Single Engine Ops: Who's Responsibility?
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At the end of the day, it is all an economic trade-off. In Maricopa County, where Mesa is located, the City of Mesa has 3 ships (now two going back to three by august), Phoenix has 12 (1 is a twin), Maricopa County Sheriff has 4, Arizona DPS has 4 and all the other cities are talking about getting their own.
So, you take 22 single engine ships in tight budgets and you covert them to twins in acquisition, training and operating costs.
If you look at the total number of accidents/incidents relating to engine failure in the last twenty years resulting in an autorotation, the grand total is one encounter. This one.
If you assume public safety money is fixed, you can cut the ships or hours in the air and do a cost/risk analysis of what happens without a ship in the air. Is an officer shot, do they lose a suspect, is the high speed chase worse? Or, do you cut the number of officers on the ground?
With respect to police air units, the American system has done that analysis and come to the conclusion that factoring in risk versus reward, singles are the way to go.
So, you take 22 single engine ships in tight budgets and you covert them to twins in acquisition, training and operating costs.
If you look at the total number of accidents/incidents relating to engine failure in the last twenty years resulting in an autorotation, the grand total is one encounter. This one.
If you assume public safety money is fixed, you can cut the ships or hours in the air and do a cost/risk analysis of what happens without a ship in the air. Is an officer shot, do they lose a suspect, is the high speed chase worse? Or, do you cut the number of officers on the ground?
With respect to police air units, the American system has done that analysis and come to the conclusion that factoring in risk versus reward, singles are the way to go.
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when the engine fails in a single you have to land, sometimes messy, very occassionally fatal.
when the engine fails in a twin, sometimes it is non-eventful, sometimes it is an accident and sometimes fatal.
BUT sometimes in a twin you also have a fatal accident that you would not have had in a single, from other causes. the critical components have to work harder to pay for for the occasional imunity. Less engine failure accidents paid for by more gearbox/tailrotor/freewheel units/fuel systems/ performance cost/ tail boom failures/ 'pilot error' (shut down wrong engine, confusion etc) etc
All things will happen in aviation to some extent.
PROPORTIONATE REGULATION does not call for twins.
the sums don't add up, gazelles just did not have an engine failure rate that justified twins FULL STOP
when the engine fails in a twin, sometimes it is non-eventful, sometimes it is an accident and sometimes fatal.
BUT sometimes in a twin you also have a fatal accident that you would not have had in a single, from other causes. the critical components have to work harder to pay for for the occasional imunity. Less engine failure accidents paid for by more gearbox/tailrotor/freewheel units/fuel systems/ performance cost/ tail boom failures/ 'pilot error' (shut down wrong engine, confusion etc) etc
All things will happen in aviation to some extent.
PROPORTIONATE REGULATION does not call for twins.
the sums don't add up, gazelles just did not have an engine failure rate that justified twins FULL STOP
Purveyor of Egg Liqueur to Lucifer
I'm hearing an argument that suggests that all air ambulance & police helicopters should be Robinsons. 
Now, just where does that line get drawn?
AnFi
Lol, sometimes AnFI (really!) your posts are really quite laughable.
Now, just where does that line get drawn?
AnFi
the sums don't add up, gazelles just did not have an engine failure rate that justified twins FULL STOP
Avoid imitations
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Trying to convince some exponents of the "single engine is best" theory is pointless. Even though they have little or nil experience of multi engined aircraft, (and probably little prospect of flying them which may explain their stance), they think they know better than folk with a far broader experience .... and better than the regulatory authorities.
Some obviously fail to realise, or choose to ignore, the fact that all pilots now flying twin engined helicopters began their careers flying singles.
Some obviously fail to realise, or choose to ignore, the fact that all pilots now flying twin engined helicopters began their careers flying singles.
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GoodGrief, why would singles not be flying in those situations? Why the banging head symbol? I just don't understand that one.......
The engine failures were both in truely appaling weather, one was in 65kt surface wind 20 miles out over the northern English Channel and one over NI with a 300' cloudbase and 45kt wind.
GoodGrief, why would singles not be flying in those situations? Why the banging head symbol? I just don't understand that one.......
2. Common sense.
3. 20NM out at 65kts wind. What happened to 'autorotation to shore'? And the sea state in that is ? Floats wouldn't really help now, would they?
4. 300ft cloud base at 45kts. You'd be buzzing around at 200ft or even at tree top level? What happened to the 500ft rule?
Maybe I'm too much of a coward and know to say 'NO'.
C'mon, you want to stir the pot ?
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Common sense?? When you have to get a job done and it is within the aircraft limits, why not??
Auto to shore, I will accept that, so singles will limit how you operate if there are any areas of water??
Common Sense?? Matey, see above.
What 500ft rule??
Ok then, lets 'stir the pot' whatever that means.
Auto to shore, I will accept that, so singles will limit how you operate if there are any areas of water??
Common Sense?? Matey, see above.
What 500ft rule??
Ok then, lets 'stir the pot' whatever that means.
Engine failures are debated as theoretical events and dismissed with statistics-except to those of us who have had an engine failure. It then becomes the primary consideration in whatever you do for the rest of your life.
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ss:
"AnFi Quote:
the sums don't add up, gazelles just did not have an engine failure rate that justified twins FULL STOP
Lol, sometimes AnFI (really!) your posts are really quite laughable."
Excuse me! Are you actually saying something or just trying to discredit? - the fact of the matter is Gazelle losses through engine failure were negligable - Lynx losses through engine failure have not been - the utility of the gazelle was huge and it's bang per buck for the tax payer was high.
I know of three (UK MIL) Lynx engine related accidents although i know of no (UK MIL) engine failure accidents (not that I'd be surprised if there had been).
Not to mention the extreme downside of performance for 30yrs for lynx caused by carrying spare engines, instead of useful payload.
Substance, not just rudeness. SS!
Huey Racer : "Shall we now pull out all the crashes with the S-92´s, the 332´s, the AW139´s and all the other multi-engine aircraft that went down in the past 2 years, killing everybody on board?" good point , carrying two engines does not seem to have delivered anything like 100,000 times lower loss rate. Irritating when the facts get in the way of a determined ignorant theory.
"AnFi Quote:
the sums don't add up, gazelles just did not have an engine failure rate that justified twins FULL STOP
Lol, sometimes AnFI (really!) your posts are really quite laughable."
Excuse me! Are you actually saying something or just trying to discredit? - the fact of the matter is Gazelle losses through engine failure were negligable - Lynx losses through engine failure have not been - the utility of the gazelle was huge and it's bang per buck for the tax payer was high.
I know of three (UK MIL) Lynx engine related accidents although i know of no (UK MIL) engine failure accidents (not that I'd be surprised if there had been).
Not to mention the extreme downside of performance for 30yrs for lynx caused by carrying spare engines, instead of useful payload.
Substance, not just rudeness. SS!
Huey Racer : "Shall we now pull out all the crashes with the S-92´s, the 332´s, the AW139´s and all the other multi-engine aircraft that went down in the past 2 years, killing everybody on board?" good point , carrying two engines does not seem to have delivered anything like 100,000 times lower loss rate. Irritating when the facts get in the way of a determined ignorant theory.
Purveyor of Egg Liqueur to Lucifer
Oh AnGi, there you go again!
Are you really suggesting that the Gazelle could have fulfilled the role that the Lynx was brought in for!
As I said before, your posts are laughable.
Instead of saying 'you know of ....' please post links
(Did you see what I did there!)
Are you really suggesting that the Gazelle could have fulfilled the role that the Lynx was brought in for!
As I said before, your posts are laughable.
Instead of saying 'you know of ....' please post links
(Did you see what I did there!)
Purveyor of Egg Liqueur to Lucifer
and what does;
... mean?
I'm not going to trawl through the relevant reports, but your argument is flawed when your side is looked at sensibly and not restricted within certain parameters to meet your needs;
http://aviation-safety.net/wikibase/wiki.php?id=46173
I know of three (UK MIL) Lynx engine related accidents although i know of no (UK MIL) engine failure accidents (not that I'd be surprised if there had been).
I'm not going to trawl through the relevant reports, but your argument is flawed when your side is looked at sensibly and not restricted within certain parameters to meet your needs;
http://aviation-safety.net/wikibase/wiki.php?id=46173
Last edited by SilsoeSid; 29th Jun 2014 at 22:31. Reason: link to end silly irrelevant restrictive side of discussion
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"Last edited by SilsoeSid; 29th Jun 2014 at 23:31. Reason: link to end silly irrelevant restrictive side of discussion"
Err too many sherbets?
Your example is of an obscure user, unlicesed to fly, NOT killing themselves!!
It is possible to find a Gazelle fatal due engine, but you have to go a long way back in time and far out in geography.
The reason to use the UK MIL is that the other circustances are controlled, avoiding side issues like whether the people had licenses.
It is not easy to provide a list of UK MIL engine related crashes in LYNX because it seems that the data is obscured. Your friend was killed in one, those nice chaps were killed in Afg, some other nice guys hit the water (both engines shut down, for some odd reason). Many ex-lynx drivers have told me of their accidents and close shaves. They don't appear to be documented
.
SS; "Are you really suggesting that the Gazelle could have fulfilled the role that the Lynx was brought in for!"
Errr, No, obviously not.
The point was the engine related accident rate.
Not whether it could land on ships, or had a sliding door.
Imagine the high performance machine a Lynx could have been as a single.
Err too many sherbets?
Your example is of an obscure user, unlicesed to fly, NOT killing themselves!!
It is possible to find a Gazelle fatal due engine, but you have to go a long way back in time and far out in geography.
The reason to use the UK MIL is that the other circustances are controlled, avoiding side issues like whether the people had licenses.
It is not easy to provide a list of UK MIL engine related crashes in LYNX because it seems that the data is obscured. Your friend was killed in one, those nice chaps were killed in Afg, some other nice guys hit the water (both engines shut down, for some odd reason). Many ex-lynx drivers have told me of their accidents and close shaves. They don't appear to be documented
.SS; "Are you really suggesting that the Gazelle could have fulfilled the role that the Lynx was brought in for!"
Errr, No, obviously not.
The point was the engine related accident rate.
Not whether it could land on ships, or had a sliding door.
Imagine the high performance machine a Lynx could have been as a single.
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AnFi
I thought that the double ditching, one fatal in the GM had shut you up for a while, evidently not.
The engine argument is one thing. Saying that components on a S-92 or EC225 are more stressed is garbage.
Twins tend to be better equipped and IFR capable. You can't really do that in a single if you actually want to carry anything.
I thought that the double ditching, one fatal in the GM had shut you up for a while, evidently not.
The engine argument is one thing. Saying that components on a S-92 or EC225 are more stressed is garbage.
Twins tend to be better equipped and IFR capable. You can't really do that in a single if you actually want to carry anything.
Purveyor of Egg Liqueur to Lucifer
AnGi;
As I say, laughable posts!
1.The outcome would have been worse if it was single engined.
"Crashed on emergency landing after cockpit had filled with smoke. Caught fire and burnt."
2. Cause not yet known.
3. The 'for some reason' the engines shut down was because they ran out of fuel having been misdirected on the way back to 'mother'.
"During Exercise Marstrike05 is was misdirected back to HMS Nottingham. It ran out of fuel 41 miles from the ship and made a controlled ditching alongside MV Wilhelm Schulte in Indian Ocean 120 miles off Oman. It sank in 2,800 meters of water but the crew were rescued safely"
Aviation Safety Network > ASN Aviation Safety WikiBase > Lynx
A long way back (2011 fgs!), but not as far back as your Lynx examples, and with you mentioning Lynx incidents in Afghanistan & the Indian Ocean, how does Geography affect this discussion?
ASN Aircraft accident 20-AUG-2011 Aérospatiale SA 342L1 Gazelle L611
ASN Aircraft accident 19-JAN-2010 Aérospatiale SA 342K Gazelle CN-AIP
Etc
Aviation Safety Network > ASN Aviation Safety WikiBase > Gazelle
It is not easy to provide a list of UK MIL engine related crashes in LYNX because it seems that the data is obscured. Your friend was killed in one, those nice chaps were killed in Afg, some other nice guys hit the water (both engines shut down, for some odd reason). Many ex-lynx drivers have told me of their accidents and close shaves. They don't appear to be documented.
1.The outcome would have been worse if it was single engined.
"Crashed on emergency landing after cockpit had filled with smoke. Caught fire and burnt."
2. Cause not yet known.
3. The 'for some reason' the engines shut down was because they ran out of fuel having been misdirected on the way back to 'mother'.
"During Exercise Marstrike05 is was misdirected back to HMS Nottingham. It ran out of fuel 41 miles from the ship and made a controlled ditching alongside MV Wilhelm Schulte in Indian Ocean 120 miles off Oman. It sank in 2,800 meters of water but the crew were rescued safely"
Aviation Safety Network > ASN Aviation Safety WikiBase > Lynx
It is possible to find a Gazelle fatal due engine, but you have to go a long way back in time and far out in geography.
ASN Aircraft accident 20-AUG-2011 Aérospatiale SA 342L1 Gazelle L611
ASN Aircraft accident 19-JAN-2010 Aérospatiale SA 342K Gazelle CN-AIP
Etc
Aviation Safety Network > ASN Aviation Safety WikiBase > Gazelle
Purveyor of Egg Liqueur to Lucifer
AnGi;
Wow, even more high performance than the Worlds fastest helicopter! 
Imagine the high performance machine a Lynx could have been as a single.
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Wow, even more high performance than the Worlds fastest helicopter!
Last edited by chopjock; 30th Jun 2014 at 08:49.
In 25 years of flying around in helicopters, i've met numerous people (and i'm one of them myself) who have said "and if that had happened in a single we'd have been stuffed".
I've never met anyone who said "If i'd been in a twin we'd have been stuffed".
Will two engines always save you? No.
Are two engines more expensive? Yes.
Does having two engines increase the statistical likelihood of having one of them fail? Yes, of course.
If you have an engine failure in a twin do you have a chance of flying away from it? Yes
If you have an engine failure in a single can you fly away? No
I've never met anyone who said "If i'd been in a twin we'd have been stuffed".
Will two engines always save you? No.
Are two engines more expensive? Yes.
Does having two engines increase the statistical likelihood of having one of them fail? Yes, of course.
If you have an engine failure in a twin do you have a chance of flying away from it? Yes
If you have an engine failure in a single can you fly away? No
I love the comment made about how fast the topic of conversation has changed to Singles Vs Twins.....and then you notice that the gap between posts 49 and 50 is.....4 years!!
Meanwhile back at the ranch....Most here are talking from an insiders perspective (obviously!) because we are all passionate players in some shape or form...but...remember this: two types of people run this world: Lawyers and accountants. It is they who make the final strategic decisions because they are able to stand outside the box and determine if the operation will succeed or collapse.
They have determined that on the whole, in the round, at the end of the day - singles beat twins hands down for cost effectiveness. SAFETY really does come second even though the opposite mantra is shouted from the roof tops (this is so that the industry can be seen to be PC).
Example:
15 years ago the FAA and the (now) NTSB came to the conclusion that the design flaw in the 737's rudder screwjack mechanism was cheaper to resolve by paying out to all the deceased familes of those who crashed or would crash in future; compared to grounding the entire global fleet and replacing said defect.
In the cold light of day, these two organisations determined that the final cost to insurance companies of the death of a US citizen was: (1999) $186.
They did the maths. looked at the probabilities and the dollar won - hands down.
Same goes for modern jets flying over the oceans of the world on ONE engine.
RISK = frequency x outcome.
And so it came to pass that on the whole it is better for the organisation to fly singles because the impact of losing one single and its entire crew is marginal/minimal.
UNLESS you are onboard at the time.
I had the inlet guide vanes on my SeaKing (S61) shut in the hover over a sea state 7.
I had a compressor blade go in my AS355 over the middle of a city.
I have had compressor stall in another AS355 incident.
In any or all of those - I suspect my chances of being here today would have been seriously curtailed if those incidents had been on singles. Thus I am biased but in the big picture, my subjective overview is lost in the noise that is corporate diligence and the bottom line: money.
Try responding to this thread thru the eyes of an accountant or lawyer?
Meanwhile back at the ranch....Most here are talking from an insiders perspective (obviously!) because we are all passionate players in some shape or form...but...remember this: two types of people run this world: Lawyers and accountants. It is they who make the final strategic decisions because they are able to stand outside the box and determine if the operation will succeed or collapse.
They have determined that on the whole, in the round, at the end of the day - singles beat twins hands down for cost effectiveness. SAFETY really does come second even though the opposite mantra is shouted from the roof tops (this is so that the industry can be seen to be PC).
Example:
15 years ago the FAA and the (now) NTSB came to the conclusion that the design flaw in the 737's rudder screwjack mechanism was cheaper to resolve by paying out to all the deceased familes of those who crashed or would crash in future; compared to grounding the entire global fleet and replacing said defect.
In the cold light of day, these two organisations determined that the final cost to insurance companies of the death of a US citizen was: (1999) $186.
They did the maths. looked at the probabilities and the dollar won - hands down.
Same goes for modern jets flying over the oceans of the world on ONE engine.
RISK = frequency x outcome.
And so it came to pass that on the whole it is better for the organisation to fly singles because the impact of losing one single and its entire crew is marginal/minimal.
UNLESS you are onboard at the time.
I had the inlet guide vanes on my SeaKing (S61) shut in the hover over a sea state 7.
I had a compressor blade go in my AS355 over the middle of a city.
I have had compressor stall in another AS355 incident.
In any or all of those - I suspect my chances of being here today would have been seriously curtailed if those incidents had been on singles. Thus I am biased but in the big picture, my subjective overview is lost in the noise that is corporate diligence and the bottom line: money.
Try responding to this thread thru the eyes of an accountant or lawyer?