Thanks AGAIN JimL,
So, at least we'll have means to determine the deck edge clearing based on FM even with the possibility of forced landing in water when full PC1 can't be achived because of enviormental/economical factors.
PC2e (see Figure 5); is a development of PC2 where deck-edge clearance and a continued take-off without ditching are both taken into consideration (i.e. drop down is calculated - see the graphs in Attachment A) - this is more appropriate (but not exclusively so) to a hostile environment. It can be regarded as meeting the ICAO definition of PC1; but, (depending on how the regulation is written) the possibility of taking some exposure is provided to the pilot when the circumstances leave no other course of action. Exposure in this case is not due to performance per se but to some operational condition (simplistically, it can be regarded as the case when entry or exit path to/from the helideck is not clear of obstacles or when operating to a moving deck).
As was discussed in 6.3 above, all three cases above are influence by environmental conditions, of which wind is the most critical. Experience of offshore pilots (and modelling results) indicates that exposure ceases to be an issue when the headwind component is greater than 35kts.
Regards.
Aser