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Single Engine Ops: Who's Responsibility?
Oil and gas companies, some large corporations and most government departments either have policy or guidelines addressing flight in single engine aircraft. Presumably the insurers of celebrities also issue terms covering the use of charter flights by their policy holders?
What obligation do you think charter companies have to ensure their passengers understand that they are chartering a single engine aircraft? http://bauergriffinonline.com/bfm_ga..._K_B-GR_01.JPG Mrs Cruise (Katie Holmes) boards an Astar at Wall Street Heliport with daughter Suri Cruise in arms. |
In America's litigous society charter operators might do well to check that their client's understand this, especially given that they have the resources to take action in the event of an incident but then the firm would have to make sure that such information was equally shared with non-celebrity pax.
Small firms running only single engine ships just want the money and publicity so they probably don't mind. Two questions if anyone can respond! 1. Can anyone provide me with a first hand incident of a total engine loss in a twin as a result of mechanical failure (no external influences such as water/foreign object ingestion)ie: a 100% pure mechanical failure. 2. Does anyone know where US helo pilots hang out online? There are a few on pprune but not as many as I'd like. Any info welcome. Hasta la vista! |
Yellow and Blue...
Oil and gas companies, some large corporations and most government departments either have policy or guidelines addressing flight in single engine aircraft. And you are wrong---the GOM is full of single engine helicopters. Most government contracted helicopters are also single engine, certainly for DOI, USFS, BLM etc.... You will find that the vast majority of celebrities know what they are flying in---a fair bunch of them own their own aircraft. Hell man: Small firms running only single engine ships just want the money and publicity so they probably don't mind. Most US helicopter pilots hang out on JH. |
Typical pig-headed US attitude there Gordy that nicely explains the poor US safety record.
Too often people who can afford to fly safely don't due to their igonrance of the risks (including the hostile environment risks). I'm glad to see that BP are sticking to their principles and limiting SE helicopters to shore patrols in the GOM. |
Sorry, I read the UK CAA reports & MORs - have I missed a load of failures in the donkey dept of SEHs ?
I see a lot of chip lights, hydraulics and other bits failing in twins - which leads to a forced landing and the inevitable report - but I see far great reliability and less stress in SEH. Insurance companies would prefer that we all stay on the ground in a cottonball and never go anywhere - hence some of the ridiculous "keyman" requirements which sometimes include mandatory multi-engines for any flying. As ever, it's a way to ramp the premium by creating a risk far greater than it really is. |
Was actually wanting to know about first hand 100% mechanical engine failures because I've never actually met anyone who's had one!
The stats show than singles are pretty much as safe (if not safer) but I guess its the 'what if factor'. Here is something I've always wanted to know ... In a fixed wing you have (to a larger extent) seperate systems as a result of individually mounted engines but in helos (aside from the engines) the majority of other systems are shared. Does this represent a lower safety threashold for twin helos vs. twin fixed wings? |
Shell Management
Typical pig-headed US attitude there Gordy that nicely explains the poor US safety record. |
I wish to publicly apologize to Gordy (and anyone else) if I am causing the cr*p to curdle! It is not my intention.
I am genuinely interested because one day I expect I will leave the Swedish Defence Forces and maybe I will have to join a small company which is operating single engine aircraft and these issue will become relevant to me. I feel that singles are perfectly safe because of the helicopter's ability to auto-rotate. If the aircraft is flown along safe single engine routes (open spaces below) and at the right height with the right visibility then it is perfectly safe. |
It would be nice to go and look long term records of accidents and compare them between singles and twins. What I would like say is that helicopters have a lot of single parts, which will broke also. Major parts are at least: tail rotor, Gearbox(es), rotor system itself etc.
First thing is go and look where to work and how the company manage all services. Also pilots have a responsibility to operate aircraft's by the manuals as well. All limit exceeds are bad news and if you do not have any kind of flight monitoring systems (like most older single engine helicopters don't have) will reduce your safety. That's why you need to be honest, if it happened accidentally. I don't believe anybody exceed limits for in purpose anyways. Single engines are very reliable nowadays, if you look flight time records. That's imaze me, but it is true. All big sight-seeing companies basically use singles and they flies a lot. Offshore is the other operation for singles. Reason for using singles in some part of areas are small platforms where you cannot build a big helideck for twins. Well' you can use EC135's or other same size aircrafts, but operational costs are total different then. Money might be the only reason to use singles, but they can be safe. Hostile |
I do feel that there are some very important factors relating to twin engine helo ops, especially the shared dynamic systems. I realize its very similar for fixed wings but multi engine fw do have the advantage of largely separate propulsion/thrust units and which I believe offers an added level of safety.
One solution, from a cost perspective, would be an engine technology which allows for very high short term power demands of say up to 10-20 mins (for emergency single engine operations) from smaller engines which would offer more economic operating costs for twins. But, the way things are going in the H&S world we live in I am sure singles will end up as trainers and private use only. Here's a single op that recently had the hangar door closed on them: Rescue copter loses out | Stuff.co.nz |
The letter claims that since January 1999 there have been 17 incidents in which helicopters either needed to shut down engines due to warnings, or made precautionary landings because of mechanical failures or warnings. All these incidents were during air ambulance operations.
Do others think this is a high No, of problems ? for Air ambulance work |
500e Heli Man
Some of those 17 reports will have been filled by myself, both in singles and twins. This is a sad case of the Civil Aviation Authority using "incident" reporting to try and justify their stance - many of those reports (I'm assuming) will have been for "chip lights", 'fluctuating oil pressure" etc, pilots responded to the "warnings" and carried out a precautionary landing, or shut a second engine down. Many of these reports, most probably, where cleared quickly by an engineer, then an incident report was generated. This is good practice, but now our CAA are trying to suggest that these 17 reports indicate that engines are not reliable, and this is how the media will take it! Yes I accept, engine failures do happen, but the overall risk needs to be assessed against the added cost of operating 2 engines. |
Hell Man
I had the Compressor Drive shaft shear in an Agusta A109C, total power loss from that engine with TOT off the clock. That said, I also had the turbine let go in an AB205, total and instant power loss. No pre-determined cause in either instance, just the 'sh1t happens' category. So that's one all in the single / twin argument in my personal experience. JJ |
Last year I lost a friend in a single engine eurocopter, he was inspecting electricity lines somewhere on the west coast of Ireland when the chopper (EI-IHL) sufferred a mechanical failure, main gear wheel disintegrated. Pilot survived the resulting crash but he did'nt.
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Speculating :
Perhaps the most likely cause of a double engine failure would not be a mechanical fault with the engines, but loss of fuel - i.e running out of ( useable ) fuel, causing them go very quiet. This could be attributed to pilot error, poor maintenance, or possibly even mechanical failure of some sort, perhaps even a multiple bird strike in the right ( wrong ) place, but none of these are restricted to twin engine aircraft, and are just as likely / unlikely in a single - probably even more so in some cases. I can ony think of a couple of examples of twin failures - The Dyfed-Powys 109 G-DPPH that ran out of useable fuel in 2001 following maintenance to fuel pumps, and I seem to recall there was an incident back in the '80's / 90's ( I think ) where a Police twin squirrel ( or maybe even a 902 ) lost fuel supply because of detached fuel line(s) - resulting in an auto and run on landing into a field. Can't find any details on that one though. http://i34.photobucket.com/albums/d1.../Coconutty.jpg |
Hi Rick.
Unfortunately, the rule is the rule, and the current director of CAA is going to the letter of the law, rather than the intent, and churing through all the laws to see what we are doing wrong. Apart from the BK running into trees a few years ago, i'm struggling to think of any serious incidents that have been on EMS ops in NZ... somehow there are 17 in 10 yrs. Last major one was a JR flying into a white out, and the army wrecking an Iroquois on Mt Cook, both in the 80's.:rolleyes: like you said chip lights and pressure fluctuations, which wouldn't have been reported 20 yrs ago, just talked to the engineers, check it out, watch it, fix it... |
Was not asking about engine failure in singles (even I had a flame out in an Iroquois in Nam) nor about 'double' engine failure in twins but ... a single engine failure in a twin.
Jellycopter has had it in a 109C. Congrats! You're the flirst helo jock I've 'met' to whom this has happened! The thing is, and the reason for my asking, is that these incidents of mechanical engine failure must be very rare. I'm trying to establish how frequently a second engine keeps an aircraft from calamity vs. single engine. I guess Jelly landed pretty smartly after the failure but some twin ops (over water at night) etc. may require sustained flight. What are the stats? Are twins statistically safer than singles? |
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Are twins statistically safer than singles?
The unanswerable question. You seem to have strayed from "engine failures" to a wider view of incidents. Even "bolkow" above hasn't stuck to engine failure as a cause - but was the gear failure caused by too much torque from 2 engines ? The only facts I know are that 2 engines cause more stress for related systems, and that the advances made in engine reliability over the past 40 years have still not made it through the system with a decent set of regulations for SEH. (In the UK & Europe). There is still a heavy bias against SEH when the stats and the reality don't demand it. Can all twins at all weights operating at, say, 750ft AGL safely depart the area when a power unit fails ? No. Can the same machines safely auto to the ground from that height ? No. |
I've read thru the thread posted by thecontroller and it is interesting.
I can understand the reg bodies pushing for better safety (that's good) but don't know whether twins = better safety period? I seem to remember the UK going through a period of fatal TwinStar crashes flying VIP/Corporates - the extra engines didn't help then! I think the answer in the long run may simply be to produce really reliable, well powered and highly fuel efficient turbines so that twin safety, performance and economy is beyond question. |
Hell Man!
I think the answer in the long run may simply be to produce really reliable, well powered and highly fuel efficient turbines so that twin safety, performance and economy is beyond question. A Stark Industries Arc Reactor powered turbine!!! :E http://t1.gstatic.com/images?q=tbn:N...inimamente.jpg |
From what I have seen, read and heard, the major reason why IMO the US seems to have more accidents than the JAA countries is that a larger percentage of what we do with helicopters is deeper within the 'Money' Curve, aka HV Curve. I haven't seen any heli-logging or rappelling in Europe, except the rappelling done by police or special ops people.
As for the age old question of a twin being safer than a single. The accident records here in the US, show almost no difference between twin and single. If an actual engine failure does occur in a turbine engine it is usually fuel related. If it is a mechanical failure (quite rare, considering the number of hours flown) with the engines side by side in most installations, parts quite often end up in the 'good' engine. As for the containment ring, all that seems to do is ensure that the parts go into the good engine, not through it. I can say that I speak with some experience. In my flying career I have had 9 engine failure events. Surprisingly, only four were in piston engines. One was caused by a system failure that filled the oil tank with avgas and burned out the engine. It was traced to an AD note that wasn't complied with. Another was caused by a shop that didn't overhaul a fuel control unit that they claimed they did and the engine flooded out. The other two were caused by cylinder failures. Which is always a weak point in turbocharged engines. Two of the turbine engines had T wheels come apart due to improper overhaul (by the outside vendor). One was caused by an oil pump failure and another was a FCU failure. And the last, was a FOD failure. These were ALL multi engine aircraft. IMO the more engines you add the more your risk of an engine failure increases exponentially. Further more, except for the piston fuel control unit failure, which happened in cruise flight, all happened on takeoff. From what information I have gotten, a majority of actual engine failures happen right after a major power change and most often when the power has been increased. The engines feed from the same fuel tank, so any fuel issues, lack of or contamination will affect both engines. And the engines are connected to the same transmissions, with a few exceptions. Many of the mechanical failures over here are not engine issues, but component issues like transmissions. On top of that many twins have a minimum single engine speed, which would make landing on a hospital heliport difficult if not impossible. Personally, I feel just as safe in a single engine helicopter as I do in a twin. As for a single engine airplane, that really depends. |
Combining gear-boxes...
I think I recall something about combining gear box failures being a main issue in the North Sea operations. Is this true? If so, then that would be a definate factor against twin engined "reliability".
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Two pilots will ALWAYS be safer than two engines. 'Pilot error' accounts for th vast majority of crashes.
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Exactamundo, controller.
Clearly it is a "given" that twins are safer than singles, "everyone knows that", its "obvious". Isn't it? If the complxity of an aircraft increases as the exponential of the number of engines and the vast majority of accidents are primarily or largely down to errors in flying/handling the problem is it any wonder that twins are little different to singles in the stats? I'm pretty sure that the minor safety advantage of the second engine is negated not only by the added complexity and variety of potential faults, but also the likelihood of mishandling them. Two pilots, well, if they're trained as a crew maybe better, but two single-pilot pilots flying together because a charter client demanded it? Hmm...Sometimes a little knowledge is not so clever after all. As to the "responsibility" of telling a client what he's flying in - why? Caveat Emptor. If he's concerned he'll ask. We'll be finding reasons to provide them type-related accident statistics next! |
Well put Agaricus.
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ricksheli
You make a valid point! However, the CAA has been backed into a corner by the rescue trusts which have been deliberately misinterpreting the rule for years, and then using their massive public sympathy card every time they are challenged. Combine that with a Minister of Transport who has been warning them behind the scenes for quite some time that they need to up their game. This week he said it very publically. Super F The Director is interpreting the rule as it was intended. The exemption that is allowed to the performance criteria is for life or death situations. Broken legs or even backs usually aren't. Most medical cases, whilst often serious, aren't life or death situations. A key issue is that of inter-hospital transfers! To use the exemption to justify using a single egined helicopter for an inter-hospital transfer is simply not credible. In the time that it takes to prep a patient, even a critically ill/injured patient, for a flight and arrange everything at the receiving hospitals end a suitable machine could be sourced. The event which has alarmed many people in the corridors of power happened last September - well after this issue became public. It was a Longranger suffering a main bearing failure shortly after landing at Taranaki Base Hospital. It had just bought a patient back from Wellington Hospital. Both of those hospital pads are deemed to require Category A, Performance Class 1 aircraft to operate to and fro because of how built out they are. TK |
TK
Your information about the LongRanger into Taranaki Base Hospital is totally wrong. Sounds like the CAA/ ministers changing information to suit their argument. The facts: Helicopter was on a positioning flight from port, engine oil pressure began "fluctuating", helicopter landed at Base Hospital with full power, shut down normally. Fault traced to engine oil scavenge pump failure, but the point is, didn't result in engine failure, the fault allowed plenty of time for a safe powered landing, the pilot did exactly what the flight manual required. As for medical transfer from Wellington - no. I can tell you the next flight after repair and air test was a flight to Wellington Hospital and the flight nurse signed to allow use of 13a. |
Very well put Agaricus bisporus. It seems that far too many clients (and pilots sometimes...) believe that engines are the only failures that can possibly occur in helicopters. :ugh:
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Te Kahu
i agree about the trusts going at it and using sympathy to not have to comply. re the intent, i was referring to LIB4 which is the biggest foul up anyone has ever seen. interesting seeing a LR land in Carisbrook at the end of the test match, took off striaght out over the crowd, didn't even try to gain any altitude. Waiting for CAA to jump on that one... Can't see it as being a sec13 excuise, and they are rescue heli operators and should know better... you should google Taranaki Base, you should be able to do a steep turning descent and take off in most singles, and keep the grass below you, not like some of the other hospitals. Interesting that Tom Cruise lets his wife and kid in a single and he flys around in twins??? |
Ricksheli.
Far cop. One is always willing to put one's hand up and call wrong if the facts dictate so. You appear to have intimate detail about this incident which I'm hoping means you might be able to answer a question or two! How long did the Longranger sit on the hospital pad until the engine was swapped out? Also, the fact that it had to shutdown and stay on the hospital pad for XXX days/weeks/months while the engine was swapped out means it complied with Cat A, Performance Class 1 how? How long can a Longranger/C30 keep performing at full power with a failed oil scavenge pump before it's performance degrades and becomes a problem? And, Port of Taranaki to Taranaki Base Hospital is how many metres? I am sitting with a former senior manager of one of New Zealand's biggest hospitals and he just bout fell of his chair laughing at your suggestion that the flights out of New Plymouth are signed off by a flight nurse. "That's a sad joke...Tell that guy not to say that to loudly in case the hospital's insurers hear," were his comments! By the way, what was the nature of the injury/illness of that flight which was signed off by a flight nurse? Do tell? SuperF I think you will find that the owner of that Longranger simply doesn't agree with that rule and is just ignoring it! As well as the department I do wonder if his insurers were watching the test? TK |
Coconutty: The Dyfed Powys helo ran out of fuel because of pilot error, on Christmas Day 2001. He mis read the FRC's. No mechanical issues.
I have flown 3000hrs on Gazelles in my time. Probably approximates to 2500 -3000 flights in one. Not one power failure. In fact up until then there was not one recorded engine failure of a gazelle in the military until CB had one on finals to Predannack! I have flown approx 4000hrs in twins and I have experienced half a dozen 'forced landings' because of the complexities of flying twins. Statistically the odds of a SEH experiencing total power loss are something like 14,000,000 : 1. I have to say (apart from some helos requiring 2 engines to carry all the weight around), I suspect the 1 engine Vs 2 engine argument is all about perceived theoretical permutations and that 'pucker factor' flying over hostile terrain on 1 engine. People can't grasp the odds. You would have to fly every day for 112 years before you died in a plane crash - yet thousands of people will never fly through fear of flying. Interesting topic of conversation. |
Had a compressor blade come off and destroy the rest of the compressor in a 109Aii.
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TK
Quite happy to answer some questions you asked: "How long did the Longranger sit on the hospital pad until the engine was swapped out?" It was only on the helipad until the ground handling wheels where attached and a/c pushed into hanger! The heliport is big enough for several helicopters, if thats your point? SuperF has a very valid point, I believe Taranaki Base Hospital is suitable for certain singles (B206, B206L, R44, AS350 etc) all helicopters have differing auto performance and I think in some singles you could plan an approach / departure for at Taranaki Base Hospital. Unfortunately the Taranaki Rescue Trust operate a A119 and that won't comply, the shame of it is that its new, and has a PT6 engine, probably the best turbine engine out there. TK You asked:"Also, the fact that it had to shutdown and stay on the hospital pad for XXX days/weeks/months while the engine was swapped out means it complied with Cat A, Performance Class 1 how?" Its a single so can not comply with Cat A, Performance Class 1, but if the hospital has suitable approach / departure routes and the helicopter has suitable auto performance this may not be a problem. TK you asked: "How long can a Longranger/C30 keep performing at full power with a failed oil scavenge pump before it's performance degrades and becomes a problem? " It would seem long enough to make a safe landing, but perhaps RR could answer that one? TK you asked:"Port of Taranaki to Taranaki Base Hospital is how many metres?" Just over 1nm, a park and school playing fields in between, the helicopter had been flying for the previous half hour, why the question? TK stated:"I am sitting with a former senior manager of one of New Zealand's biggest hospitals and he just bout fell of his chair laughing at your suggestion that the flights out of New Plymouth are signed off by a flight nurse. "That's a sad joke...Tell that guy not to say that to loudly in case the hospital's insurers hear," were his comments!" If you are an EMS helicopter, the best people on board to assess the patient would be a doctor, paramedic or flight nurse, not flight crew. I wouldn't land at an elevated helipad in a single with a patient on board unless the medical crew expressed a critical requirement to do so. This was the case, and the flight nurse had no problem making a statement to the effect. Certainly no "joke" or "laughing matter". |
Ricksheli. Thanks for that. No one could argue that they are not perfectly reasonable answers. But, isn't the point that at the present point in time the department deems the Taranaki Base Hospital pad to be a Cat A, Performance Class 1 pad and really everything else is irrelevant?
What work have the local operators done with the department to convince them that there is a safe approach/departure path for singles? In regard to a flight nurse signing off the 13A exemption! I would be interested to see what the insurance companies of the aircraft owner and the DHB would say. It is clearly outside the intent of the rule and the exemption. For example! Last year the Palmerston North rescue squirrel brought a man into Wellington Hospital who had an angle grinder embedded in this forehead. That certainly met the intent of of the exemption. It is highly dubious that many of the accident cases and certainly most of the inter-hospital transfer cases come anywhere near meeting the intent of the exemption. If the comment of Mr Wickham from the Phillips Trust typifies the attitude the rescue trusts, then the public should be concerned about how their money is being spent and the level of service they are being provided. It is my understanding that the Director's letter IS the response to their request for exemption. The Square Trust rescue helicopter is "flying in the face" of air safety rules that ban single-engine craft from helipads in congested areas, and could be grounded within weeks. The Civil Aviation Authority (CAA) has told operators and district health boards that from the end of August it will enforce rules governing the ability of helicopters to make emergency landings in populated areas in the case of engine failure. The Square Trust rescue helicopter is based at Palmerston North Hospital. In the case of any breaches brought to the CAA's attention after that date, 10 days' grace would be granted to comply with the regulations before the authority ordered operators to stop flying, said director Steve Douglas. The Central Regions Emergency Services Trust (CREST), which uses Helipro's BK 117 twin-engine helicopters, has offered to come to the rescue of the service. But the Philips Search and Rescue Trust, which manages the Square Trust's operations, said it is not breaking the rules. Chief executive David Wickham said the safety rules were more complex than a single-versus-twin engine debate, and the trust was operating professionally and responsibly. Helipro pilot Rick Lucas said the rules were clear. He said there was no doubt the approaches to the Palmerston North Hospital helipad meant flying over a congested area. "An engine failure would have absolutely catastrophic consequences, yet they are still flying." Mr Wickham said the prospect of having to invest in twin-engine helicopters was far from inevitable. "The wheels aren't going to fall off the service in Palmerston North, with or without CREST." Compliance with safety rules had to be professionally assessed, flight by flight, depending on variables such as the weight of the load, wind conditions, and whether there was medical advice that it was a life-and-death situation for the patient on board, Mr Wickham said. "The degree to which you expose people on the ground to risk has to be considered against the danger to the person on board if you don't make the landing." He said the Civil Aviation Authority had spelt out its time line for enforcing the rules, but it was still unclear whether changes would have to be made to comply with those rules. Just in case, the trust had applied for an exemption, "what we thought was the best, most robust case", but hadn't had a formal response. In the meantime, it had lined up options for sourcing twin-engine helicopters. Mr Wickham said twin-engine helicopters cost twice as much to run but were not twice as safe. "But we can't crystallise any of that until we know more." MidCentral Health group manager for support services Jeff Small said he couldn't comment at present on whether the single-engine helicopter service could continue to operate. Talks with the Philips Trust, which holds a contract to provide air transport services until the middle of next year, were continuing. |
TK
With regard to your comment "...... But, isn't the point that at the present point in time the department deems the Taranaki Base Hospital pad to be a Cat A, Performance Class 1 pad and really everything else is irrelevant?" Do you know that the department has deemed the pad to be Cat A, Performance Class 1? I only know that the operator has decided that the A119 cannot comply, so is now operating elsewhere. Every helicopter has differing performance, which will be affected by AUW, some twin engine helicopters at a high AUW will not comply either. The press, and non helicopter pilots (Trust managers etc), have really been struggling to understand the issue. |
ricksheli. Good point squire. No I don't know that the department has deemed that as an absolute fact. I strayed into the dead man's curve equivalent - the assumption.
I assumed that as Mr Mark Marsters, the chair of the local trust, has been in the media several times recently saying they had asked CAA for an exemption to keep operating from the hospital; then the department had told him/his trust that singles do not comply in and out of that pad. Why else would they feel the need to apply for an exemption? Also, as much Hugh Jones is not always the most pleasant of human beings; one has to think quite hard as to why he would refuse, as operator of the A119 for the Taranaki trust, to continue to operate out of the hospital pad following the Director of CAA delivering his letter. But, you are right I have made an assumption, not stated a fact. However, I agree whole heartedly with you about the level of knowledge - or lack there of - about these matters of both the media and some trust managers/boards/chairs. The level of their ignorance is a mix of sad, scary and funny all at the same time. TK (edited for typo) |
Kiwis raise $1.5m for rescue helicopter Despite tough economic times, New Zealanders have set a record with donations to this year's Westpac Rescue Helicopter Appeal. Almost $1.5 million was donated, and organisers of the appeal say every cent will go to the 16 rescue helicopter trusts nationwide. Rescue helicopters undertook almost 5,000 missions last year, each costing thousands of dollars. - NEWSTALK ZB TK |
The increasing farce which is the operation of the Phillips Rescue Trust has gone to a new level.
A friend of mine was at Palmerston North Hospital the other day and witnessed their AS350fx depart the pad using a Cat A profile i.e. backing up and then flying away. Hard to fathom the rationale of that anywhere, let alone out of a built up urban environment. |
A friend of mine was at Palmerston North Hospital the other day and witnessed their AS350fx depart the pad using a Cat A profile i.e. backing up and then flying away. Hard to fathom the rationale of that anywhere, let alone out of a built up urban environment. In other words he might be trying to keep his max risk to the pad area. |
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