SAR S-92 Missing Ireland

[cncpc]

I spend much of my life floating around at or below safety altitude (Navaid calibration and procedure validation). I'm struggling to understand why anyone would knowingly design a letdown which incorporates the only highpoint within a number of miles.

No one did.

[Dublinboy]

Hi probably out of my league here but been following the thread..this was so tragic and I'm like every one else just wondering how? From my limited experience ppl fixed wing .I have to ask the question if the chart provided as shown in the report shows the spot elevation as 282 at blckmo had the crew access to this prior or during the flight or just totally misread it?..it was there to be seen but maybe they had no access to it? Seems very strange ...also I think some else already mentioned it looks to me like it was intended only for the lighthouse to lighthouse route guide and It was never intended to be used outside the range that it covers

[Al-bert]

GKaplan I suppose an alert "Height, Height" doesn't do as well phonetically!

what's wrong with 'CHECK HEIGHT' 'CHECK HEIGHT' for radalt bug? Always grabbed my attention!

[oleary]

Although there are a number of quite significant contributory factors, I think the main point here is that regardless of whether a published procedure is followed or not, any low-level flight over water in IMC, at night or in marginal conditions MUST use the radar as the PRIMARY navigation aid. If a radar return cannot be positively, visually identified it MUST NOT be overflown. Besides islands there are plenty of moving marine obstacles that can easily reach 300ft or more which would not be on any map, chart or in any database. Whether radar guidance is achieved from front or back seats is a matter of procedure but it would be a designated crewmember’s responsibility to monitor and constantly verbally update the obstacle situation as seen on the radar. Although I know nothing of CHC’s procedures I would assume that this is SOP, especially for SAR.

Everyone makes mistakes, I’ve made plenty and seen very capable colleagues do the same. Most of the time some procedure, mechanism or technology prevents a tragic outcome, sadly not so on this occasion. I’m sure there is much to learn here.

For donkey's years we did exactly what Woolf describes but in two-crew cockpits (non SAR) using much more primitive equipment - because it worked.

[Search&Rescue]

Although there are a number of quite significant contributory factors, I think the main point here is that regardless of whether a published procedure is followed or not, any low-level flight over water in IMC, at night or in marginal conditions MUST use the radar as the PRIMARY navigation aid. If a radar return cannot be positively, visually identified it MUST NOT be overflown. Besides islands there are plenty of moving marine obstacles that can easily reach 300ft or more which would not be on any map, chart or in any database. Whether radar guidance is achieved from front or back seats is a matter of procedure but it would be a designated crewmember’s responsibility to monitor and constantly verbally update the obstacle situation as seen on the radar. Although I know nothing of CHC’s procedures I would assume that this is SOP, especially for SAR.

Everyone makes mistakes, I’ve made plenty and seen very capable colleagues do the same. Most of the time some procedure, mechanism or technology prevents a tragic outcome, sadly not so on this occasion. I’m sure there is much to learn here.

Well said Woolf!

[GKaplan]

GKaplan

what's wrong with 'CHECK HEIGHT' 'CHECK HEIGHT' for radalt bug? Always grabbed my attention!

Nothing wrong with "CHECK HEIGHT".

Just answering gulliBell's question about the S92 :)

[catch21]

Regarding section 3.5.8 of the report, Operator's Route Guide, I would suggest two things:

APBSS, as shown, is a two-way route between Black Rock and Blacksod helipads because leg 5, BLKSD -> BKSDB is shown as an outbound leg from Blacksod, and legs 2/6 & 1/7 (BKSDB <-> BKSDA & BKSDA <-> BLKMO) are shown as two-way legs to and from Black Rock.

Also that footnote 16 on the same page, APBSS: The Operator informed the Investigation that APBSS stands for 'Approach Blacksod South' is very much worthy of further scrutiny.

[Twenty2B]

Notwithstanding all the factors involved here, my intuition says that it's not sensible to set large obstacles as way points in an otherwise empty sea. I recall a Greek ferry disaster where prominent rocks near a port where used as a waypoint, the autopilot performing a fantastic job of guiding the vessel to that very point (with equally tragic consequences).

[MagentaL]

Why would the operator provide their S92 crews with a route between two helipads, one of which is unsuitable for an S92, and then call the route 'Approach Blacksod South'. It seems to me it was most definitely intended as an approach route to Blacksod.

[llamaman]

Regarding section 3.5.8 of the report, Operator's Route Guide, I would suggest two things:

APBSS, as shown, is a two-way route between Black Rock and Blacksod helipads because leg 5, BLKSD -> BKSDB is shown as an outbound leg from Blacksod, and legs 2/6 & 1/7 (BKSDB <-> BKSDA & BKSDA <-> BLKMO) are shown as two-way legs to and from Black Rock.

Also that footnote 16 on the same page, APBSS: The Operator informed the Investigation that APBSS stands for 'Approach Blacksod South' is very much worthy of further scrutiny.

To my mind that 'Operator's Route Guide' illustrated in the report looks very much like a VFR approach/departure chart. Not an instrument let-down procedure. Any thoughts?

[SASless]

Greek Ferries run at the same height as those Rocks......Helicopters oddly enough are supposed to operate well above the Rocks. Point taken but Instrument Approaches ashore seem to work fine if that basic rule is followed.

What would be an acceptable offset from the hard bits?

How would you choose where to locate that Offset Point?

[gulliBell]

As a starting point, what do you infer the "route" to be?


I don't know what the route was, because the CVR transcript of the approach brief wasn't in the report.

[gulliBell]

Barometric altitude bug: when the a/c descends below the preset altitude you get a "MINIMUMS, MINIMUMS" aural alert. I suppose that makes sense as the minimums used for normal instrument approaches are altitudes (DA, MDA).

When the a/c descends below the RADALT bug, you get an "ALTITUDE, ALTITUDE" aural alert.


This is the behaviour in the S92? What I'm familiar with, in a non-SAR Honeywell cockpit, when you arrive at, descend below, or climb above a preset altitude you just get a single beep and a visual warning. When you descend below a bugged radalt height you just get a light on the analog radalt display with no aural warning, or when you descend towards a set DH, which is referenced to the radalt (and not barometric altitude), you get MINIMA MINIMA aural warning, and a visual warning.

[G0ULI]

Having read all the posts and the accident report, two things seem to point towards a crew that were perhaps a bit too relaxed and complacent. Mention is made that there was very little conversation being carried on in the aircraft other than for operational reasons and secondly the pilot taking four seconds to question the instructions from the rear crew member warning of an obstruction ahead, then using the autopilot heading change to alter course.

I appreciate that scud running at 200 feet in the dark is no place to be suddenly taking manual control and flying a violent evasive manoeuvre without warning.

But I am struck by how laid back the crew were, especially considering that neither pilot had operated into that area for some time and there is no mention in the report of briefing for possible hazards on the approach or a missed approach procedure. That would surely have been mentioned even at this early stage of the investigation.

Do we end up with a fully fitted out SAR helicopter involved in CFIT due to complacency, or is there some deeper fault with the system that goes beyond having maps that showed different and insufficient details of hazards depending on the scale selected.

[gulliBell]

To my mind that 'Operator's Route Guide' illustrated in the report looks very much like a VFR approach/departure chart. Not an IMC let-down procedure. Any thoughts?

Why would it appear in the Operator S92 flight documents as a VFR approach/departure procedure if the S92 is too big to operate from Blackrock helipad? It might be a weird depiction of an IMC let-down procedure, depends on what the accompanying notes on page 2 says.

[gulliBell]

...and secondly the pilot taking four seconds to question the instructions from the rear crew member warning of an obstruction ahead, then using the autopilot heading change to alter course.


This is the classic characterisation of a "magenta pilot" (refer to a few pages earlier in that AA training video).


I appreciate that scud running at 200 feet in the dark is no place to be suddenly taking manual control and flying a violent evasive manoeuvre without warning.
.

A manually flown, immediate and affirmative evasive manoeuvre was required by either pilot in this instance the moment the rear crew obstacle warning was understood. Instead of 6+ seconds flying straight and level on an autopilot HDG coupled mode at a rock. The CRM evident in issuing the warning, and then responding to it, was too complacent. I think in Human Factors training they call this a "laissez faire" type crew.

[IRCG SMC WHITEY]

The more I look at the Operator's Route Guide, it looks like it may have been "adapted" from a CIL plate for supply/maintainence purposes.
The rocks bearing 280 degrees 1.32km, from Blackrock Lighthouse, are known as Carrickaduff, the northwesterly (145mrs long, height unknown) one is the bulkier of the two.

[cncpc]

To my mind that 'Operator's Route Guide' illustrated in the report looks very much like a VFR approach/departure chart. Not an instrument let-down procedure. Any thoughts?

Those are my thoughts. Other than it is based on an aircraft departing the Black Rock helipad.

Just above, someone in the know of the history suggests it does come from a previous operators procedure in supply maintenance flights. There was a poster on here who used to fly the B-105 into Black Rock, perhaps he can shed some light.

There was a post above challenging the point to point mostly VFR nature of this route because if an S92 can't go there, why is it in the guide for that aircraft? I've never seen a route guide that was aircraft specific, rather than company specific, but...could be.

[Mark Six]

Several posters keep insisting the Route Guide was some kind of woefully inadequate IMC letdown procedure or instrument approach plate. I believe you're giving it a status it doesn't deserve, and then criticising the designer, management, etc based on your own misinterpretation of its purpose. The IMC letdown had already been achieved prior to commencing the route shown on the diagram. No doubt the company has night/IMC overwater letdown procedures which presumably is what the crew followed prior to routing towards Blackrock. According to the report,

"The Commander's stated intent was to complete the APP1 procedure prior to turning east towards waypoint BLKMO to commence the arrival route to Blacksod Lighthouse."
The APP1 procedure was the descent to 200'.

[SASless]

We also have pondered why being at 200 feet AGL with 10 Miles to run to Blacksod, with no NVG's in very marginal weather at Night was thought safer than utilizing the full capabilities of the aircraft to complete a pre-planned, surveyed, trained, and checked IMC procedure.

That...is a very fair question to ask Management.

[cncpc]

I don't know what the route was, because the CVR transcript of the approach brief wasn't in the report.

I meant what do you infer the "route" to be that relates to that particular "plate" in the guide.

Is it not from Blackrock pad to Blacksod pad?

If so, is that not a procedure in which running into Blackrock from the west is not something that would even be contemplated?

Not arguing, I find your input very informed and helpful.

[llamaman]

Why would it appear in the Operator S92 flight documents as a VFR approach/departure procedure if the S92 is too big to operate from Blackrock helipad? It might be a weird depiction of an IMC let-down procedure, depends on what the accompanying notes on page 2 says.

It doesn't look like it is designed for the purpose of landing at Blackrock. Merely that Blackrock is the start/end point for the procedure.

Whether the procedure the crew elected to fly was appropriate will be assessed in the full report. Likewise, the genesis of such a procedure will be analysed.

Tragic though this incident was I believe this an opportunity to take a holistic view of the way SAR Ops are tasked and conducted. For a long time the status quo has been for an 'RCC' (or equivalent) to receive a request for assistance and task an asset accordingly. In my opinion this can sometimes be an overly simplistic process with tasking decisions often being made by non-aviators. Clearly, the aircraft captain has a veto on any tasking but human nature makes it very hard to say no; all rescue organisations by their very nature are 'can do'. The methodology of SAR tasking has not changed in decades. It is rooted in an era when 'jobs' were generally more simplistic in their nature (range, weather conditions etc.). In this case a crew on the East coast of Ireland were woken in the early hours of the morning to top-cover a rescue in the Atlantic via a let-down to an austere refuel site in poor conditions.

If this hadn't been a scramble I wander how much time the average crew would have put in to planning and briefing a similar profile? My point is that a lot is expected of SAR crews and this is an opportunity (in Eire at least) to improve safety margins.

[[email protected]]

Is it not from Blackrock pad to Blacksod pad? No, I think that it is a legacy procedure going from an obvious local feature (Blackrock) to the intended LS of Blacksod. There is no reason to think of Blackrock as a LS or helipad because it is no use in any way shape or form to a SAR helicopter - the idea that it is a route from one LS to another I think is nonsense.

Trouble is, in the middle of the night when you are tasked to the area and need to get to the refuel site, it is too easy to pull out the company letdown chart and follow it without thinking about what you are actually doing.

I think there are a lot of questions to be asked about the company procedures in Ireland and I would be surprised if in UK Bristow and HMCG are not taking a long look at their procedures to ensure they are squeaky clean and appropriate to the terrain.

[SASless]

Earilier I posted very similar thoughts re a Bottom Up review of not only this flight but the entire Irish Helicopter SAR Operation much as was done a few years back for the U.K. Offshore Oil Helicopter Industry following a crash.

From a very distant perspective.....it is overdue.

A great deal is asked of SAR crews and they deserve all the help they can get in making their work as safe as possible considering the conditions in which they so often find themselves flying!

UK SAR might take this opportunity to ask themselves some hard questions as well.

[IRCG SMC WHITEY]

Question: Report says R116 was on a heading 120 degrees magnetic, what would the course over the ground have been taking tailwind correction into account ??

[Democritus]

......Just above, someone in the know of the history suggests it does come from a previous operators procedure in supply maintenance flights. There was a poster on here who used to fly the B-105 into Black Rock, perhaps he can shed some light.........

Sorry, my experience there was 45 years ago so is not really valid as so much will have changed in the years since then. From my distant memory I had a line check on all Irish lighthouse pads and then got on with it. It was single pilot day only VMC work.

[oleary]

To my mind that 'Operator's Route Guide' illustrated in the report looks very much like a VFR approach/departure chart. Not an instrument let-down procedure. Any thoughts?

When I flew for Okanagan (precursor company to CHC) in the 70's and 80's we had proper company IFR approach charts that met regulatory standards. I very much doubt this was ever intended to be an IFR approach.

[Al-bert]

Lamaman For a long time the status quo has been for an 'RCC' (or equivalent) to receive a request for assistance and task an asset accordingly. In my opinion this can sometimes be an overly simplistic process with tasking decisions often being made by non-aviators.

WRONG! Back in the not so distant past UK RCC Controllers were all aviators, of one brevet or another and sometimes with RAF MRT experience too.

[llamaman]

Lamaman

WRONG! Back in the not so distant past UK RCC Controllers were all aviators, of one brevet or another and sometimes with RAF MRT experience too.

Al-bert. I'm aware of that (albeit UK-specific). If you note the tense you'll see that my comment regarding non-aviators refers to the present and not the past.

[Al-bert]

I'm sorry Llamaman, that wasn't clear to me. I assumed the second sentence was linked to the first - for a long time the status quo etc! My bad, as magenta kids no doubt say :ok:

[cncpc]

There is no reason to think of Blackrock as a LS or helipad because it is no use in any way shape or form to a SAR helicopter - the idea that it is a route from one LS to another I think is nonsense.


I don't think it's nonsense and some others on here don't. I don't know how describing what is almost perfectly obvious as "nonsense" contributes to understanding this accident, particularly when a theory of mistaking a VFR transit route for a "letdown" procedure does contribute to that understanding.

The accident report does contribute as well. It says that this approach was conducted in two phases. An APP1 letdown to 200 feet. Then proceeding at 200 feet to hook into the first point in the Blacksod South Arrival. Believing that it is "nonsense" that the "route" is a VFR transit route based on a departure off Blackrock sets the table for this tragedy.

Both helipads at each terminus of the route carry special pink circle markings that other waypoints do not. They carry their elevation, which other waypoints do not.

Blackrock Light is in fact an LS. The Blacksod lightkeeper is responsible for the Blackrock Light. He has to go there from Blacksod pad to Blackrock pad. Right now, that is the situation. It was the situation at the time of this accident and for a long time before. Because helicopter is the only way to connect between the two, it hardly nonsense that there is a route between them and that is published in a route guide.

A helicopter landed there to bring in the AAIU investigators in this incident.

If some people, including very experienced helicopter pilots on this forum, can't agree that this is just a VFR transit layout for pad to pad flights, then it isn't difficult to see how this crew, unfamiliar with the area, and in the dark of night and weather, didn't understand that this route meant for a helicopter taking off from Blackrock and bringing maintenance people back to Blacksod, or vice versa, can't be patched into at 200 feet.

Maybe someone said "Hey, this isn't an IFR approach" and someone else said "Nonsense".

[Red5ive]

Earilier I posted very similar thoughts re a Bottom Up review of not only this flight but the entire Irish Helicopter SAR Operation much as was done a few years back for the U.K. Offshore Oil Helicopter Industry following a crash.



So far nothing from the minister (https://twitter.com/Shane_RossTD)in charge or his dept (http://www.dttas.ie/) .....

The thing is CHC operates in both regions, so you would think they have learnt and applied lessons from UK tragedies....

[LordFlashheart]

Yes it is for SAR, dont mix SAR with CAT.
Every country have its own regulation.

Be that as it may, the point is that terrain ID (when operating near terrain) should be via the terrain overlay and not weather RADAR (which is only used offshore for ID-ing non-terrain obstacles and targets, boats/rigs and the like) in this case.

Therefore, the LOW ALT selection is not a good choice at night/IMC for this approach. Not that this would have helped them with the terrain not being in the database.

In the end they shouldn't have been at that altitude. Simply, the chart should have had much more info, especially segment 'not below' altitudes and vertical guidance (as a minimum). However, other holes in the reason model's swiss cheese lined up for this to happen (no terrain in database and selection of LOW ALT).

[LordFlashheart]

Not sure if it has changed in the uk but when I left I found that 30nm restriction was only in australia.

Si

I thought it was brought across from the UK, initially. But I may be wrong.

[BluSdUp]

You all need Approved IFR approaches.
What you are doing now is pure madness.
The last days discussions scares the bejezzs out of me.
What you do over open water, I would do any day at flap 10 and 165kts down to 200 feet to get visual. If anyone let me into one of those new 737 800 Poseidons ! Perfectly safe.
But to apply the same heading for shore or over land requires a proper tested and approved IFR approach.
Make it happen, it is only money.
Good Luck

[ring gear]

:DIt is clear the captain did know that BLKMO was not just a waypoint over the sea but an island, because when the CVR picks up the ALTITUDE call out, she says: "Eh just a small little island.... that's BLMO itself" So the question is how did she know it was an island, and what information about its height did she have? Did she have good enough information, but had misinterpreted it? She clearly did not realise it was 300ft high.

Furthermore I find it very surprising that you'd track over what you knew was an island at night at 200ft at all - and if you did, you would surely have made a comment in advance to the crew to expect an ALTITUDE alert - and what clearance on the radalt to expect, as it was so little. But why would you not just climb to add some clearance for good measure? There was no reason not to.

What little CVR talk there is gives me the impression this crew were not completely sure of the terrain ahead and were relying significantly on radar and possibly EGPWS to provide information to keep them safe.

As is clear from a considerable number of the 980 posts on this thread, both radar and EGPWS have their complexities, that mean that one has to be very knowledgable about them in order to be able to 100% rely on them to be able to avoid obstacles flying at 200ft at night.

Which brings us back to the madness of this approach - it must surely have been totally unnecessary to carry it out at 200ft from so far out, over known islands at night. Getting into Blacksod safely in the prevailing weather should not have been a particularly difficult task for this helicopter. Basic flight planning with identification of a sensible let-down path and monitoring position with nothing more detailed than a 1:500,000 moving map was all that was required. And they had this and much more.

It should not have absolutely needed a formal approach (though admittedly very advantageous) or more equipment on the aircraft. It seems to me that a danger of too much external control with SOPs and sophisticated aircraft equipment to rely on, is that, whilst having clear and obvious benefits that we need, risk is increased in one way by reducing the amount of original thinking and decision making pilots undertake. So they can easily get worse at it, as probably happened here.
:D:D:D
Totally, totally agree.....good summation. I think many of the respondents so far are dooming our industry to disappear further and further down the spiral of the gordian knot of over regulation.... in the endeavour of removing responsibility from those positions ie Captains who are getting paid (or should be getting paid) to do so.

RG

[SASless]

I respectfully suggest we save that innovative thinking for those occasions that require it. When a bit of that old fashioned prior planning makes sense....and actually promotes safety then we should take advantage of it.

Look us in the Eye and deny having canned Approach procedures for landing sites that are known well known in advance....exactly like Blacksod with it being a re-fueling point.....would not greatly enhance safety.

I doubt you can....or will.

No doubt a knee jerk reaction that leads to invalid restrictions and Rules that do nothing to improve safety is a bad thing but well thought out effective changes can only help prevent future accidents and loss of lives.

Change for change sake is not what is being suggested but rather realistic improvements.

[agirl]

If some people, including very experienced helicopter pilots on this forum, can't agree that this is just a VFR transit layout for pad to pad flights, then it isn't difficult to see how this crew, unfamiliar with the area, and in the dark of night and weather, didn't understand that this route meant for a helicopter taking off from Blackrock and bringing maintenance people back to Blacksod, or vice versa, can't be patched into at 200 feet.

I think you may be right in what you are saying about the route guide. It seems to answer a lot of questions as to why they ended up where they did.

Please excuse me if my questions sound silly but, as they were flying from the east coast, would there have been an option to enter "approach Blacksod east" and, if so, would that still have brought them out beyond Blackrock?

Also, the following is the conversation that some people are referring to when they say Capt. Fitzpatrick thought they were already at Blackrock when they were overflying the smaller islands near Blackrock:

Co-pilot : Ok so small target at six miles eleven o'clock Large out to the right there.
Commander: Just a small little island....that's BLMO itself.

To me it actually looks like the commander is responding to both parts of the statement as there is a pause within her answer - the small target is "just a small little island" and then possibly pointed to Blackrock as the large target.

Perhaps they did see a flash from the lighthouse in the distance just at that point in time and flew towards it without, as seems to be now apparent, knowing the height?

[jimf671]

We know what their heading was in the last seconds but their path across the ground may have brought them along the edge of the light's red sector. So what would they have seen and what would they have taken from that? Every 500m at 80 knots they should see a flash of white or red. Was the cloud base really 300 to 400 feet or was it below 282 feet?

[cncpc]

I think you may be right in what you are saying about the route guide. It seems to answer a lot of questions as to why they ended up where they did.

Please excuse me if my questions sound silly but, as they were flying from the east coast, would there have been an option to enter "approach Blacksod east" and, if so, would that still have brought them out beyond Blackrock?

Also, the following is the conversation that some people are referring to when they say Capt. Fitzpatrick thought they were already at Blackrock when they were overflying the smaller islands near Blackrock:

Co-pilot : Ok so small target at six miles eleven o'clock Large out to the right there.
Commander: Just a small little island....that's BLMO itself.

To me it actually looks like the commander is responding to both parts of the statement as there is a pause within her answer - the small target is "just a small little island" and then possibly pointed to Blackrock as the large target.

Perhaps they did see a flash from the lighthouse in the distance just at that point in time and flew towards it without, as seems to be now apparent, knowing the height?

A girl...

It is a complex question on why they "...ended up where they did". I think that what some of us think about this "route" answers the question of why in hell a letdown procedure was "designed" around a 300 foot rock. It wasn't.

If the pilots of R116 though it was, something is badly wrong. However, there are some very qualified SAR people on this forum, and it seems that generally, a letdown out there doesn't need a procedure, it is something that the crew and aircraft can accomplish routinely. I think they just push a button with APP1 on it.

Once that is done, and they are at 200 feet, and they think they are on a procedure in which BLKMO is next, they are doomed unless the system gives them adequate warning of what is out there that they are unaware of and they can recover from the brink.

I don't know the answer to your question of Blackrock East. I expect Blackrock is a VFR only approach, while Blacksod obviously can be approached IFR in some fashion. My experience of autopilot coupled navs is that you set your destination and once nearby you call up the available approaches and activate one and the autopilot begins to fly that. I don't know how the S-92 system works, and most importantly I don't know if these homemade approaches become canned, i.e. programmed into the FMS.

However that may have come to be, it is clear that neither Captain Fitzpatrick or Capt. Duffy were aware of a 300 foot rock in what they were doing. It seems they were discovering things as they went, but as others have pointed out, some things said by Capt. Fitzpatrick don't make sense. Neither does the 200 foot altitude.

My background is in fixed wing supervisory management, safety systems, and some crash investigation supporting litigation counsel and testifying, including one accident in Ireland involving the IAA. I'm more a questions than answers person at this stage, but maybe somebody else here can answer your questions.

Back in the mid 90's I was having a pint with an Aer Lingus 747 captain in Willy Ryan's there by the Phoenix Park entrance and we were talking about competition for Aer Lingus and Ryanair. At some point he said, "Padraig, aviation over here is really a cottage industry."

I know that that cottage industry has a fine safety record, yet this accident has some features, such as this "approach" and two helicopters on the same mission not knowing where the other is, that indicate the CHC at least isn't running the tightest of operations. The questions being asked by the other lads are valid questions.

[gulliBell]

We know what their heading was in the last seconds but their path across the ground may have brought them along the edge of the light's red sector.

So what would they have seen and what would they have taken from that? Every 500m at 80 knots they should see a flash of white or red. Was the cloud base really 300 to 400 feet or was it below 282 feet?

The surface wind was 220deg/20kt and they were heading 122deg/80kt i.e. almost all right crosswind which explains the track shown in fig 6 of about 110deg. The transcript notes the pilot saying "groundspeed gonna start increasing", I wouldn't have thought by much as it's almost all crosswind.

The aftercast says 300' cloud base, and their baro altimeter was indicating 300'. So they would have been just in/out of the bottom of it at 200' radalt with mostly downward visibility. But I would have thought at that short range, even if the light was 80' deep in cloud, the white light of the lighthouse would have lit them up like a christmas tree at least once before they finally saw the rock maybe a second or 2 before impact (they were on the seaward white side of the lighthouse).

I'm surprised the pilot said nothing in the last 14 seconds of the recording, 9 seconds of which was post impact. I suspect the "we're gone" comment from the co-pilot came about one second after they hit the rock, which were the last words recorded from any crew member.

[gulliBell]

A girl...

...Once that is done, and they are at 200 feet, and they think they are on a procedure in which BLKMO is next, they are doomed unless the system gives them adequate warning of what is out there that they are unaware of and they can recover from the brink...

The things available to save them were:
1. planning,
2. outside visual reference, and
3. aircraft systems.

Planning didn't work because it's a certainty none of the four crew saw the 282' spot height at BLKMO that was marked on their chart. And if there was a note about it written in the supporting text of the chart - which there should have been - they didn't see that either.

That leaves them to the mercy of outside visual reference, and aircraft systems to save them. It's reasonably certain they didn't see the white flash of the lighthouse, likely because nobody was looking forward outside despite being on a visual segment. If the weather was that low that they couldn't see ahead of them they shouldn't have been on a visual segment.

So now they are down to the mercy of aircraft systems to save them. The systems available to them were:
1. radar
2. FLIR
3. search light
4. EGPWS

The radar should have given them ample warning of land directly ahead. It's inexplicable to me how the radar didn't save them, other than operator error.
The FLIR, via rear crew advisory, gave them 14 seconds notice of the rock ahead of them.
The searchlight might have been useful to them, I suspect it wasn't on...if I'm flying around low level at night I like to have the big light on. Maybe there were operational reasons it wasn't on, I don't know.
And finally, the EGPWS. I'm a complete novice on this system, but from the little I understand, the "low altitude" function was enabled which significantly reduces boundary warnings. However, mode 6 was still available to them which enables an "ALTITUDE ALTITUDE" callout. And that's exactly what they got 27 seconds before impact, and again at 2 seconds before impact. My reading of it the EGPWS was doing exactly what it was programmed to do, despite the terrain data issue which has been highlighted. The comments column in the CVR transcript attributes this warning to the radalt. As I mentioned a few pages earlier, I've never seen a radalt associated with an ALTITUDE warning, I doubt very much that the radalt initiated this warning in this instance, it was the EGPWS issuing the warning exactly as it was designed to do for the mode it was commanded to be in. An ALTITUDE ALTITUDE warning from a EGPWS must be responded to by crew avoiding action as set out in SOP. But as I said, I'm a novice on this aspect.

If all these things don't save you, and any one of which would have saved them, I don't know what else to say.

[catch21]

Planning a landing at 2am, cloud at 300', 100 miles from your home base, you will be looking for a formal procedure, paper or FMS. The question is, what formal procedures for Blacksod were available in R116?


'APBSS' clearly was. Was this the only formal procedure available?

[[email protected]]

cpnpc - you seem slightly obsessed about the procedure being from LS (blackrock) to LS (blacksod).

Why would a company that doesn't do lighthouse transfer work and can't land the S-92 at Blackrock because the LS is too small, have a procedure to go from Blackrock to Blacksod?

We all agree the procedure is poor and that they didn't need to descend to 200' until much later in the route but it isn't a VFR procedure - why on earth, if you were VMC and coming from the East, would you fly 10 miles West past your intended LS (Blacksod) ?

It is quite clear it was intended as a poor weather/night procedure - just not well written or depicted on the page.

[oleary]

The things available to save them were:
1. planning,
2. outside visual reference, and
3. aircraft systems.

Planning didn't work because it's a certainty none of the four crew saw the 282' spot height at BLKMO that was marked on their chart. And if there was a note about it written in the supporting text of the chart - which there should have been - they didn't see that either.

That leaves them to the mercy of outside visual reference, and aircraft systems to save them. It's reasonably certain they didn't see the white flash of the lighthouse, likely because nobody was looking forward outside despite being on a visual segment. If the weather was that low that they couldn't see ahead of them they shouldn't have been on a visual segment.

So now they are down to the mercy of aircraft systems to save them. The radar should have given them ample warning of land directly ahead. It's inexplicable to me how the radar didn't save them. The other aircraft system available to save them was the FLIR, and that, via rear crew advisory, gave them 14 seconds notice of the rock ahead of them. The searchlight might have been useful to them, I suspect it wasn't on...if I'm flying around low level at night I like to have the big light on. Maybe there were operational reasons it wasn't on, I don't know.

"It's explicable to me how the radar didn't save them." That's my read - and I did the same stuff with 212's, 76's, 61's and 214ST's for many years.

[catch21]

..
Why would a company that doesn't do lighthouse transfer work and can't land the S-92 at Blackrock because the LS is too small, have a procedure to go from Blackrock to Blacksod?

.

Exactly! That's exactly the point. Why was that formal procedure available when self-evidently it wasn't fit-for-purpose?

Aside weather radar, EGPWS, NV, FLIR, moving maps, Black Rock light and paper maps that may have saved the day, if it was the only formal procedure available the strategy 1) let down to 200' 2) follow the procedure will have the inevitable consequences.

If it wasn't the only formal procedure available, one question is: why was APBSS chosen?

[P3 Bellows]

Gullibell

I doubt very much that the radalt initiated this warning in this instance, it was the EGPWS issuing the warning exactly as it was designed to do for the mode it was commanded to be in. An ALTITUDE ALTITUDE warning from a EGPWS must be responded to by crew avoiding action as set out in SOP. But as I said, I'm a novice on this aspect.

The "Altitude; Altitude" warning is directly triggered by the radalt. It has nothing to do with the EGPWS system.

It is triggered by descending below bugged height. If you have the radalt bug at 180' and you go below that height you get the "Altitude; Altitude" warning.

The reason it is "Altitude; Altitude" and not "Check Height" is because it uses "American English" and they don't understand the difference between height and altitude.

You state that you are a novice but you are happy to make statements that are factually incorrect and based on nothing but assumption and your limited knowledge of other aircraft systems.

PPrune at its best.

[Mark Six]

Gullibell, the aircraft I fly has much the same equipment and avionics as the R116, including the exact same model of EGPWS. Descent below the preset RADALT height (in this case 180') will cause an "Altitude, Altitude" warning from the RADALT. There is no 'Altitude, Altitude" aural alert associated with the EGPWS. Some of the terrain associated alerts are "desensitised" when landing gear is lowered. The crew of R116 selected LOW ALT mode on the EGPWS. I don't know about R116 but in the A/C I fly it is only possible to display either the EGPWS page or the weather radar picture, not both on the same display. If your display is in weather mode and an EGPWS alert is triggered the display will automatically switch from weather to TAWS. Obviously you don't want to suddenly lose your radar picture at a vital stage of a rig approach or when using radar for weather/terrain avoidance so LOW ALT is enabled to reduce the threshold for EGPWS warnings. It seems counter intuitive to desensitise your EGPWS when flying at low altitude but that is often what is called for.

[helicrazi]

Gullibell, the aircraft I fly has much the same equipment and avionics as the R116, including the exact same model of EGPWS. Descent below the preset RADALT height (in this case 180') will cause an "Altitude, Altitude" warning from the RADALT. There is no 'Altitude, Altitude" aural alert associated with the EGPWS. Some of the terrain associated alerts are "desensitised" when landing gear is lowered. The crew of R116 selected LOW ALT mode on the EGPWS. I don't know about R116 but in the A/C I fly it is only possible to display either the EGPWS page or the weather radar picture, not both on the same display. If your display is in weather mode and an EGPWS alert is triggered the display will automatically switch from weather to TAWS. Obviously you don't want to suddenly lose your radar picture at a vital stage of a rig approach or when using radar for weather/terrain avoidance so LOW ALT is enabled to reduce the threshold for EGPWS warnings. It seems counter intuitive to desensitise your EGPWS when flying at low altitude but that is often what is called for.

Although as long as TAWS is displayed on a screen it wont 'pop up' and replace your weather radar, this can be done by displaying TAWS in the ARC mode of the PFD, then you have both TAWS and Weather on the screens side by side.

[cncpc]

cpnpc - you seem slightly obsessed about the procedure being from LS (blackrock) to LS (blacksod).

Why would a company that doesn't do lighthouse transfer work and can't land the S-92 at Blackrock because the LS is too small, have a procedure to go from Blackrock to Blacksod?



Nonsense. Obsessed?

I'm not obsessed at all. It is a VFR arrival departure procedure from helipad to helipad. I have no idea why you don't want to admit that, yet you make the strongest argument that it is.

You are the one who asks, quite correctly, why a letdown procedure would be centered over the highest point out there in the ocean. BLKMO is marked because it is a helipad. Just like Blacksod is marked.

Who cares about the S92 not being able to land there? Is that the only questionable thing in this whole mess? Helicopters transit quite regularly between Blacksod and Black Rock. At some point, CHC may have operated helicopters that can be operated there. Other agencies of the Irish government may provide the helicopters. The route may have been designed before the S-92's and added to CHC's route book.

How to fix this. Put large black letters at the top of APBSS that say "For VFR use only". And for good measure "No PT" beside BLKMO.

[Mark Six]

Although as long as TAWS is displayed on a screen it wont 'pop up' and replace your weather radar, this can be done by displaying TAWS in the ARC mode of the PFD, then you have both TAWS and Weather on the screens side by side.

Absolutely correct. Was just trying to keep it simple and explain why the crew may have selected LOW ALT mode. Mind you the RFM states that LOW ALT is not to be used in IMC except during a rig approach.

[helicrazi]

Absolutely correct. Was just trying to keep it simple and explain why the crew may have selected LOW ALT mode. Mind you the RFM states that LOW ALT is not to be used in IMC except during a rig approach.

I was just making the point before the 92 slayers jump in!:ok:

[GKaplan]

And finally, the EGPWS. I'm a complete novice on this system, but from the little I understand, the "low altitude" function was enabled which significantly reduces boundary warnings. However, mode 6 was still available to them which enables an "ALTITUDE ALTITUDE" callout. And that's exactly what they got 27 seconds before impact, and again at 2 seconds before impact. My reading of it the EGPWS was doing exactly what it was programmed to do, despite the terrain data issue which has been highlighted. The comments column in the CVR transcript attributes this warning to the radalt. As I mentioned a few pages earlier, I've never seen a radalt associated with an ALTITUDE warning, I doubt very much that the radalt initiated this warning in this instance, it was the EGPWS issuing the warning exactly as it was designed to do for the mode it was commanded to be in. An ALTITUDE ALTITUDE warning from a EGPWS must be responded to by crew avoiding action as set out in SOP. But as I said, I'm a novice on this aspect.

So much for me taking the time to give the exact aural alerts (post #1008, which you acknowledged in #1028).
Maybe I should have answered what you asked then: "Yes, it is the behaviour of the S92!"

Mode 6 is a 'non-database' mode of the EGPWS, which uses RADALT height as the primary input. I refer to post #1008 for its calls.
The EGPWS look ahead alerting mode (which uses the database) gives "CAUTION TERRAIN", or "WARNING TERRAIN" calls, depending on the 'time to impact' calculated.
The comments column in the CVR transcript is correct.

Only 1600 hours on S92, what do I know?

[XA290]

Coastal radar navigation from the last millennium

25 Years ago, GPS was in its infancy as far as helicopters were concerned. Indeed, DECCA was still the primary navigation tool employed by helicopters involved in Oil and Gas and SAR both in the U.K. and Ireland. DECCA had moved on from the MK 19 roller map to the RNav1 and later the RNav2 computers but they were point-to-point navigation systems. There were no moving maps in helicopters in the 1990s. There was also no electronic nav kit in the back of civilian SAR S61s.

Coastal Navigation and let-down procedures for SAR using a point-to-point RNav2 computer was fraught with danger. Particularly when using DECCA as it was prone to atmospheric interference on that dark and stormy night when you would be quite possibly using it in anger.

For this reason, your position had to be confirmed against a separate source and this was the radar. Putting a waypoint on a piece of rock or a headland confirmed your position. If the waypoint appeared under an appropriate shaped radar return that cross referenced with the paper map you were holding you were where the DECCA RNav thought you were and let-down could proceed safely.

Back in 1995 the SAR contract was operated by Irish Helicopters and they had a waypoint on Black Rock as an IP for a let-down to Black Sod. It was called something different then to the one CHC use now but it was on the rock for the reasons I give above.

It was to confirm your position in an S61 using a generally good but possibly unreliable DECCA nav system and a good distance out from Black Sod to allow height loss after over flying the rock.

It seems that a legacy from a past generation using past generation kit was left in use and the seeds of this tragedy were sown in the early 1990s.

I hope this may shed some light on how this came about from a historical perspective and why there was a waypoint on Black Rock and not mid channel.

[SARWannabe]

All that fancy kit, and seemingly using aircraft modes because they CAN be used, rather than using the safest mode to achieve the safest outcome. Whats wrong with looking at a chart, having a published inbound heading with respect to terrain/obstacles and flying an OBS approach, 3nm 1000ft, 2nm 700ft, 1nm 400ft, and either a sensible MDA/H, or in SAR world, continuing to a reduced MDH/auto-hover. All this flying along at 200ft still IMC using radar, then apparently ignoring radar returns(!) seems bonkers and totally unnecessary. Maybe they were clear of cloud, but they were essentially IMC. It seems such an unnecessary loss of life, especially for the poor radar operator, who whilst 'unlicensed' from a flight crew perspective, seemed to have the best situational awareness of the immediate danger.

Addition: I don't doubt that it CAN be done safely, of course it can, and has been for years, and remains bread and butter for many of you, but, it can't be the safest way of achieving the objective of landing at a known helipad for a routine fuel stop. At the very least, have a moving map showing actual OS data or marine cartography, that would immediately depict something as substantial as and island when flying 200ft over water. You can get that for $100 on an iPad, and sadly that alone when referenced against the radar return could have prevented this tragedy.

[gulliBell]

Mode 6 is a 'non-database' mode of the EGPWS, which uses RADALT height as the primary input. I refer to post #1008 for its calls.

OK, I understand that. All I know on this, apart from your enlightenment, is what I read in the report at 3.5.5. When I'm trying to wrangle with that in my head against the "ALTITUDE ALTITUDE" aural alert recorded on the CVR, it makes me assume that that warning was a EGPWS mode 6 warning that may have required a formal crew response by SOP. So it wasn't an EGPWS warning as such, merely an advisory that you have descended below a bugged RA height.
How would an EGPWS mode 6 warning be triggered and indicated, to differentiate it from a descent below bugged RA advisory? I think what you are saying is they are one and the same.

[ukv1145]

To be slightly pedantic, ALL aural alerts on the S92 except 'AIRSPEED, AIRSPEED' come from the EGPWS box (note: not triggered by - the recordings reside within the EGPWS processor and can be triggered externally as well as internally) So if you lose the EGPWS you lose all system aural warnings.

[helicrazi]

OK, I understand that. All I know on this, apart from your enlightenment, is what I read in the report at 3.5.5. When I'm trying to wrangle with that in my head against the "ALTITUDE ALTITUDE" aural alert recorded on the CVR, it makes me assume that that warning was a EGPWS mode 6 warning that may have required a formal crew response by SOP. So it wasn't an EGPWS warning as such, merely an advisory that you have descended below a bugged RA height.
How would an EGPWS mode 6 warning be triggered and indicated, to differentiate it from a descent below bugged RA advisory? I think what you are saying is they are one and the same.


As I understand it, Mode 6 is a customer decided preset altitude read out, and gives the actual altitude (or more correctly height as we know it with reference to rad alt) if the customer has chosen 200 ft to be called in mode 6, then that's what is says, TWO HUNDRED. the preset / default is 'ONE HUNDRED'

[gulliBell]

I just grabbed the EGPWS manual from our technical library...it helps when trying to understand something like this to have the book to refer to. Here is what it says:

Mode 6 provides audio call-outs for descent below predefined altitudes and minimums. The call-outs produce
aural output indications, but do not produce visual indications.
A “MINIMUMS-MINIMUMS” callout is provided based on the decision height discrete with gear down (less
than 90 Kts or less than 200 ft AGL in fixed gear aircraft). With Low Altitude Mode selected or with gear up
(greater than 90 Kts), the message “ALTITUDE ALTITUDE” sounds when transitioning below the selected
decision height.
An optional input gives the ability to force the Mode 6 audio level to lower audio volume. This lets the aircrew
control the Mode 6 volume level with activation of windscreen rain removal, or if they desire lower volume
call-outs at all times.
The EGPWS uses engine torque sensing to detect autorotation. The autorotation call-outs occur at 200 ft and
100 ft. If the gear is not down by 400 ft, an audio “TOO LOW, GEAR” warning sounds.
An excessive bank angle warning is provided based on Radio Altitude, Roll Attitude and Roll Rate. The
“BANK ANGLE” aural warning is given twice and then suppressed unless the roll angle increases by an
additional 20%.
A tail strike warning function is based on Radio Altitude, Pitch Attitude, Pitch Rate and Barometric Altitude
Rate. The voice message “TAIL TOO LOW” sounds continuously while in the warning boundary. Failure
Annunciations Monitor the EGPWS through an annunciator on the annunciator panel. The GPWS INOP
annunciator illuminates to indicate that a mode in the GPWS function is inoperative or degraded.

And importantly, this written in bold in a CAUTION box

The pilot must maintain visual contact with all terrain and obstacles at all times when using the Low
Altitude mode. The Low Altitude mode must not be engaged during IFR conditions. The look down
angle is reduced with Low Altitude engaged. Warning time is greatly reduced.

[P3 Bellows]

Gullibell

I just grabbed the EGPWS manual from our technical library...it helps when trying to understand something like this to have the book to refer to. Here is what it says:

Was it a generic EGPWS manual or the S92A flight manual that you grabbed?

The only reason I ask is because what you describe does not sound like the EGPWS as configured in the S92A. I have been searching for the EGPWS windscreen rain removal mode for years now without success.

As you say "it helps when trying to understand................"

After 50+ posts on this topic you are becoming a bit like white noise now.

[[email protected]]

I'm not obsessed at all. It is a VFR arrival departure procedure from helipad to helipad no, it is a WP to WP arrival/departure procedure and XA290 clearly gives you the history of the procedure and why it came to be - it is entirely legacy as I suspected.

Sadly, not updated for the modern age other than changing the WP names and designed for non-nvd night letdowns where a big flashing light on a rock would be a good way of confirming your position.

[BluSdUp]

Remote contributing factor?
Could the crew have confused the height of Slingo Blacrock Lighthouse ( 80feet) and Mayo by asosiation. Not likely, but you never know.

[Lude-og]

Coastal radar navigation from the last millennium

25 Years ago, GPS was in its infancy as far as helicopters were concerned. Indeed, DECCA was still the primary navigation tool employed by helicopters involved in Oil and Gas and SAR both in the U.K. and Ireland. DECCA had moved on from the MK 19 roller map to the RNav1 and later the RNav2 computers but they were point-to-point navigation systems. There were no moving maps in helicopters in the 1990s. There was also no electronic nav kit in the back of civilian SAR S61s.

Coastal Navigation and let-down procedures for SAR using a point-to-point RNav2 computer was fraught with danger. Particularly when using DECCA as it was prone to atmospheric interference on that dark and stormy night when you would be quite possibly using it in anger.

For this reason, your position had to be confirmed against a separate source and this was the radar. Putting a waypoint on a piece of rock or a headland confirmed your position. If the waypoint appeared under an appropriate shaped radar return that cross referenced with the paper map you were holding you were where the DECCA RNav thought you were and let-down could proceed safely.

Back in 1995 the SAR contract was operated by Irish Helicopters and they had a waypoint on Black Rock as an IP for a let-down to Black Sod. It was called something different then to the one CHC use now but it was on the rock for the reasons I give above.

It was to confirm your position in an S61 using a generally good but possibly unreliable DECCA nav system and a good distance out from Black Sod to allow height loss after over flying the rock.

It seems that a legacy from a past generation using past generation kit was left in use and the seeds of this tragedy were sown in the early 1990s.

I hope this may shed some light on how this came about from a historical perspective and why there was a waypoint on Black Rock and not mid channel.

Beat me to it XA290. I was jut about to mention the legacy of the original Rescue 115 S-61 operated by Irish Helicopters in the nineties.

[IRCG SMC WHITEY]

Cobbled this together from the Report
2093

[GKaplan]

I think what you are saying is they are one and the same.

Yes.

Just as said by ukv1145 : "To be slightly pedantic, ALL aural alerts on the S92 except 'AIRSPEED, AIRSPEED' come from the EGPWS box (note: not triggered by - the recordings reside within the EGPWS processor and can be triggered externally as well as internally) So if you lose the EGPWS you lose all system aural warnings."

[gulliBell]

..Was it a generic EGPWS manual or the S92A flight manual that you grabbed? .

Honeywell Mark XXII Helicopter EGPWS manual (equipment cited in 3.5.1 as being fitted to the S92)

[dervish]

The Irish AAIU prelim report is well written. The section on EGPWS is revealing for what it doesn't say. Honeywell seem at pains to point out the database is supplied by someone else, but on their website claim it is proprietary to themselves. The AAIU obviously isn't happy and says it it still trying to fully understand this issue. More to come I think.

[gulliBell]

..Honeywell seem at pains to point out the database is supplied by someone else, but on their website claim it is proprietary to themselves.

All I can find in the manual (2012 version) is this:

"The terrain database is the heart of the EGPWS. The database includes information regarding terrain, airports
and obstacles such as towers, buildings and antennas, that are 100 ft or taller. It is important to know that
wires are not a part of the database at this time.
The system compares aircraft position and motion against the terrain and obstacle database to provide its
cautions and warnings. EPWS also provides non-database related warnings. It does so using a term known
as geometric altitude, which is derived from radar altitude, a GPS altitude, barometric pressure and aircraft
motion calculations"

[DOUBLE BOGEY]

I would offer a bait - STABILISED APPROACH to MDA/H & MAPT

[SASless]

What does the Manual say about User supplied data for inclusion in Updates?

[ZFD]

This EASA info gives the two scenarios for data base approval.

"There are two types of Letters of Acceptance

Type 1 LOA
Letter of acceptance granted where a Navigation Database supplier complies with EUROCAE ED-76 / RTCA DO-200A documents with no identified compatibility with an aircraft system. A Type 1 LOA confirms that the processes for producing navigation data comply with these Conditions and the documented Data Quality Requirements. A Type 1 LOA may not release navigation databases directly to end users.

Type 2 LOA
Letter of acceptance granted where a Navigation Database supplier complies with EUROCAE ED-76 / RTCA DO-200A documents and provides data compatible with specified avionics system(s). A Type 2 LOA confirms that the processes for producing navigation data comply with these Conditions and the documented Data Quality Requirements for the avionics systems specified. The Data Quality Requirements must be provided by or agreed with the specified equipment design organisation in accordance with a formal arrangement. A Type 2 LOA may release navigation databases directly to end users. Such releases may also include data packing tools, where the use of such tools has been demonstrated to be ED-76/DO-200A compliant. A Type 2 LOA holder may interface directly with data originators (such as State AIP providers and operators), or may use data supplied by a Type 1 LOA in which case interfaces with data originators may not be necessary."

https://www.easa.europa.eu/navigation-database-suppliers-letters-acceptance

[gulliBell]

What does the Manual say about User supplied data for inclusion in Updates?

Nothing.

But I do recall contacting the terrain and obstacle database provider (about 5 years ago), and asked how to get the data for the area I was operating in updated because it was woefully inadequate. As I recall, the process had to be directed via the local CAA, and it quickly became apparent to me that nothing was going to happen any time soon. So I didn't bother pursuing it.

[SASless]

So....we know Blackrock was not correctly represented in the current database....and there is no effective procedure to correct known deficiencies?

[gulliBell]

So....we know Blackrock was not correctly represented in the current database....and there is no effective procedure to correct known deficiencies?

There is a procedure, but as I mentioned, I tried to get an update happening for the area I was operating in but didn't follow it through because, after the exchange of several emails, I sensed I'd get nowhere with it for a very long time. The terrain and obstacle database subscription update service was expensive, and the data of our area was either wrong, or missing. The effectiveness of the system predicated on incomplete data was thus compromised, with little prospect of getting it corrected, and I would never rely on it for operational use. We just decided to opt out of paying for the update service altogether. For terrain avoidance in coastal areas I could always rely on the aircraft weather radar, and it was free. We did however stick with navdata update services as a current navdata is required to despatch an IFR helicopter in IMC. There is no such requirement for the terrain/obstacle database to be current.

[agirl]

I just grabbed the EGPWS manual from our technical library...it helps when trying to understand something like this to have the book to refer to. Here is what it says:

Mode 6 provides audio call-outs for descent below predefined altitudes and minimums.

The report seems to suggest that they were in Mode 4B:

Mode 4B
: When the landing gear is lowered, Mode 4B becomes active and the boundary decreases to 100ft when above 120 kts. As airspeed decreases below 120 kts the warning boundary decreases to 10 ft
at 80 kts. The landing gear was down at the time of the accident.

[[email protected]]

So, one question is - even if Blackrock had been in the database, would the EGPWS have alerted with the gear down at a speed of less than 80kts?

The interim report seems to indicate the look forward boundary is only 10' at 80 kts and only 100' at 120 kts with the gear down. At 120 kts the aircraft is travelling at more than 180 ft/sec and even at 75 kts it is doing over 110 ft/sec.
Are these boundaries reasonable for a helicopter at low level?

Perhaps the SOP for putting the gear down so early needs to be revisited.

[gulliBell]

..The landing gear was down at the time of the accident.

In mode 4B, if the landing gear was down at the time of the accident, below 120kts, the aural warning at time stamp 2.03.09.026 on the CVR should have been "TOO LOW TERRAIN". The aural warning actually recorded at that time was 'TOO LOW GEAR", which means the gear was up. If the gear was up then the system couldn't have been in mode 4B, it would be in mode 4A. The standard boundary for mode 4A is at 150' RA. That's my understanding of reading the manual.

The report says low altitude switch was engaged. This is what the manual says about that:

"A LOW ALT switch allows for helicopter operations that require low altitude flight. Use this function for
flight at low altitude in VFR conditions. Engaging this function:
ƒƒ Inhibits Mode 1
ƒƒ Significantly reduces Mode 2 warning boundaries
ƒƒ Significantly reduces Mode 4 warning boundaries
ƒƒ Enables Mode 6 “Altitude-Altitude” call-out
ƒƒ Reduces Terrain Advisory look ahead distance
Low Altitude operation is defined as operation below 500 ft AGL, in a high-density metropolitan environment
with high-rise buildings, below 1,250 ft AGL when the GPS is not operational or is providing poor accuracy,
or airport maneuvering where airspeeds exceed 50 Kts"

[Rivet]

Could someone kindly tell me what the MSA is in the area of the approach they used.

[jimf671]

Since the aircraft had suffered 10 seconds of substantial impacts and considerable damage at the time of that call, our minds should be open to the idea that automated calls in that period do not reflect the true status before impact.

[MagentaL]

In mode 4B, if the landing gear was down at the time of the accident, below 120kts, the aural warning at time stamp 2.03.09.026 on the CVR should have been "TOO LOW TERRAIN". The aural warning actually recorded at that time was 'TOO LOW GEAR", which means the gear was up. If the gear was up then the system couldn't have been in mode 4B. That's my understanding of reading the manual.

The report says low altitude switch was engaged. This is what the manual says about that:

"A LOW ALT switch allows for helicopter operations that require low altitude flight. Use this function for
flight at low altitude in VFR conditions. Engaging this function:
ƒƒ Inhibits Mode 1
ƒƒ Significantly reduces Mode 2 warning boundaries
ƒƒ Significantly reduces Mode 4 warning boundaries
ƒƒ Enables Mode 6 “Altitude-Altitude” call-out
ƒƒ Reduces Terrain Advisory look ahead distance
Low Altitude operation is defined as operation below 500 ft AGL, in a high-density metropolitan environment
with high-rise buildings, below 1,250 ft AGL when the GPS is not operational or is providing poor accuracy,
or airport maneuvering where airspeeds exceed 50 Kts"

The gear was extended during the descent and 3 greens confirmed locked down. As per interim report. The "Two low gear warning" was likely due damage from impact.

[gulliBell]

So, one question is - even if Blackrock had been in the database, would the EGPWS have alerted with the gear down at a speed of less than 80kts?.

From the manual:

"When the landing gear lowers, Mode 4B becomes active and the boundary decreases to 100 ft when
above 120 Kts (100 Kts on fixed gear aircraft). As airspeed decreases below 120 Kts, the warning boundary
decreases to 10 ft at 80 Kts. The voice message is “TOO LOW TERRAIN”."

I don't know how the boundary changes given the LOW ALT mode was engaged, I can't see anything on that other than "significantly reduces mode 4 boundaries".

[gulliBell]

The gear was extended during the descent and 3 greens confirmed locked down.

OK, that is definitive then.

[smcc63]

Re gear down see section 5.5 last bullet point, AAIU report,
Gear was down and three green lights

[Tezzer 007]

Hi. My apologies, I am just an interested civilian so I'll be brief.
IAA ICAO charts use a red circle as the symbol for a lighthouse.The "Approach Blacksod South" route guide being used had two of these red circles. One at BLKMO marked 282. One at BLKSD marked 43. According to Irish Lights those heights given are the heights of the lights on the lighthouses in those two locations.
So the map provided seems to provide the information that BLKMO is a lighthouse at 282 feet ASL.
I think it was unfortunate that the hazard warnings were also in red circles, albeit slightly larger, and even more so that BLKMO was #1. That left open the possibility of misinterpretation that it was a starting point, not an indicator to refer to the written text.

[GKaplan]

OK, that is definitive then.

Also from the report:
footnote on page 13, but more importantly section 6.3 "Wreckage found on the sea bed" on page 27 :ok:

[GKaplan]

I don't know how the boundary changes given the LOW ALT mode was engaged, I can't see anything on that other than "significantly reduces mode 4 boundaries".

With LOW ALT, all TERRAIN warnings are inhibited, you get only GEAR warnings below 60kts, and the upper height boundary is reduced from 150ft to 100ft (for mode 4A - it's already 100ft for 4B).

[ukv1145]

I think there is some confusion here. Mode 4 and all its sub modes are vertical modes only, based on rad alt, not look forward based on the database.

[GKaplan]

I think there is some confusion here. Mode 4 and all its sub modes are vertical modes only, based on rad alt, not look forward based on the database.

Agree.
All modes 1 to 6 are 'non-database' modes, all of which use the RADALT height as their primary input.
They are all defined automatically by the a/c configuration and require no pilot input.

The look ahead mode (using the database) is not numbered, hence the confusion I guess :)

[GKaplan]

So, one question is - even if Blackrock had been in the database, would the EGPWS have alerted with the gear down at a speed of less than 80kts?

The interim report seems to indicate the look forward boundary is only 10' at 80 kts and only 100' at 120 kts with the gear down. At 120 kts the aircraft is travelling at more than 180 ft/sec and even at 75 kts it is doing over 110 ft/sec.
Are these boundaries reasonable for a helicopter at low level?

Perhaps the SOP for putting the gear down so early needs to be revisited.

If it had been in the database the short answer is yes.

"The system uses measured and predicted flight path data together with database information to look ahead for threats. The look-ahead area is based on ground track and flight path angle, corrected for any turns. It uses a 6º climb out angle so it is assuming a rate of climb to clear the obstacle or terrain of ten times the groundspeed (for example, 1000 feet/min at 100 knots groundspeed).
The system should give at least 30 seconds warning of any threat (that is, just over one mile at 120 knots).
Detection of a threat will generate a yellow threat caution area on the display, accompanied by a yellow TERRAIN or OBSTACLE caption on the ADI and a "Caution, terrain" (or "Caution, obstacle") aural warning. This aural warning is repeated twice, continuously at 7-second intervals, if the threat persists.
If the aircraft closes to within 20 seconds of potential collision, the display threat area and ADI captions change to red and the aural warning changes to a continuous "Warning, terrain" or "Warning, obstacle"."

---

What can be discussed I guess is the Mode 2 "excessive terrain closure rate" (just to repeat, a 'non-database' mode :) )

"This mode is designed to warn of excessive closure rates to terrain, primarily in the cruise. It uses RADALT height and rate to determine closure rate, but it also takes account of landing gear position, ILS information and airspeed. There are two submodes, 2A for the cruise and 2B for approach and landing.
Both submodes are inhibited if terrain data is of high integrity, in LOW ALT and in autorotation.
Otherwise, the modes are active below 300 feet AGL on takeoff and below 1200 feet AGL in the cruise

There are two boundaries, defined by RADALT height and closure rate. The inner boundary goes from 1600 feet/min at 30 feet to 1920 feet/min at 400 feet then up to 650 feet at 3120 feet/min. The upper ROD limit is 10000 feet/min. This boundary assumes a speed of 90 knots. As airspeed increases beyond 90 knots, the boundary expands from the 650 feet point to 1250 feet at 6000 feet/min, the upper height limit.
If the boundary is penetrated either horizontally or from above, an aural "Terrain, terrain" warning is generated together with the yellow TERRAIN caption on the ADI. If the flight path continues to penetrate the boundary, one second later a "Pull up" warning is generated together with the red PULL UP caption on the ADI. The warning will continue until the boundary is vacated.

Mode 2A is operational when the landing gear is up and height is above 30 feet.
Mode 2B provides a desensitised envelope for approach and landing. It is enabled with the landing gear down, if an ILS approach is in progress and the aircraft is within two dots of glide slope centre, and during the first 60 seconds after takeoff. The alert boundary is from 100 to 300 feet AGL; penetration of the boundary generates a single "Terrain" aural warning, repeated continuously, with associated TERRAIN caption on the ADI."

Just to be clear, when referring to vertical speeds the boundaries are defined by the RADALT rate of change (ie 'does the needle move fast?') rather than the actual aircraft vertical speed :)

[cncpc]

Could someone kindly tell me what the MSA is in the area of the approach they used.

If you center the 25 miles on Blacksod, it seems the determining height is on Achill, so probably 3100 if the criteria is 1000 above. They came across at 4000.

If a real IFR approach were to be centered around Blackrock as an IAF, the design standard would be for a crossing height of 1400 feet with that designated as the initial approach phase. 500 feet for the next waypoint BKSDA.

[Ber Nooly]

Just for info, here's a map of all locations involved. The ship ws 30 km closer to Blackrock than Dublin.

http://www.boards.ie/vbulletin/attachment.php?attachmentid=414732&stc=1&d=1492287333

[[email protected]]

GKplan and others - I am basing my questions on the facts included in the interim report which many people seem not to have bothered to read before they post here.

If the IAAB have got their facts wrong then discuss the GPWS boundaries but I suspect it is unlikely that they have.

Rivet - I expect there is a permission in their AOC to operate IMC below MSA over water.

[sudden twang]

A couple of Qs if I may,
The crew were employed by CHC on contract to the ICG is that correct?
If so were the crew trained on the S92 by the CHC training team that operate oil and gas on the N Sea or was their training bespoke to SAR and SAR in Ireland in particular?
We're their SOPs the same as oil and gas with additions/ dispensations for SAR?
Thanks in advance.

[P3 Bellows]

OK, that is definitive then.

Have you actually read the report?

:ugh:

[cncpc]

Rivet - I expect there is a permission in their AOC to operate IMC below MSA over water.

It's in uncontrolled airspace, so yes, you have to have some means of making an approach.

So let's say they have such a permission, which I don't doubt, what happens when they come over land in the water?

I know what you are saying, but the method of achieving that safely seems dubious or uncertain.

In Canada, operators who work in uncontrolled airspace have to construct "company routes' and have a company route manual, or a part in their ops manual. A route has to incorporate terrain clearance standards that are published, and it has to be approved before the regulator. If I remember, I think a company can do that on its own.

A company can't design its own approach, or it can but it has to be approved by an approved approach design firm. Didn't used to be that way but it is now. And then the approach has to be published in the Restricted Canada Air Pilot. Long time, not overnight.

The alternative is a cloud breaking procedure, which I'm thinking is a descent to MSA.

Sort of what went on here, but perhaps lacking regulatory approval and a requirement to comply with some standard.

[ukv1145]

GKplan and others - I am basing my questions on the facts included in the interim report which many people seem not to have bothered to read before they post here.

If the IAAB have got their facts wrong then discuss the GPWS boundaries but I suspect it is unlikely that they have.

Rivet - I expect there is a permission in their AOC to operate IMC below MSA over water.

Agree Crab that some appear not to have read the report. Just trying to clarify that the note 15 in the report refers to mode 4b which is entirely predicated on rad alt and is a height boundary not a forward boundary. This is a basic GPWS mode that does not look forward, only down. The only relevance of airspeed is as a switch to change the height at which a warning will sound and also the actual warning sounded.

[GKaplan]

GKplan and others - I am basing my questions on the facts included in the interim report which many people seem not to have bothered to read before they post here.

If the IAAB have got their facts wrong then discuss the GPWS boundaries but I suspect it is unlikely that they have.

And I based my answers (copy and paste) on CHC Ireland's manual.
Should be fairly close...


So, one question is - even if Blackrock had been in the database, would the EGPWS have alerted with the gear down at a speed of less than 80kts?

The interim report seems to indicate the look forward boundary is only 10' at 80 kts and only 100' at 120 kts with the gear down. At 120 kts the aircraft is travelling at more than 180 ft/sec and even at 75 kts it is doing over 110 ft/sec.
Are these boundaries reasonable for a helicopter at low level?

Perhaps the SOP for putting the gear down so early needs to be revisited.


Actually in that case the AAIB isn't very clear, but I guess a footnote is not the most appropriate place to start copying a manual :)

This would have been a bit clearer: Mode 4B is active between 10 and 100 feet RADALT height with the gear down and speed above 80 knots. The upper boundary varies linearly from 10 feet at 80 knots to 100 feet at 120 knots or greater.

So (as ukv1145 rightly said), it is a height boundary not a forward one.

A confusion (as said before by others) exists in some minds between mode4 and 'look ahead'.

There is no relation between the look ahead (database) mode and the position of the gear. (and that answers your first question Crab. It is a yes, regardless of gear or speed. The remark about lowering the gear too early is not relevant).

Not selecting LOW ALT on the other hand might have given a mode 2 warning (not sure it would have been sufficient however, given the steepness of the island slope/cliff).

[[email protected]]

GKaplan and ukv1145 - OK, I get the subtleties now with the modes and the LOW ALT selection - so we are saying that the mode 2 would have alerted if Blackrock had been in the database and the LOW ALT mode had not been selected?

[ukv1145]

GKaplan and ukv1145 - OK, I get the subtleties now with the modes and the LOW ALT selection - so we are saying that the mode 2 would have alerted if Blackrock had been in the database and the LOW ALT mode had not been selected?

No, not quite. All of the numbered modes are legacy modes, designed before the eventuality of the terrain database and the enhanced 'look forward mode', so it would not have made any difference to mode 2 if Blackrock was in the database. Mode 2 MAY have triggered a warning if it had not been inhibited (boundaries reduced) by the Low Alt switch but this would depend on the nature of the terrain overflown, it will not give sufficient warning to very steeply rising terrain such as a cliff (which I imagine to be the case with Blackrock) as it is still only using the rad alt to look down and the warning will be given based on the rate of change of that rad alt signal.

[Offshore pilot]

When operating offhore or at the coastline correct radar tuning is essential. Incorrect gain or tilt can make surface targets or islands invincible. Moving map and GWPS depend on correct data base and GPS position. A operational radar correctly tuned is the best insurance to confirm a flight path free of obstacles. Combination of Radar, FLIR, Moving Map, GPWS will give a good situation awareness. A SAR operator will normally describe a standard MFD set up for low level navigation.

[Brother]

Remember this one in China? I can't find an AAIB report, I am not sure that one was ever done. Captain was A.L-T, a true gent.

It doesn't add anything material here but it does illustrate the difficulty of assessing terrain on a weather radar, even if its your primary means.

G-TIGN Accident Details On 22/05/1989
Skip Navigation Links
Date 22/05/1989
Registration G-TIGN
Aircraft registration | UK Civil Aviation Authority (http://www.caa.co.uk/application.aspx?catid=60&pagetype=65&appid=1&mode=detailnosummary&fullregmark=TIGN)
https://www.google.com/search?q=G-TIGN
Aircraft Type AS332
Manufacturer Eurocopter
Fatal Yes
Narrative A/C FLEW INTO A HILLSIDE IN BAD WEATHER & BURNT OUT. 3 FATALITIES.
Details A/C WAS LIMITED TO VFR FLT ONLY, IN ACCORDANCE WITH OPS MANUAL, DUE U/S AREA NAV. IT WAS OPERATING WITH A CREW OF TWO PILOTS (1 BRITISH, 1 CHINESE) PLUS INTERPRETER. WHILE RETURNING FROM AN OFFSHORE OIL PLATFORM IN POOR WEATHER AND USING RETURNS FROM LAND ON THE WEATHER RADAR, DESCENDING FROM 2000FT TO MAINTAIN VMC, THE A/C STRUCK STEEPLY SLOPING GROUND AT ABOUT 600FT & CAUGHT FIRE KILLING ALL 3 OCCUPANTS. INVSTGN BY CHINESE AUTHORITIES WITH AAIB PARTICIPATION. CAA CLOSURE: FULL REPORT NOT PUBLISHED BY CHINESE AUTHORITY. OPR HAS AMENDED OPERATIONS MANUAL. NO FURTHER CAA ACTION APPROPRIATE.

[Fareastdriver]

I put forward this theory in post #143

The cockpit transcript was depressingly similar. The captain advised the co-pilot (pf) to turn around. As he was Chinese without Level 4 in English this was relayed by the interpreter. He queried the heading and this also went back and forth through the interpreter. When it was resolved he commenced the turn but half way round the helicopter struck the top of the hill killing all three.

The radar was found to be 5 degrees nose up which would have masked the coast close up in front of them.

[[email protected]]

Incorrect gain or tilt can make surface targets or islands invincible. quite an ironic typo :(

[[email protected]]

ukv1145 - understood, thanks:ok:

[dClbydalpha]

Had Blackrock been in the database then there would have been a red blob on their flight path. Which may have caused a recheck of the SA picture.

[AAKEE]

It doesn't add anything material here but it does illustrate the difficulty of assessing terrain on a weather radar, even if its your primary means.

Seen the statement before in this tread about the wheather radar.
Newer used a Wx-only radar, but I have used and am using Wx+SAR-radars( including Primus 701A wich I think is used in the S92 SAR?)
In my opinion these radars will detect and show small islands and rock regardless of mode and that they are safe and for awoiding terrain when flying over sea. Of course, as with all equipment, you need to be trained with to use it and I think we can safely assume that this crew was trained.
Earlier days of SAR only had the SAR/Wx-radar to rely on, combined with paper maps/sea carts for close-to-land operations, at least where I come from. In my world the radar picture superseeds moving map if seing ground/osbtacle on the radar( of course you should use all system that adds on SA).

I would absolutely think that the radar could be trusted, and that the radar should have been one of the first slice of the swiss cheese. The EGPWS should be one of the last. Said to see that it did not do the work this time.

[[email protected]]

So, between a regulator that refused to permit use of NVD and an operator who didn't update or check the database or review the letdown procedures, there seems to be room for a few lawsuits.............

[twinboom]

Well here we are 56 pages on. Would you Rotorhead chaps/esses please indulge me because, in a sense, I was there at Page Zero having visited Malin Head, as a tourist, earlier that day and noted the Coastguard HQ. Whilst I was tucked up in a hotel bed outside London/Derry Dara and Mark and their crewmates were outbound "to the rescue". When I awoke the accident had happened - so why, apart from that co-incidence of geography, do I feel so affected and why this post?
Ans: Many many years ago I was rescued, severely hypothermic, from the freezing 'oggin, at night, by an SAR Heli crew (for those who might wish to guess which incident 'twas in Europe but not UK).
Recently retired after 15,000+ fixed-wing professional flying hours you will understand why the SAR community has throughout retained a special place in my heart.
I also have a contribution to make in the understanding of how this seems to have come about - in the interest, as always, of learning lessons and sadly, in this case, pointing out one that does not seem to have been learnt by the Operator. Do you Rotorheady peeps remember 'Impact Erebus'? The Air NZ DC10 that CFITed into the Antarctic in late 1979. The proximate cause was Sector White Out but the single largest contributing factor was the fact that the Airline's Flight Planning Dept. had changed the stored Flight Plan in the FMS the day before (non-trivially, they moved the inbound track 27nm East!) and NOT TOLD the Crew. The latter carried out a conscientious brief based, unknowingly, on the wrong data - Ringing any bells here? It did with me within 24 hrs and 50+ pages ago and I trust you will agree worth sharing. Keep safe guys and girls, and Thanks again tb

[rotorspeed]

There is clearly a great deal of S92 SAR expertise following this thread. The co-pilot, who was monitoring the radar, called a "small target at 6 miles at 11 o'clock" when they were 1 mile west of Blackrock. Do others agree this could have been Duvillaun More island? Followed by "Large out to the right there, ehm" - pretty vague. Achill Island maybe, assuming the lack of distance and bearing meant it was not too relevant? Hard to believe such a casual comment would be so vague if it was Blackrock a mile away - and anyway, that would have been ahead, not to the right.

What do the radar experts think about the notion that Duvillaun and Achill were seen, but not, apparently Blackrock? Are there radar modes and settings that could explain that?

Given that the captain was targeting 200ft before turning back east for BLKMO, assuming say a 70kt GS and the APP1 500ft/min descent, I make that passing Blackrock eastbound at about 1000ft. And again, it seems this wasn't seen on radar either, though perhaps to be more expected as still 700ft below.

It appears it was the FLIR operator that picked up Blackrock. The time from the rear crew observation to the impact was about 13 secs, so that would mean it was seen at 550m range, assuming 90kts GS. Again do our S92 experts agree with that, and what might that tell us about visibility and IMC/VMC? What range does FLIR have in clear air and cloud?

Apologies if some of this has been answered before - a lot of ground has been covered!

[P3 Bellows]

Crab,

So, between a regulator that refused to permit use of NVD

What's your source for this? Genuinely interested.

P3

[Al-bert]

Sorry to all you current guys who love the complexity of all the Gucci modes, bells and whistles that the S-92 enjoys, and you guys well versed in procedures and plates for everything. All those 'advantages' were directly responsible for this CFIT. It simply would not, indeed could not, have happened to a simple 'steam age' Sea King. KISS seems appropriate - so much has been lost for such little gain it seems. I wonder, has any SAR job been done with an S-92 that wouldn't have been done by a Sea King? :ugh:

ps: like P3, genuinely interested!

[DOUBLE BOGEY]

I believe that if they had mandated and flown a stabilised approached to a an MAPT for BLACKSOD this accident could not have happened. The vertical profile designed such that all obstacles are cleared in the entire FATO.

Amateur Letdown procedures such as this one, or, the mistaken belief that "because we are SAR, the rules and conventions need not apply" lead to events like this.

The considerations of safety offered by the FLIR, RADAR, MOVING MAP, NVG are just that. Only considerations to add value. However, the letdown profile should be designed such that reliance on these systems alone, the ensure separation, is the first hole in the swiss cheese.

Offshore ARAs and SAR Let-downs mid-ocean, ultimately rely on the WX RADAR for final separation but the vertical and horizontal profiles are now mandated to ensure the best possible performance from the RADAR.

What astounds me here is why, with FLIR available on the MFDs, this was not selected to supplement the RADAR return on the other MFD.

I suspect this accident will focus on the performance and robustness of the EGPWS database, which in my view would be a mistake. EGPWS will only ever be the "Virtual World". The RADAR and the FLIR offering information about the "Real" world.

Using NVG to navigate and avoid obstacles this far away from the TLOF is surely a last resort. I appreciate NVGs would add value during the final landing phase but this far out, just a distraction for the 2 available all-weather - primary sources of the Real world, RADAR and FLIR.

[G0ULI]

I think the absence of NVD is a bit of a red herring considering the helicopter was fitted with FLIR equipment. If lifting a casualty from a vessel, it would be normal to illuminate the lifting area with deck lighting. For sea and cliff rescue, there is a searchlight. NVD is more likely to be a hinderance than a help in most rescue operations since the pilot(s) should be positioning according to the directions from the winchman.

All the equipment in the world is not going to help if the crew are provided with less than complete navigation information, a flawed approach procedure, and fail to recognise and react promptly when there are several indications that they are flying into danger.

In this instance there was a self confirmatory bias at work where the crew were clearly not entirely sure of their position, hadn't flown in the area for ages, and were drawn into the trap of assuming that various rocks and islets that they spotted indicated that they were more or less on track and on course. The FLIR equipment did give advanced warning of the obstruction ahead but they simply did not appreciate the danger because it didn't fit with their situational map, a trap most pilots will have fallen into at one time or another.

A tragic accident that this experienced crew could and should have been capable of avoiding, despite the flawed navigation data and a completely unsuitable approach plan given the weather conditions at the time.

[John Eacott]

Sorry to all you current guys who love the complexity of all the Gucci modes, bells and whistles that the S-92 enjoys, and you guys well versed in procedures and plates for everything. All those 'advantages' were directly responsible for this CFIT. It simply would not, indeed could not, have happened to a simple 'steam age' Sea King.

I would dispute that: on 21st March 1974 054 from 824NAS flew into a 220ft high cliff on the Lizard Peninsular when positioning at night at 200ft radalt hold (due to doppler plot slippage was the BOI finding). Why the radar failed to give an indication that all was not well was never established, all four on board were killed.

[Al-bert]

I would dispute that: on 21st March 1974 054 from 824NAS flew into a 220ft high cliff on the Lizard Peninsular when positioning at night at 200ft radalt hold (due to doppler plot slippage was the BOI finding). Why the radar failed to give an indication that all was not well was never established, all four on board were killed.

Sorry John, I should have said RAF Sea King. All our procedures were post 1978 - lessons clearly had been learned.

[S76Heavy]

What astounds me here is why, with FLIR available on the MFDs, this was not selected to supplement the RADAR return on the other MFD.

The unit I was privileged to fly SAR with, did not allow it because the (cockpit) screen did not easily show which way the FLIR was pointing. It would be too easy to swerve to avoid something seen on te screen and smash into it because the FLIR was actually looking at an obstacle sideways.
We did, however, have a running commentary from the FLIR operator when he was operating the FLIR and we always acted upon any doubt expressed by any crew member. This was Maritime SAR in a rocky environment.

As an offshore pilot, I have used and use the radar as my primary means to remain clear of solid stuff when below MSA over water. Moving map and GPS/FMS are fancy calculators, the radar gives me a fix. Because it is a wx radar, I play with the tilt to see if there is anything missed on the previous sweep. It does not have an " ideal" setting, not even on mapping mode. I do not overfly anything I have not visually (mk1 eyeball) identified beforehand, as it has been pointed out by other contributors that sometimes stuff sails in the way that is high enough to seriously ruin your day.
I am old enough to have worked with just a monochrome radar and decca; anything later I consider a bonus. A MPP is still only " most probable" according to the calculator; reality may differ.

A tragic accident and I write this with the full benefit of hindsight.

[SASless]

Al-Bert,



Why would an Approach Plate for a preplanned IMC Procedure that had been surveyed, trained for, checked, and used incorporating the Gucci abilities of the FMS and other equipment cause an accident like this?

I submit the absence of that is the main contributing cause of this accident.

Times change as does technology....and we should change with it.

Eacott Reminded you that Steam Age 61's had their bad days and you then admitted post one such bad day....changes in the way business was done was effected.

So why not do the same after this one?

[Georg1na]

John - ref below


"I would dispute that: on 21st March 1974 054 from 824NAS flew into a 220ft high cliff on the Lizard Peninsular when positioning at night at 200ft radalt hold (due to doppler plot slippage was the BOI finding). Why the radar failed to give an indication that all was not well was never established, all four on board were killed."


Was it not something to do with MTI that meant the land did not show on the screen?

[[email protected]]

I think the absence of NVD is a bit of a red herring considering the helicopter was fitted with FLIR equipment. If lifting a casualty from a vessel, it would be normal to illuminate the lifting area with deck lighting. For sea and cliff rescue, there is a searchlight. NVD is more likely to be a hinderance than a help in most rescue operations since the pilot(s) should be positioning according to the directions from the winchman. Gouli - I am assuming from your comments that you haven't done SAR with NVG. Whilst the actual rescue is usually done on white light (or mixed with NVG) it is the getting to the rescue where NVG really come into their own.

DB - the best 'real world' view is out of the front window and with NVG on they would have seen the rock long before it became an issue.

Rotorspeed - as previously mentioned, FLIR does not look through cloud since it relies on the thermal differences between the objects it is looking at - in cloud the water droplets attenuate almost all the thermal energy and make everything look uniform.

P3 Bellows - it was mentioned earlier ISTR that the IAA wouldn't allow civilian use of NVD - a bit behind the times really since just about everyone else does it now.

[sudden twang]

CHC
Multi pilot
Hi Tech
Questions over SOPs/OM
Loss of SA Not noticing.
Questions of briefing for the let down.
A/C serviceable
CFIT low level or LOCFIT
All apply to G WNSB also.

[Search&Rescue]

Seen the statement before in this tread about the wheather radar.
Newer used a Wx-only radar, but I have used and am using Wx+SAR-radars( including Primus 701A wich I think is used in the S92 SAR?)
In my opinion these radars will detect and show small islands and rock regardless of mode and that they are safe and for awoiding terrain when flying over sea. Of course, as with all equipment, you need to be trained with to use it and I think we can safely assume that this crew was trained.
Earlier days of SAR only had the SAR/Wx-radar to rely on, combined with paper maps/sea carts for close-to-land operations, at least where I come from. In my world the radar picture superseeds moving map if seing ground/osbtacle on the radar( of course you should use all system that adds on SA).

I would absolutely think that the radar could be trusted, and that the radar should have been one of the first slice of the swiss cheese. The EGPWS should be one of the last. Said to see that it did not do the work this time.

Well said AAKEE!

Unfortunately 10 nm scale is not that perfect to detect obstacles within range 1,3-0,6 NM.

[Brutal]

S76 Heavy, couldn't agree more.....Radar!!!!!!

There are many holes in this piece of cheese that have been discussed....They all played a part, However, simplifying the situation, whether Blackrock was in/not in the database, an Imc letdown, a vmc night letdown etc etc...I don't care what the situation was, really the bottom line comes down to using the radar.. This IS your primary piece of Equipment that will save the day...When I used to fly offshore, even night VMC letdowns into the blackness, play with the radar, use the different modes, tilt, adjust, re-adjust, check all clear ahead, start the letdown...during the whole procedure, in any turn, the level off, I'd still be adjusting the tilt, etc, re-look where you are going, keep the communications going, and if the other pilot told me there was now a return , even if I was expecting something there, I wouldn't assume it was x until I could clearly see it, and if not visible, climb or turn well away until visual, etc.. and even though I am PF, I'll now take a glance too, see what's ahead, work together as a crew, not just take his/her word for it...and adjust accordingly...etc...I have used FLIR but we didn't have that offshore, didn't have other crew members apart from the other pilot, the rigs were in the gps but tankers passing through were not, doesn't matter, use the radar...don't need flir, gps doesn't show every possible target...doesn't matter, use the radar....and if I was x miles away from my destination and I was told to come left/right, alarm bells would have gone off?? Why come left or right? what the hell is out there? I am gobsmacked at the lack of use/poor comms from the radar operator and almost blasé attitude from the P1? If you were unfamiliar with an area too I would have been even extra cautious...used properly, at some point in the turn a large blob on the radar screen would have caught your attention even if it was off the screen on the last known approach track which has been suggested here due to drift!. It is easy in Hindsight to criticise, but as professionals, I am amazed and saddened at the total waste of life of 4 crew members, who I have the utmost respect for going out day and night to save others....
SAR is different from offshore, letting down towards land/rocks is different to letting down towards rigs, I have done both, but, the RADAR was still the primary tool to stop you hitting something....

RIP all the crew members, and I wish all the family members find the strength to get through this difficult time......

[jimf671]

... with NVG on they would have seen the rock long before it became an issue. ...

Agreed.

---------------

[terminus mos]

Brutal wrote:

SAR is different from offshore, letting down towards land/rocks is different to letting down towards rigs, I have done both, but, the RADAR was still the primary tool to stop you hitting something....

Long time since I did an ARA, but isn't the SOP to have the radar at 2.5nm?

[[email protected]]

What will be interesting is how the operators deal with the crew issues which have been noted and will inevitably form part of the final report.

Will the operators and regulators hide the shortcomings in equipment and procedures behind any failures of the crew to monitor the radar and conduct the letdown correctly?

We are often told about 'just-culture' in Safety Management Systems but how will that stand up to pressure from the operator to avoid and blame/litigation?

[griffothefog]

I put forward this theory in post #143

The cockpit transcript was depressingly similar. The captain advised the co-pilot (pf) to turn around. As he was Chinese without Level 4 in English this was relayed by the interpreter. He queried the heading and this also went back and forth through the interpreter. When it was resolved he commenced the turn but half way round the helicopter struck the top of the hill killing all three.

The radar was found to be 5 degrees nose up which would have masked the coast close up in front of them.
Sounds like ALT a great friend and mentor... 😢

[puntosaurus]

The thing which is hardest to explain here is that we know the copilot looked at the radar screen about 30s before impact and called a small radar return at 6nm/11 o'clock. At this point he was just under 1nm from Blackrock, so what happened to the Blackrock return ?

Assuming the radar return was Duvillaun More then it's about 0.5nm across from the radar's perspective. At 6nm the circumference around the aircraft is about 36nm (6nm*2pi). Let's say the radar sweeps out 60 degrees of that, ie. 1/6th of the circumference or a 6nm arc. It follows that Duvillaun More would have a lateral extent of 8% (0.5/6) of the sweep.

Run the same calculations for Blackrock which presents a lateral extent of about .12nm at about 1nm range and it turns out that it would occupy a similar amount of the sweep. Given the heading and drift of the aircraft those returns might well have been adjacent on the sweep although very different distances away.

It has also been suggested that Duvillaun More and Blackrock would have painted very different pictures on the screen because of the different topography and distances involved. I'm thinking Duvillaun More may have been more of a blob, but Blackrock has some 'stealth' features, sharp edges and flat surfaces angled away from the radar. In addition there might have been some clutter on the screen which might still include some weather in the solid IMC above even though the radar was in ground mapping mode.

I'd love to know from a SAR driver with lots of experience of interpreting weather radar pictures using the fit in this aircraft to speculate on what the radar picture might actually have been. Somehow the Blackrock return was misinterpreted but how ? Would the Carrick Islands just in front of them have appeared on the screen and lulled them into believing that the Blackrock return was a similar low feature ? Could Blackrock have looked like sea clutter or weather somehow ? Could Blackrock itself have created a local weather effect that masked the island ?

[Fareastdriver]

It's a sad fact of life that if a fully serviceable aeroplane flies into something it's not the aeroplane's fault.

[DOUBLE BOGEY]

Its an interesting point Punto. I am not SAR but a few ARAs in the past. I generally aimed the RADAR slightly below the horizon, maybe 3 degrees nose down, turned the gain to full, always in WX mode, and then backed off the gain to remove the sea clutter, leaving (what I believed) to be the hard bits behind.

I recall most people I flew with did mostly the same procedure. Although an handful would obsess about which mode they wanted. I think "Search" modes featured a lot in these discussions, but if in Command, I always resolutely insisted on the WX mode and the technique I have described.

Having written this, and now as we review this accident, it seems bizarre that we have not formally mandated an exact technique for setting the RADAR up. (Maybe in some other organisations they have).

Anyone have any other techniques they would like to share or has anyone been subjected to a "Mandatory" setup.

In fact I change my story a bit having thought about it. What I did was never relied on the angle of dangle indication. I would turn the gain full up, turn the head down until I had total sea clutter, or in calm, targets crystal clear where I expected them to be. Then I backed off the gain until the sea just about disappeared. Funny what comes back when you read what you wrote previously. Nope, I never used the angle of dangle thingy.

[llamaman]

There could be some cognitive issues here regarding what the crew were seeing versus what they were expecting to see.

If I was running the investigation I would be insisting on an S92 flying the same profile (day VMC) in the same configuration to have a look at the indications prior to the point of impact. Obviously you can't replicate the weather conditions so the radar returns would be a variable but it would be a very useful exercise.

[puntosaurus]

It's Ireland. It's very easy to replicate the weather conditions.

Less facetiously, I think that is a great idea. I wonder if with the sharp vertical extent and it's proximity, and it's stealthy qualities, Blackrock looked very similar at 1nm to the Carrick Islands at this point .2/3nm away. If the crew could rationalise away the Carrick Islands, then it would be easy to do the same for Blackrock.

[Fareastdriver]

On the CVR it has the co-pilot reporting a contact at 11 o'clock, 6 miles at 32secs or about 0.75 n.m. before impact. Drumacappel wasn't at six miles then; it started at about 5 miles. What was at six miles was the highest point of the island on the eastern side. A radar tilted at 0 degrees would have seen the coast, one titled up wouldn't.

[G0ULI]

From personal experience with marine radar, the images generated with a range scale set to three miles or less are pretty useless due to sea clutter. Also at these ranges there is the possibilty of very strong radar returns activating protective devices that are designed to prevent radar transmitter energy from destroying the very sensitive receiver section. In effect, the more powerful the radar return, the more likely that the receiver will be desensitised and effectively nothing will be displayed on the screen.

This is a very simplistic explanation of why they maybe saw nothing on the radar screen, as there are numerous settings that all interact and affect the radar picture. Depending on the wavelength of the radar, cloud and rain reflections can also absorb or reflect sufficient energy to blind the radar receiver at close ranges.

I had several years mucking about with the marine stuff including installations and commissioning, if anyone feels the need to argue or debate the details via PM.

[Michael Gee]

not my league but were they Night VMC at 200 ft and did not see from afar the light on Blackrock flashing? Was the light house working 100%?

[cncpc]

not my league but were they Night VMC at 200 ft and did not see from afar the light on Blackrock flashing? Was the light house working 100%?

It's likely the light was in cloud.

[[email protected]]

And that the 'heads-in' mindset along with the likelihood they didn't even realise there was a lighthouse there meant they weren't looking for it.

[Al-bert]

Al-Bert,



Why would an Approach Plate for a preplanned IMC Procedure that had been surveyed, trained for, checked, and used incorporating the Gucci abilities of the FMS and other equipment cause an accident like this?

I submit the absence of that is the main contributing cause of this accident.

Times change as does technology....and we should change with it.

Eacott Reminded you that Steam Age 61's had their bad days and you then admitted post one such bad day....changes in the way business was done was effected.

So why not do the same after this one?

Sorry SAS - I don't understand your post - yes times change, in this unfortunate crew's case for the worse. Over complication of navaids in an overworked cockpit, a procedure mistakenly flown because it wasn't an IFR plate, unreliable data inputs to the nav kit, rear crew not totally involved in the procedure (poor CRM) - all or any of these things may have contributed to the cfit. Mr Eacott referred to an early RN SK (not a 61) cfit - I assume RN procedures changed post that crash and the RAF procedures followed, and in time incorporated GPS and NVD's. Tragic accident to an experienced crew that shouldn't have occurred and yes, I've been to Blacksod on a few occasions too.

[dClbydalpha]

And that the 'heads-in' mindset along with the likelihood they didn't even realise there was a lighthouse there meant they weren't looking for it.

And if they weren't looking for it, it is possible they weren't monitoring the other sources of information to look for it either. I didn't see if the report has details on the radar range settings. Can the radar range be set separately from the display range?

Does anyone know what sensor configuration the EO/IR turret has? Is the aircraft capable of displaying two video outputs at once?

[roundwego]

Any helicopter weather radar I have used (excluding that fitted to civilian AW machines) have been good down to half a mile for obstacle avoidance as long as it is in the correct mode. It's no good leaving it in wx mode because the gain is then fixed and non adjustable in order to optimise the observance of Level 3 weather returns which equate to an active thunderstorm (or very heavy rain).

In absolute contradiction of Double Bogey above, use of the correct Search mode is vital. There will be at least one which is optimisied for short range selection which will reduce the pulse length and increase the pulse frequency. When level at 200' or thereabouts, tilt control should be set about level which will give about +/- 3 to 5 degrees of scan above and below the horizontal depending on the diameter of the aerial. The larger the aerial, the narrower the beam will be in both horizontal and vertical plane. If the radar is set correctly, Black Rock should have been painting loud and clear.

[Ex Machina]

DB

You might want to check your memory as the gain function does not work in weather mode. The important point about using search 1 or 2 modes when looking for a rig or ship is that it is short range (20nms or less) and the PRF is increased. To put it simply, higher PRFs transmit more energy in a given time, which produces stronger and more defined radar reflections. The best picture will be provided by a combination of search modes, tilt and appropriate gain setting.

[DOUBLE BOGEY]

Ex Marina, you could be right. It's a few years since I used the radar in anger but I was pretty sure that how I managed it. The Search functions in my experience are too complex, probably for the reasons you describe and I do remember a few times realising we had no return on a target that was definitely there and realising the copilot had selected a search mode. A quick switch to WX mode and sudenly the target is a nice big red blob.

[dClbydalpha]

In my experience a TSO compliant radar will not allow the operator to change gain in weather mode.

[Brutal]

sorry gents, but maybe everyone who uses the radar offshore/sar should do some reading, my goodness!!!!!

Primus 660 radar

The GAIN knob is a single–turn rotary control and push/pull switch that is used to control the receiver gain. Push in on the GAIN switch to enter the system into the preset calibrated gain mode. Calibrated gain is the normal mode and is used for weather avoidance. In calibrated gain, the rotary portion of the GAIN control does nothing. In calibrated gain, the color bar legend is labeled 1,2,3,4 in WX mode or 1,2,3 in GMAP mode.
Pull out on the GAIN switch to enter the system into the variable gain mode with VAR (variance) displayed in the color bar. Variable gain is useful for additional weather analysis and for ground mapping. In WX mode, variable gain can increase receiver sensitivity over the calibrated level to show very weak targets or it can be reduced below the calibrated level to eliminate weak returns.
WARNING
HAZARDOUS TARGETS CAN BE ELIMINATED FROM THE DIS- PLAY WITH LOW SETTINGS OF VARIABLE GAIN.

:{

Maybe this crew were as familiar as some here with the equipment they were using then it's no wonder accidents happen..(I am not saying they were, but some of the answers here from professionals who use wx radar is shockingly scary)!!!:sad:

[SASless]

Round,


When level at 200' or thereabouts, tilt control should be set about level which will give about +/- 3 to 5 degrees of scan above and below the horizontal depending on the diameter of the aerial.

"Level" to what would be the Horizon and compensating for Aircraft Pitch Attitude variation of what would otherwise be Wings Level in Pitch due to the speed it is flying? Is that the "Level" to which you refer?

[DOUBLE BOGEY]

Brutal, thank you for confirming my actions. However your adminoishments also apply to me because I learned the Radar procedure a long while back and really just kept applying it to each new box we were equipped with.

Like I said for me the simpler the better. Start with max gain WX mode point at the sea and trim the radar up until the picture is clearer and reduce the gain to remove sea clutter. Served me well but maybe I should have read the books a little more.

[GKaplan]

All references to 'search' modes (SR1 or 2) denote Puma pilots and are not relevant to the Honeywell Primus 701 used in the S92. No such modes there :p. (Ok, unless you think of 'ground mapping' modes as the same. Don't shoot! ;) )

[AAKEE]

Round,
"Level" to what would be the Horizon and compensating for Aircraft Pitch Attitude variation of what would otherwise be Wings Level in Pitch due to the speed it is flying? Is that the "Level" to which you refer?

The 701A is gyrostab:ed up to 30 degree of combined nose up/down/bank angle.
The tilt value is refering to the horizon( info from IRS i think).

Depending on antenna, a wild guess of size the radar lobe on the S92 is somewhere around 8 degrees... wich means it will see 4 degrees up and down with zero tilt. Thats the zone of 'good returns', it will see and plot up to total of 14 degrees but not with the "calibrated" gain.
Rules of thumb for radar is one degree at one mile(Nm) makes 100 foot. So at 200 foot with zero tilt it should have sen ground(the sea level) as close as 0,5 mile in front.

[AAKEE]

sorry gents, but maybe everyone who uses the radar offshore/sar should do some reading, my goodness!!!!!

Primus 660 radar

The GAIN knob is a single...

I think most offshore/SAR people knows how to tune a radar.

You could start by refering to manuals for a search and rescue/ weather radar.

In some purpose, they dont do exactly the same thing. For wx, yes but...

[dClbydalpha]

Can any S92 operators tell me the size/colour of FMS WP symbols? Are they overlayed on top of the radar video?

[puntosaurus]

What a generous series of posts DB. And your original observation is very insightful. How could there not be an SOP for something this crucial. Let's hope there was here, and let's hope it's published in the final report.

Looks like roundwego is doing some research into the consequences of the Primus using the GMAP2 setting with 10nm range, so let's hope something good comes of that. It's suggestive that these settings are specifically referred to in the report as increasing the amount of clutter on the screen, and it was a high seastate night.

Would still love to know from users of this sort of kit what a rocky outcrop looks like on radar vs a distant headland. All the radar energy from any point in the scan's azimuth will come back from a very narrow range which the screen ought to interpret as a rough coastline rather than as a blob. And there should be nothing at all behind the coastline as it's in radar shadow. I think someone else was talking about this earlier.

Very hard to see how you could miss a feature like that and yet spot a generic blob at 6nm. But as they weren't expecting a rock, maybe they just tuned out or rationalised the echo as something unthreatening.

[Ex Machina]

Brutal,

That might be the case on the Primus 660 but not the Telephonics RDR 1500B/1600/1700A systems. IIRC the L2 and 225 were fitted with RDR 1600 as standard in the UK so in Wx mode the receiver gain is preset and cannot be changed by the pilot. That is why I suggested a memory check for DB as I know he flew those types.

Shockingly scary? Perhaps not - it depends on your kit!

[AAKEE]

Brutal,

That might be the case on the Primus 660 but not the Telephonics RDR 1500B/1600/1700A systems. IIRC the L2 and 225 were fitted with RDR 1600 as standard in the UK so in Wx mode the receiver gain is preset and cannot be changed by the pilot.

In Primus 701A the gain can be adjusted also in Wx mode. It can also easily be reset to calculated( fixed gain) to get the appropriate WX readings with correct colors. When used in Wx Alert mode the gain is fixed and cannot be changed.
If the above apply to S92 due to implementation etc, I do not know.

[Brutal]

Thank you ex-machina, I cannot remember ever using a wx radar where the gain could not be adjusted in wx mode....maybe I have been flying too long??

AAKEE
"I think most offshore/SAR people knows how to tune a radar".

Sorry to inform you that many times I have witnessed, especially during checks pilots not properly using the radar...ARA overhead, in the descent I noticed a return that would be on our inbound track, we levelled off, turned to face the inbound track and had already reduced speed, then proceeded with the descent, with the tilt only just giving us a return at six miles, but not the previous target...when the P1 was questioned he hadn't noticed the return outbound and hadn't bothered to re-adjust the tilt to look for potential returns closer, and not understood that the reduction in airspeed made the nose pitch up slightly more, and lose the first return...very very simple errors, but potentially lethal....again, my post was not on specific radar types, but pilots failing to use/utilise/understand radar and it's pitfalls.

DB, I remember being taught that way too, full gain to start, adjust tilt, etc...:ok:

[SASless]

What was the CHC In-Service training routine for ICG Pilots and Crew?

Many years ago as UK SAR was being shifted to the Civvie side from the Military....Crab and others raised concerns that then existing Training Hours and array of Training Tasks might decline.

Anyone able to share their knowledge about ICG training?

[AAKEE]

For the comments on the 10nm scale, I dont se a big problem using 10mile scale.
This scale still shows everyrhing, scaled down though.

For a let down to hover( transition down) we use a fixed scale, more zoomed in than 10 nm. But then you do this close to something, and need to see this more in detail. I think there also a good thing to use a standard setting making you refer to the picture at a 'known' scale.

For a descent to below clouds and the plan to continue flying I think the idea to see radar returns that give you SA in the radar picture, for example the shore line or islands is good, that may be the reason for that selection. Too zoomed in and you loose the SA and the easy relation to a map/moving map and so on.
(I would have worked with radar settings, and scale to make sure but thats not the point here).

[Hot_LZ]

The wx mode of the S92 radar IS gain adjustable.

Something the size of Blackrock could not be missed whether in WX or GMAP. Quite a large return would be bright red on the screen, whether on a 10mile scale or smaller. Even if the gain was badly set there is still a noticeable difference in return colour. At 200' the tilt would have to be greater than +5 to start shrinking the contact.

LZ

[Pruneface]

I've been lurking here for the past few weeks since the tragic accident and haven't posted. However I have a question that is troubling me and would be grateful for any clarification that can be provided by y'all. I have read the AAIU report, and have looked at a number of Coast Guard related information resources that are available on the web.

My reading suggests that the IRCG ought never to have been tasked to deal with the SAR/Medevac incident in the first place. According to the AAIU report, "The position of the FV at the time of the call was N 54 17.450’, W 014 06.944’, which was 141 nm and bearing 270 degrees from Eagle Island, Co. Mayo. "

The North Westerly boundary of the Irish SAR responsibility is contained in the IRCG SAR framework, previously linked to here and available at http://www.dttas.ie/sites/default/files/publications/maritime/english/irish-national-maritime-search-and-rescue-sar-framework/sar-framework.pdf

The Irish SAR 'box' is contained within the area identified by the coordinates laid out in Appendix 1.1 of that framework. These coordinates are listed as:

55 20N 006 55W - 55 25N 007 20W
55 20N 008 15W - 54 45N 009 00W
54 34N 010 00W - 54 00N 015 00W
51 00N 015 00W - 51 00N 008 00W
52 20N 005 30W - 53 55N 005 30W
54 25N 008 10W - 55 22N 006 55W

A depiction of that area is contained at Image 1 attached to this post.

Anything outside the Irish box lies with the designated UK SAR area, to be dealt with by UK-based SAR rather than Irish SAR. and is depicted on Image 2, which is taken from Annex 1 of the Strategic Overview of UK's SAR Operations published in January of this year.

Finally, Image 3 depicts my placing of the published coordinates of the North Westerly extremity of the "Irish SAR box", coupled with the coordinates of the FV published by the AAIU.

My question is this: Have I totally made a hames of placing the published coordinates onto my Google Maps?

Or,

Did that FV makes its call within the UK realm of responsibility, rather than that of the IRCG? If so, when the FV contacted Malin on that night, why did Malin start the whole process of tasking Irish SAR resources when the FV did not lie within its area of responsibility. Why did Malin not hand off to the UK- based SAR services instead?

[G0ULI]

The radar transmitter is pumping out pulses of energy of up to 1,000 watts. The receiver is designed to respond to returning echo signals measured in micro watts, a millionth of a watt. Even if the transmit/receive protection circuits work in around a microsecond, you will see nothing within a 300 metre range. If they take three microseconds to switch over, you are blind to everything within a kilometre. We are talking millionths of a second here to switch from 1000 watts out to a few millionths of a watt coming back! The technology is well proven, but transmit/receive delays increase as equipment ages, so close in blind spots get bigger. A crew may actually perceive the radar equipment as working better as it ages because of an apparent reduction in close in sea clutter.

As stated earlier, very strong local reflections can overwhelm the receiver protection circuits and render the radar blind even at longer ranges. It is possible to tune the radar to reduce transmitter power, reduce or tune out sea clutter, reduce receiver sensitivity, and digitally enhance the display picture, but this takes time and a certain degree of skill to optimise the settings.

Judging from the cockpit transcripts, I am pretty certain that the radar did not display Black Rock in any recognisable form due to the weather conditions at the time, incorrect mode or adjustment of the radar receiver, slow changeover of the transmit/receive protection devices, or possibly overload of the receiver circuits due to very high return signal levels. None of these scenarios would necessarily be apparent or present any real problems to the crew over open water looking for a vessel, particularly at longer range settings.

If Black Rock wasn't showing on the radar display, then the scepticism voiced by the pilot and delay in changing course, in response to the warning from the FLIR operator, makes perfect sense.

[player104]

I'm trying to inform myself of wx radar and its ground mapping mode, how it works, what it might look like etc.

I found the following old video helpful and in particular the part at 33:55 time linked below:

https://youtu.be/O4UxlOBvTkI?t=1975

and the attached image seems to show the red crescent shape of a mountain and its shadow into the "ground stripe"

[jimf671]

That works out Pruneface. Double-checked the AAIU report and the Irish SAR Framework and put the numbers in Google Earth and it works out about 11nm into the UK SRR.

[Pruneface]

That works out Pruneface. Double-checked the AAIU report and the Irish SAR Framework and put the numbers in Google Earth and it works out about 11nm into the UK SRR.
Thanks for your confirmation. I thought I was losing it for a while there.

So, if the FV was actually in the UK SAR area of responsibility at the time of the call, why was the UK SAR not the prime mover, using if necessary and by dint of International Agreement, the Sligo SAR resource (on a call for assistance) but not obviously requiring the Dublin based R116 to get involved. In addition, considerable mention has been made in respect of the 'out-of-hours unavailability' of the Irish Aer Corps CASA resource(s) and indeed, the IAC has on occasion been denigrated for this since the crash.

Perhaps I'm over egging the importance of this in my own mind, and perhaps a very fluid 'boundary' exists worldwide between SAR areas of responsibility and all this is irrelevant, but I'm just getting a very bad feeling about this tasking and each of the individual missions that flowed from it, some of which in themselves create questions that have not been satisfactorily answered, not including the specific questions surrounding the crash itself that the IIAU is dealing with.

[Search&Rescue]

For the comments on the 10nm scale, I dont se a big problem using 10mile scale.
This scale still shows everyrhing, scaled down though.

For a let down to hover( transition down) we use a fixed scale, more zoomed in than 10 nm. But then you do this close to something, and need to see this more in detail. I think there also a good thing to use a standard setting making you refer to the picture at a 'known' scale.

For a descent to below clouds and the plan to continue flying I think the idea to see radar returns that give you SA in the radar picture, for example the shore line or islands is good, that may be the reason for that selection. Too zoomed in and you loose the SA and the easy relation to a map/moving map and so on.
(I would have worked with radar settings, and scale to make sure but thats not the point here).

Sorry AAKEE, but I disagree... If you are cruising at 200 ft RHT and NAV/LNAV coupled you are heading (or actually tracking) towards an obstacle which is 300 ft AGL high... and you don't have a visual contact with the target at distances 1,3 nm or 0,6 nm (ALTITUDE WARNING)... I think that the 10 nm scale was not the best option in order to avoid the collision... Then if the crew was not aware of the high obstacle ahead, it will be a SA issue and a different story...

Btw. I highly respect "Irish Aviation Community" and I know that the crew members were true professionals! RIP.

[Al-bert]

What was the CHC In-Service training routine for ICG Pilots and Crew?

Many years ago as UK SAR was being shifted to the Civvie side from the Military....Crab and others raised concerns that then existing Training Hours and array of Training Tasks might decline.

Anyone able to share their knowledge about ICG training?

Hi SAS, I'm waiting for a reply to this one too! :hmm:

[G0ULI]

player104

A useful video that shows some of the pitfalls when interpreting the radar display. However note the range settings on the display and target return distances of between 20 and 40 miles. At close range settings the display can be much harder to interpret although all the points mentioned still apply.

[[email protected]]

Pruneface - the whole point of SAR is giving the quickest response, regardless of international boundaries - how long do you think it would take to task a UK-based aircraft (probably from Caernafon) to fly across Ireland, refuel and then go to the FV compared to tasking the Sligo aircraft to something that might technically be outside their area?

The vessel may also have been steaming towards the mainland (this is normal to reduce the range) and could well have been estimated to be inside the Irish area by the time the rendevous happened.

That aside, the Irish area really should be expanded now they have better aircraft - they would never go more than 160 nm out with the S-61 but the S92 has a far better RoA.

Gouli - are you sure about your radar theory? The minimum distance for the radar on the Sea King was 75m which is why it was so good at coastal and vessel letdowns.

[IRCG SMC WHITEY]

Crab.
You got it spot on. IRCG would have been tasked by HMCG as being closest useable asset.
As for expanding the Irish SAR Region . . . thats mired in ancient politics best left out of this forum

[AAKEE]

Gouli - are you sure about your radar theory? The minimum distance for the radar on the Sea King was 75m which is why it was so good at coastal and vessel letdowns.

The min range is about 0.1Nm (from my memory) in SEA mode. In ground mapping, ehhh, I'd say around 0.15. It is a bigger value in WX mode, that'll be aound the numbers given by Gouli.
Gouli, its a 10kW radar, with 8kW as nominal power.

For others, about the radar painted picture: the screen will only show where the radar pulse hit somethig. From low level towards a very steep high hill higer then your height the closest part painted on screen will be the first hit close to sea, and the furtest will be the upper part of lobe hitting higher on the slope further away.( a vertical steep will only paint a thin line).
From wikipedia pictures, they flew towards this small island short side, that is quite steep. Wiki say Blackrock measures 400m length and 200m width, thats 0.1nm wide. So the radar picture will show a very small width( seen in track perspective). The length it will paint is the steep's horizontal difference + the "beach". From pictures that looks like a maximum of half length, ie also about 200m or 0.1nm.

[Pltnorway]

Can any S92 operators tell me the size/colour of FMS WP symbols? Are they overlayed on top of the radar video?

That is a very valid question.

With the radar set to 10 NM range on the PM's (copilot) NAV screen in this case, the waypoint symbol for "BLKMO" would hide the radar return from Blackrock. If using 5 NM, or even better 2.5 NM range, the return from Blackrock would be relatively larger than the waypoint symbol, and hence get your attention.

I tried this a couple of days ago (in the S92 with the Primus 701A radar) using an oil rig as "Blackrock". With 10 NM range, GMAP2, optimal gain and tilt, and at a distance of 1-2 NM from the oil rig it was very difficult to actually spot the return because of the waypoint symbol. Blackrock might have given a slightly larger return than an oil rig though.

[rotorspeed]

I'm staggered at the number of posts about radar operation and differing views and understanding about it - it is obviously very complex. It therefore seems all the more extraordinary that a crew select an approach type (long transit at 200ft) that relies for safety on radar, which clearly has a lot of risks associated with its use (that they probably didn't fully realise), to rely on for obstacle avoidance. The route guidance the crew followed has been criticised heavily by some - but the chart itself did not include any vertical profile so was surely obviously not an IMC let down procedure. I guess the associated notes might include minimum heights, but it seems highly unlikely. So why did the crew choose to carry out the whole route at 200ft? Was it too much automatic default to the over sea APP1 coupled approach mode, without enough thinking?

Clearly this procedure has important uses for SAR, but by using it here the crew put themselves in a position of having to rely on a complex system - radar - with considerable risks to be safe.

Safety of course is all about risk minimisation and the risks of using a simple IMC let down, minimising distance at low height, relying on GPS waypoints, seem to be far less to me. Blacksod really doesn't look a tight, tricky location to get into. With the two GPS systems accuracy would be pretty much guaranteed, and it would have been easy to verify position using other tools such as RadAlt anyway. And all the benefits of radar and FLIR could also still used, but with far less risk of hitting anything if - as seems here - radar use is flawed.

Furthermore such an approach would take far less flight crew attention - frankly it could have been flown single pilot without problem.

So why did the crew apparently choose to blend the APP1 approach mode with this VFR inter lighthouse route guidance? Or maybe they didn't choose it - could it have been specified by the operator to do this? And they didn't question it?

[leopold bloom]

Pruneface - the whole point of SAR is giving the quickest response, regardless of international boundaries - how long do you think it would take to task a UK-based aircraft (probably from Caernafon) to fly across Ireland, refuel and then go to the FV compared to tasking the Sligo aircraft to something that might technically be outside their area?

The vessel may also have been steaming towards the mainland (this is normal to reduce the range) and could well have been estimated to be inside the Irish area by the time the rendevous happened.

That aside, the Irish area really should be expanded now they have better aircraft - they would never go more than 160 nm out with the S-61 but the S92 has a far better RoA.

Gouli - are you sure about your radar theory? The minimum distance for the radar on the Sea King was 75m which is why it was so good at coastal and vessel letdowns.

I think what the officer means is "theoretical minimum range".

[SASless]

Ai-Bert,

I raised this before in the thread well back in the many posts and repeated it again for reasons you understand.

The standards, method, curriculum, and time devoted to Initial and Currency Training is a very important issue that bears close study by the Investigators.

I was hoping those with first hand experience would offer some insight into the CHC/Irish Coast Guard. operation training program.

Crab and other SAR folks have expressed concerns back during the U.K. Transition to the current system..

[sargs]

Gouli:
The radar transmitter is pumping out pulses of energy of up to 1,000 watts. The receiver is designed to respond to returning echo signals measured in micro watts, a millionth of a watt. Even if the transmit/receive protection circuits work in around a microsecond, you will see nothing within a 300 metre range. If they take three microseconds to switch over, you are blind to everything within a kilometre. We are talking millionths of a second here to switch from 1000 watts out to a few millionths of a watt coming back! The technology is well proven, but transmit/receive delays increase as equipment ages, so close in blind spots get bigger. A crew may actually perceive the radar equipment as working better as it ages because of an apparent reduction in close in sea clutter.As an ex-SAR radar operator I've tried to stay out of this debate - I used to operate a search radar, not a weather radar, but the statement above was a step too far. Minimum Range (Rmin) is a function of pulse width, or pulse duration (interchangeable terms), caused by a pulse requiring time to be transmitted, hit something and return. For example, with a radar with a pulse duration of 1 microsecond the pulse leading edge can travel out for 0.5 microsecond (at the speed of light, and when the receiver is effectively 'blind'), hit something, and travel back to the radar in the following 0.5 microsecond. Using the equation, Rmin = C x PD/2, if C = 300,000,000 m/s (approx) then Rmin in this case is 150 m. As Crab says, the Sea King radar had an Rmin of 75m due to its PD of 0.5 microseconds.

There usually aren't any complex "transmit/receive protection circuits" in the manner suggested as they are usually simple isolators (with no moving parts) that allow microwave energy to pass in one direction but not the other. You are mixing up circuits within the receiver which are designed to prevent very large targets swamping smaller ones by raising the receiver Automatic Gain Control too high.


"Transmit/receive delays increase as equipment ages?" That's just wrong.


Finally, I never perceived the apparent lack of information on my radar screen as an indication it was "working better."

[G0ULI]

crab

Radar operates at the speed of light, 300,000 kilometres per second, or 300 metres every millionth of a second. Modern electronic components have reduced the size and increased the power of radar systems, but there is a physical limit to how much functionality can be built into a single system. Low power motion detector systems can operate at ranges of a few feet, but a system capable of picking up targets at a range of 40 miles will have its' performance compromised at very close ranges due to the laws of physics. In order to obtain unhindered close range performance, the use of two identical physically coupled but electrically isolated scanning dishes would be required. The sheer size of such an antenna system would preclude fitting in most aircraft.

I am as certain as I can be that the crew did not see Black Rock on the radar display and that Black Rock was certainly not presented on the display or recognised as presenting imminent danger. I am also sure that such an experienced crew were lulled into a false sense of security by perhaps not appreciating the ultimate physical limits of the radar system due to weather and possibly a latent deterioration in system performance due to the ageing of components.

A flawed approach pattern, lack of detailed mapping information, radar returns that were "unreliable" at close range and a loss of situational awareness in dodgy weather all combined to create the circumstances for this tragedy to happen. The classic holes in the swiss cheese lining up analogy of many aviation accidents.

sargs

Yes, 75 metres is a theoretical minimum range with a half microsecond transmit/receive switchover. You are quite correct that quarter wave stubs of waveguide are used to provide almost perfect isolation between the transmit and receive sections and that no electronic components are necessary to provide this isolation, just careful design and adherence to mechanical tolerances. But radar waveguide alters in size due to temperature changes and/or mechanical damage when knocked so some part of the transmitter energy can end up being fed towards the receiver circuits as the transmit pulse is fired off. To cater for this, there is a very high speed schottky diode mounted across the waveguide of the receiver section designed to short out if receive signals exceed a small fraction of a volt. It is this component that ages and needs to be replaced at regular intervals. When I worked for Marconi, every radar engineer carried half a dozen replacements in their tool kit. It was standard practice to replace them on every visit for servicing or fault finding.

[[email protected]]

Gouli - I refer you to the post above yours by sargs regarding radar theory:ok:

If modern weather/search radars in helicopters are so difficult to setup and use accurately, why on earth is there not a dedicated and properly trained radar operator doing it in a modern SAR helicopter rather than a co-pilot (often the least experienced member of the crew) being given the task on top of all his other duties?

leopold - yes quite right as always:)

[G0ULI]

crab

Modern radar systems are brilliant. Operation has been simplified with automatic optimisation to present the clearest possible display, but they are not infallible.

[212man]

That is a very valid question.

With the radar set to 10 NM range on the PM's (copilot) NAV screen in this case, the waypoint symbol for "BLKMO" would hide the radar return from Blackrock. If using 5 NM, or even better 2.5 NM range, the return from Blackrock would be relatively larger than the waypoint symbol, and hence get your attention.

I tried this a couple of days ago (in the S92 with the Primus 701A radar) using an oil rig as "Blackrock". With 10 NM range, GMAP2, optimal gain and tilt, and at a distance of 1-2 NM from the oil rig it was very difficult to actually spot the return because of the waypoint symbol. Blackrock might have given a slightly larger return than an oil rig though.

To add another relevant part to the question - both the waypoint symbol and the strongest GMAP returns are magenta. It may well be that a particular range set up will result in the Blackrock return being somewhat masked by the waypoint symbol and labelling, and I'm sure the AAIU will replicate the conditions. More so, if the illumination levels are dimmed down to enhance night vision.

On that point, I feel that Al-berts' rather pejorative remarks about "children of the magenta line" are misplaced in this context. The expression usually refers to young pilots that have never known anything other than glass cockpits and automation - in this case both pilots had spent 20 odd years each flying S61s. Relative newcomers to the magenta line perhaps.....

[sargs]

Gouli

When I worked for MarconiThat'll be the radar company that ceased operations 30 years ago? :hmm:

[roundwego]

The Primus 701 is nearly 30 years old

[SASless]

Proven technology?

Anything better on the market that could be installed in place of the current fit?

[[email protected]]

Relative newcomers to the magenta line perhaps..... I think that might be a very valid point in that after a couple of years of 'magenta' all those hard-won lessons on old technology get forgotten and reliance on the new and shiny kit becomes absolute.

[FC80]

crab

Radar operates at the speed of light, 300,000,000 kilometres per second, or 300 metres every millionth of a second. Modern electronic components have reduced the size and increased the power of radar systems, but there is a physical limit to how much functionality can be built into a single system. Low power motion detector systems can operate at ranges of a few feet, but a system capable of picking up targets at a range of 40 miles will have its' performance compromised at very close ranges due to the laws of physics. In order to obtain unhindered close range performance, the use of two identical physically coupled but electrically isolated scanning dishes would be required. The sheer size of such an antenna system would preclude fitting in most aircraft.

I am as certain as I can be that the crew did not see Black Rock on the radar display and that Black Rock was certainly not presented on the display or recognised as presenting imminent danger. I am also sure that such an experienced crew were lulled into a false sense of security by perhaps not appreciating the ultimate physical limits of the radar system due to weather and possibly a latent deterioration in system performance due to the ageing of components.

A flawed approach pattern, lack of detailed mapping information, radar returns that were "unreliable" at close range and a loss of situational awareness in dodgy weather all combined to create the circumstances for this tragedy to happen. The classic holes in the swiss cheese lining up analogy of many aviation accidents.

sargs

Yes, 75 metres is a theoretical minimum range with a half microsecond transmit/receive switchover. You are quite correct that quarter wave stubs of waveguide are used to provide almost perfect isolation between the transmit and receive sections and that no electronic components are necessary to provide this isolation, just careful design and adherence to mechanical tolerances. But radar waveguide alters in size due to temperature changes and/or mechanical damage when knocked so some part of the transmitter energy can end up being fed towards the receiver circuits as the transmit pulse is fired off. To cater for this, there is a very high speed schottky diode mounted across the waveguide of the receiver section designed to short out if receive signals exceed a small fraction of a volt. It is this component that ages and needs to be replaced at regular intervals. When I worked for Marconi, every radar engineer carried half a dozen replacements in their tool kit. It was standard practice to replace them on every visit for servicing or fault finding.

G0ULI - you are polluting this thread with misinformation and utterly erroneous conjecture based on experience that has got absolutely nothing to do with the subject in hand.

:ugh:

[S76Heavy]

I think that might be a very valid point in that after a couple of years of 'magenta' all those hard-won lessons on old technology get forgotten and reliance on the new and shiny kit becomes absolute.

Which is why you need to switch off all the fancy stuff, once in a while and do it old style. Not a popular view in H&S dominated industries like aviation, but it helps to appreciate what the fancy bits can and cannot do for you. Ue it when you must, but when you train it has got to come off every now and again.

With regard to using the radar for ground mapping: I never trust the thing to show me what I need to see, so I constantly select short to medium ranges, adjust gain, tilt and mode just to make sure I don't miss anything that might harm us. Low level below MSA, especially at night/in poor visibility is a dangerous place to be. Changing scales and modes also helps in showing something hidden under a waypoint marker. Never take anything for granted ..

[Pruneface]

how long do you think it would take to task a UK-based aircraft (probably from Caernafon) to fly across Ireland, refuel and then go to the FV compared to tasking the Sligo aircraft to something that might technically be outside their area?


The Dublin helicopter was 140 nm from the refuelling site at Blacksod. Caernarfon was 70 nm further away. So the answer to your question is that the extra travel time involved would have been approx 30 minutes.

My point is not about taking Sligo out of the picture. I can see why Sligo would have been tasked, even if HMCG was the principal mover.

[llamaman]

Having flown pre, post, and during the magenta revolution and experienced the full spectrum of technology across approx four decades worth of aircraft innovation I believe it is overly-simplistic just to blame the technology (and over-reliance on it). Crews have been routinely flying serviceable aircraft into the ground since aviation began.

The reasons vary and causes range from straightforward to vastly complex. Wherever there is human decision-making involved in a system (of any kind) there will be accidents. James Reason's 'Swiss-cheese' model is an eye-catching representation of the way that a combination of errors conspire to cause tragedy. Even this though is a simplistic view; the investigators on this one will have a hell of a job exposing all the relevant factors, and their complicated relationships, that caused this tragedy.

Those that shout "more training" and "less automation" may feel better but the picture is vastly more complicated than that. Learning from accidents like this will no doubt help safety culture to evolve but, in my opinion, the human element combined with the limits of current technology will continue to conspire and result in accidents.

I admired Bristow's optimism with their recent 'Target Zero' safety program and statement that they genuinely believe that accident rates can be reduced to zero. I'm not so sure.

[dClbydalpha]

That is a very valid question.

With the radar set to 10 NM range on the PM's (copilot) NAV screen in this case, the waypoint symbol for "BLKMO" would hide the radar return from Blackrock. If using 5 NM, or even better 2.5 NM range, the return from Blackrock would be relatively larger than the waypoint symbol, and hence get your attention.

I tried this a couple of days ago (in the S92 with the Primus 701A radar) using an oil rig as "Blackrock". With 10 NM range, GMAP2, optimal gain and tilt, and at a distance of 1-2 NM from the oil rig it was very difficult to actually spot the return because of the waypoint symbol. Blackrock might have given a slightly larger return than an oil rig though.

Thanks, my beer mat calculations had Blackrock as sub tending 900m at a couple of miles (including antenna beamwidth). At 10 nm display across, then each pixel would be about 50m and so 18 pixels. Symbols are often between 16 and 32 pixels. My concern was that if a symbol was coincident with the return then it might not have been as compelling an indication as it should. Particularly if not being looked for. All built on assumptions of what display ranges were selected so just wild conjecture. Thanks for the answer.

For those calculating radar MDR remember it is not just PW but also the Receiver Recovery Time that has to be used in the calculation.

[G0ULI]

FC80

The aircraft flew into a rock that clearly was not visible or obvious to the crew on the radar display. I (and others) have proposed several reasons how and why this could happen.

It is indeed a long time since I was a hands on radar engineer but the physics hasn't changed since then, only the equipment has got smaller and lighter.

[drugsdontwork]

FC80

The aircraft flew into a rock that clearly was not visible or obvious to the crew on the radar display. I (and others) have proposed several reasons how and why this could happen.

It is indeed a long time since I was a hands on radar engineer but the physics hasn't changed since then, only the equipment has got smaller and lighter.

How do you know the island was not visible on radar? Much more likely that they could see it. Perhaps thought the route they were flying was some sort of safe low level route.

[G0ULI]

Transcript from the CVR suggests that they were not aware of their position in relation to Black Rock. If it had been clearly visible on the radar, someone would have commented on it. It was the FLIR operator that alerted the pilot to the presence of something ahead.

This crew were betrayed by a combination of factors with inadequate navigational data and a failure of the radar to highlight the presence of Black Rock immediately ahead for some reason being primary factors.

[Tezzer 007]

Transcript from the CVR suggests that they were not aware of their position in relation to Black Rock. If it had been clearly visible on the radar, someone would have commented on it. It was the FLIR operator that alerted the pilot to the presence of something ahead.

This crew were betrayed by a combination of factors with inadequate navigational data and a failure of the radar to highlight the presence of Black Rock immediately ahead for some reason being primary factors.

They inputted BLKMO into the FMS. BLKMO is Black Rock.

[oleary]

player104

A useful video that shows some of the pitfalls when interpreting the radar display. However note the range settings on the display and target return distances of between 20 and 40 miles. At close range settings the display can be much harder to interpret although all the points mentioned still apply.

All the years I did this (70's and 80's) we would NEVER overfly a target at 200' IMC. Think of a rig with a couple of workboats steaming around or a group of ships moving in different directions. If you were cheating a bit (not that I ever did) when you got inside 1/2 mile you offset the target 10 degrees so that if you didn't get visual at least you wouldn't hit the darn thing.

[puntosaurus]

Tezzer. They loaded the APBSS approach (well, flight plan really) which included BLKMO as it's first waypoint. They clearly did not know that BLKMO was Blackrock and that Blackrock was a 300ft tall lump of rock. Part of that was their fault for not reading the notes to the plate and the captions on the plate, but a large share of the issue rests with the operator for not making clear what this chart and approach was designed for, and more importantly what it was not designed for.

O'leary. What's becoming clear is that BLKMO didn't appear as a target (which they would have avoided), it most likely appeared as a caption for BLKMO (which they were aiming for) which happened to be obscuring the target.

[Ex Machina]

Gouli,

"One point three err miles to run to eh blackmo…
and after that its bravo kilo sierra delta alpha..."

Would indicate that the PM knew where they were - what they clearly were not aware of was the vertical extent of the island or they would not have been at 200 ft asl.

[212man]

I'm guessing there have been numerous 92 SAR crews around the bazaars (UK, Eire, Canada, US, Australia and Brunei) using their training sorties to fly towards small islands and trying to replicate situations where they can't see them on radar! If not, might be an idea!

[oleary]

O'leary. What's becoming clear is that BLKMO didn't appear as a target (which they would have avoided), it most likely appeared as a caption for BLKMO (which they were aiming for) which happened to be obscuring the target.

I considered that possibility. The radar we used was primitive and had a simple black/orange display but even with sea or ice clutter we could still clearly define shoreline and islands. The only thing I can think is that somehow they had their MFDs set up incorrectly - but how would that be possible given the experience level of the crew?

[Pltnorway]

Thanks, my beer mat calculations had Blackrock as sub tending 900m at a couple of miles (including antenna beamwidth). At 10 nm display across, then each pixel would be about 50m and so 18 pixels. Symbols are often between 16 and 32 pixels. My concern was that if a symbol was coincident with the return then it might not have been as compelling an indication as it should. Particularly if not being looked for. All built on assumptions of what display ranges were selected so just wild conjecture. Thanks for the answer.

For those calculating radar MDR remember it is not just PW but also the Receiver Recovery Time that has to be used in the calculation.

Assumptions? Didn't the preliminary report state that the PF requested the PM to select 10 NM range?

[cncpc]

They inputted BLKMO into the FMS. BLKMO is Black Rock.

Yes, it is, as it turns out. That does not mean the crew were aware that it was a waypoint that was located with a rock sticking 300 feet out of the ocean. They very clearly were not.

In answer to a question posed by Rotorspeed about why they would select an APP1 mode for descent, and whether that was imposed by the operator, it would be helpful to have 5 more minutes of the CVR before what is in the report.

I think the report makes it clear that the APBSS diagram was being used. It is not clear if the waypoints in that diagram are structured into a selectable approach in the FMS. If they are, then that supports a view that this is "imposed by the operator". The next question is if the operator imposes it as an IFR approach. If that is so, it is clearly inadequate, lacking vertical guidance.

There are a couple of features of this diagram that have the potential for the crew being led into the danger of presuming it is an IFR procedure for IMC conditions. The first is the lighter blue shading on either side of the leg lines. That shading only appears over water, except at BLCKMO. It does not appear over any terrain, or so it appears. I expect most would think it indicates an obstacle free safe space. Which it does. Even at 200 feet. Except for Blackrock, or over land around Blacksod.

The second feature is that it cannot be flown visually, although it obviously can be flown VFR. However to go from waypoint to waypoint, the flight must utilize instrumentation in the cockpit. Other than the helipads/lights, the other waypoints cannot be identified visually.

So the waypoints must be in the nav databases of helicopters which use this route. That would have to include the helicopters which use it for its primary purpose, transiting between Blacksod and Blackrock. Those aren't S-92s. But they are helicopters. We know an Air Corps machine was used to place the investigators there. So some other operator has a version of that diagram, and somehow CHC has it in its route guide. Legacy procedure seems reasonable.

It seems this crew has little to no local knowledge. That fact alone, and the availability of APBSS in the aircraft, underly this accident to a considerable degree.

Great discussion on radar. One thing from the CVR that stands out is that the crew operated on an assumption about the environment they were in. They were wrong to believe 200 feet was a safe altitude. When Capt. Duffy says something large to the right, it is obvious that assumption is challenged and that 200 feet, where they are and at 75 knots, may be/was a dangerous place to be and that a climb to MSA was a priority, followed by a different lookdown with the radar. Radar guys, they will see the picture then, or no? SAR pilots, yes or no on the immediate climb?

I would be interested on hearing how synthetic vision gear may have avoided this. Is it true that like EGPWS, if Blackrock isn't in the database, same problem?

If the purpose of the preliminary report is to immediately advise other operators and aircrew of issues, I think another five minutes of immediately preceeding CVR would be very enlightening for that purpose.

[Al-bert]

Having flown pre, post, and during the magenta revolution and experienced the full spectrum of technology across approx four decades worth of aircraft innovation I believe it is overly-simplistic just to blame the technology (and over-reliance on it). Crews have been routinely flying serviceable aircraft into the ground since aviation began.

The reasons vary and causes range from straightforward to vastly complex. Wherever there is human decision-making involved in a system (of any kind) there will be accidents. James Reason's 'Swiss-cheese' model is an eye-catching representation of the way that a combination of errors conspire to cause tragedy. Even this though is a simplistic view; the investigators on this one will have a hell of a job exposing all the relevant factors, and their complicated relationships, that caused this tragedy.

Those that shout "more training" and "less automation" may feel better but the picture is vastly more complicated than that. Learning from accidents like this will no doubt help safety culture to evolve but, in my opinion, the human element combined with the limits of current technology will continue to conspire and result in accidents.

I admired Bristow's optimism with their recent 'Target Zero' safety program and statement that they genuinely believe that accident rates can be reduced to zero. I'm not so sure.

Exactly Llamaman - the 'kit' has become vastly more complex yet training hours are reduced and, the task remains the same. Has there ever been a job that this new kit has made possible compared to what we had before - I doubt it somehow!

[cncpc]

Simple fix for the future?

Lose leg 1 from the diagram. Make BKSDA the IAF. Procedure turn right at MSA and descending after IAF to 2000. Balance unchanged other than putting in crossing altitudes for the next waypoints, MDA in the last leg, and a missed procedure. Draft a proper chart.

Don't make all the crossing altitudes after BKSDA at 200 feet. Same question arises, why spend more time down that low than necessary.

[cncpc]

On APBSS, what are those red circles with numbers in them?

[puntosaurus]

I'm guessing there have been numerous 92 SAR crews around the bazaars (UK, Eire, Canada, US, Australia and Brunei) using their training sorties to fly towards small islands and trying to replicate situations where they can't see them on radar! If not, might be an idea!

Amen to that ! Let's hope they setup a waypoint on top of the island and post something on here so we can see the challenges faced by this crew.

cnpc. The assumption is that they refer to notes in the supporting pages. And I don't think the operator should be in the market for simple fixes. They should either publish approaches that are fit for purpose or not publish approaches at all and rely on the SAR training and alleviations to allow crews to find the safest approach.

[sycamore]

Has anyone access to a 1:250k low-level chart/map of the area,as permanent off-shore installations should have their maximum height shown(and I assume a lighthouse is an installation) ?
The crew flew very close/overhead on the outbound leg and then let-down,so they must have seen Blkrck on radar at their transit altitude,even at a longer range.It is dominant enough to not appear as just a `blob`.

The VFR Transit plate shows a figure of `282` next to the waypoint at Blkrck...could they have taken that as a track to there ,as opposed to the height of the lighthouse?
Do SAR crews have access to a `lighthouse directory,carried in the aircraft,and coastal charts..?

Can the radar in the S92 be stabilised during transitions ,where the aircraft attitude is changing with speed,to it`s last `manual` input,or still require a manual input/reset once stabilised at the final attitude..?

[palacio802]

I'm a Spanish SAR pilot with offshore experience.

IMHO what led to the disaster was the human factor, with no doubt. Wrong procedures (200 ft over the sea at night, OMG!!!) and perhaps some lack of training (low recent experience, no local familiarization...). I see from some photos that at least the captain had transitioned from the "old fashioned" Sea King to the "state of the art" S92. This represents a huge leap in terms of technology and it's not easy to adapt to the new machine, I guess. So, if we talk about crew experience, we should have this in mind. Long experience but not so long in the type.

[cncpc]

The crew flew very close/overhead on the outbound leg and then let-down,so they must have seen Blkrck on radar at their transit altitude,even at a longer range.It is dominant enough to not appear as just a `blob`.

The VFR Transit plate shows a figure of `282` next to the waypoint at Blkrck...could they have taken that as a track to there ,as opposed to the height of the lighthouse?


If I remember, the report says they had left 4000 for 2500, probably after clearing Achill, and were likely at 2500 abeam Blackrock. Reasonable they would have seen something at 2500, if they were looking down radar wise. I think they were in the clag then, but only on assumption that 300 and above was all cloud. May not be correct.

I think that 282 is the height of the helipad. Page 2 of APBSS reportedly says 310 for the lighthouse.

[cncpc]

I'm a Spanish SAR pilot with offshore experience.

IMHO what led to the disaster was the human factor, with no doubt. Wrong procedures (200 ft over the sea at night, OMG!!!) and perhaps some lack of training (low recent experience, no local familiarization...). I see from some photos that at least the captain had transitioned from the "old fashioned" Sea King to the "state of the art" S92. This represents a huge leap in terms of technology and it's not easy to adapt to the new machine, I guess. So, if we talk about crew experience, we should have this in mind. Long experience but not so long in the type.

How would you have flown it? Specifically, could you, not would you, have made the same mistake with what you were given in the cockpit, information wise? Factor in that you started the mission with an idea that you were going direct ship. Gracias.

[Al-bert]

I'm a Spanish SAR pilot with offshore experience.

IMHO what led to the disaster was the human factor, with no doubt. Wrong procedures (200 ft over the sea at night, OMG!!!) and perhaps some lack of training (low recent experience, no local familiarization...). I see from some photos that at least the captain had transitioned from the "old fashioned" Sea King to the "state of the art" S92. This represents a huge leap in terms of technology and it's not easy to adapt to the new machine, I guess. So, if we talk about crew experience, we should have this in mind. Long experience but not so long in the type.

I don't know what photos Senor but I believe the front enders were ex S61 - totally different beast to the Sea King which had a Search Radar as well as several other more advanced features including engines and airframe differences - so not the same at all. But I agree with your point re Human Factors, adaptation to new tech and type experience.
:rolleyes:

[sudden twang]

There was no response to my Q in 1108 or assertion in 1135.
IMHO the radar was a safety net but the issue is why was the safety net needed?
If that's not addressed then this will happen again.
That's all from me.

[[email protected]]

And because of the complexity of the newer kit - layers of menus and sub-menus and with different design philosophies on different bits of kit - you need more training hours to learn them and keep on top of them.

How often do the crews have to go to the simulator and is that just for emergencies training/checks or are they getting scenario-based training where the kit can be fully utilised in a safe environment?

[[email protected]]

Sudden twang - they could have utilised the S92's capabilities with a letdown within 5 miles of Blacksod and never got anywhere near Blackrock.

They didn't but instead were drawn down an 'approved' route which was unsuitable in terms of design and warnings of the hazards.

Palacio - why are you so horrified by 200' at night? Granted they went down far to early but it is a good height for manoeuvre and final approach using SAR modes - especially if someone has given you NVD to use.

[louisnewmark]

Al-Bert: I hear you regarding kit complexity vs capability, but I also know that you have not operated a modern SAR aircraft with all that 'complexity' to be able to make a fair comparison. What it normally provides is, ironically for this scenario, far greater situational awareness, especially for the pilots whose quality of SA is no longer solely reliant on the quality of a dedicated radar operator's 'mouth music'...but ex-S61 crews will know that! In that respect operating a modern aircraft normally (!) takes up less mental capacity, not more. For this reason, I wonder if there was a degree of cognitive bias at work here: the Irish crew were expecting very low-lying rocks rather than a big island, so that's how they interpreted their displays.

[AAKEE]

In the transcript at 2:02,29 Copilot/PM says "OK so small target at six miles eleven o’clock Large out to the right there ehm".

Response "Roger" from the Commander and about two seconds later "Eh just a small little island...that´s BLMO itself".

As I'm reading this, it seems that they see BLKMO on the radar?( says "BLMO" but meaning BLKMO ?)
Am I reading it wrong ?

[cncpc]

International pilot groups are highly critical of the publication of the CVR in the prelim report.

It is said that the conversations do not contribute to any understanding of the causes of the accident.

Not sure that that is a completely accurate sentiment, but is true that generally these things don't come out at this stage and that they have certainly been sensationalized in the media.

I do think the aviation community does have a better understanding as a result of the publication because they certainly do give insights into what was going on in the cockpit as the danger developed. I don't think they discredit or dishonour the memories of the crew. They certainly evoke sadness and empathy for the situation they came to be in.

Publication of Rescue 116 crew?s final words condemned (http://www.irishtimes.com/news/social-affairs/publication-of-rescue-116-crew-s-final-words-condemned-1.3053312)

[puntosaurus]

Aakee. Nobody knows what the copilot was referring to in that 'Large' comment, although there has been speculation. It has been pointed out before that the commander's subsequent comment about BLMO was in response to a EGPWS callout 'Altitude, Altitude'. The consensus is that that this was triggered by the Carrick Islands 0.65nm to the WNW of Blackrock.

Crab. Sudden Twang refers to posts where he/she has asked about where the crew received their training on the S92, and whether there are questions about the operator's SOPs that align with those on the G-WNSB accident.

[Al-bert]

Al-Bert: I hear you regarding kit complexity vs capability, but I also know that you have not operated a modern SAR aircraft with all that 'complexity' to be able to make a fair comparison. What it normally provides is, ironically for this scenario, far greater situational awareness, especially for the pilots whose quality of SA is no longer solely reliant on the quality of a dedicated radar operator's 'mouth music'...but ex-S61 crews will know that! In that respect operating a modern aircraft normally (!) takes up less mental capacity, not more. For this reason, I wonder if there was a degree of cognitive bias at work here: the Irish crew were expecting very low-lying rocks rather than a big island, so that's how they interpreted their displays.

Have you operated an RAF Sea King with full NVG fit Louis? There didn't seem to be much SA for this poor crew. You are right, I have never operated an S92 nor do I wish to but in 22 years of SAR I seemed to retain SA fairly well. As I said before - the job is the same - it appears to have become more complex, at least for the front enders. Sometimes there was poetry in the 'mouth music' which you scoff at - perhaps you were RN? :rolleyes:

[drugsdontwork]

I prefer 200' in the SAR S-92 to the Sea King Mk3 for what it's worth. It's generations ahead in terms of safety, with VHOLD and go around facilities if required. You can have an FMS route in as an overall guiding magenta line on the NAV display, but I would definitely use heading hold to steer to avoid overflying targets (small islands or boats).

[dClbydalpha]

... What it normally provides is, ironically for this scenario, far greater situational awareness ... takes up less mental capacity, not more. For this reason, I wonder if there was a degree of cognitive bias at work here: the Irish crew were expecting very low-lying rocks rather than a big island, so that's how they interpreted their displays.

That's also what I see. But will add that transferring old procedures to a new cockpit is often underestimated as a task.

In this case once the initial mental picture of the scenario was created, all that additional SA just provided confirmation. What was required was something to look wrong. EGPWS could have done that, with a significantly red blob of terrain. NVDs could also have done that with a looming piece of land.

[oleary]

Palacio - why are you so horrified by 200' at night? Granted they went down far to early but it is a good height for manoeuvre and final approach using SAR modes - especially if someone has given you NVD to use.

I have no problem with 200' at night, but I am sure as h*ll glued to the radar and radalt. If ANYTHING doesn't feel right - climb up and sort it out then go back down.

And yes, as Al-bert says, the Sea King and SK61 Mark I/II are totally different bits of kit.

[palacio802]

Sudden twang - they could have utilised the S92's capabilities with a letdown within 5 miles of Blacksod and never got anywhere near Blackrock.

They didn't but instead were drawn down an 'approved' route which was unsuitable in terms of design and warnings of the hazards.

Palacio - why are you so horrified by 200' at night? Granted they went down far to early but it is a good height for manoeuvre and final approach using SAR modes - especially if someone has given you NVD to use.

Well, it's a good question. I have the opinion that the way the helicopter is flown depends highly on where the pilots come from. S61 is a helicopter designed for the Navy. In the Navy pilots don't fear to fly near the sea surface. While Bell 412 is more for Army operations. And you can notice it if you analyse how these helicopters are flown.

I'm from the Air Force. In the AF we see helicopters as another type of plane. We use to think that if you don't have contact with the ground, the higher, the safer. Flying at 200' feet is inherently dangerous. An autopilot failure with mode disengagement can make you lose more than 100' feet. Not mentioning a tail rotor failure.

I think that at night, even with NVG you should keep 500' except when in final approach (being this approach to a helipad or a vessel). I don't think NVG gives you much clues when flying over the sea (this is my experience).

[Al-bert]

Well, it's a good question. I have the opinion that the way the helicopter is flown depends highly on where the pilots come from. S61 is a helicopter designed for the Navy. In the Navy pilots don't fear to fly near the sea surface. While Bell 412 is more for Army operations. And you can notice it if you analyse how these helicopters are flown.

I'm from the Air Force. In the AF we see helicopters as another type of plane. We use to think that if you don't have contact with the ground, the higher, the safer. Flying at 200' feet is inherently dangerous. An autopilot failure with mode disengagement can make you lose more than 100' feet. Not mentioning a tail rotor failure.

I think that at night, even with NVG you should keep 500' except when in final approach (being this approach to a helipad or a vessel). I don't think NVG gives you much clues when flying over the sea (this is my experience).

I'm staying out of this one! :oh:

[puntosaurus]

HaHaHa. I get very nervous over about 1500ft.

[palacio802]

I don't know what photos Senor but I believe the front enders were ex S61 - totally different beast to the Sea King which had a Search Radar as well as several other more advanced features including engines and airframe differences - so not the same at all. But I agree with your point re Human Factors, adaptation to new tech and type experience.
:rolleyes:

Yes. you are right, sorry. It was a S61.

[Al-bert]

HaHaHa. I get very nervous over about 1500ft.

:ok: me too punto!

I saw the mess a CH53 could make losing a drag damper at around 3500ft, it lost one blade and was descending ok until it lost the second around 1500' :eek:

[smcc63]

In the transcript at 2:02,29 Copilot/PM says "OK so small target at six miles eleven o’clock Large out to the right there ehm".

Response "Roger" from the Commander and about two seconds later "Eh just a small little island...that´s BLMO itself".

As I'm reading this, it seems that they see BLKMO on the radar?( says "BLMO" but meaning BLKMO ?)
Am I reading it wrong ?
The pilot in command is acknowledging an "altitude "aural alert

[llamaman]

For those lamenting the advances in technology/automation in the cockpit I'm assuming they've not operated a latest generation helicopter.

There is a step-change in the improvement in SA in a modern cockpit when the equipment is used (and trained for) correctly and procedures/SOPs are safe.

Safety is obviously a subjective concept. It is the product of a sound 'just' culture and an organisation that genuinely puts safety before profit.

[gulliBell]

The pilot in command is acknowledging an "altitude "aural alert

This conclusion is ambiguous if based just on reading the CVR transcript alone. As discussed before, listening to the recording was required to come to this conclusion.

[gulliBell]

In this case once the initial mental picture of the scenario was created, all that additional SA just provided confirmation. What was required was something to look wrong. EGPWS could have done that, with a significantly red blob of terrain. NVDs could also have done that with a looming piece of land.

They had FLIR and the pilots were told of the obstacle ahead 15 seconds before impact. If the EGPWS had painted a red blob in-front of them, would they have reacted any differently from basically being told by the radar operator there is a red blob ahead? If the FLIR didn't look wrong enough, and the radar didn't look wrong enough, would a little blob of red on the EGPWS and an aural terrain warning have triggered immediate avoiding action?

[gulliBell]

..Crab. Sudden Twang refers to posts where he/she has asked about where the crew received their training on the S92..

I heard from somebody who used to work at Flight Safety that the crew did their S92 training at Flight Safety (Stavanger perhaps?).

[gulliBell]

..I think that at night, even with NVG you should keep 500' except when in final approach (being this approach to a helipad or a vessel). I don't think NVG gives you much clues when flying over the sea (this is my experience).

How effective would NVG be in this environment i..e over water, under cloud? If they didn't see the lighthouse from 1.3nm away tends to suggest they weren't looking outside, would they have been looking outside if they had NVG?

[jimf671]

In a coastal environment in conditions under cloud where the naked eye just sees a wall of blackness you can see coastlines, islands, unlit buildings, vessels. That would usually be the case even on the same night that NVG would fail in the bottom of a tight valley inland.

[sunnywa]

I have been following this thread and have learnt a lot about radar theory and EGPWS use, so I thank you fellow pilots out there for teaching me some new tricks. If I can maybe raise a few points ( I am a SAR pilot with similar systems in my aircraft type):


1. Many posts have been critical of the descent profile and why they made such a long flight at 200ft. I suspect that because the APBSS approach is not an IFR procedure, the crew realised they would have to get visual below the cloud (300-400ft) to then track toward Blacksod via the APBSS guidance (I would love to know the purpose of the APBSS, VFR vs IFR, what is it there for?). To do this descent, many operators have a 'no closer' clause in their OM so I would think they have to descend clear of all land (looking at the map, it might be 5-10nm) to get visual below cloud before they then would be allowed to turn back towards their fuelling point. If they were any higher, they would have been IMC and since there appears to be no IFR arrival plate to Blacksod, then this would not have been feasible.
2. NVG would have definitely been a final safety feature as they (I believe) would have seen the large rock ahead of them. I have flown a lot of NVG over water and even on the darkest nights, the contrast should have alerted a scanning pilot as to their danger.
3. Some people have mentioned lack of talk on the CVR as complacency. I don't believe this for a second as this crew were at low level, in the dark and in an unfamiliar area. I bet their arousal level was through the roof.


I look at this sad and preventable accident and see much to learn on a personal and organisational level. I am not going to armchair quarterback the crew as I am honest enough to think that some of the decisions made would have been the same if I was in the aircraft. I think the basic problem was the crew did not realise the BLKMO was 300ft high and for some inexplicable reason, they did not see it on radar. If only Blacksod had an IFR RNAV approach, this accident would not have been occurred and four fine persons would still be doing the job they loved.

[Scattercat]

I have been following this thread and have learnt a lot about radar theory and EGPWS use, so I thank you fellow pilots out there for teaching me some new tricks. If I can maybe raise a few points ( I am a SAR pilot with similar systems in my aircraft type):


1. Many posts have been critical of the descent profile and why they made such a long flight at 200ft. I suspect that because the APBSS approach is not an IFR procedure, the crew realised they would have to get visual below the cloud (300-400ft) to then track toward Blacksod via the APBSS guidance (I would love to know the purpose of the APBSS, VFR vs IFR, what is it there for?). To do this descent, many operators have a 'no closer' clause in their OM so I would think they have to descend clear of all land (looking at the map, it might be 5-10nm) to get visual below cloud before they then would be allowed to turn back towards their fuelling point. If they were any higher, they would have been IMC and since there appears to be no IFR arrival plate to Blacksod, then this would not have been feasible.
2. NVG would have definitely been a final safety feature as they (I believe) would have seen the large rock ahead of them. I have flown a lot of NVG over water and even on the darkest nights, the contrast should have alerted a scanning pilot as to their danger.
3. Some people have mentioned lack of talk on the CVR as complacency. I don't believe this for a second as this crew were at low level, in the dark and in an unfamiliar area. I bet their arousal level was through the roof.


I look at this sad and preventable accident and see much to learn on a personal and organisational level. I am not going to armchair quarterback the crew as I am honest enough to think that some of the decisions made would have been the same if I was in the aircraft. I think the basic problem was the crew did not realise the BLKMO was 300ft high and for some inexplicable reason, they did not see it on radar. If only Blacksod had an IFR RNAV approach, this accident would not have been occurred and four fine persons would still be doing the job they loved.

I too have been closely following and have learnt from this sad thread.

1) In my operating area (Australia), regulations are very specific with regard to the way we must operate in IMC (IFR) and VMC (VFR). If you can't maintain visual reference with the ground or water, navigate visually, maintain aircraft attitude visually, you are operating in IMC. When operating under the IFR, I can ONLY descend below MSA when following a prescribed, approved, promulgated procedure. This may include a company procedure that has been formally designed and has been approved by the regulator.
To my mind, this route, was never an IFR procedure and was never intended as such. Remember that they descended to 200' & hit Blackrock BEFORE the start of this route. It seems to me that for whatever reason, this crew has paid the ultimate price for placing their lives in the hands of a "procedure" that was not fit for the purpose it was used for.

2) NVG would most likely have enabled visual flight & would have almost certainly allowed the crew to have picked up the light, if not the island itself, as they approached Blackrock. I currently spend quite a lot of my time below 200' at night over-water in low visibility conditions and appreciate the level of SA they can provide in concert with radar, FLIR, LNAV, Searchlight etc.

3) Low level, low visibility navigation must employ all available resources, from Mk 1 eyeball (looking out the bl**dy window), to all the bells & whistles available in a modern, 4 crew, SAR configured aircraft.

I for one, try to put myself in the position of this crew, as I know I can & do make errors, & ask myself what I can learn to be safer in the future.

[oleary]

Well said, mate.

[DOUBLE BOGEY]

Scatter Cat and Sunnywa. Your posts are honest and loyal to the SAR community which I respect a lot.

a lot of confusing and sometimes conflicting information on this thread. However we know that descending below MSA over the sea, can only ever be safely done with an ACCURATE RADAR IMAGE. FLIR and NVG add value but the RADAR and the RADALT are priority.

I have operated under 2 assumptions for 30 years, 1. that the radar locks out at 0.5 Nm and 2. You need to start the RADAR with as full and cluttered an image as you can tune in, and then back it off for clarity. This may not have been the correct scientific approach.

This crew were monitoring the radar. The CVR has calls accordingly. Something went tragically wrong with the WX radar setup, serviceability or software.

While in the SAR community there will be options now to recommend NVGs IFR letdowns etc, taking into account all possible safety systems, for the O&G community, they continue to do this kind of letdown in solid IMC (ARA) with ONLY the RADAR to rely on.

In older aircraft I have flown where the RADAR has its own "Telly" not much went wrong. It either worked or it didn't. However in modern multidisplay overlay technologies I have experienced a few kinds of software glitches which I am ashamed to say, fixed by some reconfiguration and rarely reported.

If this terrible event was caused by a faulty radar image or overlay problem we as a community need to start accurately documenting the insidious issues with overlay technology.

[gulliBell]

The accident aircraft seemed to be operating in some quasi-interim flight category, negotiating a phase between IFR and VFR. They certainly weren't on an IFR procedure, no IFR procedure starts at 200'. And they had switched on low altitude mode which is a VFR only mode, so that is a conscious decision that transition from IFR to VFR had occurred. But they weren't VFR otherwise they would have seen the lighthouse 1.3nm directly in-front of them. If VFR somebody has to be looking outside.

Do all the modern tools in these advanced SAR helicopters lull a crew into a false security? I dare say, if they were in a lesser equipped aircraft maybe this accident would have never happened. Or, if this was just a scenario given to them for a check-ride in a simulator, instead of an operational mission, whether they would have done the same thing with the examiner watching them?

I agree with Scattercat. Follow the IFR until you can see where you are going and maintain obstacle clearance by visual reference, no matter how much modern equipment you have that might tempt you to do otherwise. If you are VFR, it shouldn't be of much consequence that a lighthouse isn't in your terrain/obstacle database.

[DOUBLE BOGEY]

Gullibell, the mission of SAR is to letdown over the ocean, acquire the target and save people. What they were doing may not have been the Ideal approach certainly the vertical profile, but in principle it is the bread and butter of SAR and for that matter, an ARA. In this respect we all operate with the RADAR and the RADALT. They were using both. The key to understanding how the missed they rock lies with the RADAR. FLIR on their MFDs may have helped as might NVG. However as an ARA can quite legitimately get you to 200 feet and still be in solid IMC, only the RADAR can keep you safe, or so we have all assumed.

Knowing exactly how the RADAR was tuned and what procedures there were in place to achieve this is core to the interests of all of us flying over the oceans doing Letdowns or ARAs.

In most Organisations the tuning of the Radar is informally taught during line training, legacy driven, and on this hill of hindsight may well be inadequate.

For all persons in a supervisory role in the SAR and O&G I would recommend this issue alone is rapidly addressed and the training formalised to standardise to an ideal setup for each individual type of equipment. overlay issues must be addressed.

The IFR /VFR arguments are a red herring when taken in the wider context of the average mission profile, that is, to descend in IMC to a target.

[helicrazi]

So, correct me if I'm wrong, or point out what I'm misunderstanding,

The radar must have been set up correctly based upon,

1. The gain picking up a large target at 6 miles, assuming it was land. Gain adjusted correctly for land.

2. The tilt picking up the same target, too low it wouldn't have seen out to 6 miles, too high, it would have looked over it, as it picked one up at 6 miles then the tilt should have captures the more immediate target?

[[email protected]]

In most Organisations the tuning of the Radar is informally taught during line training, legacy driven, and on this hill of hindsight may well be inadequate. that is a most telling statement DB - especially given your previous statementHowever as an ARA can quite legitimately get you to 200 feet and still be in solid IMC, only the RADAR can keep you safe, or so we have all assumed. perhaps the attitude to training for the radar has slipped across from oil and gas to SAR.

We come back to replacing a dedicated and fully trained radar operator with a co-pilot - cheaper but clearly far less effective.

As for NVG - everyone who uses them properly knows that the higher you go the less effective they are - lower is better with goggles hence 200' as a common figure.

[helicrazi]

that is a most telling statement DB - especially given your previous statement perhaps the attitude to training for the radar has slipped across from oil and gas to SAR.

We come back to replacing a dedicated and fully trained radar operator with a co-pilot - cheaper but clearly far less effective.

As for NVG - everyone who uses them properly knows that the higher you go the less effective they are - lower is better with goggles hence 200' as a common figure.

The co-pilot will help you out of a disorientation though

[coyote_ie]

[QUOTE=Woolf;9741140]Although there are a number of quite significant contributory factors, I think the main point here is that regardless of whether a published procedure is followed or not, any low-level flight over water in IMC, at night or in marginal conditions MUST use the radar as the PRIMARY navigation aid. If a radar return cannot be positively, visually identified it MUST NOT be overflown. Besides islands there are plenty of moving marine obstacles that can easily reach 300ft or more which would not be on any map, chart or in any database. Whether radar guidance is achieved from front or back seats is a matter of procedure but it would be a designated crewmember’s responsibility to monitor and constantly verbally update the obstacle situation as seen on the radar. Although I know nothing of CHC’s procedures I would assume that this is SOP, especially for SAR.

Very good point.

[Scattercat]

The IFR /VFR arguments are a red herring when taken in the wider context of the average mission profile, that is, to descend in IMC to a target.

My comments above are more concerned with IMC / VMC conditions & the "how to" rather than the rules governing such. Yes, the correct use of the radar, should form a very important part of the picture, but it should be cross-checked with all other available data sources. The advent of reliable, GPS based navigation systems, allows for RNAV only IMC letdowns, which should then complement radar return information. I would be concerned if, during an ARA, the rig GPS location was not where the radar was painting a target, & visa versa.

[[email protected]]

The co-pilot will help you out of a disorientation though yes, one of his primary duties is to monitor the handling pilot - instead we get him heads down playing with the radar!

[helicrazi]

yes, one of his primary duties is to monitor the handling pilot - instead we get him heads down playing with the radar!

A good PM will know when to divert attention and 'play with the radar' usually when the aircraft is in a safe configuration, i.e. fully coupled and no inputs being made. Anyhow, you make a good point, PM cant be 100% monitoring as there are other duties.

[cncpc]

How effective would NVG be in this environment i..e over water, under cloud? If they didn't see the lighthouse from 1.3nm away tends to suggest they weren't looking outside, would they have been looking outside if they had NVG?

We don't really know what the cloud base was at, or what level of cloud coverage there was, or how thick the bottom layer was. It was a full moon that night. The presumed weather is based on a aftercast shown in the weather section of the prelim report. Ceiling 300-400 feet. It is possible, or certain, that the light was in deep enough cloud that the crew couldn't see it.

It is known that an hour and a half after the accident R118 was on scene, in search mode, and found wreckage and a survivor floating in the water. Presumably in the same conditions that the accident occured in. Close in to Blackrock. Whatever systems they used to accomplish this did work for them. It's been overlooked in all of this, but that was an outstanding bit of SAR work.

[DOUBLE BOGEY]

CRAB as often is the case, you totally miss a point while you concentrate on scoring points.

O&G pilots fly ARAs to 200 feet using, these days, a CDFA type profile. They are taught to NEVER fly over a red blob unless at 1500 feet. The DR is 0.75 Nm (to cope with separation during a go-around and in recognition that the RADAR is not very good inside 1/2nm.

They will never have Rear Crew, FLIR or NVGs. We need to learn what this crew did and why they did it:

1. Did they really choose to fly over red blobs at 200 feet with the RADALT complaining?
2. Did they see Blackrock on the RADAR and choose to fly over it.?

Or, was the RADAR picture crap due to tuning, setup, malfunctions etc.

Whatever the case SETUP and PROTOCOLS concerning the RADAR almost certainly IS the FINAL HOLE in a pretty porous Swiss cheese that night.

The other holes variously:

1. Recency (as admitted on the CVR)
2. Route Familiarity (as admitted on the CVR)
3. Lack of CDFA procedures (dirty dive too early)
4. ****ty manuals with poor labelling (heights on charts not properly displayed).
5. Poorly designed SOP for the AHCAS setup. (No FLIR selected in cockpit)
6. A really badly designed letdown procedure masquerading as a route ( or vice versa) that, and get this clear, routes the bloody helicopter over terrain when surrounding it is many square miles of open ocean. Absolutely no excuse or reason for this. Since the days of DECCA we can fly to points in space, clear of obstacless waypoints and use the surround terrain on the edges of the radar as validation. Flying over the terrain to validate the waypoint is a joke for a crew and machine designed to find a dinghy in the vastness of the ocean.

[Mars]

Excluding any loose ends that will be found from the wreckage, the interim report contains most that is required to understand what happened. It is likely that a combination of company organizational issues and SAR culture were the key elements. It resulted in a bad plan that was executed accurately.

Helicomparator makes an interesting point that the culture of SAR in the civil era needs a review; it would benefit from a process similar to that used in CAP 1145.

It is likely that APBSS was a VFR procedure that had been in place for some time. Blackrock is an island that, in VFR, can be seen from a distance; it allows an accurate placing of the aircraft for a series of visual manoeuvres leading to a VFR approach to Blacksod. It is unlikely that it was ever risk assessed for use in weather below VFR limits (cloud base - day 600ft, night 1,200ft; visibility – day 1,500m (800m for short periods), night 5km).

Descent from IMC to VMC/VFR in Class G airspace over the water is permitted in accordance with procedures Approved by the Authority; such a procedure would be permitted only with a serviceable RADAR and to an altitude/height where a continuation of the flight under VFR would be possible. (It is likely that SAR has a derogation from the VFR minima under operational conditions.)

The SOPs of SAR (and additional equipment on board) permit a let-down, and a continuation of flight, over water below normal VFR limits – this would have been standard for the SAR crew. It is likely that this alleviation would extend to the approach and landing at Blacksod (which appears to be the refuelling site of choice).

The linking of the en-route descent (to SAR limits) and the APBSS approach (under SAR limits) from Blackrock to Blacksod does not appear to have been risk assessed when the APBSS procedure was incorporated into the SAR Operations Manual. If it had then there should have been bold warnings on the plate and/or a limitation on height and visibility on the route.

The lack of an instrument approach to Blacksod under conditions where it was a principal SAR refuelling site appears to be an organizational issue.

The lack of adequate notation on the APBSS plate appears to be an organizational issue.

The combination of SAR culture and standard VFR routing to Blackrock/Blacksod increased the probability of an accident. It would appear that, the Captain was unaware of the height of the terrain/obstructions on Blackrock (from the CVR “Eh just a small little island… that’s B L M O itself”). The choice of APBSS routing and SAR limits probably resulted from a misunderstanding that Blackrock posed no threat and was intended to be overflown - from there confirmatory bias was in play.

It was unfortunate that Blackrock was missing from the EGPWS data-base - an issue that now has to be addressed in the provision of the eTOD for EGPWS and synthetic vision systems. The lack of knowledge on the thread about the functioning of EGPWS is a little sad; however, in mitigation, this is a device that does not require anything from the pilot but reaction to the ‘callout’ (questioning the EGPWS would be counterproductive). Had Blackrock been in the data-base, it is likely that it would have been 'called out' in the lookahead function.

This was an unfortunate accident that, hopefully, will result in an examination of civil SAR and leading to a process of improvement.

[gulliBell]

..We need to learn what this crew did and why they did it:



We know much of what they did, what we don't know is why they did what they did. The approach briefing, which isn't in the CVR transcript, would be useful to understand the options contemplated, and what course of action was decided.

Regarding training. When crews are sent to the simulator for training, the instructors expect the trainees to know how to use the radar, and all those other things. There is no time allocated for teaching these things. In my experience, it is regrettably common to find recurrent trainees with weak knowledge of aircraft limitations let alone the intricacies of how to tune their weather radar. This tells me that thorough on-going structured training at the operator level is lacking. Whether these observations can be applied more widely across the industry, or whether it is limited to our client base, I don't know. I've seen trainees turn on the weather radar and just blast through an active thunderstorm with lighting and maintain course just because ATC gave them a heading to steer. Even cranking up the turbulence level to maximum doesn't cause them to think a different plan might be a better idea. Sometimes pilots can be their own worse enemy.

[212man]

1. Did they really choose to fly over red blobs at 200 feet with the RADALT complaining?

As has been pointed out already, they were in GMAP mode and so the islands would have been Magenta 'blobs', and this raises the very real possibility that the return for Blackrock could potentially have been partially masked by the magenta waypoint symbol and name label. I'm sure SAR crews will have been experimenting with this already by now to see if they can replicate it.

[palacio802]

I agree with most of you guys. Specially with the "holes" listed by double bogey.

But we shouldn't forget that the ultimate cause of the accident is the failure of the crew in changing the heading of the aircraft. They KNEW they had an obstacle just in from of them up to 15 seconds before the crash.

The CVR suggests that the copilot received the command to change the course and used his control knob. But the helicopter didn't change its course, as the graphic shows. Why? Perhaps the AP mode selected. What do you think about this?

[212man]

The CVR suggests that the copilot received the command to change the course and used his control knob. But the helicopter didn't change its course, as the graphic shows. Why? Perhaps the AP mode selected. What do you think about this?

I think it's a poor SOP and that the PF should be making the mode selection and HDG bug setting.

[sunnywa]

212 Man

My reading of the transcript is that the PF (PIC) was giving directions to the PM to first select Hdg mode (assume they were in Nav mode tracking DTO BLKMO) then never got around to telling the PM to turn before the Rear Aircrewman started to call urgently. This was the period when a heading change of any type might have worked. The PF did not seem to actually select or turn the heading.

[212man]

212 Man

My reading of the transcript is that the PF (PIC) was giving directions to the PM to first select Hdg mode (assume they were in Nav mode tracking DTO BLKMO) then never got around to telling the PM to turn before the Rear Aircrewman started to call urgently. This was the period when a heading change of any type might have worked. The PF did not seem to actually select or turn the heading.

Exactly, hence my comment that it's a poor SOP and I don't just mean for instances where immediate action is required - it blurs the PF/PM roles and is not reflected in the FW world of automation.