Rescue helo operators fight NZ CAA
JimL,
Perhaps we can get Nick Lappos to remind us of the probability of a single engine failure....seems it was something along the lines of .000000008 or something like that. I would have to assume if you had two engines the probability would double that.
How do we arrive at an "acceptable risk" definition?
It would appear even the CAA admits there is no way to eliminate all risk and will accept deviations. Why would a pre-2002 heliport be eligible for continued use if it fails to meet the new requirements if risk avoidance is the basis for these regulations?
Is this not a contradiction of the CAA's own position by its own interpetation of the rules?
Perhaps we can get Nick Lappos to remind us of the probability of a single engine failure....seems it was something along the lines of .000000008 or something like that. I would have to assume if you had two engines the probability would double that.
How do we arrive at an "acceptable risk" definition?
It would appear even the CAA admits there is no way to eliminate all risk and will accept deviations. Why would a pre-2002 heliport be eligible for continued use if it fails to meet the new requirements if risk avoidance is the basis for these regulations?
Is this not a contradiction of the CAA's own position by its own interpetation of the rules?
You don't need Nick to provide that information - it is 1:100,000 flight hours. If you have two engines, the probability of one failing is 2:100,000 flight hours (two engines twice the exposure). The effect of failure is nil when in PC1 (or nil when above 200ft in PC2); or a forced landing when in PC3 (or when below 200ft in PC2).
The probability of both failing from independent causes is the probability of the first times the probability of the second - i.e. 1:10,000,000,000.
Acceptable risk is generally decided by society - on the basis of what is unacceptable risk. Risk is quantitatively stated in some rules - FAR/CS 29.1309 being the most well known (1:1,000,000,000). Acceptable risk is conditioned by the number of passengers exposed; that is why operational rules vary with the number of passengers carried.
None of what has been discussed is of the CAA's making; most of the rules are now provided by/for Europe - previously the JAA and now EASA. The basis for the 2002 deadline was to provide an incentive for improvement of landing sites at hospitals; no one wanted new helipads (in cities) to be too small or so badly sited that they would not be able to be used in PC1 (and it was size and location not helicopter performance that was the driver). At the time of the provision of the alleviation, 2002 was in the future.
Jim
The probability of both failing from independent causes is the probability of the first times the probability of the second - i.e. 1:10,000,000,000.
Acceptable risk is generally decided by society - on the basis of what is unacceptable risk. Risk is quantitatively stated in some rules - FAR/CS 29.1309 being the most well known (1:1,000,000,000). Acceptable risk is conditioned by the number of passengers exposed; that is why operational rules vary with the number of passengers carried.
None of what has been discussed is of the CAA's making; most of the rules are now provided by/for Europe - previously the JAA and now EASA. The basis for the 2002 deadline was to provide an incentive for improvement of landing sites at hospitals; no one wanted new helipads (in cities) to be too small or so badly sited that they would not be able to be used in PC1 (and it was size and location not helicopter performance that was the driver). At the time of the provision of the alleviation, 2002 was in the future.
Jim
JimL,
This link takes you to an FAA document that compares JAR Safety measures to the FAA standard and defines incident rates and other measures used.
http://www.faa.gov/library/manuals/a...Chap3_1200.PDF
While you were posting I was googling and found the following at a previous posting here at pprune by Nick.
At the risk of incurring his wrath twice in one day.....here is his post from before.
This link takes you to an FAA document that compares JAR Safety measures to the FAA standard and defines incident rates and other measures used.
http://www.faa.gov/library/manuals/a...Chap3_1200.PDF
While you were posting I was googling and found the following at a previous posting here at pprune by Nick.
At the risk of incurring his wrath twice in one day.....here is his post from before.
Nick Lappos18th October 2002, 13:00
Some statistic approximations about failures, (a failure is a total catastrophic loss of full function):
Turbine engines fail at about 1: 250,000 hours for engine cause, about 1:100,000 hours for all causes (fuel lines, tanks, pilot fingers on switches).
Transmissions, rotors and such tough stuff fails about 1:10,000,000 hours to 1:100,000,000)
So, for a 10,000 helicopter fleet, where they each fly 500 hours per year, (this is approximately the world's civil helo fleet) we collectively log 5 million hours per year.
At the above failure rates, we can expect an engine failure every week (50 per year), a main rotor or main transmission failure every two years.
If we include all the military helos in the world (10,000 in the US alone, about the same for the rest of the world) we would triple the usage, and therefore increase the likelihood of occurrence by a factor of three.
Three engine failures a week, and a major rotor/transmission failure every 8 months.
To examine what it means to any one of us, we have to fly 200 years at 500 hours per year to get an engine failure, and we have to fly for 20,000 years before a transmission or rotor fails.
To compare to cars, in the US, one person dies about every 25,000,000 miles driven (100 million cars at 10,000 miles each, at 40,000 fatalities). If you drive 10,000 miles per year, you can expect to be killed every 2500 years in your car. This is slightly conservative, because there might be more than one occupant in the typical car, but then again, everything else in this post isn an approximation
Some statistic approximations about failures, (a failure is a total catastrophic loss of full function):
Turbine engines fail at about 1: 250,000 hours for engine cause, about 1:100,000 hours for all causes (fuel lines, tanks, pilot fingers on switches).
Transmissions, rotors and such tough stuff fails about 1:10,000,000 hours to 1:100,000,000)
So, for a 10,000 helicopter fleet, where they each fly 500 hours per year, (this is approximately the world's civil helo fleet) we collectively log 5 million hours per year.
At the above failure rates, we can expect an engine failure every week (50 per year), a main rotor or main transmission failure every two years.
If we include all the military helos in the world (10,000 in the US alone, about the same for the rest of the world) we would triple the usage, and therefore increase the likelihood of occurrence by a factor of three.
Three engine failures a week, and a major rotor/transmission failure every 8 months.
To examine what it means to any one of us, we have to fly 200 years at 500 hours per year to get an engine failure, and we have to fly for 20,000 years before a transmission or rotor fails.
To compare to cars, in the US, one person dies about every 25,000,000 miles driven (100 million cars at 10,000 miles each, at 40,000 fatalities). If you drive 10,000 miles per year, you can expect to be killed every 2500 years in your car. This is slightly conservative, because there might be more than one occupant in the typical car, but then again, everything else in this post isn an approximation
Last edited by SASless; 26th Jan 2009 at 19:05.
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Jim L. The Wellington BK is a B2 that was upgraded from a B1. However, I understand that it didn't have the B2 torque guages installed so it can't be operated to the B2 OEI charts.
SAS. I expect it was a very easy position to have formed given your experiences elsewhere. The situation is NZ is exacerbated by a highly cynical manipulation of the rules and of the public by some of the trusts and operators of rescue services. Some have just ignored the rules that exist.
That's not to say there is a strong argument for singles these days. But, there has been no attempt to put up an argument, lobby, etc etc. Some here have just ignored the rules knowing that as soon as CAA moved they'd be able to kick up public sympathy.
Wait for the report or research or some such to be released down here to show how safe singles are and trying to button hole CAA as been unreasonable and putting people's lives at risk. (I gather it is being prepared as we speak by a lawyer! If that's not cynical I don't know what is.)
This is in no way a comment on the pilots, especially not the younger ones just getting going in their careers who have been given a chance with some of these operators.
TK
SAS. I expect it was a very easy position to have formed given your experiences elsewhere. The situation is NZ is exacerbated by a highly cynical manipulation of the rules and of the public by some of the trusts and operators of rescue services. Some have just ignored the rules that exist.
That's not to say there is a strong argument for singles these days. But, there has been no attempt to put up an argument, lobby, etc etc. Some here have just ignored the rules knowing that as soon as CAA moved they'd be able to kick up public sympathy.
Wait for the report or research or some such to be released down here to show how safe singles are and trying to button hole CAA as been unreasonable and putting people's lives at risk. (I gather it is being prepared as we speak by a lawyer! If that's not cynical I don't know what is.)
This is in no way a comment on the pilots, especially not the younger ones just getting going in their careers who have been given a chance with some of these operators.
TK
Thanks Te_Kahu.
SASless - a very interesting paper very much a standard text and one that has been accepted world-wide and which now is part of the ICAO work on SMS.
Nick, as always, has provided an extremely interesting overview; examination of the failure rates for engines will show that the 1:100,000 is a mean figure with some below and some above. This figure was confirmed when the Risk Assessment was provided for justification of Exposure on the North Sea.
Returning to the referenced FAA work, you will see that that the engine failure rate comes into the categorisation of 'Probable'; further examination of the Risk Matrix in figure 3.9 will show that the application of 'Probable' to the grid with a likely consequence of 'Major' (or worse) puts the operation into the 'High Risk' category (which cannot be ignored).
Lastly Nick's treatise, quite reasonably because of the audience, puts the emphasis on the risk to a single pilot. ICAO, States and organisations, whilst still considering the individual pilot, have to take a wider view and address systematic risk.
My reading of the NZ CAR text (notwithstanding the incorrect categorisation of the Performance Classes) indicates that this is exactly what was being considered for the Wellington site.
Jim
SASless - a very interesting paper very much a standard text and one that has been accepted world-wide and which now is part of the ICAO work on SMS.
Nick, as always, has provided an extremely interesting overview; examination of the failure rates for engines will show that the 1:100,000 is a mean figure with some below and some above. This figure was confirmed when the Risk Assessment was provided for justification of Exposure on the North Sea.
Returning to the referenced FAA work, you will see that that the engine failure rate comes into the categorisation of 'Probable'; further examination of the Risk Matrix in figure 3.9 will show that the application of 'Probable' to the grid with a likely consequence of 'Major' (or worse) puts the operation into the 'High Risk' category (which cannot be ignored).
Lastly Nick's treatise, quite reasonably because of the audience, puts the emphasis on the risk to a single pilot. ICAO, States and organisations, whilst still considering the individual pilot, have to take a wider view and address systematic risk.
My reading of the NZ CAR text (notwithstanding the incorrect categorisation of the Performance Classes) indicates that this is exactly what was being considered for the Wellington site.
Jim
Let's muddy the waters yet again....
The given probability is based upon per flight hour is it not?
Thus if you assume five minutes of exposure for landing and takeoff....for a total of ten minutes per HEMS flight....would that not kick the probability back by a factor of six?
Then if one considers the actual number of operations and begin to calculate the exposure in that way....I would think the stats are altered by more than a lot.
I am a devout believer in strong twins for HEMS work so I am not banging a drum for singles but I am on the side of using accurate application of statistics in making decisions.
Did you guys not just have a record setting over-water rescue where a single engined aircraft went right alongside a Twin? What does that say about the view on safety while arguing about this pad in Wellington.
It would have been permissible to fly the victim (a hand injury...non-life threatening) over all that cold seawater but not land him at the hospital in question.
The lawyer just might be able to present a valid argument.
The given probability is based upon per flight hour is it not?
Thus if you assume five minutes of exposure for landing and takeoff....for a total of ten minutes per HEMS flight....would that not kick the probability back by a factor of six?
Then if one considers the actual number of operations and begin to calculate the exposure in that way....I would think the stats are altered by more than a lot.
I am a devout believer in strong twins for HEMS work so I am not banging a drum for singles but I am on the side of using accurate application of statistics in making decisions.
Did you guys not just have a record setting over-water rescue where a single engined aircraft went right alongside a Twin? What does that say about the view on safety while arguing about this pad in Wellington.
It would have been permissible to fly the victim (a hand injury...non-life threatening) over all that cold seawater but not land him at the hospital in question.
The lawyer just might be able to present a valid argument.
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SASS
Yes. This week's record replaces the previous record for over water rescue in a single. I would expect that in the future such rescues will be done by the Air Force in their shiny new NH90s.
Man recovers after chopper rescue from the sub-Antarctic | NATIONAL
Here is some vid taken from the B3.
They're now saying in this news story that the hand injury was potentially life threatening. But without a little more information it is a touch hard to imagine how.
A little more digging and it has been suggested to me that the Director of NZ CAA was motivated into acting by complaints about use of the Wellington Hospital pad outside of the regs and that maybe the hospital's insurers are getting a little twitchy. That is but a suggestion though.
TK
Yes. This week's record replaces the previous record for over water rescue in a single. I would expect that in the future such rescues will be done by the Air Force in their shiny new NH90s.
Man recovers after chopper rescue from the sub-Antarctic | NATIONAL
Here is some vid taken from the B3.
They're now saying in this news story that the hand injury was potentially life threatening. But without a little more information it is a touch hard to imagine how.
A little more digging and it has been suggested to me that the Director of NZ CAA was motivated into acting by complaints about use of the Wellington Hospital pad outside of the regs and that maybe the hospital's insurers are getting a little twitchy. That is but a suggestion though.
TK
There Is A Story Here Me Thinks!
After the Rescue while being interviewed....a quote from one of the pilots involved in the rescue.
"Don't ask me to go if there's another one out there, because I wouldn't...it's as simple as that."
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SASS What I think what Graeme was trying to say is that he would not go without another helo providing the top cover. Up until recently our marine rescue authorities would send a plane as top cover.
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The probability of both failing from independent causes is the probability of the first times the probability of the second - i.e. 1:10,000,000,000
How many complete engine failures (as in all engines on the aircraft) failures of airliners have we had in the time since turbine/turbojet/turbofan engines have been the primary type of power?
In light of the "bazillion" hours flown I would imagine that number is still awfully small.
Again...we accept risks or there would be no flying done ever.
The question is to define what is an "acceptable risk"?
I would climb into a US Air flight today without any hesitation.....beyond the normal reluctance to be a back seat driver.
I cannot say that about a HEMS ride in this country however....no thank you...I will go by ground!
In light of the "bazillion" hours flown I would imagine that number is still awfully small.
Again...we accept risks or there would be no flying done ever.
The question is to define what is an "acceptable risk"?
I would climb into a US Air flight today without any hesitation.....beyond the normal reluctance to be a back seat driver.
I cannot say that about a HEMS ride in this country however....no thank you...I will go by ground!
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Bugger...
I would suggest that the rescue helicopter based in Palmerston North is going to be buggered if the feds dig their heals in on this one. The Squirrel would average a trip a day from Palmerston North to Wellington and it would be a safe bet to assume that 50% of the flights are not life and death.
It is not the end of the world of course as the Philips Trust will just need to pick up a BK from somewhere and problem solved.
It is not the end of the world of course as the Philips Trust will just need to pick up a BK from somewhere and problem solved.
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Bugger Bugger....
Putting a BK in Palmy wouldnt help - it wont achieve cat A performance in a medical config.... see posts above.
The CAA have a duty to uphold and enforce the rules weather we as pilots agree or disagree with the rules they are enforcing - it would be irresponsible and against their mandate to expect anything less. The fact its taken them this long to react to a blatent rule breaking by almost all rescue operations in NZ is dissapointing.
If you disagree with the rules then maybe you should have taken more notice of the rule making process or maybe you should be campaining to have the current rules changed, there are avenues for this and the AIA and ALPA could help. Short of this pick up the phone and call John Fogden.
In the meantime I would suggest there are many in the firing line if an incident were to happen, the hospitals for holding the part 139 helipad certification and not enforcing its requirements, the heli operator and the PIC would be done for using a certified helipad and not being able to comply.
Hey - just get a helicopter that will comply then everyone would be happy!
The CAA have a duty to uphold and enforce the rules weather we as pilots agree or disagree with the rules they are enforcing - it would be irresponsible and against their mandate to expect anything less. The fact its taken them this long to react to a blatent rule breaking by almost all rescue operations in NZ is dissapointing.
If you disagree with the rules then maybe you should have taken more notice of the rule making process or maybe you should be campaining to have the current rules changed, there are avenues for this and the AIA and ALPA could help. Short of this pick up the phone and call John Fogden.
In the meantime I would suggest there are many in the firing line if an incident were to happen, the hospitals for holding the part 139 helipad certification and not enforcing its requirements, the heli operator and the PIC would be done for using a certified helipad and not being able to comply.
Hey - just get a helicopter that will comply then everyone would be happy!
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My understanding is that a B2 BK has Cat A performance but with weight limitations i.e. 2,850 kgs as opposed to 3,250. Palmerston North is only a 45 minute flight away!
I understand Airwork in Auckland are, or will soon be, trialling the new Lycoming which will give the B2 Cat A at MAUW.
TK
I understand Airwork in Auckland are, or will soon be, trialling the new Lycoming which will give the B2 Cat A at MAUW.
TK
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And if they fit the upgraded torque gauge. Not all BK117 B2's in NZ seem to have had them fitted due cost. ($30,000 ?) They are not required to either, but it creates different B2's.
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What about Palmerston North
So if Wellington hospital requires a twin engine helicopter why is one not required to fly into Palmerston North hospital? I would suggest that an engine failure while landing or departing either of these pads would have a similar outcome.
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Performance
Ok having a look through the flight manual of a B2 BK117 Cat A operations into Wellington are not problem.
Empty weight 2000kg, Pilot 95kg, Patient 95kg, Crew 190kg, Fuel 380kg, EMS kit 200kg?
Total weight 2960kg
Looking at the graph the BK could maintain Cat A performance up to 37 deg C at this weight.
On a more realistic 25 deg C summer day 3200 kg is achievable at 1000 DA.
This is a B2 that has an OEI torque limit of 125%. Carry out service bulletin 117-125 and this is increased to 140%
Empty weight 2000kg, Pilot 95kg, Patient 95kg, Crew 190kg, Fuel 380kg, EMS kit 200kg?
Total weight 2960kg
Looking at the graph the BK could maintain Cat A performance up to 37 deg C at this weight.
On a more realistic 25 deg C summer day 3200 kg is achievable at 1000 DA.
This is a B2 that has an OEI torque limit of 125%. Carry out service bulletin 117-125 and this is increased to 140%
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BK117B2 Performance Cat A VTOL (as the pad would be),
All figures are for the WA Police BK with EMS fit so might vary slightly:
Basic Weight 2050kg, with kit (Pilot, Doc, medic + patient) = 2510kg
Max Weight 2900kg corrected for DA (Doesn't include medical equipment but does include stretcher)
Elev zero ft
ISA = Max 2830kg, = 320kg fuel
ISA+10, 2760kg, Fuel 250kg
ISA+20, (a stretch for wellington me thinks), 2700kg, 190kg fuel
so it is doable for arrival off a job.
All figures are for the WA Police BK with EMS fit so might vary slightly:
Basic Weight 2050kg, with kit (Pilot, Doc, medic + patient) = 2510kg
Max Weight 2900kg corrected for DA (Doesn't include medical equipment but does include stretcher)
Elev zero ft
ISA = Max 2830kg, = 320kg fuel
ISA+10, 2760kg, Fuel 250kg
ISA+20, (a stretch for wellington me thinks), 2700kg, 190kg fuel
so it is doable for arrival off a job.
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I saw the Palmerston North Squirrel fly into Wellington airport not hospital on Thursday. A friend who lives near the hospital says only the "Westpac chopper" - which is Lifeflight's BK - has been coming to the hospital over the last week and a half.
Curious, given the initial outcry to the media.
TK
Curious, given the initial outcry to the media.
TK