Helitester, sure.
Here is a further extract from the paper (which has been extended to cover this issue) that might explain the situation as it changed over the years. The revised paper is available at:
https://www.dropbox.com/s/7bi41w1gh5...dures.pdf?dl=0
To keep these posts small enough not to drown the readers, additional extracts could be posted if considered to be worthwhile.
Differences in Terminology between Part 29 (FAA FAR 29 and EASA CS 29) – Certification, and ICAO Annexes
US FAR 29, was first produced in 1961 with the following announcement – ‘PART 29 – Airworthiness Standards: Transport Category Rotorcraft [New]: Federal Aviation Regulations to replace Part 7 of the Civil Air Regulations is a part of the Agency recodification program announced in Draft Release 61-25, published in the Federal Register on November 15, 1961 (26 F.R. 10698)’.
It is understood that it was (as is nearly always the case) developed from aeroplane text. The language, terminology, and guidance on means of compliance, have not changed substantially (in that respect) since that date.
The provision of FAR 29 occurred many years before other than rudimentary regulations for operations or heliport design existed, and before there was any notion of harmonising the codes (worldwide) to reduce the ‘manufacturers’, ‘helicopter operators’, and ‘heliport designers’ burden for exporting/importing, or operating to/from or in, other States - without having to recertify to a local code or regulation.
The ICAO Helicopter Annexes 6, 8 and 14 (the basis for
International Standards) were produced in 1989, under a similar development process. The subgroup of the Heliops Panel - which was responsible for the provision of helicopter SARPs of Annex 8, Airworthiness of Aircraft, ensured that they were sufficiently objective that compliance through existing Codes (US FAR 29, UK BCARs and other minor ones) could be achieved without substantial changes to those codes.
However, in an attempt to bring operations and heliport design up to date and relevant for the next century, new concepts, along with appropriate terminology, were developed and then woven into the three new Annexes. That decision resulted not only in the Performance Classes (a more appropriate means of capturing the variability of operational performance) but also more detailed terminology for the identification and bounding of areas on heliports and, probably more importantly at that time, helidecks.
Unfortunately, this (necessary) divergence took operations out of lock-step with the certification code language and terminology. The term ‘operating in Category A’ which had been used up to now was no longer appropriate and was replaced by ‘Operating in Performance Class 1’[1]; this was reflected in the ICAO definition of Category A in which the former ‘utilizing’ was replaced with ‘providing a capability’.
[1] Where Performance Class 1 is the application of the Category A procedure to the PC1 heliport (surfaces and slopes) and the local obstacle environment.