SAR S-92 Missing Ireland

[Special 25]

I understand that unlike the Sea Marshall which is just a basic PLB (local reception), modern aircrew PLB's all transmit direct to satellite with a GPS position. The COSPAS - SARSAT system will receive a PLB and triangulate the position within a short period of time - Before that, it should have a GPS position from the device - Within a few mins, Search & Rescue all over the world will be alerted and your Ops Centre will be getting a call to know that you are potentially in trouble.

Unlike local 121.5 / AIS PLB's, these sorts of beacons are not allowed to have automatic transmission. They have to be manually activated - by law.

[lowfat]

I think you will find that the pax plb's caused a big problem on one of the recent numerous puma ditchings. To the point that they confused the system and one of the crash recommendations was to remove then from the pax.
Im sure someone will be along to correct me.

found it

https://stv.tv/news/scotland/105022-...eliver-report/

[[email protected]]

Special - a 406Mhz beacon is what you are talking about and they send a databurst transmission every 50 seconds or so in two hexadecimalgroups. One has the identity of the beacon (they are required to be registered) and the second has the GPS position in it. They also transmit a continuous 121.5 tone.

It isn't triangulation - that is what the old satellite system used and it could give large errors.

The data is downloaded to an earth station (Land User Terminal) when the satellite is in view of it.

Lowfat - yes, in that case the'smart' beacons from the aircraft didn't transmit because they recognised an apparent stronger signal (the wrist beacons) and didn't operate properly.

[Red5ive]

Granuaile waited till just before midnight to dock in Galway. Probably better to offload wreckage in the dark of night.

Coast Guard extends search area for two missing crew

It also plans to resume sub-sea scans of the helicopter crash site 13km west of the north Mayo coast when weather settles on Thursday.

Air Accident Investigation Unit (AAIU), which plans to examine it at its facility in Gormanston, Co Meath.

https://www.irishtimes.com/news/irel...crew-1.3036814

[Gadgetman496]

Originally Posted by Red5ive

Granuaile waited till just before midnight to dock in Galway. Probably better to offload wreckage in the dark of night. I think it said in one of the newspaper articles the AAIU will move it to a big shed near Dublin.

She had to wait for the high tide, nothing sinister about the timing. Alot of rock as you enter Galway.

[Red5ive]

Originally Posted by Gadgetman496

She had to wait for the high tide, nothing sinister about the timing. Alot of rock as you enter Galway.

That and wait for a space to dock.

The less photo's of the wreckage in the media, the better for those affected by the crash.

[[email protected]]

Industry Insider - interestingly, the blurb on those beacons highlights that the AIS function is line of sight only - your line of sight from sea level (ie MOB) is extremely limited, especially in a big sea. These beacons don't transmit on 406Mhz so they don't have the satellite capability that they seem to imply and 121.5 isn't monitored by satellite any more, just used for homing by SAR.

[dClbydalpha]

The regulations require 406 PLBs to be manually activated. My assumption is that this is due to the need to avoid inadvertent activation.

Should we now be creating a system for remote activated PLBs?

[RVDT]

With regard to all the waffle about COSPAS SARSAT, PLB's etc etc.

If it wasn't for AIS which is an optional fitment and not for safety of flight you would possibly STILL be looking for this aircraft.

ADELT didn't work.

ELT didn't work and not possible underwater anyway.

Radar track - outside coverage?

I may have missed something?

Something to think about for the future.

[ukv1145]

Originally Posted by RVDT

With regard to all the waffle about COSPAS SARSAT, PLB's etc etc.

If it wasn't for AIS which is an optional fitment and not for safety of flight you would possibly STILL be looking for this aircraft.

ADELT didn't work.

ELT didn't work and not possible underwater anyway.

Radar track - outside coverage?

I may have missed something?

Something to think about for the future.

Missed the operators own flight following system. CHC certainly had this fitted to the SAR cabs. It will have had a higher sample rate than AIS and is GPS/Satcomm based rather than the VHF line of sight of AIS. CHC used to use Skytrac, not sure if they still do. Obviously won't have heard much of this as the data will be password protected and not in the public domain.

[9Aplus]

Fully agree with RVDT
Coasts with many islands and rocks can be real challenge to any locator from standard
old 121,5 and on.
Sea environment and high waves is another problem.
On land GSM location from another aircraft can be useful technology.
On sea only sort of permanent tracking network can gain some time to rescue services.
Technologies like FR24, FLARM, OGN in some kind of voluntary networks can bring
some benefits, hopefully.

[dClbydalpha]

We're beginning to mix topics here. There is a difference between.
1) establishing that an aircraft incident has occurred and where.
2) finding an aircraft post incident.
3) finding personnel post incident.

I'll also add AIS is not limited to LOS.

[[email protected]]

I'll also add AIS is not limited to LOS.

if it uses the growing number of satellites with a dedeicated AIS receiver, is it not technically S-AIS?

If VHF only then it is definitely LOS.

[dClbydalpha]

Originally Posted by [email protected]

if it uses the growing number of satellites with a dedeicated AIS receiver, is it not technically S-AIS?

If VHF only then it is definitely LOS.

Technically all satellite comms involves at least two LOS segments, but generally satcom is considered BLOS.

AIS is VHF, and is relayed through satellites giving the system BLOS capability.

For ships there is no impact on installation, for aircraft the obvious has to be considered.

[Concentric]

Originally Posted by dClbydalpha

For ships there is no impact on installation, for aircraft the obvious has to be considered.

And for remote lighthouses...?

[dClbydalpha]

Originally Posted by Concentric

And for remote lighthouses...?

Whatever is required, but
Would people need to track a lighthouse BLOS?

[satsuma]

I recall many Irish winch crew choosing not to wear their STASS bottles on their life jacket but stowing them close to their work station for use when required.

[IRCG SMC WHITEY]

Any one wishing to check tides for Blacksod Bay should consult the UKHO EasyTide site and navigate your way to Blacksod Bay.
Regarding rapid airspeed change circa impact time, could this be due to helo richocheting off Blackrock and electrics powering down?

[Concentric]

Originally Posted by dClbydalpha

Whatever is required, but
Would people need to track a lighthouse BLOS?

What I was hinting at was that ships use AIS to avoid collisions. The fishing boat with injured crewman had AIS but probably not the fancier systems CHC track their assets with. The S-92 transmitted AIS and as a SAR ac would be expected to have AIS detection in order to help find and identify target vessels.

The Black Rock lighthouse appears on MarineTraffic AIS (see below) giving its height, range and light signature. VHF may not work underwater but it will penetrate rain or low cloud better than 19th century flashing lights. One thing it does not appear to have is a radar beacon whereas Bull Rock for example does.

[[email protected]]

Mitchaa - I can't think of a situation when they wouldn't wear their immersion suits, especially at night.

As Satsuma has said , they had a version (I don't know which one) of STASS (Short Term Air Supply System) and will have trained using it in the dunker.

Dclbydaplha - so it is S-AIS The original concept of AIS was a LOS collision avoidance IIRC.