Suspected unapproved parts update

Suspected unapproved parts update

By Fred Workley

April 1998

Fred Workley

Suspected unapproved parts (SUPS) continue to be of concern to all those who install parts on aircraft. The Federal Aviation Administration (FAA) has just released the advanced copy of the new Advisory Circular on Detecting and Reporting Suspected Unapproved Parts. AC No. 21-29B will replace AC21-29A, dated July 16, 1992. Suspected Unapproved Parts (SUP) is a part, component, or material that is suspected of not meeting the requirements of an "approved part." Counterfeit parts are clearly unapproved parts according to the AC.

The part, according to the AC, may not be "approved" for many reasons, some of which include findings such as a different finish, color, size, incomplete or altered paperwork, and missing or improper identification per FAR Part 45. The AC points out that an "approved Part" which is used in an incorrect application should be addressed as a potential Part 43 violation. It is not considered a reportable SUP. Other Unapproved Parts, according the revised AC, are parts which have been improperly returned to service. In other words, parts maintained contrary to FAR Part 43 or Part 145.

Parts are considered SUPs if they have been maintained, rebuilt, altered, overhauled, or approved for return to service by persons or facilities not authorized to perform these services under Part 43 and /or Part 145. Parts which have been inspected and/or tested by persons not authorized to determine conformity to FAA-approved design data may be SUPs. Subsequently, these parts may also be found to be acceptable for installation with the performance of some maintenance which might be an inspection.

Also considered SUPs are parts which are shipped directly to the user by a manufacturer, supplier, or distributor, where the parts were not produced under the authority of the FAA, or in accordance with an FAA production approval (PC, APIS, PMA, or TSO) for that specific part. Parts are SUPs if they are shipped to an end user by a Production Approval Holder Ôs (PAH) supplier who does not have direct ship authority from the PAH.

Production runs that do not pass through an approved quality system are SUPs. Also considered SUPs are new parts which have passed through a PAHs quality system and are not found to conform to the approved design/data. On the other hand, parts damaged due to warranty or shipping are not considered SUPs. This damage may make these parts unserviceable, but they are not SUPs.

The AC also categorizes as SUPs parts that have been maintained, rebuilt, overhauled, altered, or approved for return to service and then found not to confirm to approved data. This would include parts produced by an owner/operator for the purpose of maintaining or altering their own product, or that have been approved for return to service and later found not to conform to approved data.

It is important for you to understand that the definition of SUPs does not include parts currently in the inspection or repair process. Thus, parts removed for maintenance are not SUPs, whether or not they have removal-record traceability. Parts in this status may be considered not acceptable for installation because they are worn out, broken, past their life limit, exceed their shelf life, or require inspection an/or repair. In other works, these parts are not presently serviceable, but not necessarily unapproved. Once maintenance has been accomplished, in accordance with Part 43 and proper maintenance records prepared, these parts may be installed on a Type Certificated aircraft by an installer.

Study the new Advisory Circular, AC 21-29B when it is available to you. It contains definitions for approved and suspected unapproved parts. There is an interesting section on the background of the SUPs issue. The AC also gives guidelines for detection of SUPs in the procurement and acceptance procedures. Reporting procedures and the instructions for FAA Form 8120-11, the SUPs Notification form, are also in this Advisory Circular.

Some problems are ongoing. Reading Advisory Circular, AC No: 20-125, dated 12/10/85, is as current today as it was then. The problem is water in aviation fuel. Water in fuel continues to contribute to aircraft incidents and accidents. Water can enter fuel at any step in the fuel handling chain. Keeping fuel free of water is called keeping it dry. The responsibility for maintaining dry fuel is a joint responsibility of the aircraft manufacturer, maintenance personnel, each person who handles the fuel from the refinery to the aircraft, and the pilot who flies the aircraft. We want to be sure that only clean and dry fuel is received into storage and delivered into an aircraft.

What are we looking for? Water occurs in aviation fuels in two forms: dissolved and free. All aviation fuels dissolve water in varying amounts depending on fuel composition and temperature. Dissolved water is not a problem, but if the temperature cools enough, the dissolved water condenses into free water.

Free water can appear either as water slugs or as entrained water. A water slug may be a pint or less, or it may be gallons in a large fuel tank. Entrained water is suspended in tiny droplets in the fuel. Individual droplets may not be visible to the eye, but fuel will appear cloudy or hazy depending on their size and density. These droplets can join together to form large drops or slugs of free water.

There are a number of ways to detect water in fuel. Entrained water can be detected by testing with a clean and dry clear glass bottle. If the fuel is acceptably dry it will appear bright with a fluorescent appearance and will not be cloudy or hazy. This is known as the "clean and bright" test. The fuel is clean when it is clear and is bright when it is dry. The container should be large enough to provide a test sample of 10 ounces or more.

The white bucket test, or stainless steel bucket test is useful when checking for water in jet fuel. Obtain an unchipped, spotlessly clean, white porcelain, enameled, or a stainless steel bucket (approximately 10-quart size). Drain 4 or 5 inches of fuel into the bucket. With a clean mixing paddle, stir the fuel into a swirling "tornado-shaped" cone; remove the paddle. As the swirling stops, contaminants and water will gather under the vortex at the center of the bucket bottom. Add several drops of household red food dye. The dye will mix with any water in the bottom of the bucket. If no water is present, the dye will settle in the bottom of the bucket.

There are also water sensitive papers available that will change color in the presence of water. Water detectors are specially made for determining free or entrained water in jet fuels.

When a chemical test is requested by a customer or local authority, the Hydro and Aqua-Glo II detector kits are recommended. The Hydro Kit chemical powder is sensitive to water concentrations down to 30 ppm (parts per million). The Aqua-Glo II Kit can detect levels of water as low as one ppm. When you are maintaining fuel systems, you should consult the manufacturers' maintenance manuals and service information, as well as airworthiness directives, for the latest requirements and information .

Particular attention should be given to checks for water and to the removal of all water from fuel tank pump drains, fuel system line drains, gascolators, strainers, and filters where drain plugs/caps are provided to check and drain an aircraft system of water. Drain plugs/caps should be removed for checks and properly reinstalled. If quick drains are not installed in places required by an airworthiness directive, recommended by the manufacturer, or at points that can be checked frequently, such information should be brought to the attention of the owner/operator for corrective action.

For airplanes equipped with bladder type fuel cells, the general condition and security of each of the cells and the installation should be inspected to ensure that the bladder has not deteriorated or loosened from its mountings. These conditions will cause wrinkles, wells, or depressions to form where water can accumulate, avoid drainage, and, eventually, find its way to an engine in flight.

Fuel tank filler openings and attachments would be checked for security, general condition, and sealing. Fuel tank caps should be checked for their general condition, plus security and proper sealing when installed. Fuel tank filler opening scupper drains should be checked for free flow to prevent both the accumulation of water in the tank and the entrance of water into the fuel system.

FAA AC No: 20-125 says that there are two reported problem areas. The first is continuing failures of the vented fuel caps installed on aircraft. Failures included warped, broken, and leaking caps. The second problem area is the fuel tank drains. Many airplanes are equipped with fuel reservoirs (separate tanks) in addition to the wing fuel tanks. On these airplanes, the fuel reservoirs, as well as the wing fuel tanks, should be checked for contamination when water or other contaminants are found in the fuel system. Refer to the appropriate owner's manual for fuel reservoir location and proper draining procedures. Additionally, manufacturer's service information can be referenced for installation of fuel tank quick drain-kits.

The best way to avoid water in fuel is to make it the responsibility of everyone in the fuel handling chain. The aircraft technician plays a major role in this chain and periodically should review shop procedures to ensure that the fuel is "clean and bright."