Police heli engine problems?
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Police heli engine problems?
There seems to be an awful lot of reported engine problems, mainly chips and oil press problems on Police helis using the Alison 250 engines (BO105 / AS355). Is this pure coincidence, or are these helis being abused in some way - maybe "scramble" starts being employed hence no 1 minute warm-up period being oberved? And that question goes to.....the Plod pilots.
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PurplePitot / Cyclic Hotline. You may think the Alison is crap, but that doesn't really answer my question,sorry! I have flown the same 206 for 7 years, nearly 1,000 hrs with only one chip event ( which proved spurious anyway) So maybe my question should have been "Why is the Alison engine crap in the police role in the UK, but OK in my (and many other people's) JetRanger(s)?" Lack of or incorrect maintenance maybe? Is too much expected of it in the BO105 / AS355 fit?
Come on boys, at least when Lu calls the R22 crap, he backs it up with (his version of ) the facts. Letsbe hearing from you
Come on boys, at least when Lu calls the R22 crap, he backs it up with (his version of ) the facts. Letsbe hearing from you
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Jeez guys, this is starting to sound like that ridiculous justhelicopters.com site......this is crap, that’s crap......I thought this one had a little more substance.
I have spent the lion's share of 7000 hrs at the top of an 'OGE hover at near MAUW' with GEs, Pratts, Turbomecas, Lycomings, and Allisons spinning behind me or overhead in various forms, and have seen them all go for ****. I have seen 206Bs with 20,000 hrs which have never experienced an engine problem, and a brand new 350BA (<300hrs TT) spit the engine out the back. In the vast majority of cases, the cause can be traced to poor operational habits, or substandard maintenance or overhaul practices. Of course there are exceptions.... early LTS-101s for example, early C-28s, even the beloved Arriel has seen some untimely spur gear failures which have been going on for quite some time (first one I saw was 93, and it's still happening today re: LA police).
Point is, rarely does a properly operated, maintained or overhauled engine fail. When they do, it's usually a 'one-of', and not a fundamental design flaw.
Stevie, as you said, the 1 minute 'warm-up' period is indeed that, a period to reduce thermal stress on the engine before running it up, and not a generator or battery limitation as is sometimes believed. Most other manufacturers have some form of restriction on this as well.
For widgeon: The C-47 seems to be holding up very well, as is its brother, the C40 in the B430. The C-47 experienced some early FADEC issues which were traced to a wiring harness vendor. Otherwise the first six years has been remarkably good, with most overhauls resulting in only minor repair work.
I have spent the lion's share of 7000 hrs at the top of an 'OGE hover at near MAUW' with GEs, Pratts, Turbomecas, Lycomings, and Allisons spinning behind me or overhead in various forms, and have seen them all go for ****. I have seen 206Bs with 20,000 hrs which have never experienced an engine problem, and a brand new 350BA (<300hrs TT) spit the engine out the back. In the vast majority of cases, the cause can be traced to poor operational habits, or substandard maintenance or overhaul practices. Of course there are exceptions.... early LTS-101s for example, early C-28s, even the beloved Arriel has seen some untimely spur gear failures which have been going on for quite some time (first one I saw was 93, and it's still happening today re: LA police).
Point is, rarely does a properly operated, maintained or overhauled engine fail. When they do, it's usually a 'one-of', and not a fundamental design flaw.
Stevie, as you said, the 1 minute 'warm-up' period is indeed that, a period to reduce thermal stress on the engine before running it up, and not a generator or battery limitation as is sometimes believed. Most other manufacturers have some form of restriction on this as well.
For widgeon: The C-47 seems to be holding up very well, as is its brother, the C40 in the B430. The C-47 experienced some early FADEC issues which were traced to a wiring harness vendor. Otherwise the first six years has been remarkably good, with most overhauls resulting in only minor repair work.
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I tend to agree with psyclic, CTD, now that I've heard that other alisons operating in less strenuous circumstances don't suffer 'chips' and other engine headaches as much as police alisons, perhaps there is substance to it. It is common in this industry to read about compressor blades / chip lights / combiner gearbox debris playing up on the C250F. I couldn't finger maintenance in our instance...perhaps it's me!!!!!!!
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Thermal runaway.
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Thermal runaway.
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I'm sure you're right that a harder working engine will suffer more than one which is screaming all day. TC, do you fly a TwinStar? It's been a while since I flew a 355 but it seems to me that while operating with both cooking they're not working too hard, certainly not as hard as one works in most single applications.
I worked on a base for years that ran up to 9 H500s over 1000 hrs/yr each, mostly doing heavy sling and precision longline work. We had one engine failure in 10 years, and that was a compressor which let go 18 hrs out of overhaul.
Anyway, I'm not into defending Allison, but in reality, there are far more of them floating around than anything else right now, so one is bound to hear of more problems.
Have a safe one, no matter what you're in.
I worked on a base for years that ran up to 9 H500s over 1000 hrs/yr each, mostly doing heavy sling and precision longline work. We had one engine failure in 10 years, and that was a compressor which let go 18 hrs out of overhaul.
Anyway, I'm not into defending Allison, but in reality, there are far more of them floating around than anything else right now, so one is bound to hear of more problems.
Have a safe one, no matter what you're in.
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Dear All,
Have been flogging around in a 1989 BO105 - 11000 hours + on the frame,
for a few years now. All of the flights were Police related, and have to say that the one minute warm up - although a great idea, does tend to knock the rapid response that plod require. It's a sad fact that some types of operation do tend to knack the hardware somewhat, but we seem to limit our 'chips' with the Facet filter setup, apart from rebuild debris that is. The old 105 did tend to leak some, but providing the labyrinth seals were well run in, and the weather above zero (c) the "rapid start" and take off could be performed ok. The problems you have heard of with the C20B are correct, but they must be understood in the context of the job the craft is being put to.
Have been flogging around in a 1989 BO105 - 11000 hours + on the frame,
for a few years now. All of the flights were Police related, and have to say that the one minute warm up - although a great idea, does tend to knock the rapid response that plod require. It's a sad fact that some types of operation do tend to knack the hardware somewhat, but we seem to limit our 'chips' with the Facet filter setup, apart from rebuild debris that is. The old 105 did tend to leak some, but providing the labyrinth seals were well run in, and the weather above zero (c) the "rapid start" and take off could be performed ok. The problems you have heard of with the C20B are correct, but they must be understood in the context of the job the craft is being put to.
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I also agree with CTD.
I have 10,000 hours + on the C18, C20, C20B, and C47 with very few problems. I typically have an aircraft assigned to the base for 2000 to 4000 hours, and have always reached the Alison (RR) TBO's.
I can't say this about my Ariel time, as I have seen one of those come apart...luckily I was very near the ground.
I have 10,000 hours + on the C18, C20, C20B, and C47 with very few problems. I typically have an aircraft assigned to the base for 2000 to 4000 hours, and have always reached the Alison (RR) TBO's.
I can't say this about my Ariel time, as I have seen one of those come apart...luckily I was very near the ground.
