Aerospace-Military Elastomer Standards
All elastomer manufacturers and the products that they produce for the Aerospace or Military Industries must meet stringent standards. The manufacturer must meet standards for organization, regulation, quality control, and manufacturing processes. The elastomer products themselves must meet standards for materials, design, function, and technology.
The Aerospace and Military industries are economically vital, technically advanced, and internationally intertwined. Worldwide certification, sale and safe operation of aircraft and military equipment relies upon a large body of overlapping government and manufacturing regulations and standards within the industry.
Some of the major standards in use in the international Aerospace and Military industries include:
United States Military Standards
The United States Department of Defense (DOD) has evolved an extensive set of standards (MIL-STD) and specifications (MIL-SPEC) to ensure proper maintenance, repair, and operational performance (MRO) of all parts and equipment. These standards and specifications must be met by any supplier to the United States military. MIL-STD and MIL-SPEC requirements aim to maximize component interchangeability, standardization, and training. Because of the size and scope of DOD procurement, many of these standards have by default become worldwide standards.
However, the excessive proliferation of strict standards within the US military was found to have drawbacks – imposing unnecessary restrictions, increased costs, a heavy regulatory burden on the defense supply chain, and inability to quickly incorporate new technologies. Thus, the DOD began moving away from imposing its own standards. Rather, the use of industry standards is now encouraged – quality assurance standards such as ISO 9000 and ISO 9001, engineering standards such as SAE (AS and AMS series), and others. The DOD prefers now to describe the required features and performance specifications as goals, without specifying exactly how those goals should be met.
The Federal Aviation Administration regulates and oversees all aspects of civil aviation in the United States. Through its Aviation Safety (AVS) department, it has developed national Federal Aviation Regulations (FAR) which include maintenance requirements, performance standards, and practices applied to ensure the airworthiness of civil aircraft.
Many countries accept the U.S. Code of Federal Regulations (CFR) as their national code together with the Federal Aviation Regulations (FAR) prescribed by the FAA, for specific aircraft regulatory requirements.
The International Organization for Standardization (ISO) is an international non-governmental body based in Switzerland. The ISO is composed of representatives of various national standards organizations, and promotes voluntary worldwide industrial and commercial standards. Widespread ISO standards include ISO 9000 which defines quality management systems, and ISO 9001 which outlines the requirements needed to fulfill ISO 9000.
SAE International (formerly the Society of Automotive Engineers) is a professional engineering association and standards organization. SAE coordinates the development of technical standards in transportation industries based upon international industry best practices. SAE has published over 10,000 technical standards for ground vehicles and for the aerospace industry. Relevant examples of SAE standards applicable to elastomers manufactured for the Aerospace-Military industries are SAE J200 (Classification System for Rubber Materials), the AS (Aerospace Standards) series, and the AMS (Aerospace Materials Standards) series. AS 9100 is a widely adopted standardized quality management system for the aerospace industry which fully incorporates ISO 9000 while adding additional requirements for quality and safety.
ASTM International (formerly the American Society for Testing and Materials) is an international standards organization that develops and publishes voluntary industry consensus technical standards and tests for materials, products, systems, and services. ASTM standards have been adopted in many government regulations, both in the United States and internationally.
Private Aerospace Industry Standards
The aerospace industry works cooperatively within multiple frameworks to proactively develop new standards as they are needed. Many of the major aerospace manufacturers have developed their own internal or proprietary standards and testing protocols in addition to the applicable standards already existing in the industry, government, national, and international arenas. Some of those proprietary standards have evolved to become de-facto industry-wide standards. Some examples:
In addition to applicable ISO, USA, and European standards, the European conglomerate Airbus Industries has developed internal standards with the following designations: ABS (Airbus Standard), AIMS (Airbus Industries Material Specification), AITM (Airbus Industries Test Method), and AIPS (Airbus Industries Process Specification). Standards directly applicable to elastomer products include the AITM 2 series (fire and flammability testing) and the AITM 3 series (combustion and smoke toxicity testing).
Boeing, besides being one of the largest corporate consumers of external standards, has developed a set of over 110,000 internal standards. Boeing works extensively with government policymakers, regulators, procurement officials, and other entities on standards-related issues. Boeing standards directly applicable to elastomer products include BSS 7238 (testing the density of smoke generated by solid materials upon combustion) and BSS 7239 (testing method for toxic gases generation by materials upon combustion).
Bombardier has produced internal Aerospace Manuals (BM series), Materials & Process Specifications (SMP series), and Bombardier Standards. For example, the Bombardier SMP 800 standard is widely used to test surface flammability, rate of smoke generation, and smoke toxicity of elastomer products.
Overlap of standards
There is a large degree of overlap between the different sets of existing standards in the international Aerospace-Military industries. For instance, each of the standards ABD 0031, ASTM E-162, BSS 7238, FAR 25, and SMP 800 all deal with testing the fire resistance of various materials. Exactly which standard is chosen for a particular product may depend upon the identity of the manufacturer and the buyer, technical merit, and what best suits the design or manufacturing need. There is much current movement in the international Aerospace-Military industry to avoid developing duplicate standards. Instead, emphasis is being made to increase participation in existing forums such as the International Aerospace Quality Group (IAQG), which manages quality standards for the entire industry.
Interrelationship of standards
In practice, all of the internationally recognized standards are currently being used simultaneously. For example, an SAE part standard might refer to a material defined by an ASTM standard. An AIA (Aerospace Industries Association) part standard might cite an SAE coating material standard. A MIL-SPEC circuit breaker standard can cite an IEEE (Institute of Electrical and Electronics Engineers) installation test standard. The SAE, ASTM, MIL-SPEC and IEEE standards may all be referred to on a single technical drawing. Thus a supplier must be aware of the numerous standards relevant to the particular products produced.
Good Manufacturing Procedures (GMP)
All manufacturers who contribute to the Aerospace-Military supply chain must be accredited by relevant bodies as fulfilling quality management systems guidelines such as AS 9100, AS 9110, AS 9120, or equivalent standards such as the European EN 9100, EN 9110, and EN 9120.