Quality System

FAR 21.137 Quality System

FAR 21.137 requires production certificate holders to establish a written quality system covering design control, inspections, suppliers, audits, and records.

In Plain English

FAR 21.137 applies to manufacturers — anyone applying for or holding a production certificate (PC). It requires them to establish and document, in writing, a quality system that ensures every product and article conforms to its approved design and is safe to operate.

The quality system must include written procedures covering:

  • Design data control — only current, correct, approved data is used.
  • Document and data control for quality system records.
  • Supplier control, including a supplier-reporting process for nonconforming items.
  • Manufacturing process control to maintain conformity to the approved design.
  • Inspections and tests, including a flight test of each completed aircraft and a functional test of each engine and propeller.
  • Calibration of inspection, measuring, and test equipment, traceable to an FAA-acceptable standard.
  • Inspection/test status documentation.
  • Nonconforming product control, including segregation, disposition by authorized individuals, and rendering discarded articles unusable.
  • Corrective and preventive action.
  • Handling, storage, and packaging protections.
  • Quality records retention — at least 5 years (10 years for critical components under § 45.15(c)).
  • Internal audits with results reported to responsible managers.
  • In-service feedback to support the design approval holder.
  • Authorized release document procedures, when issued.

Why it matters: this regulation is the backbone of consistent, airworthy production. Pilots benefit because every certificated aircraft, engine, and propeller leaves the factory built to the same approved standard.

Regulation Text
14 CFR § 21.137
§ 21.137 Quality system. Each applicant for or holder of a production certificate must establish and describe in writing a quality system that ensures that each product and article conforms to its approved design and is in a condition for safe operation. This quality system must include: (a)Procedures for controlling design data and subsequent changes to ensure that only current, correct, and approved data is used. (b)Procedures for controlling quality system documents and data and subsequent changes to ensure that only current, correct, and approved documents and data are used. (c)Procedures that— (1) Ensure that each supplier-provided product, article, or service conforms to the production approval holder's requirements; and (2) Establish a supplier-reporting process for products, articles, or services that have been released from or provided by the supplier and subsequently found not to conform to the production approval holder's requirements. (d)Procedures for controlling manufacturing processes to ensure that each product and article conforms to its approved design. (e)Procedures for inspections and tests used to ensure that each product and article conforms to its approved design. These procedures must include the following, as applicable: (1) A flight test of each aircraft produced unless that aircraft will be exported as an unassembled aircraft. (2) A functional test of each aircraft engine and each propeller produced. (f)Procedures to ensure calibration and control of all inspection, measuring, and test equipment used in determining conformity of each product and article to its approved design. Each calibration standard must be traceable to a standard acceptable to the FAA. (g)Procedures for documenting the inspection and test status of products and articles supplied or manufactured to the approved design. (h)(1) Procedures to ensure that only products or articles that conform to their approved design are installed on a type-certificated product. These procedures must provide for the identification, documentation, evaluation, segregation, and disposition of nonconforming products and articles. Only authorized individuals may make disposition determinations. (2) Procedures to ensure that discarded articles are rendered unusable. (i)Procedures for implementing corrective and preventive actions to eliminate the causes of an actual or potential nonconformity to the approved design or noncompliance with the approved quality system. (j)Procedures to prevent damage and deterioration of each product and article during handling, storage, preservation, and packaging. (k)Procedures for identifying, storing, protecting, retrieving, and retaining quality records. A production approval holder must retain these records for at least 5 years for the products and articles manufactured under the approval and at least 10 years for critical components identified under § 45.15(c) of this chapter. (l)Procedures for planning, conducting, and documenting internal audits to ensure compliance with the approved quality system. The procedures must include reporting results of internal audits to the manager responsible for implementing corrective and preventive actions. (m)Procedures for receiving and processing feedback on in-service failures, malfunctions, and defects. These procedures must include a process for assisting the design approval holder to— (1) Address any in-service problem involving design changes; and (2) Determine if any changes to the Instructions for Continued Airworthiness are necessary. (n)Procedures for identifying, analyzing, and initiating appropriate corrective action for products or articles that have been released from the quality system and that do not conform to the applicable design data or quality system requirements. (o)Procedures for issuing authorized release documents for aircraft engines, propellers, and articles if the production approval holder intends to issue those documents. These procedures must provide for the selection, appointment, training, management, and removal of individuals authorized by the production approval holder to issue authorized release documents. Authorized release documents may be issued for new aircraft engines, propellers, and articles manufactured by the production approval holder; and for used aircraft engines, propellers, and articles when rebuilt, or altered, in accordance with § 43.3(j) of this chapter. When a production approval holder issues an authorized release document for the purpose of export, the production approval holder must comply with the procedures applicable to the export of new and used aircraft engines, propellers, and articles specified in § 21.331 and the responsibilities of exporters specified in § 21.335. [Docket No. FAA-2006-25877, Amdt. 21-92, 74 FR 53387, Oct. 16, 2009, as amended by Doc. No. FAA-2013-0933, Amdt. 21-98, 80 FR 59031, Oct. 1, 2015; Amdt. 21-98A, 80 FR 59031, Dec. 17, 2015]
Oral Exam Questions a DPE Might Ask
Q1What is the purpose of the quality system required of a production certificate holder?
Per FAR 21.137, the quality system must ensure that each product and article conforms to its approved design and is in a condition for safe operation, and it must be established and described in writing.
Q2How long must a production approval holder retain quality records?
Under FAR 21.137(k), records must be retained at least 5 years for products and articles manufactured under the approval, and at least 10 years for critical components identified under § 45.15(c).
Q3What inspection or test requirements apply to completed aircraft, engines, and propellers under the quality system?
FAR 21.137(e) requires a flight test of each aircraft produced (unless exported unassembled) and a functional test of each aircraft engine and propeller produced.
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FAR 21.137 — Production Certificate Quality System