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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.

CAP 1538 describes the development and validation of a suite of ‘Classic Mode’ EGPWS warning envelopes tailored for helicopters engaged in offshore commercial air transport (CAT) operations in support of oil and gas exploitation.
Data from helicopter operators’ Flight Data Monitoring (FDM) programmes has been used to define normal operations in terms of the flight parameters utilised for helicopter TAWS (HTAWS) warning envelopes, allowing existing warning envelopes to be refined to increase warning times and alert rates to be constrained. In addition, flight data from accidents and incidents has been used to develop two new warning envelopes and to estimate the likely improvements in performance that should be expected from the new suite of warning envelopes.
FDM data has been used to validate the warning envelopes for additional helicopter types and for additional helicopter operators. The effectiveness of the warning envelopes has been successfully demonstrated through flight simulator trials.
The research reported in this document has been used to produce a standard for Class A Helicopter Terrain Awareness Warning System (HTAWS) which has been published in CAP 1519.
Review comment:
Version 1.1 corrects minor typographical errors
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