First Article Inspection: AS9102 Forms and Requirements

A first article inspection (FAI) is a complete, documented verification of one part from the first production run against every requirement in its design data. In aerospace the content and format are set by AS9102, currently at Rev C, and the underlying requirement to verify the production process comes from AS9100 Rev D. The resulting first article inspection report (FAIR) is the record a buyer relies on when releasing a supplier into production.

What an FAI proves

The purpose is to prove the process, not just the part. A conforming first article shows that the supplier read the drawing and specifications the way the design authority intended, that the planning, programs, tooling, fixtures and inspection methods work, and that the sub-tier sources for material and special processes are correct. Those things stay true for the next lot as long as the process does not change.

That is why the first article must be a representative part from the first production run, made by the production process. A prototype cut from a different stock form on a different machine, with hand-finished features, proves little about production. Development and prototype parts that are not part of a production run, and standard catalog hardware, fall outside the scope of the standard.

An FAI does not replace lot acceptance. It is performed once for a stable process, and routine inspection continues after it.

When a full or partial FAI is required

A full FAI is required for the first production run of a new part. After that, the standard calls for the FAI to be repeated, fully or partially, when something changes that can affect fit, form or function. In general terms the triggers are:

• A change to the design.
• A change in manufacturing source, process, inspection method, tooling or material.
• A change in the location of manufacture.
• A change to the numerical control program or its translation to other media.
• A natural or man-made event that may have adversely affected the process.
• A lapse in production beyond a defined interval. Two years is the figure most often cited, and customers frequently set their own.

AS9102 gives the precise wording and customer quality clauses often add to it, so check both.

A partial FAI, often called a delta FAI, addresses only the characteristics affected by the change. It identifies the baseline FAI it builds on and states the reason for the partial. Everything unaffected stays covered by the baseline.

The three AS9102 forms

Table 1. The three AS9102 forms

Form 1: Part Number Accountability

Form 1 identifies exactly what was inspected: part number, part name, drawing revision and any additional engineering changes, serial or lot identification, the manufacturing process reference, and whether the FAI is full or partial. For an assembly it lists the detail parts and sub-assemblies with their own FAI report references, so accountability rolls up through the product structure. It carries the signatures of the person who prepared the report and the person who reviewed and approved it, plus customer approval where required.

Form 2: Product Accountability

Form 2 lists the raw materials, special processes and functional tests the design calls for, each with its specification, the source that supplied or performed it, and a reference to the certificate or report. Where the customer requires approved sources for special processes such as heat treatment, plating, anodizing, welding or nondestructive testing, the form records that the source was approved.

Form 3: Characteristic Accountability

Form 3 is the body of the report. Each design characteristic gets a row: a unique characteristic number, its location in the design data, any classification such as key or critical, the requirement with its tolerance, the result, the tooling used where it is specially designed or qualified, and a nonconformance reference if the result fails. Where a characteristic is verified on a coordinate measuring machine, the detailed output usually sits behind this form. The guide to reading a CMM inspection report covers that data.

Ballooned drawings and characteristic accountability

A ballooned drawing assigns a numbered balloon to each design characteristic, and each number corresponds to a row on Form 3. Accountability means nothing in the design data is left without a number and a result.

Design characteristics include more than dimensions. They are the dimensional, visual, functional, mechanical and material features that define the part: toleranced dimensions, geometric tolerances, surface finish, threads, edge breaks, markings, and requirements invoked through specifications.

Drawing notes are design characteristics when they impose a requirement. A note calling for 63 µin (1.6 µm) Ra unless otherwise specified, a deburr limit, a part-marking method or a process specification has to be ballooned and verified. General tolerance blocks apply to every dimension without its own tolerance, and those dimensions need rows as well.

Basic dimensions are not verified directly. They define the true position or profile, and the characteristic is the feature control frame that refers to them. The guide to reading GD&T on a drawing explains the distinction.

Reference dimensions are for information, carry no tolerance and are not acceptance criteria. Whether they are ballooned and marked as reference or left out varies by customer, so state the expectation.

Note: A callout that applies to several features, such as a hole pattern marked 8X, is a requirement on each feature. Whether the report must list each instance separately or may show a range of results is a customer decision. Specify it up front.

Common reasons FAI reports are rejected

• Unaccounted characteristics. Notes, general tolerances, flag notes and specification requirements are the usual omissions.
• No actual values. A variable characteristic is recorded as "pass" or "conforms" instead of a measured value.
• Revision mismatch. The report cites a different drawing or specification revision from the purchase order.
• Incomplete Form 2. Material certifications are missing or not traceable to the lot used, or a special process was performed by a source the customer has not approved.
• Unsuitable measurement method. The instrument lacks the resolution or accuracy for the tolerance, or there is no record of what was used.
• Open nonconformances. A failed characteristic has no disposition. An FAI is not complete until nonconformances are resolved and the affected characteristics verified again.
• Missing lower-level FAIs for the detail parts of an assembly.
• Partial FAI with no baseline reference.

Common mistake: Results that sit at exactly nominal on every characteristic. Real measurements scatter, and a reviewer will read uniform nominal values as transcribed, not measured.

FAI requirements on the purchase order

Ambiguity in the purchase order is the root of many FAI disputes. State:

• The standard and revision, for example AS9102 Rev C, and whether a full or partial FAI is expected.
• Whether the report must be approved before the production lot ships.
• The deliverable format, and whether a ballooned drawing and raw inspection reports must accompany the forms.
• How multi-instance features, reference dimensions and attribute data are to be treated.
• Any key characteristics and the data required for them.
• Approved-source requirements for material and special processes, and their flow-down to sub-tier suppliers.
• Which design data governs when the part is defined by a 3D model.

Checklist

• Confirm the drawing, model and specification revisions on the purchase order before the first production run starts.
• State the FAI standard, revision and scope in the purchase order text.
• Provide the list of approved special process sources, or state where it is found.
• Identify key and critical characteristics on the drawing.
• Require actual measured values for variable characteristics.
• Require a ballooned drawing matched to Form 3 numbering.
• State the events that trigger a new or partial FAI under the contract.
• Agree how dimensional inspection data will be supplied alongside the forms.