E-Archive
Standards Forum
in Vol. 26 - May Issue - Year 2025
Closing the Loop: Feeding Aerospace and NADCAP Audit Findings into International Specifications

Christian Tyroll
In aerospace manufacturing, compliance with internationally recognised standards is essential for safety, quality, and market access. Audits—particularly those conducted under the National Aerospace and Defense Contractors Accreditation Program (NADCAP)—serve as powerful tools to verify compliance with critical processes such as heat treatment, chemical processing, and non-destructive testing, for example.
While corrective actions following audit findings are routine, a key opportunity for sector-wide improvement lies in systematically feeding these findings back into international specifications themselves. Doing so helps close the quality loop at the global level, improving clarity, consistency, and effectiveness of aerospace standards across the supply chain.
Audit findings often expose deeper systemic issues, not just isolated process failures. In NADCAP audits, which are conducted by expert auditors, these findings can reveal gaps in the way global standards are interpreted or applied across facilities and geographies. When such issues are recurring or widespread, they may suggest that an international specification lacks clarity, sufficient technical detail, or appropriate control measures.
Most aerospace organisations respond to audit findings with corrective and preventive actions (CAPAs) at the local level. However, a more impactful approach involves channelling those findings back into the standards development process. This approach supports long-term improvement across the sector and helps prevent recurrence at other sites or within other companies.
The pathway from audit finding to international specification improvement typically involves:
- Root Cause Analysis (RCA): Identifying the systemic cause of the finding, especially where ambiguity or insufficiency in a standard contributed to the issue.
- Pattern Recognition: Observing whether the same issue has been noted in other audits, either within one supplier network or across multiple audits in different regions. If multiple manufacturers misinterpret the same clause, the standard may need to be clarified.
- Engagement with Standards Bodies: Once an issue with an international specification is identified, organisations can propose updates or clarifications to bodies such as:
○ SAE International (e.g., AMS, AS standards)
○ ISO/IEC
○ IAQG (e.g., AS9100-series standards)
○ PRI/NADCAP Task Groups, which periodically revise audit checklists and criteria
For example, during NADCAP audits for chemical processing, findings may arise related to inconsistent temperature or pH control in plating baths. A common issue is vague guidance in existing aerospace material specifications regarding frequency and method of monitoring. Some manufacturers may interpret requirements as allowing wide discretion, resulting in process variation. If similar findings are documented across multiple facilities or regions, it could well indicate a weakness not in operator compliance, but in the international specification itself.
Feeding this back to the specification owner—e.g., a relevant SAE committee—could prompt a revision such as: “Temperature must be monitored continuously using a calibrated digital sensor and recorded at intervals not exceeding 30 minutes.” Such a change enhances clarity, reduces misinterpretation, and ensures more consistent compliance across the aerospace sector globally.
Audit findings can be fed into international specifications via several formal mechanisms:
- Direct involvement in standards committees
- Submission of change proposals or ballot comments during standards revision cycles
- Participation in NADCAP Task Groups, which revise checklists like AC7108 (Chemical Processing) or AC7116 (Heat Treating), based on audit outcomes
- Collaboration with industry working groups, such as IAQG’s Supply Chain Management Handbook (SCMH) team, which develops best practices to accompany AS9100
The benefits of closing the loop include:
- Improved harmonisation, where global suppliers interpret and implement requirements in a consistent way regardless of geography
- Reduced recurrence of findings, when standards with precise language are less likely to be misapplied or misunderstood
- Stronger compliance and safety, with clearer guidance that supports more robust process control, reducing the likelihood of latent defects
- Fewer audit discrepancies, because auditors benefit from tighter criteria, leading to more objective and reproducible assessments
- And lastly, elevated industry credibility and a demonstration of commitment to continuous improvement at the structural level, not just the operational
In the field of shot peening, NADCAP findings have highlighted variability in how Almen strip curvature is measured. In some specifications, the method is loosely described, leading to inconsistent tooling and techniques. Repeated findings prompted a revision proposal to include more specific language around the type of gauge and measurement resolution required. This change was eventually adopted into both the audit checklist and an SAE AMS specification, illustrating how audit feedback—if well-documented and shared—can ripple outwards to improve global standards.
In conclusion, audit findings are not just signals of non-compliance; they are opportunities to evolve the standards that define aerospace quality. When findings are repeatedly observed across different facilities or suppliers, they often point to ambiguities or gaps in international specifications themselves. By actively contributing audit-driven insights to global standards development bodies, aerospace stakeholders can help refine and clarify the very documents that underpin their operations. In doing so, they not only reduce future audit findings—they enhance global safety, consistency, and excellence in aerospace manufacturing.
For questions, contact Christian.Tyroll@noricangroup.com
Christian Tyroll
MFN Contributing Editor
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