Key Takeaways
- First article inspection (FAI) under AS9102 is a mandatory verification process that proves a CNC supplier’s ability to produce aerospace parts that meet all engineering requirements.
- AS9102 uses three standardized forms: Form 1 for part number accountability, Form 2 for material and special-process certifications and Form 3 for dimensional and characteristic verification.
- Common FAI rejections in CNC shops come from missing ballooned drawings, incomplete traceability, out-of-tolerance results and undocumented process changes.
- Integrating FAI with an AS9100D-certified quality system creates full traceability, controlled documentation and consistent configuration management from prototype through production.
- Precision Advanced Manufacturing provides complete AS9102-compliant FAI support with integrated multi-axis CNC machining and finishing, and starts aerospace programs with documented FAI support.
FAI Triggers in Aerospace CNC Machining
AS9102 defines specific conditions that trigger a required FAI. Procurement and quality teams confirm that a full FAI is on record before production approval whenever any of the following apply:
- A new part number is introduced to the production floor.
- An engineering design revision changes form, fit or function.
- A manufacturing process change occurs, including tooling, fixturing or CNC program updates.
- A supplier change is made, including subcontractors performing special processes.
- A lapse in production exceeds the threshold defined in the customer quality plan or contract.
- A new special process is introduced, such as a thermal coating, anodizing or passivation step.
- A part is transferred to a different facility or production line.
Each trigger marks a point where the established process baseline no longer holds. A documented FAI re-establishes that baseline for the revised configuration.
AS9102 Form 1: Linking Parts to Approved Designs
Form 1 confirms that the physical part matches the approved design documentation. For CNC-machined aerospace components, this form links the part number, revision level and drawing to the actual hardware produced.
On a multi-axis milled structural housing, Form 1 captures the drawing number, revision, part name and any applicable assembly or next-higher-assembly reference. GD&T callouts on the drawing, including true position, flatness and profile tolerances, must be traceable to the ballooned drawing used in Form 3 verification.
Every note, specification and reference document listed on the engineering drawing is accounted for on Form 1. That coverage includes material specifications, finish requirements and applicable process standards.
Incomplete Form 1 packages cause many FAI rejections. A compliant shop maintains a controlled drawing release process so the revision on the shop floor always matches the revision on the FAI package.
AS9102 Form 2: Material and Process Documentation
Form 2 records material and special-process certifications. For machined aerospace parts, this form includes raw material certifications tied to the heat or lot number used in the first article, plus certifications for every special process applied to the part.
At Precision Advanced Manufacturing, finishing operations such as anodizing, passivation, plating and thermal coatings operate under one roof. This structure keeps Form 2 documentation, including processor certifications, process specifications and compliance statements, under internal control instead of spread across multiple subcontractors.
Each certification is verified against the specification on the engineering drawing before the FAI package is submitted. This step confirms that the documented process matches the design requirement.
Form 2 also captures functional test results and any customer-specified conformance data required for the part end-use environment. For flight-critical components, this documentation becomes part of the permanent quality record.
Get a quote for integrated FAI and finishing services on aerospace components.
AS9102 Form 3: Dimensional and Feature Verification
Form 3 serves as the dimensional core of the FAI. Every characteristic identified on the ballooned drawing, including dimensions, tolerances, GD&T callouts, surface finish requirements and notes, receives a balloon number, a nominal value, a tolerance band and a measured result.
For complex aerospace components, in-process CMM (coordinate measuring machine) data collection provides the primary method for capturing Form 3 results. CMM reports are generated directly from the inspection program and cross-referenced to balloon numbers on the drawing.
This approach reduces transcription errors and creates a traceable, auditable measurement record. It also supports repeatability when production moves beyond the first article.
Critical characteristics, whose variation could affect safety, airworthiness or mission performance, are identified separately and receive additional scrutiny. On tight-tolerance turned or milled parts, this group often includes bore diameters, mating surface profiles and positional tolerances on bolt patterns.
The Form 3 package must show that every characteristic was measured, that the measurement method fits the feature and that results fall within the engineering requirement. Even with a strong Form 3 process, FAI packages still fail when upstream controls break down.
Why CNC FAI Packages Get Rejected
FAI rejections delay production approval and add cost to programs. The most frequent causes in CNC machining environments fall into four categories.
Missing or incomplete ballooned drawings. Every characteristic on Form 3 must reference a balloon number on a controlled drawing. Submitting Form 3 data without a corresponding ballooned drawing causes automatic rejection because the reviewer cannot verify which drawing features were measured.
Preventive control: generate the ballooned drawing before dimensional inspection begins and treat it as a controlled document.
Incomplete material traceability. Form 2 rejections occur when material certifications are missing, when the heat or lot number on the certification does not match the material used or when a special-process certification references the wrong specification revision.
Preventive control: establish a material receiving and traveler system that ties the certification to the job from the moment raw stock enters the facility.
Out-of-tolerance features. Dimensional nonconformances on Form 3 indicate a process capability problem. These issues signal that the machining process cannot hold the required tolerance across the run.
Preventive control: run in-process CMM checks during machining of the first article instead of waiting for final inspection. Detecting a drift in a critical bore diameter during machining allows correction before the part is complete.
Undocumented process changes. If a tooling substitution, fixture modification or revised CNC program was used during first article production but not documented, the FAI package no longer represents the production process.
Preventive control: freeze the process before FAI production begins and document any deviation through a formal change notice.
FAI Inside an AS9100D Quality System
AS9102 FAI operates as part of a broader quality framework. Under AS9100D, the FAI process fits within a quality management system that governs configuration management, risk management, document control and corrective action.
Precision Advanced Manufacturing operates under AS9100D and ISO 9001:2015 certified quality systems. FAI packages are generated within a controlled documentation environment where drawing revisions, material records, inspection data and process certifications connect to a single job record.
This integration means that when a customer supplier quality engineer requests the FAI package, every required element, including Forms 1, 2 and 3, ballooned drawings, material certifications, CMM reports and special-process certifications, is retrievable from one traceable record.
Configuration management within the AS9100D system also ensures that any post-FAI engineering change is evaluated for its impact on the approved baseline. That evaluation triggers a delta or full FAI when required.
Start a manufacturability review with the engineering team before first article production begins.
Choosing Delta FAI or Full FAI
Not every change requires a complete FAI. AS9102 permits a delta, or partial, FAI when a change affects only a defined subset of the part characteristics or documentation.
A full FAI is required when a new part number is introduced, when the change affects the overall manufacturing process or when the customer contract specifies a full FAI for any revision.
A delta FAI fits situations where an engineering change affects a limited number of characteristics, a single material or process step is revised or a specific feature is redesigned without altering the broader manufacturing baseline. The delta FAI re-verifies only the affected forms and characteristics while referencing the previously approved FAI for unchanged elements.
The decision must be documented. The FAI package for a delta submission identifies the originating full FAI to establish the baseline, lists the specific changes to show what triggered the delta and provides updated form entries for affected characteristics only.
Customer approval of the delta scope is required before this approach is used on a controlled program. When uncertainty exists, a full FAI removes ambiguity and supports a strong compliance posture for flight-critical or mission-critical parts.
FAI-Ready CNC Partners for Aerospace Programs
Evaluating a CNC supplier for aerospace programs starts with four checks. The supplier needs technical capability to machine the part, a quality system that produces compliant FAI documentation, scalability from prototype to production and full traceability across materials and processes.
Precision Advanced Manufacturing delivers all four. With advanced multi-axis CNC machining, integrated sheet metal fabrication, precision welding and secondary finishing under one ITAR-registered, AS9100D-certified roof, the company executes AS9102 FAI as a standard part of every new production program.
Supplier quality engineers, procurement managers and program managers receive complete FAI packages, traceable documentation and engineering support from the first article through full-rate production.
Frequently Asked Questions
What is included in a first article inspection for aerospace machined parts?
A complete FAI under AS9102 includes three forms, plus supporting records. Form 1 covers part accountability, Form 2 covers material and process certifications and Form 3 covers dimensional verification.
The package also includes the ballooned drawing, CMM reports and any customer-required conformance data. Each form has detailed requirements that appear in the Form 1, Form 2 and Form 3 sections above.
When is a first article inspection required in aerospace machining?
A first article inspection is required whenever the established production baseline changes or a new part enters production. The seven specific triggers appear in the “FAI Triggers in Aerospace CNC Machining” section and cover scenarios from new part numbers to production lapses.
Customer contracts may add further triggers beyond the AS9102 baseline requirements.
What is the difference between a delta FAI and a full FAI?
A full FAI verifies all three AS9102 forms and every characteristic on the drawing. A delta FAI is a partial re-verification performed when a change affects only a defined subset of the part characteristics or documentation.
The delta FAI references the previously approved full FAI for unchanged elements and provides updated form entries only for the affected areas. The scope of a delta FAI must be documented and approved by the customer before use on a controlled program.
When the scope of a change is unclear or the part is flight-critical, a full FAI supports the strongest compliance posture.
How does AS9100D certification relate to AS9102 first article inspection?
AS9100D is the quality management system standard for aviation, space and defense organizations. AS9102 is the specific standard that defines first article inspection requirements.
AS9100D requires organizations to plan and control production processes, manage configuration and maintain documented records. These elements directly support AS9102 compliance.
A shop operating under a certified AS9100D quality system has the document control, traceability and process discipline needed to produce and maintain compliant FAI packages. FAI functions as one output of the broader AS9100D quality system rather than a standalone activity.
What are the most common reasons an aerospace FAI gets rejected?
The four most common rejection causes, missing ballooned drawings, incomplete certifications, out-of-tolerance results and undocumented process changes, appear in the “Why CNC FAI Packages Get Rejected” section.
Each cause points to a breakdown in process discipline before the FAI begins. Shops with robust drawing control, material receiving systems, in-process CMM inspection and formal change management prevent most rejections before the package is submitted.
