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-   -   AS332L2 Ditching off Shetland: 23rd August 2013 (https://www.pprune.org/rotorheads/522069-as332l2-ditching-off-shetland-23rd-august-2013-a.html)

Jimmy 16 31st Aug 2013 13:01

This discussion about approaches offshore is interesting in itself, but this thread is about an accident that happened on an approach to an landbase airport with "standard" approach aids, published procedures, a runway, reliable wx reports etc .

IMHO this should be considered as any other Approach / Landing Accident, fixed or rotary wing, unless of course there was a major technical issue.
(and I am not in the blame business, should anyone think so...)

HeliComparator 31st Aug 2013 13:11

Not being familiar with the S92, is the P-ILS constrained by the database only to use approaches already in the database, or can the pilot make the P-ILS to anywhere? If the latter, I suspect the CAA won't like it.

SAS, there is currently no auto-rig approach for the 225 but it is in development I believe. However, the obstacle nature of the offshore environment, and the fact that the landing point may not be in a fixed location (FPSOs swinging at anchor etc) makes me nervous about any move away from using radar. Plus, the hard bit is not the instrument approach itself, its the visual segment from the Mapt to the deck that is tricky, especially at night in marginal weather.

SASless 31st Aug 2013 13:26

HC,

What is to preclude the use of Radar in conjunction with the "Automated Approach" to ensure obstacle clearance exactly as is done now?

How many Platforms or Semi's "swing about"?

Do we not have to be concerned about mobile obstacles today....which is no different than it would be for an Automated Approach.

HeliComparator 31st Aug 2013 13:45

SAS, if the radar shows that the obstacles (and thinking in particular about the structure of the destination) is still going to be sufficiently far away at MAPt, no problem.

However for example if it transpires during the approach that the "fly by" is going to be too close, the crew have to notice, then decide whether or not to break off from the procedure and fly a manual go-around, continue manually but adjust the heading a bit, or to press on coupled and hope for the best. All a bit messy! If the world of offshore installations was a straightforward one it would be fine, but as we know it isn't. And we don't want to have 1 sort of approach for most installations and a different sort for a few.

I am not totally against the idea, its just not a universal panacea and would need to be introduced carefully and thoughtfully.

Databases for airfield approaches are fine because they tend not to move, and obstacles are controlled by safeguarding. Not so offshore, where the database reflects the notional situation extant when the database was created, but not necessarily the current situation

SASless 31st Aug 2013 14:10

If you read up on the PHI/FAA concept....it is not one size fits all.

Also...why fly a manual go around?

At DA....nothing seen....tell the AP to do the Missed Approach....and if need be fly around and repeat the Approach. Why....revert to Hands On....when you have the Auto Pilot available and capable of doing anything you tell it to do?

Instead of looking for generic ways to argue against the concept....try to figure out how to make it work....as surely there are ample place/situations it can be used.

After all....we have advanced from the Whirlwind days haven't we?

HeliComparator 31st Aug 2013 14:26

I don't know about the SK idea, but IIRC the EC / CAA idea is to make the coupled go-around straight ahead. Hence if there is an obstacle detected late, clearance becomes dependant on the RoC and its height.

I am not being obstructive, but new ideas and technologies need to be carefully considered in the real world, as well as the design office and flight test world. One problem is that the designers and testers often have little idea about the nature of the end user's world.

SASless 31st Aug 2013 14:32

Why does the approach point have to be down wind of the deck.....and not offset as it is now?

Also, with the average winds on the North Sea....what would the GS be for an Approach flown at Vy?

Could Wind Speed be one of the factors used to calculate Approach Minima?

Some days....with 30-45 knots of wind....GS would be very slow thus granting a much larger margin for the Missed Approach.

pumaboy 31st Aug 2013 14:35

About the the size of the cabins in SP familiy

I don't see the logic in reducing the number of seats in the EC225 or the L2 what is the point.

First of all the Operators/ Oil companies would not enterain it would be too expensive to operate a helicopter certified to fly with 19 seats but only fly with 14 it the operating cost's would be suicidle.:ugh:
Then it would just as easy to operate a fleet of AW139's instead and the cabin size in these sardine cans is even smaller,

With regards to the difference with the S92 and SP familiy I would rather much in an emergency escape from a SP because of the emergency exits you have a large jettison door either side larger escape windows

What do you have in a 92?

The argument is we as human beings are larger then how can you escape from the windows from the 92? :eek:

HeliComparator 31st Aug 2013 14:41

Yes I suppose there could be an argument for including wind speed as a modifying factor for the MAPtt, however the more complicated you make it, the more you create the possibility for error and or loss of SA.

Personally I think the (coupled) approach should be orientated so the the MAPt is directly downwind of the helideck, thus the last bit is flown into wind, not slightly out of wind as at present. In the old days without MFDs having everything overlayed, it could be hard to see what the ground track was relative to radar obstacles, but these days its easy.

Jimmy 16 31st Aug 2013 14:45

I have been in the North Sea helicopter business for a few years, including safety management. The saying in Norway then was that the British way of looking at safety was to protect people post accident.
The Norwegian approach was to not get the aircraft get wet in the first place.
Comments?

albatross 31st Aug 2013 14:51

This thread has certainly opened a lot of doors which need to be looked behind.
Perhaps as some have said we do need to look at our processes as a whole.

On an Offshore approach I prefer to descend and drive as I like to be stable at my DA before the offset. No descent to stop just a climb and turn to initiate in the event of a miss.

Onshore I like to be at DA slightly before the MAP.


If you are going to use a constant rate of descent to arrive exactly at your Missed Approach Point you will have to initiate your overshoot above your DA because you can't dip below a DA as you can a DH on an ILS.

Just my two cents.

Congratulations to all for efforts towards keeping this thread civil.
Some good concepts are being discussed.

212man check your PMs.

obnoxio f*ckwit 31st Aug 2013 15:12

What happened to airwave45?

He hasn't been on here for a couple of days, he added some good value to the thread.

SASless 31st Aug 2013 15:25

Pumaboy....without meaning to be condescending to your "youth".....there was a time on the North Sea that despite having 12-14 seats.....we oft times could only legally offer 1-2 seats on some runs due to the fuel requirements imposed by the CAA.

That occurred primarily because some feckwit bid the contract with the exact wrong aircraft for the length of run required.

Flying at reduced seating was not an uncommon thing in the old days due to aircraft payload limitations caused by Power limitations.

What does matter in this conversation is the Safety issues "over crowded" cabins and the lack of room for Passengers to quickly, safely, and easily gain exit from the cabin during an emergency particularly ditchings and crashes that do not afford an orderly, paced, evacuation of an up right aircraft devoid of sea water.

The Passengers have raised legitimate issues that must be addressed.

Some Pilots have also noted some issues with the Emergency exits/Door Operation on the SP family. I am sure the S-92 has some issues in the minds of the passengers.

Again, if we are to improve Safety....we have to be prepared to critically review the existing situation from every point of view.

dakarman 31st Aug 2013 15:26

With regards the removal of seats from my point of view, I see it fairly simply as the amount of volume in a space. If you remove a number of seats from any void, you not only remove the space taken up by the people but the volume and shape of the seats as well, thereby making considerably more room for those remaining to manoeuvre particularly in the event of an emergency.

In the unfortunate event of an inverted ditching - as can be witnessed in the dunker, people will move in all axes in the space available. More space (i.e. S92 cabin vs SP cabin) you would think ought to make it easier to manoeuvre therefore escape. It would be most interesting to see scientific proving of this.

I do definitely agree on window size assisting with escape particularly with the larger waistline and the doors on the SP's assisting in this although there is still the issue of the doors being opened normally and blocking the forward exits as discussed earlier in the thread despite posted warnings.

With regards the cost to operators and oil companies this would clearly be an issue however we then bring the debate back to cost vs safety - assuming of course that less seats would be safer. I was also recently informed (and I could easily be wrong here - as a bear at the back of the bus) that many contracts are based on flights not passenger numbers which would minimise the cost impact of less seats. There is also the fact that many current flights are not full - even in cases with oil companies already limiting POB to 14 in some cases.

A further 'feeling of safety' I would like to mention is access / egress with the current seating. It quite simply feels much safer (i.e. quicker and easier - therefore probably quicker to escape) to walk on and off standing nearly upright (S92) vs the bend in half and twist sideways around required in the SP class - just try getting into the forward seat of a SP in offshore gear with others already seated.

My final comment returns to comfort. Why should we have to put up with extremely uncomfortable positions getting to and from work? Why should I have to be jammed in a small space with my knees wedged against another person for a couple of hours? Are we so bad now that human comfort and dignity is ruled out to save pennies?

These are my opinions on the preference for S92 and dislike of all SP's despite potential technical benefits (EC225)

HeliComparator 31st Aug 2013 15:31

True, although given the choice I would rather put my efforts into stopping the aircraft arriving in the water in the first place, than making evacuation easier afterwards. Yes you can do both, but in reality resources are finite.

jimf671 31st Aug 2013 15:45


... I would rather put my efforts into stopping the aircraft arriving in the water in the first place ...
So would I. However, if nobody is willing to get in the back there is not much point.

SASless 31st Aug 2013 16:08

Jim....Shame! Confusing the issue with facts.....grossly unfair!

Ray Joe Czech 31st Aug 2013 17:08

I don't think it is unfair. I can't see any way of empirically working out if it is less safe having 19 in the back of a 225 than 14 when it is upside down at night in cold NE seas. There aren't enough data sets out there. Even if there were and the data said no (which, frankly, I seriously doubt it would) you still may not be able to sell that to the offshore workforce.

Finally, as we are talking about emergency egress from upside down helicopters, how did we ever arrive at a position in our industry where our passengers have rebreather equipment and the pilots don't? Oh yes, I forgot how the industry works: we'll need a couple of drowned pilots first before we can get that one approved.

pumaboy 31st Aug 2013 17:14

SAS I here what you say and you were right in the old days there was less in the back due to power restrictions.

If escape window's are an issue with the AS332L2 could EC not be approached and re-design the L2 cabin windows and make them as the EC225 cabin window's and doors thus making feel more safer for the guy's in the back, just a thought !!

Another point that needs to be addressed since you bring up safety is the HUET training :

In this thread there has been points raised when an a/c enters the water at speed a number of offshore workers would be unprepaired for a quick evacuation and there has been points raised at when the HUET enters the water it is at a slower speed but then makes it unrealistic for the people in the back, but still find it difficult to escape the HUET.

Do you not think then stricter rules need to be applied so when the HUET does enters the water it enters at a speed a little more aggresive so when it does happen in real life the people in the back would be more prepaired, after all in real life you only get one chance but in training there chances to get it right and divers to help you get out.

This maybe why offshore workers don't have the faithe in the transport that is provided to them to get them to work and nothing to do with the equipment that is being used to transport the offshore workers but are using the equipment as an argument.

I would like to hear others opinion's on this topic it is an important issue I think needs to be addressed so the guy's in the back are more comfortable travelling to work and feel safeafter all 4 people did not make it out safe in the last accident.

SAS you are 100% right safety is an issue then it needs to be addressed so everybody feels safer.l

Dma 31st Aug 2013 17:21

I agree with reducing pax load; but not with reducing available seats.

What happens when a platform has to be evacuated? Max seats available would be preferable, no?


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