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Rescue 116 Crash at Blackrock, Co Mayo(Mod note in post 1)

sparrowcar

Contact lost just before 0100 off the west coast of Achill island on a rescue mission.
Search in progress including all available ships and Rescue 115.

Hopefully a positive outcome to this.

Please keep replies civil, and respectful of the crew and their families.

Please do not speculate as to any cause unless you have a factual basis to do so (and can back it up with information released to the public).

There will be zero tolerance for troublemakers or those that choose to ignore these guidelines.

There are other moderator messages in the thread, as a result of issues that have arisen, and we will be less forgiving going forward, due to the ongoing sensitivity of this incident

As per normal boards guidance, any comments on moderation are off topic and should be addressed directly to mods or cmods by PM. Any part of posts which are off topic in such a manner may be edited or removed, with possible sanction. Non news posts will be moved to the parallel R116 Non news and discussion thread

Should any new reports, updates or news stories come out, posts which can be boiled down to "I Told You So" or other triumphalism about previous commentary will result in significant punishment.

Any threadbans will carry over to any replacement thread should this approach 10,000 posts

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Irish Steve

rwaldron21 wrote: »

This must have been asked before but I can't find any ref...

I know the light house has 12 sec strobe intervals but even so , wouldn't you spot a lighthouse a head from miles away, out the front window ?

Unless all eyes where on instruments only for a considerable amount of time ?

Depending on the weather at the time, it's possible that the light was in cloud, the light is 292 Ft, the cloudbase was estimated as being 300 Ft, so if the aftercast was even slightly wrong, the light may not have been visible

wotswattage

Shane_ef wrote: »

A combination of the weather, there altitude, there speed, the lighthouse elevation and the interval

Plus the strobes and lights mounted around the helicopter going off every few seconds and reflecting/bouncing off the clouds just above the helicopter.

Gaoth Laidir

kona wrote: »

The database that's being referred to is for the gpws, which is different from navigational database.

The database will have been designed with certain specification. Which means it may be accurate of your flying at 500ft because nobody deemed it necessary to include lower obstacles because who would.fly at 200ft at 75knots 8km out.

This accident has a number of contributions and if you removed one of them then most likely the crew wouldn't be lost

Just a note, that should read 8 NM, not km. A few people have used km tonight, which may lead to confusion. 8 NM is about 15 km.

kona

Gaoth Laidir wrote: »

Just a note, that should read 8 NM, not km. A few people have used km tonight, which may lead to confusion. 8 NM is about 15 km.

I stand corrected.

Steve

ProfessorPlum wrote: »

Kona is correct. EGPWS warnings 'look ahead' - generated by the aircraft position in relation to the map database. Rad alt generated warnings, as per GPWS, would have been useless in this situation due to the steeply rising terrain of black rock.

I agree, however from the report EGPWS was ineffective as it did not have the relevant terrain data so the only alarm that was heard on the CVR was from GPWS which is based on RA.

I don't profess to have any great knowledge on how these systems work.

Gaoth Laidir

Irish Steve wrote: »

Depending on the weather at the time, it's possible that the light was in cloud, the light is 292 282 Ft, the cloudbase was estimated as being 300 Ft, so if the aftercast was even slightly wrong, the light may not have been visible

Surface visibility at Belmullet was reported as 3 km, but at 200 ft altitude it would have been even less. However, even at 3 km visibility, flying at 80 knots (41 m/s) and with a 12-second period of the lighthouse beam, they would have only seen a flash every 500 metres of travel, so around a total of 6 flashes within their visibility range of 3 km. Flight visibility just below cloud base would have been much less than that, so in reality there may have only been 1 or 2 flashes visible to them.

Irish Steve

kona wrote: »

I don't think you understand what I'm saying.

Rad alts are more inaccurate the higher you go. 2000ft is relatively low.

The reason a rad alt gives you a accurate reading at 20000ft is because the mountain at 19000 ft is only 1000ft below.

I do. Most Radalts are configured to stop indicating above 2500 Ft indicated, for exactly that reason. The radio return at that stage is no longer strong enough to be reliable.

EGPWS can also use the height information that comes from the GPS system, but even then there can be issues where an aircraft enters a wide valley that has significant high ground either side and ahead if the ground rises rapidly, that was one of the reasons for the change from GPWS to EGPWS. The GPS altitude is as accurate vertically as it is horizontally, and it does not depend on atmospheric pressure, so that potential error is removed.

allthedoyles

Puzzles me that the crew’s beacons had been installed in the same pouch as the GPS antenna and the beacon manufacturer recommends a distance of 30cm .
This issue plus the software issue need to be sorted for present crews of SAR

Junkyard Tom

Gaoth Laidir wrote: »

there may have only been 1 or 2 flashes visible to them.

And only if they'd been looking out the window rather than focussing on instruments? Incredible how a series of factors can converge to cause such a tragic incident.

rwaldron21

I think there should be a reconstruction, via flight simulator , to show how the Black Rock Lighthouse (meant for ships) would look to a Helicopter...

I think it would clear up a lot of misconceptions..

Irish Steve

They would have been concentrating on instruments, because they were flying on instruments, in a place where their (incorrect) information told them there was nothing to worry about. Flying at night, over water, at low level, and in and out of cloud, that's the time when you are very dependent on your instruments, because there's nothing out of the window that will help you fly the aircraft, and in those weather conditions, the outside view may well cause more problems than it solves.

The other aspect is that it's very hard to work out what distance from you a lighthouse actually is, unless you can see more than one light, and then use a chart to compare the angles to get a position. In that area, at that time of night, and in that weather, they would not have seen much if they had looked out of the window.

homerjay2005

would the "pitch up" suggest their avoidance technique was to raise altitude as opposed to a movement right, as was suggest initially by the crew?

Roger_007

From reading the report I think the key part is where the commander programmed "direct to BLKMO" into the flight management system, (page 6).
Did she program in the wrong destination? It appears that the flight management system was bringing them in to land at Blackrock instead of Blacksod.
Surely the waypoint BLKMO would only be relevant if you were approaching from the west and is, in any case, it is where to start the approach to Blacksod.
Am I being too simplistic here?

kona

Irish Steve wrote: »

I do. Most Radalts are configured to stop indicating above 2500 Ft indicated, for exactly that reason. The radio return at that stage is no longer strong enough to be reliable.

EGPWS can also use the height information that comes from the GPS system, but even then there can be issues where an aircraft enters a wide valley that has significant high ground either side and ahead if the ground rises rapidly, that was one of the reasons for the change from GPWS to EGPWS. The GPS altitude is as accurate vertically as it is horizontally, and it does not depend on atmospheric pressure, so that potential error is removed.

Your getting into specific systems here, I'm not familiar with the sikorsky s92 EGPWS . It may use gps to derive its altitude. However to provide a accurate height would require it to have a number of satellites and a very accurate clock on board, this is before you take into account the built in inaccuracy in the gps systems courtesy of the USAF.
The captains altimeter usually feeds the information on height to the gpws above whichever height is deemed inaccurate for rad alts.

rwaldron21

So Enhanced Ground Positioning Warning System did not have the "lighthouse obstacle" included in an obstacle database and the "terrain of the island" was not listed on the terrain database.

How on earth, in this day and age, can such obstacles not exist on these systems.

Makes me wonder how many more Obstacles are missing........

Irish Steve

Roger_007 wrote: »

From reading the report I think the key part is where the commander programmed "direct to BLKMO" into the flight management system, (page 6).
Did she program in the wrong destination? It appears that the flight management system was bringing them in to land at Blackrock instead of Blacksod.

No, BLKMO is the start point of a pre defined route that takes the aircraft to Blacksod. While AAIU have raised significant concerns about the quality of the approach profiles provided by CHC, they have made no suggestion that the crew had made any error in terms of their intended destination, they will have clear information from the FDR that will indicate exactly where the aircraft had been planned to fly to.

Surely the waypoint BLKMO would only be relevant if you were approaching from the west and is, in any case, it is where to start the approach to Blacksod.
Am I being too simplistic here?

At the time, they were west of Blacksod, and the approach they were about to use was the correct company defined procedure to get into the Blacksod pad, so they were correct to plan to use it

Sterling Archer

homerjay2005 wrote: »

would the "pitch up" suggest their avoidance technique was to raise altitude as opposed to a movement right, as was suggest initially by the crew?

Pitch up would refer to pitching the nose of the aircraft up in an attempt to raise the altitude, it my have been used in conjunction with pitching up and right, really it looks to be an attempt to avoid the immediate threat

In heli speak pull back on the cyclic, raise the collective, apply right peddle, add power not exactly in that order

Roger_007

Irish Steve wrote: »

No, BLKMO is the start point of a pre defined route that takes the aircraft to Blacksod. While AAIU have raised significant concerns about the quality of the approach profiles provided by CHC, they have made no suggestion that the crew had made any error in terms of their intended destination, they will have clear information from the FDR that will indicate exactly where the aircraft had been planned to fly to.

At the time, they were west of Blacksod, and the approach they were about to use was the correct company defined procedure to get into the Blacksod pad, so they were correct to plan to use it

So, how come they were flying at an altitude of 200ft at the start of their approach. That makes no sense.

Shamrock841

TomOnBoard wrote: »

Further to your point, if BLKMO was at either of the two Carricks, at the point where the RA gave an ALTITUDE warning, the FMS would have had to be updated with the next waypoint as BLKMO would have been arrived at. No such additional instruction was given so it clearly suggests that the FMS was still working off the "direct to BLKMO" instruction.

I would imagine that all of the approach waypoints were loaded into the FMS during the briefing. So just like when flying a STAR and ATC give you a shortcut and you select direct to BOYNE (example) , the aircraft will continue on the planned approach.

wotswattage

The report makes for sad reading (like all these reports do I guess...), as other posters have already pointed out it was a combination of several factors all adding up at the same time to cause the tragedy. Even taking any one of the factors away it might not have been as catastrophic, and was a matter of being a handful of seconds too late to react.

Dwarf.Shortage wrote: »

BLKMO is not Blackrock Island, it's nearby but not the island.

I had a look at the approach route from Figure No. 4/I] in the report and superimposed a screenshot from the OSI Map Viewer http://maps.osi.ie/publicviewer/#V2,454024,815435,7,3 over it. Blackrock is only a squiggle on the OSI map but if you toggle on the historic map you can see it very clearly.. It seems BLKMO is either very very close to the island or actually on it so the autopilot may have taken them directly to the waypoint (and the island) at whatever speed and altitude it was set to.

Irish Steve

Roger_007 wrote: »

So, how come they were flying at an altitude of 200ft at the start of their approach. That makes no sense.

In the light of the (incomplete) information they had available to them, there was no known risk in being at that altitude, and much of their every day activity was carried out at those sorts of levels, so it would not have been unusual or out of the ordinary for them to operate at those sorts of altitudes

Having said that, my anticipation initially, in the absence of information about a standard company approach was that they would have been crossing Blackrock at about 3000 Ft, and then doing the equivalent of an ILS terminating at about 2 miles south of Blacksod, with a visual transition to land.

ProfessorPlum

Looking at the CHC approach chart again, the crosshairs at point BLKMO have an annotation '282' which would seem to refer to the height of the light at blackrock lighthouse. There's no ledgend with the chart, so I can't be 100%, but there's also an annotation of '43' at blacksod lighthouse, which is the height of the light at blacksod. So the question is, why were they navigating to a point on the approach chart at an altitude below what was indicated on the chart.

Junkyard Tom

Roger_007 wrote: »

So, how come they were flying at an altitude of 200ft at the start of their approach.

Is it unusual?

ProfessorPlum

Irish Steve wrote: »

In the light of the (incomplete) information they had available to them, there was no known risk in being at that altitude, and much of their every day activity was carried out at those sorts of levels, so it would not have been unusual or out of the ordinary for them to operate at those sorts of altitudes

Having said that, my anticipation initially, in the absence of information about a standard company approach was that they would have been crossing Blackrock at about 3000 Ft, and then doing the equivalent of an ILS terminating at about 2 miles south of Blacksod, with a visual transition to land.

But they did have information of a known risk - on the text page mentioned in the report - of blackrock altitude of 310ft. Also the 282ft light at blackrock - annotated on the approach chart. This was missed in their approach briefing.

Roger_007

Irish Steve wrote: »

In the light of the (incomplete) information they had available to them, there was no known risk in being at that altitude, and much of their every day activity was carried out at those sorts of levels, so it would not have been unusual or out of the ordinary for them to operate at those sorts of altitudes

Having said that, my anticipation initially, in the absence of information about a standard company approach was that they would have been crossing Blackrock at about 3000 Ft, and then doing the equivalent of an ILS terminating at about 2 miles south of Blacksod, with a visual transition to land.

I still think that the simple explanation is that the wrong destination was fed into the flight management system and it did exactly what it was instructed to.

ProfessorPlum

Roger_007 wrote: »

I still think that the simple explanation is that the wrong destination was fed into the flight management system and it did exactly what it was instructed to.

The AAIU report states that the company approach to blacksod was inserted and checked correctly into the FMS. So there is no question that they were intending blackrock as the destination. The intention was blacksod. The question is why they were at 200ft at waypoint BLKMO

Irish Steve

ProfessorPlum wrote: »

But they did have information - on the text page mentioned in the report - of blackrock altitude of 310ft. Also the 282ft light at blackrock - annotated on the approach chart. This was missed in their approach briefing.

And unfortunately, we have no way to know why that page was not referred to in their briefing, and it's also interesting that AAIU did not include that information in their report. I would want a lot more detail before I would be prepared to commit to flying that approach. we also do not have the information that's in their navigation system, I would expect that to have altitude at the waypoints.

We are unfortunately reduced to reading between the lines in some areas, or speculating, and I'm not going there, we may get some more detail in the final report, I suspect that AAIU are still working very hard to firm up on some of the issues that are only at present highlighted by this interim report

Steve

Roger_007 wrote: »

I still think that the simple explanation is that the wrong destination was fed into the flight management system and it did exactly what it was instructed to.

The report says nothing of the sort and to be honest I am getting really ticked off with this ill informed response.

Please explain how you came to this conclusion and why you should not be banned from this forum for ignoring all the previous warnings.

Irish Steve

Roger_007 wrote: »

I still think that the simple explanation is that the wrong destination was fed into the flight management system and it did exactly what it was instructed to.

There is no destination Blackrock, and if there were, and it had been used, I think you can be very confident that AAIU would have said so. Blackrock is not a suitable landing site for a S92, it's not big enough to take it safely, and certainly not at night.

faoiarvok

There seem to be a couple of misconceptions here that could do with being cleared up:

Navigating 'direct to' a waypoint is not the same as making that point your destination.
BLKMO was selected as the next waypoint to navigate, in the knowledge that they would continue on to a few more waypoints before arriving at Blacksod.

From the CVR transcript:

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

The "standard company approach" followed is not a Precision Approach, in that it does not include vertical guidance, and is really just a lateral route to Blacksod. Unlike a runway ILS, there was no radio beam for the aircraft to follow down to the Blacksod pad.

The vertical descent here serves a different purpose to an ILS approach or similar. The descent is being conducted in order to break through the clouds and gain visual reference for the rest of the flight. The descent was done well out from Blacksod in order to come to a low level over water that was unfortunately misunderstood to be obstacle and terrain free. The rest of the flight to Blacksod was intended to be carried out at this altitude, with the surface in sight, and with enough visibility to see and avoid terrain.

In a way, the word "approach" may have given the wrong idea to some people. The low altitude is not indicative of a desire to land soon, but of an intention to transition from instrument to visual flight rules.