I hope this post does not sound condescending - it is not intended to be.
Thanks Hummingfrog - nothing less was expected.
Check,
For ‘offshore operations’ in a hostile environment in Europe, the Standard for Approval for (new) ‘constant wear life-jackets’, the ‘liferaft ‘, the ‘survival suit’ and the ‘integrated survival suit’ is contained in the ETSOs promulgated by EASA. These ETSOs also describe the compatibility test to ensure that the survival suit and life-jacket combination is appropriate (i.e. in simple terms, matching is required).
Aser,
Your question was understood but ‘best practice’ (don’t really like the term common practice as it implies a laissez- faire attitude) sits above the regulatory requirements and takes into account the risk assessment in a more specific environment than that considered in the regulatory risk assessment. This does lead me nicely into your comment about the ICAO 10 minute rule for floats.
One of the reasons for posting on this forum is because I have been a member of teams that have considered some of the standards that apply to operations (both for commercial and general aviation); thus it is possible for me to provide an insight into the policy and justification for rule making and rule changing where others might be constrained from speaking out.
Consider the case where an operator works entirely on the continent of Europe operating an AW139 and flying passengers in, and between, continental States. On one occasion in three years, flying is across a small body of water such as the estuary of the Rhine, Gironde or the Gulf of Corinth - would you expect that helicopter to be float equipped for that flight? A risk assessment would put the probability of some failure requiring the helicopter to ditch on the specific part of that one flight at something less than 1 in 1,000,000,000 (1 x 10-9). The exposure to the ditching event is infinitesimally small.
On the other hand, and as discussed on another thread, a helicopter engaged in offshore operations in the North Sea spends its whole working life (with few exceptions) over the water in a hostile environment - which includes being exposed to an engine failure without accountability for a proportion of the take-off and landing events. The exposure to a ditching event for the North Sea Fleet is reasonably foreseeable (in fact we have just had one).
Having established the two ends of the spectrum it is clear that any rule has to provide the arbitrary line at which the requirement of fitting of the floats becomes an ICAO Standard.
During the recent work in the ICAO HTSG, the placing of that arbitrary line was considered - particularly in the light of the recent revision to FAR/JAR/CS 29. The group considered that the fitting of floats for ‘offshore operations’ should apply - without exception (a new Standard); the fitting of floats for PC3 should remain at the gliding distance to the land; for PC1 and 2, the 10 minute rule should apply for flights over a hostile environment; but for flights over a non-hostile environment, the State should be given freedom to set the limit taking into consideration the certification status of the helicopter and the reliability of the engines.
If your particular operation is over water for a large proportion of the time (as I think it is); the risk assessment undertaken by the operator would establish: (a) the probability that the environment would become transiently hostile for some flights; and (b) even if that did not interfere with normal operations, whether it would be reasonable to expect a large number of (non-trained) passengers to be able to evacuate the helicopter if it ditched without floats fitted.
We should assume from your remarks, that the operator fulfilled our expectations.
Jim