The Basic Requirements
The Repair Station Manual/Quality Control Manual (RSM/QCM) must describe the system and the procedures used for calibrating Measuring Tools and Equipment (MTE).
The repair station must calibrate MTE per intervals, procedures, and the system described in the RSM/QCM.
All MTE must be calibrated and traceable to a standard acceptable to the Federal Aviation Administration (FAA), to include those recommended by the manufacturer, and the National Institute of Standards and Technology (NIST) or other national authority. This requires an unbroken chain of documentation from the MTE through each intermediate standard used, to the acceptable standard.
Establishing Calibration Standards
14 CFR part 145 states that tooling used to make airworthiness determinations must be calibrated to a standard acceptable to the FAA. Those standards may be derived from the NIST, a standard provided by the equipment manufacturer, or other recognized standards.
The International Bureau of Weights and Measures (BIPM) is a recognized authority that maintains a global list of National Metrology Institutes (NMI). The BIPM website lists the NMI signatory countries that participate in the International Committee for Weights and Measures (CIPM). The CIPM Mutual Recognition Arrangement (MRA) signatories are acceptable to the FAA and can be found at www.bipm.org
There are many accreditation bodies that provide third-party laboratory accreditation. The International Laboratory Accreditation Cooperation (ILAC) establishes a global network for accreditation of laboratory and testing facilities. Signatories to the ILAC MRA are in full conformance with the standards of International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 17011. ILAC MRA signatories are acceptable to the FAA and can be found at www.ilac.org. Accredited laboratories have already established traceability through the assessment and accreditation process under ISO/IEC 17025. No further documentation is required once traceability is confirmed to a recognized accredited laboratory. Additionally, for foreign equipment, the standard of the country of manufacture may be used if acceptable to the Administrator.
Calibration Procedure and Records of Calibration
The Repair Station should:
- Determine calibration status of new MTE before using the new tools.
- Have written procedures to prescribe how and when MTE is recalled for calibration.
- Ensure the calibration and tracking system includes employee-owned MTE (if applicable).
- Have written procedures to establish calibration intervals.
- Maintain a list of all calibrated equipment by name, model or part number, serial number, date of calibration, and next calibration due date.
- Keep calibration records for at least 2 years.
- Identify MTE to prevent using noncalibrated equipment in the maintenance process.
- Identify MTE to include the serial number or other identification, date of the last calibration, date calibration is due, and the name or initials of the person who performed the calibration.
- Properly identify MTE that is not used to make airworthiness determinations (e.g., “reference only”).
- Have written procedures if the repair station performs in-house calibration of its MTE.
NOTE: The repair station must not perform maintenance with the same tools or test equipment which is used as the standard for performing calibrations. During initial part 145 certification, all tools and equipment must be in place at the time of certification or rating approval for inspection by the FAA. Refer to § 145.51(b).
Use of Manufacturer’s Requirements or Equivalency
The RSM/QCM must describe the system and procedures that confirm the equipment and tools recommended by the article’s manufacturer or an equivalent acceptable to the FAA.
A repair station may substitute a manufacturer’s tooling with one that is its equivalent. If the repair station uses equivalent tooling, it is responsible for the determination of equivalency. The repair station must provide a means to the FAA that will demonstrate that the tool meets the manufacturer’s standards and specifications with all respects regarding tolerances and accuracy.
The repair station’s RSM/QCM must prescribe procedures for ensuring the equipment and tools used in the performance of maintenance are those recommended by the article’s manufacturer or an equivalent acceptable to the FAA.
NOTE: This does not include industry standard tools and equipment, such as wrenches or sockets, manufactured to a recognized industry standard.
Test and measuring equipment manufactured by a repair station as an equivalent must meet or exceed the calibration standards recommended by the manufacturer of the article being measured or tested. The special equipment or test apparatus must be capable of performing all normal tests and checking all parameters of the equipment (article) under test. The level of accuracy should be equal to or better than that recommended by the manufacturer.
The equivalency can be made based upon an evaluation of a technical data file. The repair station must establish a technical data file for each piece of equivalent tooling. The file should contain but is not limited to, data, drawings, specifications, instructions, photographs, templates, certificates, and reports. In the case of calibration equipment, the technical data file should also include data sheets attesting to the accuracy when calibration standards are necessary, as well as any special manufacturing processes that are used, including gauges and recording equipment in the controlling process.
A demonstration of the functionality of the special equipment or test apparatus may be necessary to determine its equivalency.
NOTE: Designated Engineering Representatives (DER) may not approve or determine equivalency of tooling and test equipment. Neither the FAA nor a DER may approve equipment or test apparatus. The FAA and DERs may only make a finding that the functional equivalency for special equipment or test apparatus is acceptable. It is the repair station, not the FAA, that bears the burden of demonstrating equivalency.
If the repair station uses a manufacturer’s test and measuring equipment as an equivalent for equipment recommended by an article’s manufacturer, the equipment must meet the article’s calibration standards in all respects regarding tolerances, repeatability, and accuracy. This type of calibration must be traceable to a standard acceptable to the FAA.
The basis of equivalency is the requirement that the article meets the manufacturer’s standards and specifications in all respects regarding tolerances, repeatability, and accuracy.
If calibration equipment is involved during determining equivalency, adequacy of that calibration system shall be established with documented procedures to evaluate the adequacy of that calibration equipment and its traceability to a required standard.
Control, Maintenance, and Storage of MTE
The RSM/QCM must describe the system and procedures for MTE control, maintenance, use, and storage that maintains articles.
The repair station must follow its system and procedures in the RSM/QCM for MTE control, maintenance, use, and storage that maintains articles.
The repair station must have the MTE to perform maintenance, preventive maintenance, or alterations under its repair station certificate.
The MTE must be located on the premises and under the repair station’s control when the repair station is performing work.
The repair station must have the maintenance and service manuals for all MTE the repair station uses to perform the maintenance, preventive maintenance, or alterations under its repair station certificate.
The repair station must fulfill the MTE manufacturer’s requirements for control, maintenance, use, and storage.
If the repair station does not own the equipment or does not keep the equipment at the facility, the repair station must have written procedures which prescribe:
- How the repair station obtains the equipment, such as a lease agreement or rental.
- How the repair station ensures the equipment is on the premises and under the repair station’s control when repair station personnel are performing work.
- That the repair station identifies the department responsible for calibrating leased MTE.