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SAR: Search & Rescue Ops [Archive Copy]

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SAR: Search & Rescue Ops [Archive Copy]

Old 4th Jan 2006, 23:22
  #601 (permalink)  
 
Join Date: Aug 2004
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Re: UK Coastguard SAR - Bristow out??

Steve OC is correct to point out that we are not quite comparing like with like. If you want to have full de-icing and aircon the difference between the two types narrows somewhat. However if you look at what you actually need for the N North Sea:

Aircon is nice-to-have but by no means essential or even asked for by the oil companies in their tenders.

The 225 functions quite adequately with the limited icing clearance as have the 332L / L2 for many years. OK perhaps there are a couple of days a year when you can't fly due to icing, but is it worth carrying the extra weight all year just for those 2 days? Again, the oil companies don't think so otherwise they would specify it in their contracts. However the 92 does not offer a limited icing clearance. No icing clearance at all puts you at a disadvantage on the N N Sea (unless you are Norwegian) as you are stuck with grovelling around at low level with the associated poor RT, traffic congestion and high fuel consumption. To be fair to Sky, since all blades are de-iced the extra to implement full de-icing (wiring, bigger generators?) is not heavy (around 190 lbs I think) you might as well have it (have to have it?) on the 92.

So what I am saying is that if you must have de-icing, this puts the 92 in a better light, whereas if you want to continue with standard N N Sea practice and use a limited icing clearance when available, the 225 has the advantage.

Regarding the fuel burn, its very difficult to be definitive about this - I spent several hours looking at the 92 and 225 flight manuals yesterday. There are too many variables such as: The speed / fuel burn changes massively with weight, as these aircraft have such a big range of possible weights (because they have such large disposable loads). The FM I have has no data above 26150lbs for the 92. Do you compare the 2 aircraft with the same load, or both starting at gross weight or what? What speed do you want to cruise at - the 225 favours higher speeds than the 92 but at lower speeds you can possibly get marginally better range on the 92.

I think the two are pretty close. I think the 225 is marginally better, and "more better" at higher speeds, but this would not be a deciding factor for me. For me it would be the autopilot, the screen design, the ability to descend at 165 kts at a vibration level much better than an L at 130 kts, and the ability to carry full fuel and 19 pax with bags every time - I have now modified my flight planning procedures. On arrival at flight planning, assuming the flight is more than 140 miles or so I just phone the line office and order full fuel. No need to wait for the load from traffic

Steve - you will be in a position to get a handle on operating the 225 in the near future, and perhaps you will also be in a position, or already have, a handle on operating the S92? What has been lacking in these threads is much "evidence" from people who have flown both aircraft -in fact I think its only me ( I mean that has posted, not that has flown both). So I hope to hear more from you in the future!

HC
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Old 4th Jan 2006, 23:28
  #602 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

I doubt you will find anyone who has actually operated both types; just had demonstration flights in both and operated one.
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Old 4th Jan 2006, 23:30
  #603 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

Funnything...Cougar article suggested the air con was a blessing for the pax who had to wear immersion suits during the summer time due the cold water they fly over. Also...what advantage is limited icing compared to full de-icing? Seems again a lesser capability is passed off as being the same as a better option.

As to the float weight bearing capacity being just over 10 tons....do you limit the MAUW so as not to exceed that ability of the floats?

If you have only sea state 5 floats...do you restrict the aircraft from flyin if the sea state is 6 or above?
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Old 4th Jan 2006, 23:49
  #604 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

212 - Steve OC will be in the position where his company will be operating both the 92 and the 225 on the N Sea - so he will be best placed to compare the operating issues. As for me, I have only had a demo flight in the 92, but do operate the 225 so of course I am biased! (Though my opinion was already formed after my intial flight on the 92 and the 225)

SAS - as I said the aircon is "nice to have" for the passengers, but we are stuck with what the oil companies want - we are not going to pay for aircon and reduce our payloads unless the oil companies want it. Unlike the airlines, it is the bean counters who decided whether the pax will fly with us or the opposition so there is no benefit in providing comfort stuff that is not required / paid for. Sad but true!

Limited icing - I thought I had already explained that. It just depends on what you need for your location - if you are operating in the Sahara, de-icing would probably not be needed. If you are operating overland at high latitudes, de-icing would be pretty essential. The N Sea is at a latitude where limited icing clearance is adequate to get the job done safely on 99.5% of days (you don't fly on the 0.5% of days) and the extra cost (initial and maintenance) and weight of full de-icing is not justified (in the oil companies' opinion)

Floats: the post from HH was a red herring - the 225 floats are of course certified up to the gross weight of 11 tonnes.

Good question about the sea state - I don't know enough about it to give the correct answer according to Jar-Ops 3 but I do know that the 225 has a better ditching sea state certification than the 332L, L2 or the 92 at the moment, which has to be a good thing. In practice we fly until the oil companies consider that they can't get us out of the sea with their rescue boats and have recurrent training on how to get out if it turns over.

HC
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Old 5th Jan 2006, 00:57
  #605 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

Helicomp,

you are a man of much wisdom!
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Old 5th Jan 2006, 08:13
  #606 (permalink)  
 
Join Date: Jan 2006
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Re: UK Coastguard SAR - Bristow out??

The client is the MCA/DfT not an oil company.
The punters dont really care about airconditioners when they have been pulled out of the North Sea/North Atlantic,deicing would be nice to have but not essential,probably cause more grief for the engineers than its actual use would warrant.
Floats,not much use for most of the year in this part of the world with the sea states being quoted.
Has the 92 got a fuel dump facility?
Are the 92 being used for this contract modified passenger a/c or purpose built SAR variants,any one know,or is it just quessing?
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Old 5th Jan 2006, 09:20
  #607 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

Flight over a hostile environment (such as the North Sea) is regulated in JAR-OPS 3 by addressing the two issues: certification for tasks; and consequence in the event of a forced landing. Flight over a hostile environment requires the helicopter to be certificated in Category A (a subject which has been dealt with adequately in another thread) and, performance aside, is the ability to fly for extended periods with the probability that no failure will cause a catastrophic outcome. In addition to this, flight over water requires the fitting of additional safety equipment and, if that water is considered to constitute a hostile environment, certification for ditching (flight for oil support also calls for a number of practical additions to these requirements).

With specific regard to the Sea State, there is no specific boundary but the following is considered to apply:

Judgment is required when applying the definition of safe forced landing to over-water flights (the boundary between hostile and non-hostile) as injury to persons in the aircraft extends beyond the touchdown it also includes capsize and, the subsequent evacuation and access to safety equipment (such as life vests and liferafts) under difficult conditions. When attempting to allocate the boundary between hostile and non-hostile for over water flights, it is best to revert to the two main elements for Risk Assessment: the probability of the event; and the consequence:
The probability of the event will depend upon the Performance Class in which the helicopter is being operated.

The consequence of the event will depend on the Sea State of the sea over which the operation is being performance and the certification of the flotation equipment.
Over water helicopter operations are permitted in the knowledge that emergency situations may arise which may require an immediate and forced landing. Accordingly, (at amendment 9) ICAO Annex 6 Part 3 paragraphs 2.2.11 and 4.5.1, and national operating rules specify those circumstances where approved flotation and safety equipment must be carried; ICAO further states that Sea State shall be an integral part of ditching information.

Requirements for ditching approval are contained in FAR/JAR 27/29.801:
Paragraph (b) requires that measures must be taken to minimise the probability that in an emergency landing on water, the behaviour of the rotorcraft would cause immediate injury to the occupants or would make it impossible for them to escape.

Paragraph (d) requires that flotation and stability must be demonstrated in reasonably probable sea conditions.
Experience suggests that the greatest risk to the occupants in a ditching is drowning due to inability to evacuate the aircraft following capsize and subsequent flooding of the hull. FARs/JARs require the designer to select the reasonably probable wave condition for the area in which the helicopter is expected to operate and to demonstrate that the probability of capsize has been minimised. FAA and JAA have adopted an interpretation (AC29-2A para 337(a)(3)) which states that Sea State 4 is considered to satisfy the reasonably probable requirement. Most helicopters that apply for ditching approval are therefore certificated to Sea State 4.
Sea State 4 represents a wave height of 1.25 m - 2.5 m (4 ft - 8 ft) and wind speed of 17 kts - 21 kts.
The weather conditions up to Sea State 4 provide a pragmatic limit for operations within the non-hostile classification - particularly as it aligns with the standard for Certification for Ditching satisfying reasonably probable conditions. It is therefore suggested that, for operations over open sea areas, the boundary for ‘hostile’ should be set to above Sea State 4.

A recent study (CAA Paper 2005-06) of wave climates along a representative selection of main helicopter routes in the northern North Sea and West of Shetland indicates that Sea State 4 will be exceeded on 26%-36% of occasions over the whole year. During the winter period between December-February, this increases to between 51%-65%. Clearly when considering routine offshore operations in the specified area, they can be (and are) regarded as permanently hostile and any regulation should make sufficient provision to ensure that the probability of ditching is minimised.

Because the probability of flying over a Sea State of 4 is exceeded for a large proportion of the time, it has been a long standing recommendation of the JAA that AC 29 be amended to reflect those conditions (this recommendation can be seen in CAA Paper 2005-06 which can be found at - http://www.caa.co.uk/docs/33/2005_06.PDF).

Prohibition from flight when the Sea State exceeds the certification standard has never been seriously considered as it would have caused a great deal of disruption to the offshore industry. The Oil Companies have however, been instrumental in ensuring that the certification of floats is raised above the norm of Sea State 4 - hence certification for ditching on the EC225, the S92 and the A139 which is now to Sea State 6.
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Old 5th Jan 2006, 09:32
  #608 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

JimL - thanks for clearing that up and its nice to know I haven't been doing anything illegal all these years (well, as far as flying in high sea states goes anyway )

HC
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Old 5th Jan 2006, 11:05
  #609 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

Helicomparitor.

Some good interesting stuff, but I am not sure how relevant it is to SAR. Until the operator decides exactly what equipment they are going to carry, the weight and performance issues cannot be quantified. Bear in mind the manufacturers estimates on SAR equiped APS weights are VERY optimistic IME. Seastate 6 - thats not much use for N Atlantic ops is it?


267.4FWD,

Full anti icing a "nice to have"?? I imagine the Stornoway crews would have another opinion.
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Old 5th Jan 2006, 11:32
  #610 (permalink)  
 
Join Date: Oct 2001
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Re: UK Coastguard SAR - Bristow out??

On the subject of icing clearances, the "limited" icing clearance was obtained in the early eighties because Bristow wasn't prepared to pay the money for the full de-icing kit. The AS332L flight manual icing clearance is very restrictive and doesn't really give any benefit due to the +airtemp requirement at least 500' above MSA requirement. The operators had to produce "get-round-the-rules" procedures to allow a/c to depart IFR overland in icing conditions with escape routes to warmer air at low level offshore. Arriving back at on onshore base in icing conditions still requires +airtemp at least 500' above the surface (if my memory serves me correctly). This is usually ignored.
These "Operational Procedures" would never be allowed if proposed today as they do not fully take into account oei performance degradation due to blade icing.

It is about time we as pilots insist on full icing clearances for North Sea aircraft.
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Old 5th Jan 2006, 11:39
  #611 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

Thank you coalface, your words (unlike makila and hc) are the words one expects from folks who want to make our piloting task better as time goes on.

The apology hc made for lack of de-ice is interesting, and fitting the helicomparitor salesman mold. Last time he unveiled this logic, windows were equal to crashworthy seats, until his company designed the modern safety into the heliciopter, then crashworthiness became a feature!

Nice try helicomparitor, but deice of rotors is now an essential piece of kit. Welcome to the 21st century.

For those who need deice in their EC225, I suggest printing and taping the below words on their windshields, as a way to quell their concerns. If written on steel, it should survive the crash:

"(You can).... get the job done safely on 99.5% of days (you don't fly on the 0.5% of days) and the extra cost (initial and maintenance) and weight of full de-icing is not justified (in the oil companies' opinion) - Love, Helicomparitor, EC apologist"

Regarding airconditioning, safety from bird strikes and safety from turbine bursts (all lacking on the EC225, along with hundreds of additional safety features grandfathered out) the customers have chosen, and will continue to chose the modern aircraft over the grandfathered old one. Now I understand hc's need to publish the weights he has, he left out the items that customers want for safety or comfort, and then brags about how light his helo is. Nice trick, works on ppruners, maybe, but makes the oil companies and SAR contractors walk away from the unsigned EC contracts.
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Old 5th Jan 2006, 12:25
  #612 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

I have some questions....

Is there a fuel dump on the S92?

Are the vibration problems affecting the S92 worsened by higher weights or only affected by speed?

Is there anyone winching using a S92 and have they had trouble getting a stretcher in and out of the door (noting the position of the sponson) or the wire rubbing against the sponson in high wind conditions?

Does it offer SE hover performance at MTOW in nil wind conditions (UK temps)?

Is it true you can only use the windscreen wipers below 40kts airspeed? And when is any helicopter manufacturer ever going to produce a decent set of wipers for an aircraft... my car has better wipers for F#%ks sake!!!!

Just questions.... I am not contributing to the 'my helicopter is better than yours' debate although I would say that Nick and Helicomparator are equally biased although in different directions.

I think de-icing is a very good thing for SAR aircraft and I'd rather have it than not, particulary as you get it with the basic model.

The S92 has a more suitable cabin for SAR and even with the great payload debate going on at the moment the weights offered by the 92 for SAR seem suitable and certainly considerably better than the S61.

The S92 is coming anyway, it is better than the S61, it's going to have teething problems, unfortunately those problems will probably only become apparent once it is operating as a SAR aircraft and the crew will have to deal with them on the job. Let's hope we can. Frontline SAR is not a place to be testing an aircraft's suitability for the role.

And the AB139.... well the silence is deafening! Does anyone know anything about this aircraft and its suitability for SAR??
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Old 5th Jan 2006, 19:07
  #613 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

Coalface
Funny how BIH, Scotia and Bond all manage to operate quite happily with only a limited icing clearance. I think what you are forgetting is that any de-iced helicopter has to show that it can cope with a failure of the de-icing system, which is a simplex system, and can continue to fly whilst recovering to positive air temps / flying out of icing conditions.

What you refer to as get-around-the-rules procedures are in fact carefully flight tested time periods that you are allowed to fly in icing conditions without the immediate escape route of descending to warm air - 5 minutes for the 332L I seem to remember. The flight testing was of course done during the full de-icing trials and something similar will/should have been done on the 92 and these periods are specified in the approved flight manual supplement for flight in limited icing.

Of course this only works when you are flying over a relatively warm sea with airfields within 5 mins flying time of the coast, but fortunately that is the environment we fly in, and that is why deicing is not asked for or paid for by the oil companies.

Nick, you do rant on so....You either have a very short memory or you are deliberately lying, because even you finally agreed on a previous thread that the 225 has the same certification standard for bird strikes and for turbine burst protection as the 92. And it was pointed out to you that there were only a very few reversions from the FAR29 version that the 92 is certified to - those were to do with having the fuel under the cabin floor. So when you say "hundreds of safety features grandfathered out" you lose all credibility with those that know anything about it. I would give up on the 92 and stick with the new plank job if I were you....

Night Watchman
I agree that full de-icing is far more relevant to Scottish SAR as you will be flying onshore. Fuel dump, whilst less important than on the 61 due to the much better OEI OGE hover performance, is still a useful asset for a SAR machine - I wonder whether it has been specified?

After an earlier post by me on the inferiority of the L2's cabin size for SAR over the S61, I am now told by that lot down the back that its no problem once you get used to it and the guys coming from the 61 onto the L2 find the other benefits (autohover / AMC that actually works properly from the back) outweighs the size disadvantage. That's after the operation to cut off their legs below the knee of course

HC
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Old 5th Jan 2006, 19:51
  #614 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

Originally Posted by HeliComparator
Coalface
Funny how BIH, Scotia and Bond all manage to operate quite happily with only a limited icing clearance.
We all used to operate quite happily without AVAD until there were a couple of accidents involving aircraft inadvertantly hitting the water. We all used to operate the 332L without intake heating mats until the Bristow double engine failure due to engine icing. We all used to operate quite happily with basic analogue SAS systems with no height hold. Need I go on? It is people like you who hold back equipment improvements because of your "lets just make do" attitude.
As for the "carefully flight tested time periods" - what a load of crap. The Flight manual limitations may have been "carefully flight tested" (or more likely given the minimum flight testing required by the French to get the certification) but the "operational rules" were negotiated with the CAA over the desk between the gang of three Flight Ops managers and the CAA Flight Ops inspectorate. As I said before, there is no way these operational rules would pass JAR or EASA scutiny if being negotiated today.

Stop trying to hold us back in the 1970's.
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Old 5th Jan 2006, 19:59
  #615 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

As I said before, there is no way these operational rules would pass JAR or EASA scutiny if being negotiated today
How strange then that limited icing clearance concept, which until recently featured only on G-registered aircraft, has now been applied to EASA-certified EC225. So yes-way, it just did pass JAR and EASA scrutiny. Methinks you don't really know what you are talking about. Never mind, Nick needs a friend!

HC
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Old 5th Jan 2006, 20:27
  #616 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

HC, Are you saying that the operational rules which allow departure from an onshore location in icing conditions with the zero degree isotherm on the surface (previously only published in Company Operations manuals) have now been incorporated into the EC225 Flight Manual? Would love to see chapter and verse.
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Old 5th Jan 2006, 20:45
  #617 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

CF

Are you saying that the operational rules which allow departure from an onshore location in icing conditions with the zero degree isotherm on the surface (previously only published in Company Operations manuals) have now been incorporated into the EC225 Flight Manual?
Duh No, operational rules are not in flight manuals. Operational rules are in the operational rule book otherwise known as Jar-Ops 3. Only the time allowed to exit icing above the limitation is covered in the FM.

Is that the hooter - must be time to go back down the mine! But in my case, time to go on holiday so no more posts for me for 2 weeks - Nick, the field is yours, make the most of it!

HC
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Old 5th Jan 2006, 21:35
  #618 (permalink)  
 
Join Date: Oct 2001
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Re: UK Coastguard SAR - Bristow out??

HC


So does the EC225 FM allow departure from an onshore location in icing conditions with the zero degree isotherm on the surface?

Yes or No

CF
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Old 5th Jan 2006, 22:25
  #619 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

I'm definitely going on holiday any moment now...

Coaly - EASA have just certified their first ever aircraft with a limited icing clearance. Its not based on any "grandfathering" because such a certification never existed as far as the rest of Europe was concerned. 332Ls and L2s registered anywhere else in Europe have no limited icing clearance. For them its a new concept and I can assure you they have looked at it vey closely before granting it. Its true that part of the process of assuring them it was a good idea was to point out that it has been common practice on the UK side of the N Sea for 20 years + without (in my company at any rate) any reported incidents and definitely no accidents.

So if grandfathering means it has been done before then yes, it was grandfathered just like the 92 is grandfathered because it copied the idea of having 2 engines, a main rotor and a tail rotor. But use of the term "grandfathered" in my opinion is just your way of having an uninformed dig at it - maybe you are jealous but if not, I suggest you go fly the S92.

Of course Sky could have applied for a limited icing clearance for the S92 but decided not to - perhaps because the concept was not invented in their office. AB could for the 139 but I am not sure if they will.

The Ops Manual procedures are justified against JAR-OPS 3. They do not over-ride the limitations in the FM, but merely create a suitable operational framework to ensure safe ops. In fact JAR-OPS 3 is fairly vague about that at the moment (leaving it mainly up to the NAAs) and I believe there is an amendment in progress to tighten it up, to better reflect the well-tried procedures we use in the UK N Sea, so that there is a level playing field across JAA states.

The bottom line is, like it or not, the concept of limited icing clearance has worked well and safely for many years in the particular circumstances of the N Sea and full de-icing gives only a tiny operational benefit (the ability to fly on those 0.5% of days) which is outweighed by the cost and weight, in the opinion of our paymasters.

HC
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Old 5th Jan 2006, 22:26
  #620 (permalink)  
 
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Re: UK Coastguard SAR - Bristow out??

CF
Hey that's not fair you totally changed your post whilst I was answering it! Yes to your last Q
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