Who Watches for Airplane Safety

Who Watches for Airplane Safety?

From government to ground crew - we all bear responsibility for safety

Fred WorkleyBy Fred Workley

October 2000

Aircraft maintenance also includes the field of aircraft safety and reliability. There are over half a million persons involved with aircraft who perform many different duties and functions, but we all one thing in common - we bear responsibility, along with the government, for minimizing the risk to the public from a very large, complex, sophisticated technological enterprise called the aviation industry. The public receives a great benefit from our efforts, but they expect a zero probability of ever being involved in a major accident.
The report of the Committee on FAA Airworthiness Certification Procedures stated it this way in their June 1980 report, "Aircraft safety demands a 'forgiving' design that is tolerant of failure, careful production that is of the highest quality, and excellent maintenance that gives painstaking attention to detail throughout the life of the airplane. The rare fatal accident that involves airframe or equipment is almost without exception the result of a failure of at least two, and occasionally three, of these factors."
The challenge over the years is to foster a reliable system of technological vigilance based on suitable standards. The "system" still has to protect human life and the environment while respecting innovations, creativity, independence, and competition. All this needs to be done at reasonable costs to the public. People might say that they will pay for safety, but human nature is such that they buy the ticket with the lowest fare.

Safety surveillance
Those persons holding Certificates with Airframe and Powerplant Rating, or Authorizations like Inspection Authorization, or Designees of the Federal Aviation Administration and government personnel, generally do the task of safety surveillance. U. S. Code Title 49, Section 44702 "Issuance of Certificates" (d) "Delegation" says the Administrator may delegate to a qualified private person or an employee under the supervision of that person, a matter related to (A) The examination, testing, and inspection necessary to insure a certificate under this chapter; and (B) issuing the certificate. Being a designee is a privilege, not a right, and may be terminated or not renewed in accordance with FAA Order 8130.24. In addition, a person eligible to qualify as a designee is not, and shall not be, considered an employee of the United States Government according to FAA Order 8130.28A, Para 5. Designees are liable for their actions and are not federally protected for work performed or decisions made as a designee.

Determining aircraft safety
The industry's good safety record well evidences the process works. We can never be complacent about our jobs. Even though the public wants zero risk, we work in an industry with some inherent risk. There are essentially three elements that determine the safety of aircraft:
• Flight crew or pilot
• National Aviation System (NAS)
• Airworthiness/quality of the airplane
When we refer to the pilot we must also consider who has operational control over the aircraft, thus including airline flight operations and dispatchers.
The NAS includes the entire national aviation system that is the system of airports, airways, and air traffic control. Aircraft and airmen operate within the NAS. The Airman is an individual such as a mechanic, pilots, and parachute riggers, who work or operate aircraft or ancillary equipment. They are certificated under the FAA and are subject to Part 65 and Part 91 of the Federal Aviation Regulations. The airplane includes how it is designed, built and maintained.
In the aviation literature, we sometimes use the term 'safety factor.' The maintenance technicians can successfully do their part for safety only if provided with an aircraft of good design that is flown within the aircraft's design limitations. Thus we see that each of us is part of the safety factor.

Design and its impact on safety
Since everyone who is involved in the decision making process has an impact on safety, let's start by looking briefly at some design philosophies. With some interpretation, the regulations permit a manufacturer to demonstrate in the design of the aircraft that certain failures simply cannot occur and that, once demonstrated, the consequences to the structure and systems of such an "impossible" failure need not be taken into account. Here is where we have to be alert. However, structures designed not to fail when subjected to conditions within the design environment sometimes do fail, usually as a result of hazardous conditions outside the design environment. Those hazardous conditions may include perhaps faulty quality control during manufacturing, maintenance-induced damage, hard impact by ground servicing equipment, cargo-induced damage, or lavatory blue-water damage. The potential for structural damage outside the design environment leads to the possibility of a catastrophic effect that was never anticipated in the design. An example of this was brought to light in the recent findings on the crash of TWA 800. The original design did not take into account an explosive, flammable mixture in the ullage above the fuel in the aircraft's tanks, so the design did not include in-flight inerting of the ullage.

FAA responsibilities
When the Federal Aviation Administration was created by the Federal Aviation Act of 1958, and as amended in 1979, the United States Congress directed the agency to assure "the highest degree of safety" in flight. The FAA has set forth the Federal Aviation Regulations (FARs) and there is a process to award the manufacturer a Type Certificate that covers design and a Production Certificate through which the FAA provides surveillance over production.
Put another way, the FAA approves the design, fabrication, and production of each new aircraft. There is a dividing line between large aircraft and small aircraft. Aircraft under 12,500 lbs. have a similar, but not identical requirements as aircraft over 12,500 lbs. Once the aircraft is built and issued an Airworthiness Certificate, the FAA continues its surveillance of maintenance and compliance with the standards of the continuing airworthiness of each aircraft. This is done in part by designees of the FAA.
The FAA also approves and accepts 'data' used to support airworthiness. During the course of production and ongoing maintenance, the FAA reviews and approves the procedures and processes as offered by the manufacturer and the airlines. If violations are found at any time during the life of the aircraft the FAA has the authority to enforce its regulations through warnings, fines or revocations of certificates and licenses. In addition, the FAA approves Repair Stations that perform repair and overhaul functions on products holding Type Certificates like aircraft, engines and propellers. Repair Stations also maintain other components of the aircraft according to approved or accepted data.
The processes by which the FAA seeks to assure inherent safety or airworthiness of the aircraft is through type certification. Type certification involves assuring that the manufacturer's new design for a particular aircraft complies with the statute and all applicable rules and standards. The FAA rulemaking process establishes the regulations and technical standards that must be met by manufacturers and airlines in the course of designing, producing, operating, and maintaining the aircraft.
The FAA's engineering staff works closely with its counterparts in the industry. The FAA qualified airworthiness specialists have essentially two tasks: 1) Accomplish interpretations of existing regulations as related to matters of airworthiness and ongoing research, and 2) Make decisions related to questions of design philosophy and criteria involved in the type design of new aircraft (TCs), and supplemental type design certification (STCs) while working with applicants for TCs and STC on a day-to-day basis.
The FAA, to grant approval for an alteration of a product, will issue a Supplemental Type Certificate, permitting a major change in the type design. The STC is kept by the applicant and is then the basis for issuing or retaining airworthiness certificates to all aircraft (or engines or propellers) subsequently modified in the same way.

What's a DER?
The Designated Engineering Representatives (DERs) review the design and design process to ensure, on behalf of the FAA, that all aspects of the regulations are complied with. The FAA must be certain that each new design and design change meets all the regulations even though the FAA engineers cannot review each of the thousands of calculations, drawings, reports, and tests involved in the type certification process. Thus, the present system depends not only on the quality of the FAA staff but also on the assistance rendered by the DERs.
The advantage of the designee system is to provide an extension of the limited FAA staff. A DER who is employed by a manufacturer is paid by the manufacturer and is expected to report any problems to the FAA. Any potential conflict is checked by:
1. The designee's ethical motivation to maintain their reputation for technical integrity and professionalism
2. Recognizing their stake in the safety of the aircraft by assisting in this case, the manufacturer, to provide an airworthy, serviceable, and reliable airplane.
The DERs perform engineering reviews for the FAA that would traditionally also be performed by the company. The designees are under the supervision of the FAA staff. This usually frees the FAA staff to perform the most critical design decisions and approvals. The designee system works well and augments the capability of the FAA to review and certify the type design of aircraft. The FAA reviews the overall programs at key certification milestones. They closely monitor adherence to the original design concepts/design basis and safety standards.

More designees
A Designated Alteration Station (DAS) is an FAA-approved facility that specializes in major overhaul and repair of aircraft and is covered under 14 CFR, Part 21, Subpart M. The DAS must hold either a: domestic repair station (Part 145), air carrier/commercial operator (Part 121) or be a manufacturer with alteration authority (section 43.3j).
Organizational Designated Airworthiness Representatives (ODAR) for maintenance must be an employee of a PAH, air carrier (Part 121) or Repair Station (except prototype ODARS).
The Designated Airworthiness Representative (DAR) is an independent person that represents the Administrator. Designees involved with maintenance are involved with the continuing maintenance phase of the airplanes' life cycle.

The common thread for safety
The common thread is the constant need for quality assurance. Once the new aircraft leaves the manufacturer, the day-to-day FAA activity shifts from the manufacturing review staff of the FAA Regions with their designees to the respective District Office and its designees near where the aircraft is operated. As we have seen, it takes all the different players together with maintenance technicians with Airframe and Powerplant Certificates and those with Inspection Authorizations to keep the airplanes safe. As we well know, if airplanes aren't airworthy they don't fly and they don't make money. Safe airplanes fly longer by providing the accident-free service that everyone wants. We are in the business to 'Keep 'em Flying.'

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