Search and Rescue Helicopter positions

[Peter]

All very interesting contributions, many thanks to everyone. We have R125 - 128 based about 10 miles away, 125 is always the duty a/c whatever its actual airframe is, and 126 is the next call if 125 is engaged on a job. I will be watching PP and RD very carefully when I become aware that they are in my area next time!

[CoastGuardJon]

Hi Peter, whereabouts in the country are you, and are these RAF or RN units.   I believe the coastguard chartered helicopters usually call on the last two characters of their registration (but not 100%).   HM Coastguard also have 3 or 4 ocean-going salvage tugs - our local one, usually in Falmouth or Mounts Bay is Anglian Princess - situated near the busiest shipping lanes.    From 2012 the SAR operations are going to be "privatised" (not strictly the correct term, but close enough for our purposes!), and the Sea Kings (some airframes are well over 30 yrs old, and they vibrate so much they loosen your fillings) are to be withdrawn a great shame as it is a superb aircraft.   SKs have 2 engines, and whether or not the Merlins (3 engines, much bigger, heavier and more computer controlled) will take over RAF/RN SAR duties so successfully, remains to be seen.    The Merlins are a good aircraft, but there have been a couple of crashes, including one at Culdrose as it was hovering low just after take off, within the airfield perimeter, bits of rotor debris flew all over, some landing 1/4 a mile away, fortunately no-one killed, but some very serious injuries were sustained.

[Peter]

I am in Ipswich around 10 miles SE from Wattisham which is an Army Base. However the RAF run 4 Seakings from a hanger isolated away from the rest of the base. I've seen 3 helicopters in the hanger on a visit, the fourth one is usually having a major. I think that our guide said usually two airframes were ready to fly on call and a further one subject to around 3 hours notice. The callsigns are R125 up to 128 in order of readiness to fly.
There has been a major incident here, the air ambulance appeared 10 minutes ago and I presume 125 has RTB. No sign of any of theses on RB or PP plotted or on the lists.

[tarbat]

Here's an idea for Airnav to develop.  Have a lookup table in Radarbox/Shiptrax that ties the ModeS hex code of a helicopter to the MMSI code of that same helicopter.  Then combine the data from both sources to plot the helicopter on the Radarbox map.

[AirNav Support]

Are they supposed to be broadcasting on AIS? Is this a trial or just a local idea?

[Peter]

All I can say is that the Helicopter R125 was out and about this morning passing right over my house a couple of times, and did not appear anywhere at all on the lists. I concluded that only the newer units were fitted with AIS. Obviously Tarbat's sightings at the start of this thread were fitted, plus the new helicopters in Portland, but no sign yet around here. In fact I spotted the Solent units on ShipPlotter share, RB was not booted up at the time!

[tarbat]

They're on the increase.  I regularly see a SAR helicopter on ShipPlotter over the western isles, Orkney, Shetland, and Highlands.

ITU Recommendation M583 defines construction of MMSI numbers.  A recent change introduced a new format of MMSI for SAR aircraft.  SAR aircraft fitted with DSC will use MMSI's with the block 111 as the leading three characters, followed by the country MID and then three numerals to indicate the individual aircraft.

[tarbat]

There's been some progress over on a ShipPlotter forum to tie-up MMSI numbers to SAR registrations:
111232502 G-CGOC
111232503 - G-SARC
111232504 - G-CGIJ
111232505 - G-SARD
111232506 - G-CGWB

Evidently not all AIS receivers can receive the "mode B" transmissions - it needs the KATAS chip.  So, wrong forum, but Airnav you should test that the ShipTrax receiver can receive these transmissions okay.  I'll test if you want ;)

[Peter]

A very good point Tarbat! AirNav please take note, we await the new gear with interest.
Sadly have confirmed that the older RAF SeaKings around here are not fitted with AIS.

[tarbat]

Okay, just got a definitive tie-up between:
MMSI           Registration
111232501 = G-SARB

On ShipPlotter at the same time as G-SARB was on my Radarbox at 5000ft, squawking 0023 (SAR Operations).