4 ms·

This is why every air craft comes equipped with a set of MKII eyeballs. Not trying to make light of it, or anything, but this is a prime example of why good vis

This is why every air craft comes equipped with a set of MKII eyeballs. Not trying to make light of it, or anything, but this is a prime example of why good vision is a requirement of any pilot. Not familiar with this incident or whether it was night-time or during inclement weather. Regardless of the circumstance, my apologies & condolences to the friends & family of the crew and any passengers. From your short description, this seems like an easily avoided accident and I hope actions are being taken to prevent a recurrence.

Fomite 9y ago
I would put the Bayesian prior for the probability that an air sea rescue helicopter is operating in bad weather with poor visibility at "Pretty damned high".
pedrocr 9y ago
>This is why every air craft comes equipped with a set of MKII eyeballs. What was the the MKI?
- Neliquat 9y ago
  Curb feelers? Nah, I am going to go with Optically tested and Corrected vision. A uniquely human trait.
  - pedrocr 9y ago
    That's what's usually called a Mk1 eyeball, but the OP said the Mk2 eyeball so I'm curious what he considers the predecessor.
    - roryisok 9y ago
      probably just a mistake.
- tajen 9y ago
  Urban Dictionary comes to the rescue: "Mk1 Eyeballs: Unaided vision. Commonly used by military internet know it alls to confuse people in an argument." I don't know whether MkII is an upgrade to aided vision or just a new version of the confusion. http://www.urbandictionary.com/define.php?term=Mk1%20eyeball http://www.urbandictionary.com/define.php?term=Mk1%20eyeball
mikeash 9y ago
I don't think good vision is going to be much of a factor when it comes to not crashing into an island. You can spot islands at close range about as well with 20/40 vision as you can with 20/10 vision. Neither one is going to help you spot unlit terrain at night (as happened here).
roryisok 9y ago
According to the recovered black box recordings, one of the crew did see the island, but not soon enough. Probably the most shocking part is that there was a lighthouse on this island, which was operational at the time. This is shocking both because it should have been blindingly obvious to the pilot and crew that they were flying toward a lighthouse, and also that an island significant enough to have a lighthouse on it would not be on a digital mapping system. It's on Google maps - https://goo.gl/maps/Xdt7rzUErX42 https://goo.gl/maps/Xdt7rzUErX42, even has photos and information. This is not some insignificant rock How an aircraft mapping system can have such a huge omission is just mind-blowing
- theoh 9y ago
  To be clear, the deficiency was in a warning system database of 3D elevation geometry (the EGPWS) not a "mapping system". Something that is geographically notable but quite small, vertical and isolated (like Rockall) may very well also be omitted from that version of the EGPWS database. NB Blackrock is a designated navigational waypoint on the standard charts etc. which is why they were flying straight toward it on autopilot.
  - roryisok 9y ago
    > Something that is geographically notable but quite small, vertical and isolated (like Rockall) may very well also be omitted from that version of the EGPWS database. Why are "small" and "isolated" good criteria for omitting something from a database of elevation geometry? It's evidently big enough to crash into and cause loss of life.
    - theoh 9y ago
      I'm not suggesting that those are criteria, just possible contributing factors. (And I'm not trying to exonerate the suppliers. We'll see what the final report says.) If the source is some kind of DEM (digital elevation model) data, it will be a raster of elevation values at some limited resolution, so necessarily just samples of elevation. With a relatively small island/rock, the full height could be missed, and possibly then even further reduced by filtering (i.e. smoothing of DEM values, either in the process of measurement or some kind of processing). That likelihood is hinted at by this quote from the manufacturer: "Honeywell’s terrain data is sourced from our supplier [named supplier]. It is a digitized topographic map derived data set. It does not include Black Rock. We have looked at alternate sources, including SRTM and ASTER. While Black Rock is present in these alternate data sets, the actual altitude of Black Rock is considerably higher than what is indicated in these alternate data sets." The data sources they refer to: http://www2.jpl.nasa.gov/srtm/ http://www2.jpl.nasa.gov/srtm/ https://asterweb.jpl.nasa.gov/gdem.asp https://asterweb.jpl.nasa.gov/gdem.asp Again, not coming to any conclusions from this.
andyjohnson0 9y ago
It was a SAR mission, flying low at night. I'm not a pilot, but eyeballs may not have been much use. Preliminary accident report is at [1]. [1] http://www.aaiu.ie/sites/default/files/report-attachments/REPORT%202017-006%20PRELIMINARY.pdf http://www.aaiu.ie/sites/default/files/report-attachments/RE...

Fomite 9y ago

I would put the Bayesian prior for the probability that an air sea rescue helicopter is operating in bad weather with poor visibility at "Pretty damned high".

pedrocr 9y ago

>This is why every air craft comes equipped with a set of MKII eyeballs. What was the the MKI?

Neliquat 9y ago
Curb feelers? Nah, I am going to go with Optically tested and Corrected vision. A uniquely human trait.
- pedrocr 9y ago
  That's what's usually called a Mk1 eyeball, but the OP said the Mk2 eyeball so I'm curious what he considers the predecessor.
  - roryisok 9y ago
    probably just a mistake.
tajen 9y ago
Urban Dictionary comes to the rescue: "Mk1 Eyeballs: Unaided vision. Commonly used by military internet know it alls to confuse people in an argument." I don't know whether MkII is an upgrade to aided vision or just a new version of the confusion. http://www.urbandictionary.com/define.php?term=Mk1%20eyeball http://www.urbandictionary.com/define.php?term=Mk1%20eyeball

mikeash 9y ago

I don't think good vision is going to be much of a factor when it comes to not crashing into an island. You can spot islands at close range about as well with 20/40 vision as you can with 20/10 vision. Neither one is going to help you spot unlit terrain at night (as happened here).

roryisok 9y ago

According to the recovered black box recordings, one of the crew did see the island, but not soon enough. Probably the most shocking part is that there was a lighthouse on this island, which was operational at the time. This is shocking both because it should have been blindingly obvious to the pilot and crew that they were flying toward a lighthouse, and also that an island significant enough to have a lighthouse on it would not be on a digital mapping system. It's on Google maps - https://goo.gl/maps/Xdt7rzUErX42 https://goo.gl/maps/Xdt7rzUErX42, even has photos and information. This is not some insignificant rock How an aircraft mapping system can have such a huge omission is just mind-blowing

theoh 9y ago
To be clear, the deficiency was in a warning system database of 3D elevation geometry (the EGPWS) not a "mapping system". Something that is geographically notable but quite small, vertical and isolated (like Rockall) may very well also be omitted from that version of the EGPWS database. NB Blackrock is a designated navigational waypoint on the standard charts etc. which is why they were flying straight toward it on autopilot.
- roryisok 9y ago
  > Something that is geographically notable but quite small, vertical and isolated (like Rockall) may very well also be omitted from that version of the EGPWS database. Why are "small" and "isolated" good criteria for omitting something from a database of elevation geometry? It's evidently big enough to crash into and cause loss of life.
  - theoh 9y ago
    I'm not suggesting that those are criteria, just possible contributing factors. (And I'm not trying to exonerate the suppliers. We'll see what the final report says.) If the source is some kind of DEM (digital elevation model) data, it will be a raster of elevation values at some limited resolution, so necessarily just samples of elevation. With a relatively small island/rock, the full height could be missed, and possibly then even further reduced by filtering (i.e. smoothing of DEM values, either in the process of measurement or some kind of processing). That likelihood is hinted at by this quote from the manufacturer: "Honeywell’s terrain data is sourced from our supplier [named supplier]. It is a digitized topographic map derived data set. It does not include Black Rock. We have looked at alternate sources, including SRTM and ASTER. While Black Rock is present in these alternate data sets, the actual altitude of Black Rock is considerably higher than what is indicated in these alternate data sets." The data sources they refer to: http://www2.jpl.nasa.gov/srtm/ http://www2.jpl.nasa.gov/srtm/ https://asterweb.jpl.nasa.gov/gdem.asp https://asterweb.jpl.nasa.gov/gdem.asp Again, not coming to any conclusions from this.

andyjohnson0 9y ago

It was a SAR mission, flying low at night. I'm not a pilot, but eyeballs may not have been much use. Preliminary accident report is at [1]. [1] http://www.aaiu.ie/sites/default/files/report-attachments/REPORT%202017-006%20PRELIMINARY.pdf http://www.aaiu.ie/sites/default/files/report-attachments/RE...