---
kind: "range"
citation: "14 C.F.R. §§ 135.423–135.443"
title: "14"
from: "135.423"
to: "135.443"
count: 12
url: "https://uscodex.org/cfr/14/135.423..135.443"
---

# §135.423. Maintenance, preventive maintenance, and alteration organization.

- (a) Each certificate holder that performs any of its maintenance (other than required inspections), preventive maintenance, or alterations, and each person with whom it arranges for the performance of that work, must have an organization adequate to perform the work.
- (b) Each certificate holder that performs any inspections required by its manual under [§ 135.427(b)](/cfr/14/135.427.md?p=b) (2) or (3), (in this subpart referred to as required inspections), and each person with whom it arranges for the performance of that work, must have an organization adequate to perform that work.
- (c) Each person performing required inspections in addition to other maintenance, preventive maintenance, or alterations, shall organize the performance of those functions so as to separate the required inspection functions from the other maintenance, preventive maintenance, and alteration functions. The separation shall be below the level of administrative control at which overall responsibility for the required inspection functions and other maintenance, preventive maintenance, and alteration functions is exercised.

# §135.425. Maintenance, preventive maintenance, and alteration programs.


Each certificate holder shall have an inspection program and a program covering other maintenance, preventive maintenance, and alterations, that ensures that—

- (a) Maintenance, preventive maintenance, and alterations performed by it, or by other persons, are performed under the certificate holder's manual;
- (b) Competent personnel and adequate facilities and equipment are provided for the proper performance of maintenance, preventive maintenance, and alterations; and
- (c) Each aircraft released to service is airworthy and has been properly maintained for operation under this part.

# §135.426. Contract maintenance.

- (a) A certificate holder may arrange with another person for the performance of maintenance, preventive maintenance, and alterations as authorized in [§ 135.437(a)](/cfr/14/135.437.md?p=a) only if the certificate holder has met all the requirements in this section. For purposes of this section—
  - (1) A maintenance provider is any person who performs maintenance, preventive maintenance, or an alteration for a certificate holder other than a person who is trained by and employed directly by that certificate holder.
  - (2) Covered work means any of the following:
    - (i) Essential maintenance that could result in a failure, malfunction, or defect endangering the safe operation of an aircraft if not performed properly or if improper parts or materials are used;
    - (ii) Regularly scheduled maintenance; or
    - (iii) **A required inspection item on an aircraft.**
  - (3) Directly in charge means having responsibility for covered work performed by a maintenance provider. A representative of the certificate holder directly in charge of covered work does not need to physically observe and direct each maintenance provider constantly, but must be available for consultation on matters requiring instruction or decision.
- (b) Each certificate holder must be directly in charge of all covered work done for it by a maintenance provider.
- (c) Each maintenance provider must perform all covered work in accordance with the certificate holder's maintenance manual.
- (d) No maintenance provider may perform covered work unless that work is carried out under the supervision and control of the certificate holder.
- (e) Each certificate holder who contracts for maintenance, preventive maintenance, or alterations must develop and implement policies, procedures, methods, and instructions for the accomplishment of all contracted maintenance, preventive maintenance, and alterations. These policies, procedures, methods, and instructions must provide for the maintenance, preventive maintenance, and alterations to be performed in accordance with the certificate holder's maintenance program and maintenance manual.
- (f) Each certificate holder who contracts for maintenance, preventive maintenance, or alterations must ensure that its system for the continuing analysis and surveillance of the maintenance, preventive maintenance, and alterations carried out by a maintenance provider, as required by [§ 135.431(a)](/cfr/14/135.431.md?p=a), contains procedures for oversight of all contracted covered work.
- (g) The policies, procedures, methods, and instructions required by paragraphs [(e)](#e) and [(f)](#f) of this section must be acceptable to the FAA and included in the certificate holder's maintenance manual, as required by [§ 135.427(b)(10)](/cfr/14/135.427.md?p=b-10).
- (h) Each certificate holder who contracts for maintenance, preventive maintenance, or alterations must provide to its responsible Flight Standards office, in a format acceptable to the FAA, a list that includes the name and physical (street) address, or addresses, where the work is carried out for each maintenance provider that performs work for the certificate holder, and a description of the type of maintenance, preventive maintenance, or alteration that is to be performed at each location. The list must be updated with any changes, including additions or deletions, and the updated list provided to the FAA in a format acceptable to the FAA by the last day of each calendar month.

# §135.427. Manual requirements.

- (a) Each certificate holder shall put in its manual the chart or description of the certificate holder's organization required by [§ 135.423](/cfr/14/135.423.md) and a list of persons with whom it has arranged for the performance of any of its required inspections, other maintenance, preventive maintenance, or alterations, including a general description of that work.
- (b) Each certificate holder shall put in its manual the programs required by [§ 135.425](/cfr/14/135.425.md) that must be followed in performing maintenance, preventive maintenance, and alterations of that certificate holder's aircraft, including airframes, aircraft engines, propellers, rotors, appliances, emergency equipment, and parts, and must include at least the following:
  - (1) The method of performing routine and nonroutine maintenance (other than required inspections), preventive maintenance, and alterations.
  - (2) A designation of the items of maintenance and alteration that must be inspected (required inspections) including at least those that could result in a failure, malfunction, or defect endangering the safe operation of the aircraft, if not performed properly or if improper parts or materials are used.
  - (3) The method of performing required inspections and a designation by occupational title of personnel authorized to perform each required inspection.
  - (4) Procedures for the reinspection of work performed under previous required inspection findings (buy-back procedures).
  - (5) Procedures, standards, and limits necessary for required inspections and acceptance or rejection of the items required to be inspected and for periodic inspection and calibration of precision tools, measuring devices, and test equipment.
  - (6) **Procedures to ensure that all required inspections are performed.**
  - (7) Instructions to prevent any person who performs any item of work from performing any required inspection of that work.
  - (8) Instructions and procedures to prevent any decision of an inspector regarding any required inspection from being countermanded by persons other than supervisory personnel of the inspection unit, or a person at the level of administrative control that has overall responsibility for the management of both the required inspection functions and the other maintenance, preventive maintenance, and alterations functions.
  - (9) Procedures to ensure that required inspections, other maintenance, preventive maintenance, and alterations that are not completed as a result of work interruptions are properly completed before the aircraft is released to service.
  - (10) Policies, procedures, methods, and instructions for the accomplishment of all maintenance, preventive maintenance, and alterations carried out by a maintenance provider. These policies, procedures, methods, and instructions must be acceptable to the FAA and ensure that, when followed by the maintenance provider, the maintenance, preventive maintenance, and alterations are performed in accordance with the certificate holder's maintenance program and maintenance manual.
- (c) Each certificate holder shall put in its manual a suitable system (which may include a coded system) that provides for the retention of the following information—
  - (1) A description (or reference to data acceptable to the Administrator) of the work performed;
  - (2) The name of the person performing the work if the work is performed by a person outside the organization of the certificate holder; and
  - (3) **The name or other positive identification of the individual approving the work.**
- (d) For the purposes of this part, the certificate holder must prepare that part of its manual containing maintenance information and instructions, in whole or in part, in printed form or other form, acceptable to the Administrator, that is retrievable in the English language.

# §135.429. Required inspection personnel.

- (a) No person may use any person to perform required inspections unless the person performing the inspection is appropriately certificated, properly trained, qualified, and authorized to do so.
- (b) No person may allow any person to perform a required inspection unless, at the time, the person performing that inspection is under the supervision and control of an inspection unit.
- (c) No person may perform a required inspection if that person performed the item of work required to be inspected.
- (d) In the case of rotorcraft that operate in remote areas or sites, the Administrator may approve procedures for the performance of required inspection items by a pilot when no other qualified person is available, provided—
  - (1) The pilot is employed by the certificate holder;
  - (2) It can be shown to the satisfaction of the Administrator that each pilot authorized to perform required inspections is properly trained and qualified;
  - (3) The required inspection is a result of a mechanical interruption and is not a part of a certificate holder's continuous airworthiness maintenance program;
  - (4) Each item is inspected after each flight until the item has been inspected by an appropriately certificated mechanic other than the one who originally performed the item of work; and
  - (5) Each item of work that is a required inspection item that is part of the flight control system shall be flight tested and reinspected before the aircraft is approved for return to service.
- (e) Each certificate holder shall maintain, or shall determine that each person with whom it arranges to perform its required inspections maintains, a current listing of persons who have been trained, qualified, and authorized to conduct required inspections. The persons must be identified by name, occupational title and the inspections that they are authorized to perform. The certificate holder (or person with whom it arranges to perform its required inspections) shall give written information to each person so authorized, describing the extent of that person's responsibilities, authorities, and inspectional limitations. The list shall be made available for inspection by the Administrator upon request.

# §135.431. Continuing analysis and surveillance.

- (a) Each certificate holder shall establish and maintain a system for the continuing analysis and surveillance of the performance and effectiveness of its inspection program and the program covering other maintenance, preventive maintenance, and alterations and for the correction of any deficiency in those programs, regardless of whether those programs are carried out by the certificate holder or by another person.
- (b) Whenever the Administrator finds that either or both of the programs described in [paragraph (a)](#a) of this section does not contain adequate procedures and standards to meet this part, the certificate holder shall, after notification by the Administrator, make changes in those programs requested by the Administrator.
- (c) A certificate holder may petition the Administrator to reconsider the notice to make a change in a program. The petition must be filed with the responsible Flight Standards office within 30 days after the certificate holder receives the notice. Except in the case of an emergency requiring immediate action in the interest of safety, the filing of the petition stays the notice pending a decision by the Administrator.

# §135.433. Maintenance and preventive maintenance training program.


Each certificate holder or a person performing maintenance or preventive maintenance functions for it shall have a training program to ensure that each person (including inspection personnel) who determines the adequacy of work done is fully informed about procedures and techniques and new equipment in use and is competent to perform that person's duties.


# §135.435. Certificate requirements.

- (a) Except for maintenance, preventive maintenance, alterations, and required inspections performed by a certificated repair station that is located outside the United States, each person who is directly in charge of maintenance, preventive maintenance, or alterations, and each person performing required inspections must hold an appropriate airman certificate.
- (b) For the purpose of this section, a person directly in charge is each person assigned to a position in which that person is responsible for the work of a shop or station that performs maintenance, preventive maintenance, alterations, or other functions affecting airworthiness. A person who is directly in charge need not physically observe and direct each worker constantly but must be available for consultation and decision on matters requiring instruction or decision from higher authority than that of the person performing the work.

# §135.437. Authority to perform and approve maintenance, preventive maintenance, and alterations.

- (a) A certificate holder may perform or make arrangements with other persons to perform maintenance, preventive maintenance, and alterations as provided in its maintenance manual. In addition, a certificate holder may perform these functions for another certificate holder as provided in the maintenance manual of the other certificate holder.
- (b) A certificate holder may approve any airframe, aircraft engine, propeller, rotor, or appliance for return to service after maintenance, preventive maintenance, or alterations that are performed under [paragraph (a)](#a) of this section. However, in the case of a major repair or alteration, the work must have been done in accordance with technical data approved by the Administrator.

# §135.439. Maintenance recording requirements.

- (a) Each certificate holder shall keep (using the system specified in the manual required in [§ 135.427](/cfr/14/135.427.md)) the following records for the periods specified in [paragraph (b)](#b) of this section:
  - (1) All the records necessary to show that all requirements for the issuance of an airworthiness release under [§ 135.443](/cfr/14/135.443.md) have been met.
  - (2) **Records containing the following information—**
    - (i) **The total time in service of the airframe, engine, propeller, and rotor.**
    - (ii) **The current status of life-limited parts of each airframe, engine, propeller, rotor, and appliance.**
    - (iii) The time since last overhaul of each item installed on the aircraft which are required to be overhauled on a specified time basis.
    - (iv) The identification of the current inspection status of the aircraft, including the time since the last inspections required by the inspection program under which the aircraft and its appliances are maintained.
    - (v) The current status of applicable airworthiness directives, including the date and methods of compliance, and, if the airworthiness directive involves recurring action, the time and date when the next action is required.
    - (vi) A list of current major alterations and repairs to each airframe, engine, propeller, rotor, and appliance.
- (b) Each certificate holder shall retain the records required to be kept by this section for the following periods:
  - (1) Except for the records of the last complete overhaul of each airframe, engine, propeller, rotor, and appliance the records specified in [paragraph (a)(1)](#a-1) of this section shall be retained until the work is repeated or superseded by other work or for one year after the work is performed.
  - (2) The records of the last complete overhaul of each airframe, engine, propeller, rotor, and appliance shall be retained until the work is superseded by work of equivalent scope and detail.
  - (3) The records specified in [paragraph (a)(2)](#a-2) of this section shall be retained and transferred with the aircraft at the time the aircraft is sold.
- (c) The certificate holder shall make all maintenance records required to be kept by this section available for inspection by the Administrator or any representative of the National Transportation Safety Board.

# §135.441. Transfer of maintenance records.


Each certificate holder who sells a United States registered aircraft shall transfer to the purchaser, at the time of the sale, the following records of that aircraft, in plain language form or in coded form which provides for the preservation and retrieval of information in a manner acceptable to the Administrator:

- (a) The records specified in [§ 135.439(a)(2)](/cfr/14/135.439.md?p=a-2).
- (b) The records specified in [§ 135.439(a)(1)](/cfr/14/135.439.md?p=a-1) which are not included in the records covered by [paragraph (a)](#a) of this section, except that the purchaser may allow the seller to keep physical custody of such records. However, custody of records by the seller does not relieve the purchaser of its responsibility under [§ 135.439(c)](/cfr/14/135.439.md?p=c) to make the records available for inspection by the Administrator or any representative of the National Transportation Safety Board.

# §135.443. Airworthiness release or aircraft maintenance log entry.

- (a) No certificate holder may operate an aircraft after maintenance, preventive maintenance, or alterations are performed on the aircraft unless the certificate holder prepares, or causes the person with whom the certificate holder arranges for the performance of the maintenance, preventive maintenance, or alterations, to prepare—
  - (1) An airworthiness release; or
  - (2) **An appropriate entry in the aircraft maintenance log.**
- (b) **The airworthiness release or log entry required by paragraph (a) of this section must—**
  - (1) Be prepared in accordance with the procedure in the certificate holder's manual;
  - (2) **Include a certification that—**
    - (i) The work was performed in accordance with the requirements of the certificate holder's manual;
    - (ii) All items required to be inspected were inspected by an authorized person who determined that the work was satisfactorily completed;
    - (iii) No known condition exists that would make the aircraft unairworthy; and
    - (iv) So far as the work performed is concerned, the aircraft is in condition for safe operation; and
  - (3) Be signed by an authorized certificated mechanic or repairman, except that a certificated repairman may sign the release or entry only for the work for which that person is employed and for which that person is certificated.
- (c) Notwithstanding [paragraph (b)(3)](#b-3) of this section, after maintenance, preventive maintenance, or alterations performed by a repair station located outside the United States , the airworthiness release or log entry required by [paragraph (a)](#a) of this section may be signed by a person authorized by that repair station.
- (d) Instead of restating each of the conditions of the certification required by [paragraph (b)](#b) of this section, the certificate holder may state in its manual that the signature of an authorized certificated mechanic or repairman constitutes that certification.