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UK SAR 2013 privatisation: the new thread

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UK SAR 2013 privatisation: the new thread

Old 28th Apr 2015, 01:07
  #1921 (permalink)  
 
Join Date: Nov 2009
Location: Inverness-shire, Ross-shire
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I think there are a couple of points that need highlighting.


TRIGGERED LIGHTENING: NEW SCIENCE
Although we knew some time ago that helicopters get hit by lightening, resulting in AAIB and CAA reports, it was only during 2012 and 2013 that academic work was published that allowed an understanding of the mechanism of these events and prediction of high risk.

Until recently, no mountain rescue training had ever been cancelled due to risk levels for triggered lightening.

Last month at Kintail, a mountain rescue first aid training day with hillside scenarios had to do without helicopter support because of the risk level for triggered lightening.


HELICOPTER TRAINING: BRISTOW INVERNESS
Lossiemouth has always served the busiest Scottish MRT. This was where the action was. You may have recently heard the radio interview with John Prince during which he described how he had wanted a posting to Lossiemouth for that very reason.

Bristow Inverness inherits that mantle. Unfortunately, it does so with both the AW189 problem and the storm damage problem. This has resulted in serious delays. Initial training for MRT and others, during January, was cancelled and several other such training events have also been cancelled since.

While teams in the west with S-92 experience have taken a step back, some of those in the east, like Cairngorm, have still failed to get the training that they require. It appears that a number of factors have conspired to cause that problem. Undoubtedly, one of those is vital aircrew training that has similarly fallen behind the planned advance.

From where I sit, it is better that they catch up with their NVIS training but for Cairngorm, having much of the team still never having trained with a modern helicopter three weeks into service provision and in the fourth month since the start of the work-up period, must be extremely frustrating.
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Old 28th Apr 2015, 01:56
  #1922 (permalink)  
 
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Not very often that I pipe up but I think it is warranted on this occasion.

Back in December on a rotation through Sumburgh I was grounded for two days while trying to get guys offshore. Why? Triggered lightning and a lot of red bands of it. Did the SAR guys I was sharing an office fly? Of course they did. Ok they weren't training due to TL but they were quick enough getting themselves out the door when the klaxon went off to provide top cover to a few fishing vessels that were struggling near Orkney. Quite interesting to hear also that a precautionary landing was conducted for 10 minutes when St Elmo decided to distribute his fire over parts of the aircraft.

Good call in my eyes.

LZ
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Old 28th Apr 2015, 08:57
  #1923 (permalink)  
 
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Hot LZ, as you state, TL is an issue overwater and Sumburgh is in the middle of plenty of that so their decision is quite understood and eminently valid.

However, the polar maritime air flow that gives the potential conditions for TL relies on the airmass being unstable with respect to sea temperature which, last weekend at least, was higher than the inland temperatures.

So, even if the wind was in the right direction to affect Inverness itself, it is extremely unlikely that the conditions for TL would be found even a short way inland because the land temperatures were too low to sustain the instability of the airmass.

Aberdeen is vulnerable - as proven - but cancelling mountain training on the basis of an extremely remote chance???
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Old 28th Apr 2015, 09:12
  #1924 (permalink)  
 
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Aberdeen is vulnerable - as proven - but cancelling mountain training on the basis of an extremely remote chance???
I can see it now... Met forecast puts large blob of red triggered lightning over the land area where MR exercise is to take place.... Crew read this load of tosh ( as if they would) and think it's OK cos Crab says it will be fine. Let's crack on.

Flash; Bang; Cer-ching.......... Woops

You can't just ignore a forecast. Perhaps you did in your previous life just for shi-s and giggles.
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Old 28th Apr 2015, 09:38
  #1925 (permalink)  
 
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Triggered lightning is nothing to do with overwater or not. It can occur when mixed-phase precipitation occurs (ie rain + hail or snow) which obviously tends to occur around zero centigrade. This is because the two phases have different densities and hence buoyancies and hence vertical speeds. The speed differential creates friction and static charge. Around zero C the electric field strength is maximised and the ionisation caused by engines and/or rotor blade static discharge can create a conductive path.

It only seems to be overwater because offshore IFR helicopters spend most of their time offshore, and often close to zero C in winter. There has never been a triggered strike in the summer (May to Oct -ish)

Strikes are costly but have always been extant. The current met office modelling system unfortunately has no accounting for false positive warnings - it's a self-fulfilling prophesy that it shows a warning and no one flys so no one gets struck. Personally I don't think it works very well and obviously from the met office's point of view it is better to have a false warning than a lack of warning. Taken to extreme of course if it gave a permanent warning no-one would ever get struck. OK it's not as bad as that but it is crude.

However I think Bristow is perhaps being a bit foolish in citing this reason for not doing the training, even though I'm sure we all accept that it would fly on a real shout. And playing the "safety" card is BS. It's about the cost. No-one has ever been injured from a triggered lightning strike, although one lot did get wet socks many moons ago with inadequately certified tail rotor blades.

Anyway, don't SAR boys all get vertigo above 200'AGL? It seems highly unlikely that a triggered strike could occur at low level. Too much irrational corporate risk-averseness I'm sorry to say, and too many managers who don't actually understand the science.
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Old 28th Apr 2015, 09:58
  #1926 (permalink)  
 
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CRAB

Check out the Met Office work on this.
Investigating and predicting helicopter-triggered lightning strikes - Met Office
Theire example map clearly shows overland hot-spots.
http://www.metoffice.gov.uk/media/im...n_radar_L2.jpg

After our cancellation due to triggered lightning risk I have had a look at work on this phenomenon and hope to get someone to do a piece on the subject for the Scottish Mountain Rescue magazine at some stage.


HELICOMPARATOR

Vertigo above 200'AGL? Wouldn't surprise me! However, whereas a Sea King has always tended to be flown through the glens, in an S-92 there is more of a tendency for folk to just fly across the top.

The science is still new. I would hope that in 5 years time there will be a finer honed forecast.
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Old 28th Apr 2015, 11:21
  #1927 (permalink)  
 
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Triggered lightning is nothing to do with overwater or not. It can occur when mixed-phase precipitation occurs (ie rain + hail or snow) which obviously tends to occur around zero centigrade. This is because the two phases have different densities and hence buoyancies and hence vertical speeds. The speed differential creates friction and static charge. Around zero C the electric field strength is maximised and the ionisation caused by engines and/or rotor blade static discharge can create a conductive path.
Yet SAR helicopters have been operating in the mountains in, around and below the zero degree isotherm in mixed precipitation for many years but there are no reports of triggered lightning.

The met office and caa pages highlight that overland there is usually sufficient electrical potential to trigger a lightning strike without needing a helicopter to initiate it whereas, over the sea, the cloud can be charged but not sufficiently to discharge cloud to cloud or cloud to ground - that is when the helo comes along with a vastly different electrical polarity and triggers the strike.

Jim, that radar picture shows showers both over sea and overland and rain rate - nothing new there - the fact that a helicopter suffered a lightning strike in the bounded box ( note that it is over the sea) does not mean that every shower gives the same risk.

Last edited by [email protected]; 28th Apr 2015 at 11:39.
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Old 28th Apr 2015, 11:36
  #1928 (permalink)  
 
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Investigation and prediction of helicopter-triggered lightning over the North Sea - Wilkinson - 2012 - Meteorological Applications - Wiley Online Library

All you need to know about TL - strangely no mention whatsoever about overland............

The opening line
Helicopter-triggered lightning is a phenomenon which affects operations over the North Sea during the winter.
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Old 28th Apr 2015, 11:52
  #1929 (permalink)  
 
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strangely no mention whatsoever about overland............
Probably because it was commissioned to look at operations over the North Sea.....but, you knew that.
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Old 28th Apr 2015, 11:53
  #1930 (permalink)  
 
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Well yes Crab. You have a point. One that fits with my scenario of the SK flying through the glens. And where we may be at present is "We have a S-92, we can fly anywhere. Oops, no we can't."


It looks to me like we need more science done. (Not going to hold my breath.)


In relation to the recent Kintail Ex, like all NW teams we are often using an aircraft that flies 20 minutes over the Minch to get here so over water flight is part of the overall scenario.
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Old 28th Apr 2015, 12:08
  #1931 (permalink)  
 
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Originally Posted by [email protected] View Post
Yet SAR helicopters have been operating in the mountains in, around and below the zero degree isotherm in mixed precipitation for many years but there are no reports of triggered lightning.

The met office and caa pages highlight that overland there is usually sufficient electrical potential to trigger a lightning strike without needing a helicopter to initiate it whereas, over the sea, the cloud can be charged but not sufficiently to discharge cloud to cloud or cloud to ground - that is when the helo comes along with a vastly different electrical polarity and triggers the strike.
Well firstly, if you look at the number of offshore oil support flights / hours per year, and then the number of triggered lightning strikes - around 1 or 2 a year on average IIRC, and then look at the number of onshore mil SAR flights / hours per year, you will see than on probability alone it is not surprising that there has not been a mil SAR triggered lightning strike.

I also think that a low flying helicopter is less likely to be a trigger because if there is that much electric field strength near the ground, an air to ground strike is likely to happen anyway. But I think for a heli flying at say 3000' agl the probabilities are much the same onshore as offshore. Yes there is a throwaway line about "usually" onshore, but I don't see any science behind that view.

Personally I think it was a mistake to decline training because of this risk, since there would inevitably be a publicity backlash, however I was in the Cairngorms on Sunday afternoon and there was one massive snowstorm all afternoon which closed the Lecht and the A96 and that for me would have been good enough reason to stay cosy in Ops unless I really had to go flying!
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Old 28th Apr 2015, 12:33
  #1932 (permalink)  
 
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Probably because it was commissioned to look at operations over the North Sea.....but, you knew that.
yes I did, because that was where the phenomenon was reported. Therefore extending that risk to overland ops was unscientific and using it as an excuse for cancelling MR training was poor judgement.

As HC points out, the weather was crap anyway so that would have been a far better justification.
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Old 28th Apr 2015, 13:02
  #1933 (permalink)  
 
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...because that was where the phenomenon was reported
I think HC addressed that quite well
Well firstly, if you look at the number of offshore oil support flights / hours per year, and then the number of triggered lightning strikes - around 1 or 2 a year on average IIRC, and then look at the number of onshore mil SAR flights / hours per year, you will see than on probability alone it is not surprising that there has not been a mil SAR triggered lightning strike
But, I agree with your last point
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Old 28th Apr 2015, 20:13
  #1934 (permalink)  
 
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New SAR base at Lydd is under construction.
Building under way for new Lydd SAR facilities - BBC News
mmitch.
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Old 29th Apr 2015, 06:43
  #1935 (permalink)  
 
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All leaves Humberside looking very isolated up the East Coast.
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Old 29th Apr 2015, 12:59
  #1936 (permalink)  
 
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Oh - that went down with a fizz and sigh.......
I'll ask again because people may not know that allegedly Bristow are refusing inland SAR @ night if it requires NVD's. True or False?

And are they also refusing future EMS contam transport in open cockpit helicopters?

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Old 29th Apr 2015, 13:37
  #1937 (permalink)  
 
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That can't be true TC, I have been told so often here that the new Service will be so much better and that all I have been doing is scaremongering about operational capability
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Old 29th Apr 2015, 20:18
  #1938 (permalink)  
 
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Might be totally unrelated but does anyone know why Bristows EC225 G-ZZSJ has been performing deck winching and wet winching out of Dyce?





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Old 29th Apr 2015, 20:24
  #1939 (permalink)  
 
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Practising Public Transport winching. It is quite normal to winch transfer personnel to and from tankers and loading buoys. The difference is that the aircraft has to be below HOGE, OEI weight at all times during the operation
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Old 13th May 2015, 12:31
  #1940 (permalink)  
 
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Bristow Caernarfon starting up.

G-MCGJ on site but not yet showing up on AIS or ADS-B, suggesting that the radio fit is not yet complete.

G-MCGK arrived at Dyce a few days ago and is presumably there for a couple of weeks for engineering work.



G-CIJX and G_CIJW are still at Norwich and often out around Cromer. No sign of a move to Lydd yet.
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