Low level overwater ops: radar discussion
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Low level overwater ops: radar discussion
RAF and RN Sea Kings regularly operate in bad weather at low level overwater down to 50 ft amsl during ops and training. That they are able to do so depends on a skilled radar operator working a 360 arc radar to ensure collision avoidance.
The S92 has a co pilot operated radar 120 arc weather radar, the limitations of which would be highlighted in strong cross winds and in the hover, for example; Coastal letdowns. How would an IMC (lets say 100ft cloud base, 100mtres vis, w/v 40 kts) let down to the base of a 300ft cliff in a strong onshore wind be safely achieved. This is a not uncommon occurrance, I know, I've done enough of them.
Also, when operating in the hover at night, ops or even training and in similarly poor vis for protracted periods, how is collision avoidance from surface vessels to be achieved with said radar particularly in busy sea areas like for example off Felixtowe. I might be wrong here but wasn't a Navy Lynx run down by a merchant vessel in the Adriatic some years ago? Perhaps CHC don't intend to train in those conditions. (Train hard fight easy, its the way ahead) but bearing in mind the contractual requirement to provide a service no less capable etc etc how will all round collision avoidance be achieved with the S92 in poor vis?
I did (over) hear someone once say "why would you need a radar to point anywhere but the direction you are heading?" Well, if you have to ask that ..........................!!!
I don't understand the ins and outs of certification and AOLs etc but I would like to know how CHC will cope with those circumstances described.
The S92 has a co pilot operated radar 120 arc weather radar, the limitations of which would be highlighted in strong cross winds and in the hover, for example; Coastal letdowns. How would an IMC (lets say 100ft cloud base, 100mtres vis, w/v 40 kts) let down to the base of a 300ft cliff in a strong onshore wind be safely achieved. This is a not uncommon occurrance, I know, I've done enough of them.
Also, when operating in the hover at night, ops or even training and in similarly poor vis for protracted periods, how is collision avoidance from surface vessels to be achieved with said radar particularly in busy sea areas like for example off Felixtowe. I might be wrong here but wasn't a Navy Lynx run down by a merchant vessel in the Adriatic some years ago? Perhaps CHC don't intend to train in those conditions. (Train hard fight easy, its the way ahead) but bearing in mind the contractual requirement to provide a service no less capable etc etc how will all round collision avoidance be achieved with the S92 in poor vis?
I did (over) hear someone once say "why would you need a radar to point anywhere but the direction you are heading?" Well, if you have to ask that ..........................!!!
I don't understand the ins and outs of certification and AOLs etc but I would like to know how CHC will cope with those circumstances described.
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RAF and RN Sea Kings regularly operate in bad weather at low level overwater down to 50 ft amsl during ops and training. That they are able to do so depends on a skilled radar operator working a 360 arc radar to ensure collision avoidance.
Your right I don't know how the the crews from the four CG bases have managed to survive the past 26 years without the "360"
Radar
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Rescue 1
Let me be clear. This is not a "Crabesque" rant about mil crews being "better" than civ crews. You don't have to convince me of the calibre of the CG crews past and present. I was in the business for over 30 years and I know their record, most are ex mil anyway. If you are a civil SAR operator and I gave you that impression I apologise.
My question is more about equipment. A Mil Sea King (mil registered) is able to operate in the conditions I described because it is unencumbered by the (lack of) restrictive civil certification for those conditions, and has the equipment (360 radar) to do it.
My own experience (and 30 odd years of sea king ops confirms) is that you cannot operate SAFELY in those conditions without a 360 radar whatever your SOPs and whatever other sensors you employ.
I will be happily back down if you, or anyone in CHC come to that can tell me that a safety case has been made using the S92 with it's current radar and that CHC have or will have CAA clearance to operate down to the wx limits currently used by mil Sea Kings.
If it hasn't and they haven't then they will not, as required by the contract, be able to provide the same service currently provided by the mil.
My question is more about equipment. A Mil Sea King (mil registered) is able to operate in the conditions I described because it is unencumbered by the (lack of) restrictive civil certification for those conditions, and has the equipment (360 radar) to do it.
My own experience (and 30 odd years of sea king ops confirms) is that you cannot operate SAFELY in those conditions without a 360 radar whatever your SOPs and whatever other sensors you employ.
I will be happily back down if you, or anyone in CHC come to that can tell me that a safety case has been made using the S92 with it's current radar and that CHC have or will have CAA clearance to operate down to the wx limits currently used by mil Sea Kings.
If it hasn't and they haven't then they will not, as required by the contract, be able to provide the same service currently provided by the mil.
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Folks,
Please, please don't start off the radar debate yet again on this thread; if you want to revisit this circular argument then it's all there (many times over) on the 'SAR-H to go' thread.
Facts: 1) The future UK SAR service will have helicopters equipped with a nose-mounted 120 degree radar, 2) the operational differences between 120 and 360 degree radars were well recognised by the PT and advisors, 3) the 120 degree radar solution was examined in great detail during the evaluation process by people who know what they are talking about and 4) the bidders were required to describe procedures to cope with specific scenarios posed by the PT, and these procedures were thoroughly evaluated by the PT and advisors.
I think it's safe to assume that both the preferred bidder and SAR-H PT have actually put some work into this topic, so perhaps it's better to accept the equipment that will be provided and use this thread for more constructive debate!
Louis
Please, please don't start off the radar debate yet again on this thread; if you want to revisit this circular argument then it's all there (many times over) on the 'SAR-H to go' thread.
Facts: 1) The future UK SAR service will have helicopters equipped with a nose-mounted 120 degree radar, 2) the operational differences between 120 and 360 degree radars were well recognised by the PT and advisors, 3) the 120 degree radar solution was examined in great detail during the evaluation process by people who know what they are talking about and 4) the bidders were required to describe procedures to cope with specific scenarios posed by the PT, and these procedures were thoroughly evaluated by the PT and advisors.
I think it's safe to assume that both the preferred bidder and SAR-H PT have actually put some work into this topic, so perhaps it's better to accept the equipment that will be provided and use this thread for more constructive debate!
Louis
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RAF and RN Sea Kings regularly operate in bad weather at low level overwater down to 50 ft amsl during ops and training. That they are able to do so depends on a skilled radar operator working a 360 arc radar to ensure collision avoidance.
Lost Horizon,
Don't you think the operators of the 120 arc radars are skilled at operating it? Working through any limitations it may have?
360 deg radar???? With +/- 15 deg blind arc forward and +/-5 deg blind arc rearwards, Excellent planning!
That said i think the S92 has a moving map, FLIR, digital terrain mapping, FMS navigation system, so many many tools for which to ply its trade safely.
The black magic of the radop has been exposed surely?
Lastly, I think the run down Lynx was in the Gulf region and day time! could be totally wrong on that one!
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120 vs 360 degree radar
The SAR-H contract is supposed to provide a capability no less than that currently provided. Lets stick to the facts about the different types of radar and what you can or cannot do with them. Could a mil 360 degree radar operator give a quick description of how they conduct an overwater IMC letdown in an onshore wind that would exceed the limits for hovering tail into wind; and then close to the land to get visual? If an experienced operator of a forward looking 120 degree radar could then give a description of how they would do it the rest of us would then be in a position to make informed comment.
I have edited my post to include that any systems used in the above procedures must have the necessary clearance/approval for the purpose for which they are used. I believe this rules out many of the fancy toys on the S-92 but I am prepared to be corrected.
Lets stick to facts and not let the thread degenerate.
CD
I have edited my post to include that any systems used in the above procedures must have the necessary clearance/approval for the purpose for which they are used. I believe this rules out many of the fancy toys on the S-92 but I am prepared to be corrected.
Lets stick to facts and not let the thread degenerate.
CD
Last edited by Clever Richard; 11th Feb 2010 at 17:07. Reason: Added extra caveats
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(lets say 100ft cloud base, 100mtres vis, w/v 40 kts) let down to the base of a 300ft cliff)
I too would like some information on the use of 360 degree radar in the above scenario.
100 meters is 0.05nm. That’s quite a resolution.
I have only ever had the 120 radar so I know no different. We usually have to go to another location along the cliff line where we can let down more comfortably before moving closer
More modern a/c can have fairly high cross wind limits. I believe the AW139 has 40kts demonstrated crosswind and 30kts downwind with power to weight almost double that of the Seaking.
The inertial in space autohover, moving map, terrain mapping and improved homer are certainly helpful aids.
As far as all these toys are concerned, this will have to be clarified on SAR H
The CAA have accepted it will be a free standing SAR AOC under national regulations. Ie Nothing to do with JAR/EASA. So it starts with a blank sheet and the CAA then sign it off if they are happy.
Maintenance will of course be EASA.
The CAA has always taken a sensible view on Lifesaving, however their history with training for the task has always been a little too restrictive in my opinion.
On the face of it though the 360degree radar with qualified and dedicated operator does seem to have the edge.
Regards
Marty
Now when a Radop is sorting the let down, and giving it his full attention so as not to overfly land or other radar contacts, the co-pilot gets to do nav, radios, fuel planning and most importantly monitor the handling pilots flying making safety check calls (rad alt heights) during the manoeuvering and descent to the hover.
If the co in a 92 is going to be doing the radar as well, what happens to these well-proven safety cross checks? Or does he just have to work much harder.
As for the myth of the radop being exposed pasptoo I guess you haven't seen how good they are at their job and how logical a dedicated radar op is during high workload SAROPs. The pilots can get on with their jobs and the man with the sensors can do his.
Do the CAA have a suitably experienced and qualified SAR expert who is going to sign the new AOC off?
Marty the minimum radar range on the Sea King is 75m and yes that is good resolution - it is the main reason we have been allowed to operate the way we have for many years - a good quality radar and a dedicated operator.
If the co in a 92 is going to be doing the radar as well, what happens to these well-proven safety cross checks? Or does he just have to work much harder.
As for the myth of the radop being exposed pasptoo I guess you haven't seen how good they are at their job and how logical a dedicated radar op is during high workload SAROPs. The pilots can get on with their jobs and the man with the sensors can do his.
Do the CAA have a suitably experienced and qualified SAR expert who is going to sign the new AOC off?
Marty the minimum radar range on the Sea King is 75m and yes that is good resolution - it is the main reason we have been allowed to operate the way we have for many years - a good quality radar and a dedicated operator.
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But surely, in a modern aircraft with a decent FMS, 4 axis FD and TAWS/EGPWS, "sorting the letdown" is not really anything like the hard work it used to be in the mighty king! - I admit I know zilch about SAR, but I have some experience of the latest generations of aircraft, and I know they are capable of getting to a 50' hover over the sea, close to fixed obstacles in total IMC. Obviously the unknown factor is moveable obstacles, which is clearly where the radar comes in, but I think the pilot flying and the pilot monitoring will have their workloads hugely reduced in comparison to what they experienced in older-gereration aircraft.
Last edited by Non-PC Plod; 12th Feb 2010 at 08:37.
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360 radar let down to cliff in onshore wind
Clever Rich,
Quick version as requested.
Fly at safety height overwater (1000 ft) parallel to the coast on a mapping run to check you are in the correct location and to locate any surface contacts which may be in the area.
Let down in a safe area a few miles off shore (2 - 5 miles depending on the wind) to a chosen height prior to the final let down (usually 200 ft in a Sea King)
Fly parallel to the cliff approx half to one mile off shore. With a strong on shore wind there will be a lot of onshore drift so it is important to be able to see where you are tracking and about to track in order to maintain separation from land.
Start the final let down to the chosen hover height turning the aircraft into wind at an appropriate time to position the survivor in the chosen clock code (eg 5 or 5:30). Vital to get this right, because as the speed reduces the onshore drift increases. This is a so called "modified let down" You can just turn into wind and then let down if you want but you will end up further offshore.
Once established in the hover you are pointing out to sea with the cliff behind you at whatever range you have planned for depending on the conditions (one mile?) The aircraft is then flown backwards to the cliff either by the pilots or, certainly in the latter stages, by the rear crew on Hover Trim (if you have one!!) looking out of the door to the minimum radar range. This is 75 metres in the Sea King. If you have the cliff visual you can continue if not you should abort (dead ahead , into wind, out to sea)
Throughout all this the radar operator can see the cliff and ensure separation.
With a limited arc radar there is the possibility in very strong winds that there is so much drift during the approach that the ac will be tracking outside the radar's field of view and of course, once turned away from the cliff then you can't see it at all. In light winds it will be mitigated somewhat because you can always "cock off" heading but not in strong winds.
All conditions are different but this is a generic but well established SK SOP which, as requested, indicates the advantages of a 360 radar over a 120 radar. As was pointed out on the other thread, the CG have been operating for 25 years with a 120 so I will be interested to know how they cope with this scenario.
Finally, PLEASE, PLEASE understand this is about equipment NOT people.
Out of interest, for SARH the S92 was bid with a 120 radar the 225 with a 360!
Ta
Quick version as requested.
Fly at safety height overwater (1000 ft) parallel to the coast on a mapping run to check you are in the correct location and to locate any surface contacts which may be in the area.
Let down in a safe area a few miles off shore (2 - 5 miles depending on the wind) to a chosen height prior to the final let down (usually 200 ft in a Sea King)
Fly parallel to the cliff approx half to one mile off shore. With a strong on shore wind there will be a lot of onshore drift so it is important to be able to see where you are tracking and about to track in order to maintain separation from land.
Start the final let down to the chosen hover height turning the aircraft into wind at an appropriate time to position the survivor in the chosen clock code (eg 5 or 5:30). Vital to get this right, because as the speed reduces the onshore drift increases. This is a so called "modified let down" You can just turn into wind and then let down if you want but you will end up further offshore.
Once established in the hover you are pointing out to sea with the cliff behind you at whatever range you have planned for depending on the conditions (one mile?) The aircraft is then flown backwards to the cliff either by the pilots or, certainly in the latter stages, by the rear crew on Hover Trim (if you have one!!) looking out of the door to the minimum radar range. This is 75 metres in the Sea King. If you have the cliff visual you can continue if not you should abort (dead ahead , into wind, out to sea)
Throughout all this the radar operator can see the cliff and ensure separation.
With a limited arc radar there is the possibility in very strong winds that there is so much drift during the approach that the ac will be tracking outside the radar's field of view and of course, once turned away from the cliff then you can't see it at all. In light winds it will be mitigated somewhat because you can always "cock off" heading but not in strong winds.
All conditions are different but this is a generic but well established SK SOP which, as requested, indicates the advantages of a 360 radar over a 120 radar. As was pointed out on the other thread, the CG have been operating for 25 years with a 120 so I will be interested to know how they cope with this scenario.
Finally, PLEASE, PLEASE understand this is about equipment NOT people.
Out of interest, for SARH the S92 was bid with a 120 radar the 225 with a 360!
Ta
stick 'em on a 92
why not mount the then obsolete 360 radars on the new s92's together with the then obsolete radops? Must still be some life in them.
Keep it serious guys
Keep it serious guys
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Lynx run over by ship
As part of EX Saif Sarea approx Oct 2001; Gulf of Oman. HMS Marlborough's a/c was instructed to hold posn. below 100' as (not very) fast jets were running in on a simulated attack/wasex on HMS Illustrious with VIP's from both countries on board. Lynx duly complied and sat in 50' hover watching display. Not very observant Omani patrol vessel with distracted bridgewatchkeeper then ran into tail of Lynx, chopping it off and sending Lynx into Davy Jones's locker
. Both aircrew got out; one straightforward, other one having to use STASS and inflate LSJ underwater.
. Both aircrew got out; one straightforward, other one having to use STASS and inflate LSJ underwater.
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Iron,
I am currently with an outfit that has the new technologogy but nowhere near the capability. Sadly a person who has his workload split, using a piece of albeit modern technology but, reduced minimum range and limited viewing angle cannot perform either job as well as a Sea King Co Pilot plus RadOp. I have yet to see a weather radar with a 75mtr minimum range.
What is more important is how often will you need to operate down to those extreme limits to save lives, in my experience only a few times a year. There have only been a couple of jobs that I have had to operate down to 75mtr, these jobs would not have been doable by a modern replacement. It does not matter how many nice new toys EICAS, TCAS, EGPWS, AVAD you have, a radar is the only thing to stop you hitting a moving ship in fog, the others are there for other reasons.
A helicopter was lost a few years ago in Ireland in circumstances suggested by Lost, onshore wind etc, hapily nothing similar since. At the end of the day, money will dictate capability. I am sure that the SAR-H IPT have decided that the extra cost of a 360 degree radar and dedicated operator cannot be justifed for a few jobs a year.
To answer Lost's question, in some circumstances CHC will probably not be able to cope, but there are always some jobs that you will not be able to carry out. The 360 degree radar battle is lost, accept it and get on with life.
We do not fear change, we fear being short changed.
Heads down, look out for the flack.
I am currently with an outfit that has the new technologogy but nowhere near the capability. Sadly a person who has his workload split, using a piece of albeit modern technology but, reduced minimum range and limited viewing angle cannot perform either job as well as a Sea King Co Pilot plus RadOp. I have yet to see a weather radar with a 75mtr minimum range.
What is more important is how often will you need to operate down to those extreme limits to save lives, in my experience only a few times a year. There have only been a couple of jobs that I have had to operate down to 75mtr, these jobs would not have been doable by a modern replacement. It does not matter how many nice new toys EICAS, TCAS, EGPWS, AVAD you have, a radar is the only thing to stop you hitting a moving ship in fog, the others are there for other reasons.
A helicopter was lost a few years ago in Ireland in circumstances suggested by Lost, onshore wind etc, hapily nothing similar since. At the end of the day, money will dictate capability. I am sure that the SAR-H IPT have decided that the extra cost of a 360 degree radar and dedicated operator cannot be justifed for a few jobs a year.
To answer Lost's question, in some circumstances CHC will probably not be able to cope, but there are always some jobs that you will not be able to carry out. The 360 degree radar battle is lost, accept it and get on with life.
We do not fear change, we fear being short changed.
Heads down, look out for the flack.
Hi all,
Interesting discussion and whilst we are on the topic. As one that has only really experienced using a 360 RADAR optimised for surface search ie preriscopes etc I have a question in reference to the use of weather RADAR with its various modes for search ops.
Are there any good rules of thumb that we can apply when using these RADARs for search operations in order to get the best out of them ie range, tilt (I know there are lots of variables).
We won't be using ours for IMC let downs et al just as another search tool.
Thanks in adavance.
Turkey
Interesting discussion and whilst we are on the topic. As one that has only really experienced using a 360 RADAR optimised for surface search ie preriscopes etc I have a question in reference to the use of weather RADAR with its various modes for search ops.
Are there any good rules of thumb that we can apply when using these RADARs for search operations in order to get the best out of them ie range, tilt (I know there are lots of variables).
We won't be using ours for IMC let downs et al just as another search tool.
Thanks in adavance.
Turkey
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why not mount the then obsolete 360 radars on the new s92's together with the then obsolete radops? Must still be some life in them.
Keep it serious guys
Keep it serious guys
I think it is vital that we keep it serious. You and ironchuffly's derision of the radop and of 360 degree radar is rather flippant considering the topic of discussion relates to a vital safety element of the SAR operation.
As we are primarily discuissing the S-92, I am assuming that the aircraft is certified for IFR dual pilot. Over the many years of civil and military helicopter and fixed wing operations, experience has been built up that has concluded that some flight regimes benefit from having a second pair of eyes monitoring the instruments ( that may not be the immediate focus of the handling pilot) and indeed monitoring the HP himself who may have made a simple HF mistake that could have drastic consequences.
I'm sure everyone here would agree that a co-pilot conducting such a high workload task as ensuring radar separation in an environment like the English channel, is less able to devote as much attention to the HP or indeed the FCS that may be 'flying' the aircraft.
I know of at least one mil helicopter where the introduction of FLIR screens to assist in low light ops was deemed as an unacceptable safety risk - resulting in (several) multi million pound programs to address the workload issue.
I am also intrigued as to the CAA's approach to operating IMC at low level for training. Their position on SAR Ops is clear, but the capability is also required to train on the kit, and many parts of the UK do not provide a 1000' cloud base every time you wish to go training.
Many SAR bases without approach aids regularly rely on IMC letdowns to the coasts with a low level transit once VMC below in order to rtb (Day & Night) If the clearance for IMC below Safety Alt is limited to SAROps, the ability of crews to train and rtb will be severely restricted, thereby impacting SAR Capability.
I also find it interesting that maintainers have such firm opinions on operating methods.....
Good posts Cabe lecutter and rotary girl.
Iron - the Sea King 3A has a much better autopilot than the 3 in addition to AVAD but we still monitor the other pilot during let down/ low level IMC/night manoeuvering - why? Because as too many accidents have proven, workload in the cockpit can go from manageable to unmanageable very quickly when conditions are difficult.
Iron - the Sea King 3A has a much better autopilot than the 3 in addition to AVAD but we still monitor the other pilot during let down/ low level IMC/night manoeuvering - why? Because as too many accidents have proven, workload in the cockpit can go from manageable to unmanageable very quickly when conditions are difficult.
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The argument about how frequently the ability to carry out an IMC letdown with a strong onshore wind is irrelevant. The SAR-H programme is mandated to provide a capability no less than that currently provided. So, if this procedure, which is used on SAROPs now, cannot be done once SAR-H comes in then the capability requirement has not been met.
However, once someone can explain how the procedure in question can be done using a 120 degree radar then the issue goes away.
CD
However, once someone can explain how the procedure in question can be done using a 120 degree radar then the issue goes away.
CD