We use necessary cookies to make our website work. We'd also like to use optional cookies to understand how you use it, and to help us improve it.

For more information, please read our cookie policy.

UK Civil Aviation Regulations

These are published by the CAA on our UK Regulations pages. EU Regulations and EASA Access Guides published by EASA no longer apply in the UK. Our website and publications are being reviewed to update all references. Any references to EU law and EASA Access guides should be disregarded and where applicable the equivalent UK versions referred to instead.



A new technical standard for 'Terrain Awareness & Warning Systems' fitted to helicopters operating offshore (Offshore HTAWS) has been published in Europe and North America. The upgrade will significantly enhance safety levels by increasing the warning time helicopter pilots receive of a potential impact by up to 600 per cent, affording flight crews a much better chance of avoiding accidents. Developed by a joint helicopter industry working group instigated by the UK Civil Aviation Authority (CAA), the new standard can now be adopted by regulators and applied by equipment manufacturers to their products installed in helicopter fleets globally.

In aviation, TAWS are on-board systems aimed at preventing unintentional impacts by airworthy aircraft under pilot control with the ground or sea, known in the industry as controlled flight into terrain accidents, or CFIT.

The initiative began as a response to a number of accidents involving helicopters operating in the North Sea. Subsequent analysis of the HTAWS fitted to helicopters showed that pilots were often being alerted unnecessarily, but then either too late or not at all when an impact actually happened. An earlier joint CAA-industry research project used flight data from normal operations and actual accidents to better define when accidents were likely to happen. Honeywell, the avionics manufacturer involved with the research, was then able to produce a prototype system for further testing in flight simulators, leading to the production of an interim standard which formed the basis of the comprehensive new technical standard.

The new standard has now been published by EUROCAE in Europe and RTCA in the USA and will be adopted by aviation regulators allowing manufacturers to implement the improvements in new products or as modifications to existing equipment.

Dave Howson, Research Project Manager at the CAA, said: “We are delighted to see the publication of the new standard which represents a significant milestone in rolling out this major safety benefit for helicopters flying in difficult conditions, where accidents are more likely to occur.

“This has been a great collaborative effort by regulators and the industry to achieve a real positive outcome, hopefully pointing the way to further joint aviation safety projects in the future.”

The technical standard is available from EUROCAE (ED-285) or RTCA (DO-376)