Here are some answers to those earlier questions.
Question: Who can make a brand new part?
Answer: FAA Advisory Circular 21-29, Detecting And Reporting Suspected Unapproved Parts, states that there are eleven ways that a new part can be made. They are:
- Parts Manufacturer Approval (PMA)
- Technical Standard Order (TSO)
- Type Certificate (TC) or Supplemental Type Certificate (STC)
- TC with an Approved Production Inspection System (APIS)
- Production Certificate (PC)
- Bilateral Agreement
- Any method acceptable to the Administrator
- Standard Parts (nuts and bolts)
- Owner Produced Parts
- Parts produced per STC instructions as part of an STC modification.
- Fabricated by a qualified person in the course of a repair for the purpose of returning a TC product to service (which is not for sale as a separate part) under part 43.
All this sounds like bureaucratic alphabet soup, but, of all the ways listed, Owner Produced Parts is the one most misunderstood. 14 CFR section 21.303 (b) 2 makes a provision for an aircraft owner or operator to produce parts for maintaining or altering his or her own product. Under this provision, the Owner Produced Part can only be installed in an aircraft owned or operated by that person and the Owner Produced Part cannot be produced for sale to others.
Question: How is it that an air craft owner can produce a part, but a skilled maintenance technician can’t?
Answer: The responsibility follows the money. Most rules are written so the responsibility for an action is placed with the person who has the economic authority to make it happen. (The Golden Rule)
Question: How does this owner-produced rule work? Does the owner have to make the part himself?
Answer: You can find the answers in a FAA Memorandum dated August 5, 1993, in which the assistant Chief Counsel for Regulation makes the following interpretation:
• A part does not have to be solely produced by the owner to be considered an Owner Produced Part.
• The aircraft owner must participate in the manufacture of the part in at least one of five ways for it to be considered an Owner Produced Part:
- The owner provides the manufacturer of the part with the design or performance data.
- The owner provides the manufacturer of the part with the materials.
- The owner provides the manufacturer with fabrication processes or assembly methods.
- The owner provides the manufacturer of the part with quality control procedures.
- The owner personally supervises the manufacture of the new part.
As anyone can see, the discriminators for determining owner participation in a new part’s manufacture are very specific in the interpretation. Attachment (A) to the 1993 Memorandum clearly stipulates that the FAA would not construe the ordering of a part as participating in controlling the design, manufacture, or quality of a part. The key point is that the aircraft owner must participate in the part’s manufacture.
Question: If the part is owner produced, is it also a FAA approved part? Can I install it in the owner’s aircraft?
Answer: If the Owner Produced Part has all the characteristics of an approved part, is only installed on the owner’s aircraft, and is not for sale, it would be considered a FAA approved part.
There are eleven ways (as listed earlier) to produce an FAA approved part. It doesn’t matter if a part is produced under the authority of a PMA, TC, or owner produced, it must have all the characteristics of an approved part. The four characteristics of an approved part are:
1. The part must be properly designed. A properly designed part means that the part’s design is FAA approved. Depending on the complexity of the part, a FAA approved design will have the following elements:
- Drawings, specifications to define the part’s configuration and design features.
- Information on dimensions, materials, and processes necessary to define the structural strength of the product.
- Airworthiness limitations and instructions for continued airworthiness.
- Any other data necessary to allow by comparison, the determination of airworthiness of later products of the same type.
2. The part must be produced to conform to the design. A properly produced part means the part conforms to the FAA approved design. Usually a properly produced part will have the following characteristics:
- The part complies with all applicable structural requirements of its design.
- The materials and products conform to the specifications in the design.
- The part conforms to the drawings in the design.
- The manufacturing processes, construction, and assembly of the part conform to those specified in the design.
3. The part’s production should be properly documented. A properly documented part provides evidence that the part was produced under an FAA approval and memorializes the production of the part.
4. The part must be properly maintained. A properly maintained part means that the part is maintained in accordance with the rules prescribed under 14 CFR part 43.
It is relatively easy for a part to meet the requirements of the August 5, 1993, Memorandum and qualify as an Owner Produced Part. The four characteristics of an approved part are like the four legs of a table with all four legs “equally sharing” the burden of an approved part. If one leg is missing, the table will fall over. In the same way, if any of the four characteristics of an approved part is missing, then the part may not be FAA approved.
A good example is the case of the Cherokee 140 with the collapsed nose gear, mentioned and shown in the beginning of this article. The investigation determined the following:
- The original factory nose strut lower tube was pitted.
- The aircraft owner had a strut tube locally manufactured.
- A technician who knew of the part’s origin installed the strut tube.
- The strut tube failed during the first operation, resulting in $7,000+ in damages.
Question: Was the strut-tube an Owner Produced Part?
Answer: Yes, legally it was an Owner Produced Part. The aircraft owner did participate in the manufacture of the part. The owner supplied the manufacturer a design for the part. He did this by giving the manufacturer the old lower strut tube and told him to duplicate it. (Reverse engineer)
Question: Was this a FAA approved part?
Answer: No, the part was not approved because the owner did not provide the manufacturer with an approved design or its equivalent. The part was not approved because it did not conform to the material specifications prescribed in the approved design. The part failed during its first operation and didn’t last long enough for maintenance to be a factor.
Question: Did the part producer (aircraft owner) or the maintenance technician who installed the strut-tube violate the regulations? Who should be held accountable?
Answer: The answer is both. The maintenance technician violated the rule the moment that he signed the maintenance records and approved the aircraft to return to service with the knowledge the part he installed was unapproved, that is he apparently understood that the part was produced by the owner. The question he should have asked the owner was “how the part was produced so as to meet the performance rules of 14 CFR section 43.13.” The aircraft owner violated the rule when he knowingly operated the aircraft with an unapproved and undocumented part installed.
Question: This incident with the Cherokee 140 was wasteful, tragic, and dangerous. If the aircraft owner wanted to make an Owner Produced Part, what should he have done?
• The owner should have used the original manufacture’s prints and specifications (FAA approved design). It would have saved him time, money, and maybe his life.
• Reverse engineer to develop a design if you must, but do your research and submit the resulting design to the FAA for approval. Depending on the complexity of the part, reverse engineering may result in a new design. This design is the aircraft owner’s, not the original manufacturer’s, and is not automatically FAA approved. The finished part must still meet the requirements of the performance rules of section 43.13. Always contact your local FSDO for guidance.
• Produce the new part to conform to the approved design. Nothing more, nothing less. Stronger is not always better.
The aircraft owner (part’s producer) or the technician who installs the part should document or memorialize the production of the part in the aircraft records. It would be wise if the installing technician requires the part producer (aircraft owner) to memorialize the part’s production in the aircraft records with a statement worded in a similar form as figure 1 shows.
After the part producer memorializes its production, the installing technician must make a maintenance record entry indicating that he or she installed the part. After all, installing the Owner Produced Part is a maintenance function. Aircraft owners can perform preventative maintenance, but not maintenance.
Eliminating the Confusion
A maintenance technician can repair a part, but sometimes the distinction between repairing a part and producing a brand new part is hard to determine. The circumstances surrounding the repair, the part’s complexity, availability of manufacturer’s data, and industry practices all are determining factors. For a lack of a better term, I call making this determination the “Test of Reasonableness.”
Example Scenario: An aircraft wing is damaged. The damaged parts include a wing rib, a 24-inch stringer, and wing skin. The aircraft Structural Repair Manual provides material specifications for the skin and stringer. A new wing rib is purchased from the aircraft manufacturer and the technician fabricates a stringer and wing skin using the damaged parts as a template. The technician installs these parts and repairs the wing in accordance with the manufacturer’s instructions.
Is this a repair or did the technician produce a new part? The stringer and wing skin do have a part number in the parts catalog for that aircraft, so let’s consider the following facts:
- The material specifications were published and readily available.
- The parts were simple and the fabrication processes for the parts involved common tools, skills, and standard industry practices.
- Templates for the reliable reproduction of the parts were available (Design).
- The parts were incorporated into a repair in accordance with the manufacturer’s instructions.
In this case, the “Test of Reasonableness” would determine this to be considered a repair, even though the technician did fabricate a stringer and skin.