This is an interesting thread and the comments made all have validity given the broad experience base on show.
Of course there is always more than one way to skin a cat but I think the main point here is one of risk analysis. One needs to way up the pros and cons of any flying activity in terms of the risks associated with it versus the rewards of carrying it out.
With the above in mind and given the actual topic at hand, the actual profile flown will vary slightly as a result of all the variables experienced in any given situation. This would include things like the aircraft configuration, the met conditions, the size and orientation of the helipad, time of day, the experience of the operator etc.
Having said that, the basic approch profile shouldn't vary wildly from a 'norm'. The main consideration when conducting an approach has to be the safety of the aircraft and it's occupants. With this in mind, a conservative approach is generally accepted as being the way ahead by considering all the risks involved and then designing an approach around them.
By examining the actual incident/accident statistics associated with conducting approaches to offshore platforms, only then will you know which risks should be prioritised and which can be considered less important if not irrelevant. From there, you'll have a sound basis from which to design an appropriate approach profile.
Most of the approaches endorsed in this thread have assumed that the possibility of engine failure is the predominant risk that needs to be considered when conducting an approach. Statistically (as has been pointed out previously), this has been proven not to be the case. The window of opportunity for an engine failure just prior to LDP is extremely small and therefore should be accounted for accordingly. What is a very real possiblity are threats such as hitting obstacles, reduced power margins, loss of tail rotor authority and the like.
A good example of when we appear to get our priorities right is at night. We quite rightly treat the possiblity of mis-handling the aircraft and hitting something as a considerable risk whilst putting the possiblity of an engine failure down the priority list somewhat. We go to great pains to keep the platform and the obstacles associate with it visible at all times, to keep the aircraft under control with respect to speed and ROD etc. As an engine failure is no more likely to occur during the day, the same approach to conducting an approach by day would appear logical.
Statistically, an especially steep, or shallow, approach has inherent dangers associated with it that cannot be justified given the actual risk of an engine failure. That is not to say you shouldn't consider the possibility of an engine failure but treat it in accordance with its actual risk. A 'normal' approach profile, rather than an especially steep or shallow one, allows for an approach to be flown by the pilot which would do more to reduce the real risks associated with flying to a rig than flying a potentially more hazardous approach profile in order to account for something that will in all likelihood never occur.
Cheers,
P68
