warranty, and treating it as one is how a genuine manufacturing problem turns into an argument about paperwork. What it does is move detection from the end of the order to the beginning, which is where rework is still cheap.
- The process can produce the geometry as drawn, at least once
- That the process will stay within tolerance across the run
- The drawing was interpretable and was interpreted the same way by both parties
- That the customer's design itself is correct or functional
- Material and, where specified, coating meet the stated requirement
- Performance under service load, fatigue or life-cycle conditions
- Any dimension that has been misread is caught before volume production
- That sampling afterwards is unnecessary — drift is a separate risk
How to read a report before you approve it
- Check that the balloon numbers on the drawing match the rows in the report — a missing balloon is an unmeasured dimension.Look at how close the passing values sit to the tolerance limits; comfortably inside is a process under control, hovering at the limit is one that will drift.Confirm the report is against the current drawing revision, not a superseded one.
- Check that material certificates reference the same grade and heat as the parts, not a generic mill certificate for the same grade.Where a value is out of tolerance, expect a deviation request with a technical justification — not a re-measured value.Ask which dimensions are checked on every batch afterwards, since an FAI is a one-off by design.
When an FAI is worth requiring
On a new part, a new revision, a new tool or a new supplier, an FAI is the cheapest insurance in the order. On a complex weldment, where distortion accumulates, it is close to essential.
On a repeat order of a simple bracket that has been shipping for two years, a full FAI mostly repeats work that has already been validated. In that case a shorter dimensional report against the critical features is the sensible requirement, and it costs less for both sides. Deciding which of those two applies to your part is a more useful conversation than defaulting to the fullest report available.
Frequently asked questions
What is the difference between an FAI and a dimensional report?
An FAI covers the whole drawing, balloon by balloon, and is normally issued once at the start of a programme or after a change. A dimensional report covers the features you nominate and is usually issued per batch. The FAI is broader; the dimensional report is repeatable.
Do you provide FAI reports?
Yes, on request and on production orders. The report is issued against the ballooned drawing with material certificates attached, and it is released for approval before the balance of the batch is run where the order structure allows that.
Is an FAI the same as AS9102?
AS9102 is a specific aerospace FAI standard with a defined form and reporting structure, and it requires a certification framework we do not hold. Our FAI is a drawn-up, fully ballooned dimensional report in the same spirit and provides the same engineering evidence, but it is not an AS9102 submission.
What happens if the first article fails?
The part is not shipped and the batch does not run. We identify whether the cause is the tooling, the programme or the drawing, correct it, and issue a new first article for approval. That sequence is the whole reason for doing the inspection early.
Can I approve an FAI on a deviation?
Yes, and it is a normal engineering decision. A feature that is marginally out of tolerance but functionally acceptable can be accepted with the deviation recorded, so neither side is later surprised. What is not acceptable is accepting it silently and discovering it at final inspection.
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