CalibrationKey Takeaways
- The GCAA’s CAR-145 requires approved maintenance organisations to control and calibrate tools and test equipment to an officially recognised standard, at a frequency that ensures accuracy, and to keep calibration and traceability records.
- GCAA guidance defines the “official body” as an ISO/IEC 17025 accreditation body that is an ILAC MRA signatory, a category that includes the UAE’s EIAC.
- Aviation tooling spans several calibration disciplines, such as torque, pressure, mass, dimensional, electrical, temperature and flow. Each appears as a separate line in a laboratory’s accredited scope.
- Avionics test equipment, such as RF signal generators and pitot-static test sets, is a specialist area. Ask any provider to show the exact scope line for it before you rely on a certificate.
- Intervals should follow the manufacturer’s instructions unless your own results show a different period is appropriate.
If you run or supply an MRO or an operator’s maintenance base, calibration decides whether your test results and your records stand up to an audit. Our companion piece explains why calibration matters in aviation maintenance. This guide is about the practical side: what the UAE regulator expects, how aviation tools map onto calibration disciplines, and what to check before you choose a provider for aviation calibration.
What Does the GCAA Require for Calibrated Tooling?
The requirement sits in CAR-145, the GCAA’s regulation for approved maintenance organisations, which follows the EASA Part-145 model. Section 145.40(b) says the organisation shall ensure that tools, equipment and particularly test equipment are controlled and calibrated according to an officially recognised standard, at a frequency that ensures serviceability and accuracy, and that records of calibrations and traceability to the standard used are kept (GCAA CAR-145, Issue 09, applicable from 1 March 2023).
The accompanying guidance is specific. It asks for a procedure to inspect, service and calibrate items regularly, with labels showing when the next calibration is due. It also asks for a register of precision tooling and equipment, with a record of calibrations and the standards used. Intervals should follow the equipment manufacturer’s instructions, unless the organisation can show by results that a different period suits a particular case. “Officially recognised standard” means standards published by an official body and widely recognised in air transport as good practice, or any other standard the GCAA accepts. For this purpose, an official body means an ISO/IEC 17025 accreditation body that is a full ILAC MRA signatory, among others (GCAA guidance, above).
In practice, that points to laboratories accredited by a body such as EIAC, which is listed as an ILAC MRA signatory for calibration. Check your own approval and exposition for any additional requirement.
Which Aviation Tools Fall Under Which Calibration Discipline?
“Aviation calibration” isn’t one service. A hangar’s tooling crosses several measurement disciplines, and an accredited laboratory lists each one separately in its scope.
| Typical aviation tool | Calibration discipline |
|---|---|
| Torque wrenches and fastener tools | Torque |
| Hydraulic pressure testers and pressure gauges | Pressure |
| Weights, scales and balances | Mass |
| Calipers, micrometers, gauge blocks | Dimensional |
| Multimeters, power supplies | Electrical |
| Thermometers, ovens, temperature sensors | Temperature |
| Fuel flow meters | Flow |
Scopes are narrow by design. When we read Al Saqr Engineering’s EIAC entry on 16 October 2026, it listed pneumatic pressure gauges from -97 kPa to 2 MPa and hydraulic gauges to 280 MPa, weights from 1 mg to 20 kg, balances to 1,000 kg, torque tools of about 9 to 813 N.m, dimensional instruments mostly up to 600 mm, with steel scales to 1,000 mm and measuring tapes to 50 m, temperature equipment, diesel flow from 100 to 1,200 l/min, and electrical quantities including DC and AC voltage (AC to 500 kHz), current, resistance, capacitance, frequency, insulation resistance and power. Treat that as a reading, not a promise: the EIAC directory is the authority, and for RF, pitot-static or other avionics test equipment you should ask us, or any lab, to show the accredited line item or explain in writing how the calibration is traceable.
What Makes Avionics Test Equipment Different?
Calibrating avionics test equipment means calibrating the instruments that technicians use to check an aircraft’s systems, such as RF signal generators, spectrum analysers, power meters and air data test sets, not the aircraft’s own avionics. These instruments are measured against specialist reference standards, over frequency, power or pressure ranges that general workshop labs may not cover. Before you rely on a certificate, ask which frequency or pressure range the accredited line item covers and what uncertainty is stated for it. A certificate that doesn’t cover your operating range doesn’t demonstrate traceability where you use the instrument.
What Should an Aviation Calibration Program Include?
Beyond choosing a laboratory, the CAR-145 guidance implies four habits. Keep a register of precision tooling. Label every item with its calibration status and next due date. Store each certificate with the standards used. And review intervals against results, so that stable tools can justify longer intervals and drifting ones shorter. Our guide to how calibration intervals are decided explains the method.
Plan for failures too. If a tool is found out of tolerance, ISO 9001:2015 clause 7.1.5.2 expects you to determine whether earlier measurement results were adversely affected and to act on that (ISO 9001:2015). That is only possible if the certificate records “as found” readings. See our guide to the calibration certificate for what to look for.
Should Hangar Tooling Be Calibrated On Site or in the Laboratory?
On-site work reduces tooling downtime, while laboratory work suits reference standards and anything needing adjustment. On-site work is accredited only where the scope lists customer premises for that instrument type. Our comparison of on-site versus laboratory calibration sets out the trade-offs.
What Should You Ask Before Awarding an Aviation Calibration Contract?
- Is the laboratory accredited to ISO/IEC 17025 by a body that is an ILAC MRA signatory, such as EIAC?
- Does a scope line cover my instrument type, range and the uncertainty my procedure needs?
- Is on-site calibration accredited for that instrument, or only laboratory work?
- Does the certificate give “as found” and “as left” readings?
- What turnaround should I expect, and how are critical tools protected from downtime?
- How are out-of-tolerance results reported to me?
Our guide to ISO 17025 accredited calibration shows how to check the scope.
Frequently Asked Questions
Yes, for approved maintenance organisations. CAR-145.40(b) requires tools and test equipment to be controlled and calibrated to an officially recognised standard, with records and traceability kept.
GCAA guidance points to standards from an official body, which it describes as an ISO/IEC 17025 accreditation body that is an ILAC MRA signatory, or another standard the GCAA accepts. Check your own exposition for details.
Follow the manufacturer's instructions, unless your records show a different period suits a specific tool. Tools that are dropped, repaired or found out of tolerance need prompt attention.
Only if its accredited scope covers every discipline and range you use. Check the scope for each instrument, particularly for specialist avionics test equipment.
Next Step
To see how calibration protects aircraft maintenance, read the importance of calibration in aviation, or review our aviation calibration services. To discuss your tooling list and the scope you need, contact our team.