The Past, Present and Future Direction Of Aerospace Quality Standards

Designed to solve problem of duplication and contradiction

by Dale K. Gordon

Original equipment manufacturers (OEMs) and suppliers in the aerospace community are very concerned about the proliferation of standards used to define quality system requirements. While this is certainly an issue across all industries, we need to examine exactly what is happening.

For many years the aerospace OEMs took customer and regulatory requirements, such as Mil-Q-9858, Mil-I-45208, Mil-I-1535, NATO AQAP-1 and FAR Part 21, and added company specific requirements to them. These requirements were translated into company specific documents and sent to suppliers as quality system requirements that each individual OEM performed audits against. These slightly differing requirements sometimes took on a life of their own, causing suppliers to be constantly audited to different criteria for the same basic top level standard.

As the military, NASA and the entire aerospace industry began to look for cost savings, one of the first and most logical steps was the elimination of dual or redundant quality systems and the adoption of a single process for quality assurance.

In the early '90s, the Department of Defense (DoD) head of acquisition called for a single process initiative and asked DoD procurement officers to drop as many contract specific requirements as possible and adopt commercial practices instead. Since there was no other readily available standard in place at the time, ISO 9001:1987 (and subsequently 1994) was easily accepted as the commercial equivalent quality system.

Another thing that made the ISO 9000 series of standards appealing was the growing supplier base. As products grew in complexity, the need for cost containment and reduction became more prevalent. An increasing amount of the OEM's work was contracted out so the major OEMs were looking for a simple cost effective tool to control quality in the aerospace supplier community.

While an excellent model for a quality system, ISO 9001 (and ISO 9002) is minimalist and neither fulfills all the needs of the industry nor covers the regulatory requirements. So it had to be supplemented. Supplemental requirements were easily written into the quality programs of the OEMs, but they still caused proliferation of flow down requirements to the supplier base. This was especially true in commercial aviation where the Federal Aviation Administration (FAA) sees the supplier community as an extension of the prime manufacturer.

Development of an aerospace industry standard

The problem of duplicative and contradictory requirements was long recognized by the aerospace industry, and several attempts were made along the way to find a satisfactory solution.

U.S. aerospace companies learned the hard lesson that product and service quality as a determinant in customer selection is now on par with price, delivery and performance. The problem with flow down requirements and multiple audits had not diminished in the supplier community. With the high costs of design and development and the prevalence of joint partnerships, most companies are both suppliers and customers to each other as well as to their vast supplier networks.

In 1995 several major aerospace manufacturers, recognizing the need for uniform supplier requirements, came together under the umbrella of ASQ and created the American Aerospace Quality Group (AAQG). AAQG's original aim was to procure higher quality and lower cost materials and services faster and more reliably from a stable long-term supplier base. The first effort was in the same area where other industries such as automotive had already made significant progress--process variation reduction. One area of variation reduction targeted by the AAQG was the multiple quality system requirements and specifications imposed on the aerospace supplier community.

The AAQG first discussed the use of ISO 9001 as a standalone document. Discussions with the automotive industry about the creation and use of QS-9000 firmly planted the concept that an ISO 9001 based document tailored for aerospace was doable.

The first product of this attempt at an industry standard was published by the Society of Automotive Engineers (SAE) in October 1996 as ARD 9000. Subsequent to this interim publication, some changes occurred within the AAQG, not the least of which was that the group left the umbrella of ASQ and became an SAE Aerospace Council subcommittee. The AAQG began to see its mission as creating requirements and solutions and bringing homogeneity to the quality side of the industry. Refinement of the ARD 9000 document led to a final release of a standard called AS9000 in May of 1997.1

Why is an aerospace standard necessary? Some very key concepts--not the least of which are safe, reliable and maintainable products--are missing from ISO 9001. Aerospace industry customers (airlines, DoD, aviation public, NASA and others) expect and demand that quality systems employed by manufacturers assure that products are safe and reliable, perform as intended and operate normally when maintained in accordance with the requirements of the manufacturer.

Another caveat is the recognition that in matters pertaining to civil aviation, the FAA and civil aviation authorities of other countries have the final say on acceptable practices and procedures during the design, development, manufacture, assembly and testing of civil aerospace products.

AS9000 focuses on areas that are important to the aerospace industry. It recognizes the relationships and requirements of the regulatory agencies. It recognizes that the supplier community is an extension of its own processes and procedures and therefore must be tightly controlled to reduce variation. It focuses on processes whose sensitivity can have extreme consequences to the product's safety, reliability and performance. AS9000 added 31 new requirements in the areas of:

  • 4.2--Quality system and planning.

  • 4.5--Document and data control.

  • 4.6--Procurement.

  • 4.9--Process control.

  • 4.13--Control of nonconforming material.

Some unique items include the requirement for foreign object damage control--one of the most prevalent and potentially deadly problems in the industry. It puts emphasis on the complete supply chain for any errors may have disastrous effects. It puts emphasis on the control of processes and process planning--not just the process itself but the tooling, equipment, software and people involved. Any variations from the specified requirements can build in latent defects that cannot be tolerated in service. Finally, it increases documentation of results requirements since many times at the end of the day the only evidence that processes were correctly performed is the documented evidence created while the work was being performed.

Making the standard global

While satisfied with the result of AS9000, the AAQG recognized that all the OEMs operate globally so it was necessary to include the worldwide aerospace supplier community. To this end, ISO TC 176 (the International Organization for Standardization technical committee for quality system standards) and other sectors were approached about sector specific standards. The proposal for an international standard was rejected at the time and tabled for further study.

In 1998, ISO TC 20 (aerospace) agreed to sponsor Working Group (WG) 11 to create an ISO technical paper for quality system requirements using AS9000 as a basis along with a corresponding European document called prEN 9000-1.

WG 11 included the United States, Canada, Brazil, Mexico, England, Spain, France, Germany, China, Japan and others. All recognized the need for a specific industry standard. There was one major problem: If published by ISO TC 20, the standard would take additional time and would lose its 9000 number as did the similar effort by the automotive industry (ISO/TS 16949, the international version of QS-9000).

So the decision was made to have the harmonized document, still based on the English version of ISO 9001:1994, published by each individual country's aerospace association or standards body. In the U.S. the harmonized standard is an SAE document, AS9100.2 In Europe it is AECMA EN9100, and in Japan it is SJAC9100. Others are yet to come as 9100 numbered documents.

Harmonization added almost 55 more amplifications and requirements than there are in ISO 9001. The harmonization retains all of the areas added in AS9000 and focuses on additional criteria such as design control, configuration management and process change control. It hones in even more on process and special process control. It strengthened internal audit requirements, which can lead to a healthy continuous improvement activity if used correctly.

Some examples of the additions to AS9100 include:

  • 4.2.4--References to ISO 10007 for configuration management.

  •, maintainability and safety (in design).

  • of design verification and validation.

  • verification and validation testing.

  • documentation.

  • of production process changes.

  • of production equipment, tools and numerical control programs.

  • 4.10.6--First article inspection.

The creation of this document has also had other desirable effects. It has helped spawn the creation of the International Aerospace Quality Group (IAQG), a worldwide association of aerospace companies.

Beyond a quality system standard

The creation of IAQG led to other worldwide variation reduction projects. These include:

1. Common questionnaires for an audit on the 9100 series of standards.

2. Common or similar certification processes for the 9100 requirements by registrars.

3. Quality system standard for the repair and overhaul of aerospace products.

4. Quality system standard for distributors.

5. Common nonconformance documentation.

6. Common first article inspection process.

7. Common process approval requirements (similar to production part approval requirements, or PPAP, in automotive).

These and many other projects are all aimed at getting the supply chain focused on the quality of processes, reduction of variations, and increased reliability and safety of products.

The future

Since most of the recent work was based on ISO 9001:1994, another committee has been formed within the IAQG to update the 9100 document to coincide with the ISO 9001:2000 revisions. The expectation is that the new IAQG document will lag the release of the ISO 9001:2000 version by about 12 months and will attempt to consolidate some of the 55 specific additions.

There are problems with the proposed year 2000 version of the ISO 9001 standard for the aerospace industry. The consolidation of elements in the standard eliminated specific language deemed beneficial in describing requirements. Areas such as quality planning, process control, measuring and test equipment, and inspection have been changed enough that we have some work to do to decide the best way to make the industry expectations clear. However, the revision's focus on the product and continuous improvement is seen as a real benefit.

Looking way out into the future, I have to agree with R. Dan Reid of General Motors Corp.3 Many sectors--automotive, telecommunications, medical devices and food services, in addition to aerospace--are looking at their unique quality system requirements and want to standardize within their industries. In a way, it's a real credit to ISO TC 176 that ISO 9001 is still seen as the baseline from which to start.

Some discussions between the aerospace and automotive people indicate much common ground. Both are labor intensive and process oriented manufacturing industries. We might consider looking at our quality system requirements in terms of hardware manufacturers, designers, software and commodities. We may not want sector specific standards but instead more process/commodity specific standards that are focused around a common set of requirements, with elements added or deleted to meet the needs of the customer.


1. AS9000 Quality Systems--Aerospace--Basic Quality System Standard (Warrendale, PA: Society of Automotive Engineers Inc., 1997).

2. AS9100 Quality Systems--Aerospace--Model for Quality Assurance in Design, Development, Production, Installation and Servicing (Warrendale, PA: Society of Automotive Engineers Inc., 1999).

3. R. Dan Reid, "Why QS-9000 Was Developed and What's in Its Future," Quality Progress, April 2000, pp. 96-98.

DALE K. GORDON is director of quality and business improvement for Rolls-Royce PLC's Defense North American Business Unit in Indianapolis. He is chair of the American Aerospace Quality Group and was one of the writers of the AS9100 standard. He earned a bachelor's degree in industrial engineering from General Motors Institute (now Kettering University) in Flint, MI, and a master's degree in business administration from Butler University in Indianapolis.


Send your questions about the quality and environmental management system standards and their derivatives to standardsquestions@asq.org, including your daytime phone number. Your questions will be answered by one of Quality Progress' "Standards Outlook" expert contributors.

If you would like to comment on this article, please post your remarks on the Quality Progress Discussion Board, or e-mail them to editor@asq.org.

--FM Gallant, 02-07-2008

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