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HCA standard · Moving helidecks
HCA Rev 9b: Standard measuring equipment for Helideck Monitoring Systems
The earlier HCA revision for HMS and weather data. Rev 9c replaced it as the recognised benchmark for moving helidecks from 1 October 2025; this page is kept for installations approved under Rev 9b.
Implementation note: HCA Rev 9c became the recognised benchmark for moving helidecks from 1 October 2025, replacing Rev 9b. Read the announcement →
Principles
Basic reference is made to:
- UK standards for offshore helicopter landing areas published in CAP 437
- Norwegian requirements published in BSL D 5-1.8.2
The HMS shall accurately process and integrate information from sensors for helideck movement, wind and other meteorological data, located in optimum positions to provide the required information relating to the helideck.
The measuring equipment shall provide sufficient information for the operator to complete all applicable weather sections of the standard offshore weather / helideck report provided to the helicopter operators.
All information shall be numerically displayed in relevant locations on the vessel or installation for easy communication with helicopters in flight and the helicopter land base operations. The system shall facilitate transmittal of electronic data to the helicopter land base.
Accuracy of measurements
The monitoring system, including related sensors, shall be checked and verified for accuracy and correct operation in accordance with the manufacturer’s procedures following installation (see Section 8.3). A verification report shall be provided to the owner of the installation, the helicopter operator(s) and the Helideck Certification Agency.
Accuracy shall be checked and verified whenever deemed necessary, as required by the manufacturer’s procedures or every 2 years, whichever is sooner, with a verification report issued and distributed after each periodic control.
The accuracy of meteorological data other than wind speed and direction shall comply with CAP 437, published by the UK Civil Aviation Authority, or equivalent national standards. The accuracy of the data produced by the Helideck Monitoring System shall be:
| Parameter | Accuracy | Range |
|---|---|---|
| Pitch / roll / inclination | < ±0.1° RMS | 0 to 3.5° |
| Heave rate | < ±0.1 m/s RMS | 0 to 1.3 m/s |
| Helideck accelerations (MSI) | < ±0.01 m/s² RMS | 0 to 0.2 m/s² |
| Wind speed | Under 10 kt: ±1 kt; over 10 kt: 10% | |
| Wind direction (relative to magnetic north) | Better than ±10° overall | Wind speeds over 2 kt |
Wind direction accuracy depends not only on the wind sensor, but also on the accuracy of the sensor’s orientation relative to the vessel, and of the vessel heading measurement relative to magnetic north.
Certification
Requirements
Fully defined, firm requirements:
- All lighting components should be tested by an independent test house. Photometric and colour measurements should be accredited to the version of EN ISO/IEC 17025 current at the time of testing. Angular sampling: every 10° in azimuth; every 1° from 5° to 15° and every 5° from 15° to 90° in elevation.
- All intensities shall be measured to the test procedures for helideck status lights in Appendix B of CAA Paper 2008/01, using the modified-Allard method (Appendix C) to calculate effective intensity.
Other considerations
Desirable design considerations, not formal requirements:
- Lighting components and fitments should meet safety regulations for a helideck environment, such as explosion proofing (Zone 1 or 2 as appropriate) and flammability, tested by a notified body under the ATEX directive or equivalent local hazardous-area standards.
- They should meet IEC 60529 ingress protection appropriate to location, use and cleaning, expected to be at least IP66.
- Control panels for helideck lighting are not covered. Selecting and integrating them into the installation’s safety and control systems is the responsibility of the Duty Holder or engineering contractor.
- The system and its components shall comply with all regulations relevant to the installation.
Running an HMS approved under Rev 9b?
Service, upgrade or a new system
We can recommend a service routine for your system, plan an upgrade to Rev 9c, or scope a completely new system.
Helideck standards
Related standards and revisions
CAP 437
The UK CAA standard for offshore helidecks, and the international benchmark.
Read the overview →Global · currentHCA Rev 9c
The HCA standard for HMS and weather data on moving helidecks.
Read the overview →HCA Rev 9b
The previous HCA revision, kept for installations approved under it.
You are hereHCA Rev 8c
An earlier HCA revision, kept for installations approved under it.
Read the overview →Questions about Rev 9b?
Whether your installation is approved under Rev 9b or you are planning the move to Rev 9c, our team can tell you what it means for your HMS.
Useful to include
- The asset and the helideck type
- The HMS and revision installed today
- When the next verification is due
Prefer to talk it through?
Our helideck team can walk you through servicing or upgrading an HMS approved under Rev 9b.
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