Aviation Standards

In the world of aviation maintenance, we are ruled, regulated, advised, and required to accomplish daily job functions in conjunction with something relevant and acceptable to or approved by a governing airworthiness authority. In fact, aviation rules are only part of the daily work-related regulatory and compliance requirements. A recent perusal of the Code of Federal Regulations (CFR) left no doubt in my mind that if I started at the beginning I could easily make a second career of doing nothing but reading regulations from 8:00 to 5:00 Monday through Friday for the next 30 years. Fortunately, this is not my current aspiration.

Aviation in the United States, is governed by the Federal Aviation Administration (FAA) but we also have to be in tune with some other agencies including, the Federal Communications Commission (FCC), Occupational Health and Safety Administration (OSHA), Environmental Protection Agency (EPA), Transportation Security Administration (TSA), Department of Transportation (DOT), and of course the Internal Revenue Service (IRS).

In most cases the rules tell us what we must do but are not always clear on the details. One paramount example is the following excerpt from Federal Air Regulations 43.13 regarding test equipment:
(a) Each person performing maintenance, alteration, or preventive maintenance on an aircraft, engine, propeller, or appliance shall use the methods, techniques, and practices prescribed in the current manufacturer’s maintenance manual or Instructions for Continued Airworthiness prepared by its manufacturer, or other methods, techniques, and practices acceptable to the Administrator, except as noted in §43.16. He shall use the tools, equipment, and test apparatus necessary to assure completion of the work in accordance with accepted industry practices. If special equipment or test apparatus is recommended by the manufacturer involved, he must use that equipment or apparatus or its equivalent acceptable to the Administrator.

One source of clarification of the sometimes opaque rules is the Flight Standards Information Management System (FSIMS) http://fsims.faa.gov/.
Document 8900.1 is divided into volumes containing many valuable statements. Volume 3 Chapter 15 provides a reference for the disposition of avionics test equipment:

5) Inspect all evaluation and test equipment, including precision tools and measuring devices, to ensure the following:

a) That all equipment has been tested at regular intervals and is within its required currency period

b) That test equipment calibration standards are derived from and traceable to one of the following:

  • The National Institute of Standards and Technology
  • Standards established by the test equipment manufacturer
  • If foreign manufactured test equipment, the standards of the country where it was manufactured, if approved by the Administrator

So what exactly is a standard?
According to the American Heritage Dictionary it is one of those words with several meanings and definitions including:

  • A flag, banner, or sign
  • An acknowledged measure of comparison for quantitative or qualitative value; a criterion
  • An object that under specified conditions defines, represents, or records the magnitude of a unit
  • The set proportion by weight of gold or silver to alloy metal prescribed for use in coinage
  • The commodity or commodities used to back a monetary system
  • Something, such as a practice or a product that is widely recognized or employed, especially because of its excellence
  • A degree or level of requirement, excellence, or attainment
  • A requirement of moral conduct. Often used in the plural

Other meanings in the descriptive sense include:

  • Serving as or conforming to a standard of measurement or value
  • Widely recognized or employed as a model of authority or excellence
  • Acceptable but of less than top quality: a standard grade of beef
  • Commonly used or supplied: standard car equipment
  • Synonyms: benchmark, criterion, gauge, measure

In aviation maintenance:
So just how are standards employed in the world of aviation maintenance? In reality, standards deployments are as numerous as the multiple definitions would suggest.

There are several notable standards producing agencies including:

Air Transport Association (ATA)
Founded in 1936, ATA is one of the U.S. airline trade associations. It has played a role in many government decisions regarding aviation, including the creation of the Civil Aeronautics Board and the Federal Aviation Administration, the creation of the air traffic control system, airline deregulation, and recently with the aftermath of the 9/11 attack on America. In addition it is noted for the creation of standards which are widely recognized for categorizing and defining various aspects of aviation maintenance. ATA Spec 100 contains format and content guidelines for technical manuals written by aviation manufacturers and suppliers and is used by airlines and other segments of the industry in the maintenance of their respective products. This document provides the industrywide standard for aircraft systems numbering, often referred to as ATA system or chapter numbers.

ATA is recognized by Congress, state governments, the Department of Transportation, the Federal Aviation Administration, the Department of Homeland Security, the Transportation Security Administration, the press, and the public for its representation of the industry. By working with members in the technical, legal, and political arenas, ATA continues to assist airline industry efforts to fashion policy and support measures that enhance aviation safety, security, and the vitality of our aviation system. Its employment ranks are manned by representatives from a wide range of industry disciplines, and it provides services to its constituents, including committees designed to deal with issues related to fuel, airports, engineering and maintenance, the environment, training, security, ground safety, medical issues, and international affairs.

American National Standards Institute (ANSI)
The American National Standards Institute (ANSI) has served in its capacity as administrator and coordinator of the U.S. private sector voluntary standardization system for more than 90 years. Founded in 1918 by five engineering societies and three government agencies, the Institute remains a private, nonprofit membership organization supported by a diverse constituency of private and public sector organizations. This is another organization defining the calibration criteria of many of the tools used in our profession.

A generally accepted guideline to determine if a piece of equipment requires calibration is: if a specific maintenance practice calls out to check or set a specific value (torque, pressure, voltage, etc.), the equipment used should be calibrated. When the aircraft or device was produced, it should have been tested and found to comply to a certain specification using precision equipment. When testing the in-service device to determine suitability for continued airworthiness only equipment calibrated to the same standard as those employed initially can be used to determine degradation.

Tools used only for troubleshooting may not require recertification but should be placarded accordingly. Any question regarding what should be calibrated and how, should be directed to the local airworthiness representative.

Airlines Electronic Engineering Committee (AEEC)
Many technicians in the aviation industry know of ARINC standards but may not know how they are developed and their significance. We can learn more about these areas, however, by understanding the Airlines Electronic Engineering Committee (AEEC), which develops ARINC standards. AEEC has been developing standards since its inception in 1949, 20 years after ARINC was established.

The organization is comprised of an international body of major airline operators and other airspace users who lead the development of technical standards for avionics architecture and specifications for form, fit, function, and interfaces. Avionics installed in more than 10,000 aircraft around the world are based on these ARINC standards. More than 5,000 engineers and scientists representing nearly 500 organizations participate in the AEEC standard setting process. It is standards like ARINC 429 that enable a Full Authority Digital Engine Control (FADEC) on a Pratt & Whitney engine to communicate with a Honeywell Electronic Flight Instrument System (EFIS).

In this case the standard defines a digital bus protocol including bus construction and digital word format. The advantage to our industry is obvious.

Georgia State University’s Aviation Policy Research, Aviation and Transport Studies conducted a study called “The Economic Impact of Avionics Standardization on the Airline Industry.” It estimates that the airlines save around $300 million annually from the use of ARINC standards.

International Standards Organization (ISO)
Many aviation related companies have adapted an International Standards Organization (ISO) 9000 policy to standardize their marketing, production, and support initiatives with what is known as a quality loop.

The ISO certification is an indicator that the company employs certain business standards. It also employs written procedures to be used as guidelines for all activities.

Standardization can be a great tool when the mission calls for repetitive productivity, but can become a deterrent in situations requiring creativity.

Creating a standard in and of itself is a defined process. Most of the agencies involved in standards production have their own detailed and defined methods. In general, the steps include:

  1. Concurrence from the constituency that a new standard is needed
  2. Identify the specific need and form a development committee
  3. Solicit member contributions regarding content
  4. Organizational sponsorship
  5. Submit draft of the content to the committee
  6. Revision process
  7. Submit the complete standard for committee vote

a. If approved: Present to membership
b. If rejected: Return to Step 6

Most standards in use today will include words like “should” instead of “shall” to notate compliance is an industry recognized criteria and is not necessarily mandatory.

A recent entry into standards producing groups is The National Center for Aircraft Technician Training (NCATT) http://www.ncatt.org, headquartered in Ft. Worth, TX. This organization has been established through a grant from the National Science Foundation and has allied with several aviation professional organizations.

NCATT has already established several long-needed industry programs including the aircraft electronics technician (AET) and Foreign Object Elimination/Elements (FOE) certification.

NCATT and partners are establishing industry standards for educating and certifying aircraft and aerospace technicians enabling them to be more in tune with technology of today.

Standards as applied to aviation do take on an important role but should not be confused with airworthiness regulations. In some cases the criteria defined by industry will find its way into the bureaucratic ways and means of government. Many airframe manufacturers publish “Standard Practices” in their maintenance documentation with the intent of providing technicians general guidance. In other words, rather than giving a detailed procedure to replace a hydraulic accumulator, they tell you how to torque the fittings and secure the attaching device but the methods and techniques can be applied to a wide range of operations. If this Standard Practices document is listed in the aircraft Type Certificate Data (TCD) sheet as either acceptable or approved it may be routinely used as reference for return to service.

Appropriate direction for applying “Standards” to aircraft return to service is best obtained from your local Airworthiness Agency.

Standards in the aviation maintenance field should always be synonymous with achieving excellence or becoming a benchmark. Unfortunately standardization has been applied in several areas to achieve a degree of acceptability. It can imply bringing up a lesser quality product to an industry tolerable level but also may suggest dropping high quality programs to reach the same level of mediocrity.
After all, who wants a “standard grade of beef when you can have Prime?

Jim Sparks has been in aviation for 30 years and is a licensed A&P. His career began in general aviation as a mechanic, electrician, and avionics technician. In addition to extensive hands on, Jim created and delivered educational programs for several training organizations and served as a technical representative for a manufacturer of business jets. Currently when not writing for AMT, he is the manager of aviation maintenance for a private company with a fleet including light single engine aircraft, helicopters, and several types of business jets.