These definitions were compiled from various previously published aviation reference materials and sources and they represent a commonly accepted and understood meaning of the terms shared by the drafting committee. Many of these definitions were drawn from the World Airline Technical Operations Glossary (WATOG).

Accessory- A part, subassembly, assembly or component designed for use in conjunction with or to supplement another item.

A.D. (Airworthiness Directive)- Issued by the FAA to identify those products, which have been found to be in an unsafe condition, and the FAA has prescribed inspections and the conditions and limitations, if any, under which those products may continue to be operated.

Airworthiness - The condition of an item (aircraft, aircraft system or part) that meets its type design in that the item operates in a safe manner to accomplish its intended purpose.

Alternate Part Number - An alternate part number identifies a part which fully meets required functional and structural specifications, but differs either in overall dimensions, connections, installations and/or mounting provisions and may require additional parts, rework or modification to install it in a specific location as an alternate to the subject part number.

APIS (Approved Production Inspection System) - The system by which a Type Certificate holder is authorized to produce parts without a Production Certificate. (Ref. FAR Part 21, Subpart F).

Appliance - Any instrument, mechanism, equipment, part, apparatus, appurtenance, or accessory, including communications equipment, that is used or intended to be used in operating or controlling an aircraft in flight, is installed in or attached to the aircraft, and is not part of an airframe, engine, or propeller.

Approved Data - Data, which has been approved by the Administrator, FAA, and/or operator’s engineering personnel. This may include design, maintenance and quality specifications, and manufacturer’s service bulletins.

Approved Part - A part which has been approved under FAA regulations pursuant to an operator’s engineering/quality assurance specifications applicable for installation on an aircraft or accessory by virtue of it being described, identified and included in design data utilized to establish the type certification, STC, TSO, or PMA.

As Is - Any airframe, aircraft engine, propeller, appliance, component part or material, the condition of which cannot certainly and accurately be classified and therefore its status is unknown.

Assembly - An assembly may be an end item or a component of a higher-level assembly. A number of parts, subassemblies, or any combination thereof joined together to perform a specific function and which can be disassembled without destruction of designed use.

Broker - One who for a commission or free brings parties together and assists in negotiating a contract between them.

Catastrophic - A term applicable to parts, appliances, characteristics, processes, maintenance procedures, or inspections, which if failed, omitted, or non-conforming, may, considered separately and in relation to other systems, reduce safety margins, degrade performance, or cause loss of capability to conduct certain flight operations, so as to prevent the continued safe flight and landing of the aircraft. Such conditions may require use of the Emergency Procedures of the Flight Manual. The term "catastrophic" implies a requirement for extraordinary care in technical evaluation and control to assure safety of product, personnel, and the public.

Certified Manufacturer - A manufacturer who holds a production approval under CFR 14, Part 21.

Certificate of Conformance - A document which certifies conformance to a manufacturer’s process, design, specification and materials, as well as test reports or supporting data.

Certification of Airworthiness for Export - A certificate used between countries holding a bilateral agreement, to export aircraft parts. This certificate identifies the condition of an item (aircraft component/part), that it conforms to its type design, and that it is in a condition for safe operation. Examples of this are the JAA Form 1 and the FAA Form 8130-3.

Certification Document - A document/certification stating that a part conforms to an industry or U.S. specification. NOTE: Manufacturers of standard parts are not all certificated by the FAA and therefore may not be subject to FAR requirements.

Certified Part - A part, which is approved by the FAA and manufactured by a certified person (e.g. Type Certificate Holder, Supplemental Type Certificate Holder, Production Certificate Holder, TSO Holder or PMA Holder). All of these certifications for manufacture are delineated in the FAR’s. All of them are subject to an established and approved quality control system, which assures that a part in all ways, meets its designed data.

Commercial Parts - Material or parts not regulated by a government agency, and which are:

(a) Manufactured to a unique specification;
(b) Are marketed under the identification of the manufacturer, and;
(c) Subjected to no particular quality control beyond the manufacturer’s voluntary internal control system and part or material is not sensitive to safety of flight (1).

Examples are non-essential hardware such as curtain tiebacks, smoke alarms, doorknobs, etc. That are used on an aircraft but are not specifically designed for aircraft use.

Component - Any self-contained part, combination of parts, subassemblies or units, which perform a distinctive function necessary to the operation of a system.

Conformity to FAA - Approved Design Data- An assessment of whether the material, part, or product is consistent with the FAA-Approved design data.

Consumables - Generally bulk-type materials such as fuel, lubricants, cements, compounds, paints, chemicals, dyes, splices, patches, etc., called out in maintenance and repair procedures for aircraft, engines, equipment, and component end items. These materials are items used only once.

Counterfeit Certification - A document that is a false certification with intent to deceive user.

Counterfeit Part - A part that has not been approved/certified. It does not meet the tolerances, limitations, and/or specifications delineated in its design data and/or which is not made from materials specified for that design. It is something different than what the original design calls for and it is made, and/or sold, or provided, with the intent to deceive the user.

Direct Ship Authority - A statement from a certificate holder and/or approved manufacturer to a supplier authorizing direct shipment to a buyer and date of the authorization. Domestic and foreign manufacturers (Production Certificate Holders) should authorize their suppliers of parts other than standard or commercial parts, who do not hold FAA certification for manufacture, in writing to provide any direct shipping authority and establish procedures which will ensure that the shipped parts will conform to the type design and are in an airworthy condition. A copy of the letter to the supplier from the certificate holder authorizing direct shipment and date of authorization should be included with the shipping ticket, invoice, or other transfer document containing a declaration that the individual part was produced under the terms of a FAA production approval. The shipping document should also identify the product on which the part is eligible for installation, and the Production Certificate holder’s production certificate number.

Distributor - A business that does not manufacturer its own products but purchases and resells such products. Such a business usually maintains a finished goods inventory and may provide additional value added service. May be classified as "authorized" by the manufacturer assuring direct trace ability of the products.

D.O.T. - United States Department of Transportation.

Expendable Parts - A part for which no authorized repair procedure exists or for which the cost of repair would not be economical.

FAA (Federal Aviation Administration) - The Civil Aviation Authority of the United States of America.

FAA-Approved Design Data - All drawings and specifications necessary to show the configuration of the part and all information on dimensions, tolerances, material, processes, and procedures necessary to define all characteristics of an airworthy product and every part therein.

FAA Form 8130-3 - Airworthiness Approval Tag, the tag may be used by a DMIR or Production Approval Holder (PAH) to identify a part or group of parts for export approval, for identification or for conformity determinations. The form may also be used as an approval for return to service by a FAA approved repair station, or an air carrier operating under FAR 121, 127, or 135 with a continuous airworthiness maintenance program. Export Airworthiness Approval-DAR.

FAA-PMA - Parts Manufacturer Approval. FAA/PMA is issued under Subpart K of FAR Part 21 (see PMA Below).

FAA Regulated Manufacturer - One which manufacturers under FAA certification and has a FAA approved quality control system. Certifications are issued under FAR Part 21.

FAR - Federal Aviation Regulation.

FAR 121/135 Air Carriers - Air Carriers certified under Part 121 or 135 of the Federal Aviation Regulations (FARs).

FAR 145 Repair Station - A repair station certified under Part 145 of the Federal Aviation Regulations (FARs).

IPC (Illustrated Parts Catalog) - A document provided by an O.E.M. (Original Equipment Manufacturer).
(Original Equipment Manufacturer) containing all information for the identification and requisition of replaceable parts and units.
Note: ATA specification No. 100 describes the recommended content of the document.

Inspected - A used airframe, aircraft engine, propeller, appliance or component part which has been examined by means of visual or test procedures to establish conformity with acceptable data.

JAA - Joint Aviation Authority.

JAA Form 1 - The Joint Aviation Authorities form identifying an aircraft part or parts coming into the U.S. from a foreign country that holds a bilateral agreement with the United States for exchange of such parts. May also be used by U.S. certified foreign repair stations as a maintenance release. The document alone does not automatically constitute authority to install the part, component or assembly.

Life Limited Parts - A part that has an established replacement criteria, inspection interval, or related procedure specified in the Airworthiness Limitations section of the instructions for Continued Airworthiness under FAR 21.50, 23.1529, 27.1529, 31.82, 33.4, and 35.4 or under a TSOA. This definition includes rotorcraft parts and materials identified therein which are non-redundant and the failure of which would result in a condition inhibiting or precluding an auto-rotational landing.

Major - A term applicable to parts, appliances, characteristics, processes, maintenance procedures or inspections, which if failed, omitted, or non-conforming, considered separately and related to other systems, are not catastrophic but would reduce capability of the aircraft or the ability of the crew, such as through increases in workload, to cope with adverse operating conditions or subsequent failures. Such conditions may require use of the Abnormal Procedures section of the Flight Manual. The term "major" implies a requirement for careful technical evaluation and control to assure safety of product, personnel, and the public.

Manufacturer - An organization that makes components, units or piece parts for use in the construction or maintenance of aircraft and engines.

Manufacturer’s Certification - A document which certifies conformance to manufacturer’s process, design, specification and materials, as well as test reports or supporting data.

Manufacturers Prime - An organization that makes airframes, power plants or propellers.

Minor - A term applicable to parts, appliances, characteristics, processes, maintenance procedures or inspections, which if failed, omitted, or non-conforming, considered separately and in relation to other systems, would not be major or catastrophic. Such conditions ordinarily imply no departure from use of the Normal Operating Procedures portion of the Flight Manual.

Modified - An airframe, aircraft engine, propeller, appliance, or component part, which has been altered in conformity with, approved data.

Modify - To change or alter through rework and/or through the installation or removal of an item.

New - A product, assembly, accessory, component, part or material produced in conformity with approved data that is accompanied by a manufacturer’s material certification at the time of sale, and has no operating time or cycles.

New-Unused (Surplus) - A product, assembly, accessory, component, part, or material produced in conformity with approved data which has been released as surplus by the manufacturer, owner-operator, repair facility, etc.; has no operating time cycles and may be accompanied by the manufacturer’s material certification at the time of sale, and which is being sold by a person other than the original equipment manufacturer.

Non FAA Regulated Manufacturer - One, which is not regulated by the FAA. See Standard Parts and Commercial Parts.

OEM (Original Equipment Manufacturer) - The actual manufacturer of the part, and may or may not be certified under FAR Part 21.

Owner/Operator Produced Part - A part in which the owner or operator participated in controlling the design, manufacture, and/or quality of the part.

Overhaul, Time Controlled - The reconditioning in accordance with a plan under which the time histories of individual items monitored. The monitoring system is used to schedule the removal of items before they exceed a specified time limit.

Overhauled - Describes a used aircraft, airframe, aircraft engine, propeller, appliance or component part which has been overhauled using methods, techniques, and practices acceptable to the FAA and has been disassembled, cleaned, inspected, repaired as necessary, and reassembled. In addition, it has been tested in accordance with approved standards and technical data acceptable to the FAA.

Part - One or more pieces joined together which are not normally subject to disassembly without destruction of designed use.

Parts History - Phrase used to illustrate the life of a part from its origin to the end of its useful/safe value.

PC (Production Certificate) - A certificate issued by the FAA authorizing the production of a type certified or supplemental type certified product. (Ref. FAR Part 21, Subpart G.)

PMA (Parts Manufacturer) - An approval issued by the FAA to produce a modification or replacement part for sale for installation on a type certified product. (Ref. FAR Part 21, Subpart K.) All parts produced under a PMA shall be marked in accordance with FAR $ 45.15.

Product - A product is an aircraft, aircraft engine, or propeller.

PAH (Production Approval Holder) - The holder of a Type Certificate (TC), Production Certificate (PC), Parts Manufacturer Approval (PMA), or Technical Standard Order Authorized (TSOA) with respect to a particular product or part thereof.

Person - Means an individual, firm, partnership, corporation, company, association, joint stock ownership or governmental entity. It includes a trustee, receiver, assignee, or similar representative of any of them. (Reference 14 CFR Part 1.)

Production Overruns - Parts that a manufacturer produces in addition to what was authorized by the production approval holder.

Proprietary Part - A part made and marketed by a company with legal rights or exclusive title to manufacture and sale.

Prototype - A product suitable for complete functional evaluation of mechanical and electrical design and performance.

Rebuilt - An airframe, aircraft engine, propeller, appliance, or component part which has been disassembled, cleaned, inspected, repaired as necessary, reassembled and tested to the same tolerance and limits as a new item, in conformity with approved data, using either new or used parts that conform to new part tolerance and limits or to approved oversized or undersized dimensions. An authorized manufacturer can only accomplish this.

Recoverables - Items, which may be repaired to a serviceable condition one or more times before scrapping. Repair is by rework, maintenance, preventative maintenance, rebuilding or alteration, such as welding, refinishing, recharging, etc.

Repaired - An airframe, aircraft engine, propeller, assembly, appliance, accessory, component or part which has been restored to a serviceable condition in conformity with data acceptable to the FAA.

Repairable Parts - An item, which is economically repairable and can be rehabilitated to a serviceable condition. Normally these items are assemblies but also include units without component parts, which can be reworked by maintenance, preventative, rebuilding, and alteration, cleaning, refinishing, patching, etc.

Reverse Engineering - The process of disassembling, evaluating, and redesigning a product for the purpose of duplicating a product with similar characteristics.

Rotable Parts - An item that can be economically restored to a serviceable condition and, in the normal course of operations, can be repeatedly rehabilitated to a fully serviceable condition over a period approximating the life of the flight equipment to which it is related. Rotable Parts must always utilize serialization per FAR 121.380.

Single Sourcing - A method whereby a part is procured from only one supplier.

Sole Source - The only supplier capable of meeting the requirements for an item.

Specification - A clear, complete, and accurate statement of the engineering and technical requirements for a material, an item, or a service, and the procedure to be followed to determine if the requirements are met.

STC (Supplemental Type Certificate) - A certificate issued by the FAA that authorizes the alterations of a product by introducing a major change in type design, not great enough to require a new application for a type certificate. (Ref. FAR Part 21, Subpart E.).

Standard Parts - A part or material manufactured in conformity with a specification which is established by a U.S. or foreign standards organization or manufacturer; includes design, manufacturing, test and acceptance criteria and uniform identification requirements; and is made freely available by the establishing standards organization or manufacturer without proprietary limitation.

Subassembly - Two or more parts, which form a portion of an assembly or component replaceable as a whole, but having a part or parts, which are individually replaceable.

Supplier - An organization that sells aeronautical products for use by the air 7transport industry. The products may include spare parts, information and electronic data processing requirements.

Surplus - Indicates a specified quantity of an item, which is over and above that required to meet forecasted stock requirements in support of normal operations.

Surplus Dealer - A seller of parts, which are available on the market that are not sold directly from a manufacturer or a distributor or any other approved source.

TC (Type Certificate) - A certificate issued by the FAA that approves a design for an aircraft, aircraft engine, or propeller.

Time Control - See Overhaul, Time Controlled.

Traceability - The ability via documentation to track aircraft parts, processes and materials by lot or serial number to the certified source or manufacturer of standard parts.

TSO (Technical Standard Order) - An order issued by the FAA and is a minimum standard for specified articles used on civil aircraft. (Ref. FAR Part 21, Subpart O).

TSOA (Technical Standard Order Authorization) - An FAA design and production approval issued to the manufacturer of an article, which has been found to meet a specific TSO.

Unapproved Part - AA part or material intended to be installed on a type certificated product, which is not manufactured under the approval procedures in FAR 21.305. An unapproved part includes, but is not limited to:

1) "Counterfeit" or fraudulently marked parts or material;

2) Parts shipped directly to users by manufacturers, suppliers or distributors who do not themselves maintain or provide material certification and trace ability. (e.g., Production Overruns); and

3) Parts that have not been maintained or repaired in accordance with the requirements of FAR Part 43, or that have been maintained or repaired by persons not authorized to perform these functions under FAR Parts 43 and 145.

Uncertificated Manufacturer - A manufacturer of standard or commercial parts, and does not hold any production approval issued under CFR 14, Part 21.

Undocumented Part -A part of material is undocumented when documentation is not sufficient to establish:

(1) the part was manufactured in compliance with FAR Part 21.

(2) The part was previously determined to be airworthy by an appropriately rated certificate holder;

(3) The current status of a life limited part, (e.g. accumulated hours/cycles and history).

(4) That a rotorcraft line limited part or material was manufactured under FAR Part 21.

Written Certification Documents - Any document that provides evidence that parts were produced by a manufacturer who maintains an FAA approved quality control inspections system an holds an FAA certifications in accordance with any one of Subparts F, G, K, or O of FAR Part 21. The manufacturer’s FAA issued certificate number should be evidence on the document. Standard parts should have a document/ certification stating that the part conforms to an established industry or U.S. specification.