canthover,
Yes, Category A is a set of certificating criteria.
Yes, PC1 provides engine failure accountability in all phases of flight - however a little more can be said:
The proposed revised definition of PC1 in ICAO:
sets the objective; Flight Manuals contain one, or a number of, Category A Procedures each of which provides a prescriptive method of take-off or landing compliance including a profile and data. Obstacle clearance in the climb is prescribed by the PC1 regulation and achieved using data provided by the manufacturer.
Helideck/rig procedures can never use back-up as it is too dangerous (vertical sections greater than 20ft cause problems as the pilot has a tendency to move back to keep the deck in sight).
Don’t dismiss OEI HOGE as the small twins are beginning to have this capability; Category A procedures come with a minimum helipad size; the ability to hover on one engine removes this limitation whilst still permitting PC1 (there are many (small) elevated heliports in Europe which can benefit from such a capability).
To my knowledge the A109 Power and K2 have full Category A certification in compliance with Appendix C of FAR/JAR 27 (which calls up a number of rules from FAR/JAR 29). Aircraft which were certificated before Appendix C of FAR 27 (or in compliance with the FAA AC) do not meet the airworthiness requirements. These aircraft include early marks of the AS355, the A109 and the Bo105 - some of which like the Bo105 have an STC which, when applied, can provide an equivalence that is accepted in JAR-OPS 3.
Even after the advent of Appendix C to FAR/JAR 27, some manufacturers did not apply for certification under Appendix C - the B427 comes into that category as does the MD900 - hence the B429 and the MD902. To operate in PC1 or PC2 in Europe, a helicopter has to be certificated in Category A.