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AS332L2 Ditching off Shetland: 23rd August 2013

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AS332L2 Ditching off Shetland: 23rd August 2013

Old 19th Sep 2013, 09:05
  #1801 (permalink)  
 
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Originally Posted by Hummingfrog View Post
Serf

Of course he would have had a suitable alternate such as Kirkwall, Wick or Bergen depending on the forecasts. With the following TAFs, if you are a pilot, which alternate would you have chosen?

HF
I'd have chosen Aberdeen if it was OK.
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Old 19th Sep 2013, 10:07
  #1802 (permalink)  
 
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I believe Aberdeen - Dunbar platform (Borgsten barge) - Sumburgh (refuel) - Aberdeen is a regular Total milk run.
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Old 19th Sep 2013, 10:58
  #1803 (permalink)  
 
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So fuel required at Sumburgh to make it back to Aberdeen?
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Old 19th Sep 2013, 11:13
  #1804 (permalink)  
 
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HC

In my day we could only dream of using Aberdeen as an alternate from Sumburgh coming in from the Shetland basin - it would have meant we couldn't have carried many pax!! I often used Wick which meant I could carry a full load and once actually used it (VOR/DME approach!) - in my day we got a free pen if we fuelled at Wick - they were a very friendly bunch and turn rounds were very quick. I was the only 332L who brought a full load back that day!!

HF
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Old 19th Sep 2013, 11:37
  #1805 (permalink)  
 
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Originally Posted by serf View Post
And a suitable alternate?
Originally Posted by serf View Post
I'm asking a question.
Originally Posted by serf View Post
Yes Hummingfrog I do fly and was responding to a posting which has now been deleted.
Originally Posted by serf View Post
So fuel required at Sumburgh to make it back to Aberdeen?
What exactly are you angling for, serf? Do you want someone to say that they were suffering from 'press-on-itis' and they had to land at Sumburgh because they weren't holding fuel for an alternate?

Given the forecast at Sumburgh, the crew would not have departed the Borgsten if they weren't holding sufficient fuel to fly to Sumburgh and then on to a suitable alternate. That alternate would probably have been closer than Aberdeen so, yes, they might have needed a top up at Sumburgh in order to make it to Aberdeen.
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Old 19th Sep 2013, 12:09
  #1806 (permalink)  
 
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Originally Posted by Hummingfrog
in my day we got a free pen if we fuelled at Wick - they were a very friendly bunch and turn rounds were very quick
Yup Andrew was still there last time I was in Wick, a year or so ago and dishing out the kit-kat chunkys and pens when required.
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Old 19th Sep 2013, 12:42
  #1807 (permalink)  
 
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I've been watching this thread since it started, and at the risk again of getting something hard thrown my way, some thoughts, observations and questions.

First, an observation, which may be based on wrong information, the TV reports at the time of the accident showed an approach profile that was in no way a direct approach to the airfield, if there had been any hint of fuel shortage, which I would have expected the crew to have been aware of a long time before it became critical, then a direct routing would presumably have been sought and given. On that basis, I suspect the fuel shortage is a red herring.

So, there are significant discussions about ILS/DME, or VOR/DME approached, and even NDB/DME.

In the FW world, for which all of these very old technologies were originally produced, we regularly see aircraft the size of an A380 making approaches to land in CAT3C condition, where the only visual contact is after touchdown, at 140 Kts, and needing a long strip of unobstructed runway in front of the aircraft. It happens on a regular basis, all round the world, and the number of accidents that can be attributed to autoland is very low. It was developed originally for the Trident, and they've been out of service now for a long time.

I find it hard to understand why the RW arena does not at this stage have things like GPS/DME approaches, with Radalt coupled for the landing phase, that would be capable of approaching in zero visibility, and then making an appropriate descent and flare to landing. GPS accuracy is way more precise than a localiser, or glideslope, so why has it not become a fundamental part of NS operations, with suitable equipment fitted on the rigs to provide the wide area augmentation.

If that is not accurate enough, what happened to MLS, which was supposed to be capable of more accurate resolution than ILS.
A long time ago, I got the impression that ILS was going to be phased out to free up the frequency spectrum for other broadcasting use, and replaced by a combination of MLS and GPS/DME approaches, but things seem to have gone very quiet in that area for some reason.

Last weekend, I was at a model show in Kent, and one of the things shown was a model quadcopter no more than 500mm rotorspan, it took off from a fixed point, marked by a balloon on a stick, was then flown around the area, under radio control, and then flown away from the start point, and to conclude the demonstration, the transmitter was switched off. The quad then climbed to 20 Mtrs, positioned back towards the departure point, then descended from the overhead, and landed less than 1 metre from the departure point, using electronics that are the size of a matchbox.
This was in gusty winds, so the "black box" had to work to keep things accurate, which it did.

I was already aware of this technology, and I find it slightly strange that the manufacturers and operators of commercial helicopters have not pushed very hard to get this level of technology on board, even if only in research at this stage,

So, I guess the questions I am posing are pretty simple in some respects.

Why is the NS forced to still use technology that was never designed or intended for RW operation?

Why have the capabilities that are in daily use on FW operations not finding their way down into helicopter operations. If an A380 is deemed safe to regularly land in zero visibility conditions at 140Kts, and it does not have the ability to hover, why can't a helicopter be set up to land safely in zero zero conditions using similar technologies, or better, given that MLS and GPS, along with Radalt should be capable of determining exactly where the helicopter is, laterally and vertically, and determining automatically how to get to the required point.

There will be issues with keeping the crew in the loop. and it certainly appears that there are problems already in this area, the comment about geek systems is well understood, I've worked with some of them, and if they don't have real experience at the sharp end, some of the more esoteric things that get done only serve to confuse things, so maybe some of the retired or senior NS pilots should be working with the manufacturers to develop systems that meet the needs of the task.

I don't think I'm taking an over simplistic view of things, and clearly some change would be a benefit to safety and reliability, which all involved should be happy to see.
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Old 19th Sep 2013, 13:11
  #1808 (permalink)  
 
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IS,

Did you catch the reaction by the North Sea folks to the mere mention of a Sikorksky/PHI Automated Approach Procedure that has been Certified by the FAA?

The immediate reaction was "won't work".

That is your short answer to your long question.

Landing a Jet weighing several hundred thousand pounds carrying several hundred passengers, moving at 130-140 knots onto a narrow strip of concrete without seeing the ground is seen as far simpler than developing procedures to bring a helicopter to a stabilized airspeed and height at a particular point over open water or over a runway ashore.

The Helicopter Industry is too short sighted and handicapped by a mindset that starts off finding ways "not" to be able do do something that is so innovative.

The technology exists.....making it happen is the impossible bit.


The old Sperry Helipilot system with Flight Director and a RadAlt would do an ILS Approach down to a minimum height of 50 feet AGL.....level the aircraft and track the Localizer. Yet we were limited to 200 feet DH. No effort was ever made to gain certification for lower than that by any Operator I ever flew for.

The Helicopter Industry operates to limitations imposed by their Purse....not the aircraft equipment.

Last edited by SASless; 19th Sep 2013 at 13:15.
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Old 19th Sep 2013, 14:11
  #1809 (permalink)  
 
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SAS first of all, to get it out of the way! Both SKY and EC / CAA have been working on automated rig approaches. All credit to SKY for getting there first, although I don't know how good it is in practice. Both systems will get the helicopter to the missed approach point which will probably remain at 0.75 in EASA land, or maybe squeeze down to 0.5 miles. But that is the easy bit especially with the likes of the 225's superb autopilot operation.

The tricky bit comes when the pilot has to take control and get the helicopter from the MAPt to the deck, maybe starting from only 50' above the deck (so no sight picture until the last moment).

As I think has been mentioned before, there have been no accidents during the IFR part of a rig approach, so these developments, whilst welcome, are not going to make a step change in safety since they are addressing a risk that has yet to ever become an accident.

Where SKY lag is in their minimum coupled speeds for the bit from MAPt to the deck. 50 (or is it 55, can't remember) into a typical 15 kt headwind gives 35-40 kts minimum coupled ground speed.

By contrast the 225 can be coupled to IAS down to 30 kts, say 15 kts ground speed, and ALT hold works perfectly down to zero speed. So currently I would say the 225 is by far the safer heli to make a rig approach in marginal conditions. Yes the automated approach sounds great and no doubt comes with a glossy sales brochure, but its contribution to flight safety is limited because it doesn't address the most challenging bit.
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Old 19th Sep 2013, 14:22
  #1810 (permalink)  
 
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IS I think the current situation arises due to various factors. Firstly, fancy GPS approaches are only possible with SBAS and of course its only a couple of years since EGNOS went live n Europe.

Secondly, I think we all felt that the offshore ARA was the risky bit. Onshore non-precision approaches are pretty easy by comparison, and so what could possibly go wrong?

Finally I do think EC made a mistake by not having vertical guidance built in to the FMS / Autopilot in the same way as the 92 does (even though no-one seems to use it!). Also as far as I am aware, the GPS installation is not currently certified to use SBAS (I may be out of date there, but our's certainly aren't), and I believe the standard oil and gas GPS installation is still TSO 129 and not TSO 145. Hopefully EC are progressing this now, and after this accident there will hopefully be more pressure to move to vertical guidance on an NPA.

The 225 does have fantastically precise auto hover, based on Inertial /GPS hybrid (with the emphasis on inertial) but the operational use of that has to be such that a public transport heli doesn't enter a flight regime from which recovery would be difficult in the event of a malfunction.

Edited to add the the emphasis should be on adding to safety margins, not on letting the heli "get in" on a day when it otherwise might not. We only fly to CAT 1 ILS minima, in part because if you look at how often we don't get in to Aberdeen, it is a very rare event. To go to CAT 2 requires a significant amount of additional training for a 50' reduction in DA and its just not worth it. That is presuming the destination and alternate airports even have CAT 2.

Our flight programmes are disrupted due to being unable to get in offshore, or there being no suitable alternates, or due to weather such as lightning. They are very rarely disruptions due to being unable to get in to Aberdeen because of poor vis/low cloud.

Last edited by HeliComparator; 19th Sep 2013 at 15:01.
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Old 19th Sep 2013, 15:05
  #1811 (permalink)  
 
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Originally Posted by serf View Post
So fuel required at Sumburgh to make it back to Aberdeen?
Rumour has it that the wx at Aberdeen meant that, as a destination, an alternate was required. An L2 could probably fly back from that rig with a reasonable payload, and no strong headwind (as was the case that day, direct to Aberdeen. But since an alternate was required, it could only probably do that with a fairly low payload,if at all (depending on where the alternate was). To pop into Sumburgh, nearly on the way, to gain a few extra passengers-worth of payload is obviously the sensible thing to do, and common practice.
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Old 19th Sep 2013, 15:27
  #1812 (permalink)  
 
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HC

To go to CAT 2 requires a significant amount of additional training for a 50' reduction in DA and its just not worth it.
Interesting that you need extra training to reduce the DH from 200ft to 150ft. If my brain is working today the RAF Seaking had a DH of 150ft for an ILS and PAR - this was due to the calculation of DH for various a/c which included an Aircraft Approach limitation (AAL) which was used in conjunction with the Obstacle clearance limit (OCL). This produced a DH for the Seaking of 150ft - we had no extra training for this - you just flew to that limit.

Crab may be able to confirm if this is still the case - the ILS was also manually flown as we had no coupler for approaches to airfields.

HF
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Old 19th Sep 2013, 15:40
  #1813 (permalink)  
 
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HC,

If one sets the RadAlt but to 150/100/50 feet....pick your choice....does the helicopter know the difference between CAT 1, 2, 3 etc?

I should think that fancy 225 Autopilot you slavishly praise to us constantly would quite happily drive the machine to whatever height you selected.....would it not?

Would it not hold the Airspeed you select as well?

We know it would magically track the localizer to a gnats reared as well.

Last edited by SASless; 19th Sep 2013 at 15:41.
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Old 19th Sep 2013, 16:41
  #1814 (permalink)  
 
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Interesting though discussion about potential AFCS performance to enable approaches to below Cat 1 ILS limits is, it is surely not particularly relevant to this accident's cause. Just 3 mins after the accident time, the wx at Sumburgh was not that bad - 2800m vis, scattered 200 and broken 300ft. The acft crashed 1.5miles away - almost certainly where wx was similar. Getting visual safely should not have been hard. We still come back to the progressively reducing airspeed and height below profile. There is no logic to a deliberate action of chosing this profile, surely? Why try and descend early when the airfield is pretty much at sea level anyway, and that's where you've been told the wx is ok?

Incidentally, would the approach just have been monitored horizontally on the localiser/DME, or would the crew have been monitoring an AD GPS waypoint too as back up?
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Old 19th Sep 2013, 16:45
  #1815 (permalink)  
 
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If as HC suggests....the 225 is capable of doing an auto hover....why not pick a point along the runway and do such a procedure for that point? Not talking about legality here.....just capability and feasibility.
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Old 19th Sep 2013, 17:01
  #1816 (permalink)  
 
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SASLESS

I think it all boils down to money - the 365N2 had a coupled ILS which in theory would take you down to 50ft but nobody would pay for it to be certified. If the companies can see no commercial advantage they won't pay. As HC says a 200ft DH at Aberdeen seems to be enough for 99% of Oil related flights so no need to pay for a lower DH!!

HF
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Old 19th Sep 2013, 17:27
  #1817 (permalink)  
 
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How would an approved 50" IlS minimum/reduced vis limits figure into Alternate Planning? Are there financial savings to be had there?
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Old 19th Sep 2013, 18:18
  #1818 (permalink)  
 
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HC

The Sikorsky automated Rig Approach is not so much about bad weather as about getting the aircraft to the appropriate relative position in relation to the rig / platform every time, good, bad weather day or night.

If the pilot doesn't like what he sees, just leave it alone and the aircraft will perform a safe GA. As you know, it's the GA in bad weather or at night in good weather and the transition from visual to instrument that can and has (BLUN) go wrong.

I would have thought that an automated system which delivered you stable to the same (allowing for W/V) place each time would have met with your approval, even if the box didn't say made in France by Eurocopter.
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Old 19th Sep 2013, 19:16
  #1819 (permalink)  
 
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In my day we could only dream of using Aberdeen as an alternate from Sumburgh coming in from the Shetland basin
Aberdeen-Magnus-Aberdeen direct both ways loses its appeal very quickly!
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Old 19th Sep 2013, 19:20
  #1820 (permalink)  
 
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II if you read my posts you will see that I do approve, its to that I shall not be jumping up and down shouting that its the best thing since... whatever. Yes as I said it does help, but it helps with the bit that is already quite easy these days with very precise pilot driven upper modes such as HDG, IAS and ALT and a GA button which flies the heli up and away regardless. The step from your day on the S76A, to the automatic approach systems we are talking about, would be massive. But very much less for a modern heli.
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