What a Proper Vendor-Qualification Process Looks Like in Aerospace

In aerospace engineering, a vendor isn’t just a place that makes parts — they’re an extension of your design team. A single missed tolerance, undocumented heat-treat cycle, or unverified coating thickness can cascade into rework, schedule slip, or even field failures. That’s why aerospace organizations rely on a structured, evidence-based vendor-qualification process.

Why Vendor Qualification Matters (Especially to Engineers)

Engineering teams rely on suppliers to execute tolerances, processes, and materials exactly as designed. When suppliers lack process control or documentation discipline, it affects:

• Tolerance stack integrity
• Material property reliability (heat treat, coatings, welds)
• Traceability through complex assemblies
• Repeatability across long-run production

 

For aerospace, where failure modes can hide until environmental testing or flight, the qualification process is as critical as design verification.

1. Initial Technical Screening

The qualification process begins with a paper review to determine if the supplier has the foundation to support aerospace work.

Engineers should check for:

• AS9100D certification (the standard quality system for aerospace manufacturing)
• NADCAP accreditation for special processes like heat treat, welding, plating, or NDT
• Core equipment and capabilities (CNC, CMM, welding, inspection tools)
• Experience with complex or tight-tolerance parts

Why this matters: AS9100D requires supplier evaluation and documented process control, while NADCAP provides accredited oversight for processes that cannot be fully verified after the part is produced.

2. Deep Dive on Quality Documents

Once the supplier passes the initial screen, the next step is documentation review.

Engineers should request:

• Quality manual and process flow diagrams
• Calibration records (traceable to ISO/IEC 17025 or accredited labs)
• AS9102 First Article Inspection (FAI) plan and historical FAIRs for comparable parts
• Control plans, SPC charts, and capability studies (Cpk/Ppk)

Why this matters: AS9102 is the standard for proving a supplier can meet every drawing requirement during initial production. Calibration and SPC records reveal how well their measurement systems and processes perform.

3. Counterfeit-Part Controls & Traceability

Counterfeit fasteners, materials, or electronic components can create catastrophic failures. Because of this risk, aerospace requires strict incoming inspection and mitigation controls.

The supplier should demonstrate:

• A counterfeit parts policy compliant with AS5553
• Receiving inspection with material certs, CoCs, and traceability
• Use of authorized distributors for electronics

This aligns with FAA guidance and SAE standards on counterfeit avoidance.

4. Onsite Audit: The Engineer’s Reality Check

No matter how good the documents look, the real verification happens on the shop floor.

During an onsite audit, engineers should examine:

• Actual process execution vs. documented processes
• Operator competency and training for critical tasks
• CMM inspection setups and fixture design
• Traceability at every work center
• Special-process execution (heat treat, NDT, coating lines)

NADCAP accreditation is particularly critical here, because special processes often produce results that cannot be validated through simple final inspection.

5. Sample Runs & AS9102 First Article Inspection

Before accepting a supplier into production, engineering teams should require:

• A production-intent sample run
• A complete AS9102 FAI package
• Dimensional reports
• Material, heat-treat, and coating certifications
• Surface finish and hardness verification when applicable

The evaluation should include multiple pieces to assess process capability (Cpk). This step ensures the supplier can hit tolerances consistently, not just once.

6. Contractual Controls, KPIs & Flowdowns

After technical approval, the supplier relationship is governed by documented expectations.

Key elements include:

• KPIs such as OTD, PPM defects, and first-pass yield
• SCAR (Supplier Corrective Action Request) process with required response times
• Flowdowns for AS9100D, material handling, inspection, and any customer-specific requirements
• Cybersecurity controls if handling CUI or DoD work (NIST SP 800-171, DFARS clauses)

AS9100D mandates supplier monitoring and documented corrective action for any performance deviations.

7. Cybersecurity & IP Protection

For aerospace and defense work, a supplier must protect CAD models, drawings, and technical data.

This includes:

• Compliance with NIST SP 800-171
• Self-assessment or score submission to SPRS if required
• Controlled access to data and workstations
• Incident reporting and recovery protocols

Cybersecurity failures can compromise both intellectual property and supply-chain integrity.

8. Ongoing Monitoring & Annual Requalification

Supplier qualification is not a one-time event. Engineering and quality teams should maintain:

• Monthly or quarterly supplier scorecards
• Annual audits (more frequent for high-risk categories)
• SCAR verification and closeout
• Review of new certifications, calibrations, and process changes

AS9100D emphasizes continuous supplier evaluation throughout the relationship.

Common Engineering Pitfalls to Avoid

• Approving a supplier based on price alone
• Skipping gauge R&R or assuming CMM accuracy
• Relying on undocumented special processes
• Failing to validate repeatability before production

 

Each of these leads to increased risk during integration, environmental testing, or field deployment.

Engineer-Led Qualification Reduces Long-Term Risk

A strong vendor-qualification process is not bureaucracy — it’s engineering risk reduction. With proper screening, documented capability, traceability, and continuous monitoring, suppliers become true partners in delivering reliable aerospace hardware.

For teams that design or assemble mission-critical systems, qualification isn’t optional. It’s the difference between predictable production and costly surprises.

Let’s Build the Right Solution – Together.

At KL Engineering, precision and adaptability converge to advance your objectives. Every project is custom-engineered to align with your processes, priorities, and vision – because one-size-fits-all solutions are never enough. Partner with a team that molds to your needs and delivers results engineered for you. Explore how we can elevate your next project: www.kle-inc.com