R22 accident report

[VeeAny]

Februarys AAIB Bulletin is out.

Just seems to be this one helicopter related, this month.

http://www.aaib.gov.uk/publications/bulletins/february_2005/robinson_r22_beta__g_bytd.cfm

V.

[blithe]

extract from the report:

>The aircraft ran on with sufficient force to break the skids off the aircraft at this point. Impact marks also indicate one of the rotors then hit the ground and that the aircraft rolled over, causing considerable damage and shattering the canopy,

Blimey! Thats sounds scary...

[[email protected]]

Day one at piston engine helicopter school - carb icing kills. Will people never learn?

[CRAZYBROADSWORD]

You can teach some poeple what you like very time you fly with them but the day after they get their licence they think they know better, bring back aptitude test's I say.

[Gaseous]

How long will it remain defensible/ethical to produce helicopters with carburettors?

[rollie rotors]

Gaseous,

It's the most defensible and ethical way to rid the world of idiot pilots unable to follow simple check lists.

[headsethair]

Gaseous : is your knee jerking ? There's a crucial line in this report : "However, again, his relative inexperience lead to difficulties in controlling the aircraft and resulted in a heavy and fast run-on landing."

A 70-hr pilot.

A carburretor is the least of his problems. You might as well say that the collective, cyclic, pedals and throttle control shouldn't be there - and that the instruments are useless.

Any more incidents like this and we'll be getting our own version of SFAR 73 for all helicopters in the UK. Would that be a bad thing - forcing pilots to do more training up to, say, 150 hrs ?

Be good news for the schools and instructors :ok:

[Whirlybird]

Unfortunate as such accidents are....

Hands up anyone who's never been inexperienced before they gained experience, and who's never made a mistake. :(

[UwantME2landWHERE!]

:ok: ME! Whirly.

I was born a natural, highly experienced helo pilot, but by the age of 10 I was down to being merely mediocre. By 20 I was described as adequate, and by 30 people would just shake their heads and wonder how I got the damn thing off the ground never mind back down again.:(

Oh the ravishes of time….. :{

[Gaseous]

Hair

My, my, we are defensive arn't we. Certainly my knee jerks and my eyes water when I pay my insurance premiums. This is hardly the first R22 to suffer carb icing. This guy was put in a position where his experience was inadequate because the helicopter had not got fuel injection and he made an error. Had the aircraft had injection it would not have crashed. No carb, no ice problem.

The pilot did apply carb heat but not enough. Hands up anyone who flies an R22 and has never completed a descent and found they omitted the carb heat, but got away with it.

I haven't checked but I bet there are no Raven 2 carb ice incidents!

If injection is not required why did Frank bother to put it on the Raven2???

[Bravo73]

I haven't checked but I bet there are no Raven 2 carb ice incidents!
I'd save your energy if I was you. It's quite hard to get carb icing if there isn't a 'carb'... :E


But then, you already know that...:}


If injection is not required why did Frank bother to put it on the Raven2???
Because the Raven2 was designed specifically for hot and/or high operations. The Fuel Injectors are obviously going to give you more power than the 'carb' version. The lack of carb icing is an ancillary benefit. Or at least that's my understanding of the situation.


Regards,

B73

[Gaseous]

B73
I did know!

I would take issue with this.

The Fuel Injectors are obviously going to give you more power than the 'carb' version.

There are many more things (cam profiles, compression ratios, etc.) that determine power output than carb or FI. Not least where Frank paints the red line on the MAP gauge. (I know all about pressure/density altitude so don't come back with that).

Lycoming engines were developed for fixed wing and the primary reason for fuel injection is better fuel distribution to each cylinder which allows better leaning. As far as I know ( I dont fly one) this is not recommended with a Raven2. There is loads of information on leaning on the net.

I would suggest the main reason FI was put on the Raven 2 was avoidance of induction icing. Just my opinion.

Its a pretty good reason though.

[Bravo73]

Well Gaseous, somebody seems to have rattled your cage.

Without resorting to mudslinging, let me respond to a few of your points:

I did know! Exactly. Which is why I said: But then, you already know that...

There are many more things (cam profiles, compression ratios, etc.) that determine power output than carb or FI. Of course there are. But I'm a great believer in the KISS principle (I need to be!). And, by and large, a FI version of the SAME engine will produce more power than the carb version.

As far as I know ( I dont fly one - AHA!) this (ie leaning) is not recommended with a Raven2. Not only not recommended, but not allowed. (At least not during flight).

I would suggest the main reason FI was put on the Raven 2 was avoidance of induction icing. Just my opinion. Of course it is but I'm afraid that's it's wrong. Frank needed more performance from the same engine so he chose the FI version. Even the Robinson website (http://www.robinsonheli.com/ravenii.htm) says as much: The Raven II is equipped with a fuel-injected, angle-valve, tuned-induction, IO-540 Lycoming engine which produces substantially more power and gives the Raven II greater altitude performance, more payload, and increased speed. (My emphasis). The lack of a carb icing problem is an ancillary benefit.

I'm by no means an expert on any of this but it's amazing what you learn on the RHC safety course...


Fly safe,

B73

[Genghis the Engineer]

Those who trouble to read it, will have noticed that for much of the last year GASCo's Flight Safety magazine has been having a "ban carb heating" campaign.

There are more than one way to do eliminate carb icing without a hot air carb heater, and FI is certainly one means. I can't help also noticing that it's almost impossible now to buy a "normally" carburated car any more, whilst small flying machines (with their ultra hi-tech 1950s technology engines) are still by and large using carbs.

Flying machine engines are, I'm afraid, a bit behind the drag curve !

G

[headsethair]

OK Gaseous. You know everything.

Maybe.

Sadly the majority of new pilots don't. There are many things they need to know almost as a sixth sense - and the addition of carb heat in certain conditions is just one.
There are many things that could have caused this pilot to have his accident - he's just fortunate that his failed memory (or lack of training) didn't kill or seriously injure him.
We've all done it - we've all forgotten something.

Putting FI onto the R22 engine is an impossibility.

But educating pilots to follow a well-worn, effective procedure is easy.

It seems to have worked for the vast majority of R22 pilots for 25+ years.

[Gaseous]

Rattled, no. pedantic yes.

Im glad you don't resort to mudslinging as reasoned discussion is so much more productive.

Does leaning appear in the limitations section of the POH for a Raven2. It doesn't in my old Astro POH (old and out of date) so aint illegal. I still wouldn't do it in an Astro.

KISS? It is simpler and cheaper to put in higher compression pistons than to put FI on an engine if the sole intention is more power.

The Robinson website? He would say that wouldn't he. Lawyers can read too.

I wonder if the carb issue is one of the reasons we hear rumours about the cessation of R22 production. i.e cheaper to axe it than update it - and more profitable to produce injected Raven2s without the risk of litigation from icing victims and their families.

Incidently, Lycomings solution to hot and high is to turbocharge.

See the excellent Lycoming Flyer articles on their website.

HSHair.
Why could you not put FI on a R22?. Have you checked. Have a look at a HIO360C1A or C1B.

Is the obstacle engineering or certification and cost?

Quote

But educating pilots to follow a well-worn, effective procedure is easy.

Yeah Right. Thats why this is the first R22 carb icing incident ever.


(sarcasm - not mud!)

[Bravo73]

Yep, Gaseous knows everything. Apparently.

Does leaning appear in the limitations section of the POH? Unfortunately, I don't have a copy of the POH in front of me and I won't for the next couple of weeks as I'll be out of the country. Watch this space.

The KISS was in reference to my explanation (and thinking) rather than engine design. I haven't got an engineering background but higher compression pistons implies to me greater pressures in the cylinders. This, in turn, would require either a more substantial block to withstand these pressures (and hence more weight) or reduced reliability and higher maintenance requirements. Both of which are contrary to Robinson's design ethos. I, of course, stand to be corrected.

See the excellent Lycoming Flyer articles on their website. Have you got a link?

Incidently, Lycomings solution to hot and high is to turbocharge. Are you sure? My understanding (once again, I refer you to the last 'S' of KISS) is that turbocharging is still susceptible to a loss of performance with altitude. To avoid this, you've got to look at supercharging. Which is expensive, heavy and requires even more maintenance. (All contrary to Robinson's design ethos).

But anyway, let me sum up your argument if I may be so bold. In order to avoid carb icing and the associated problems, Robinson introduced the fuel injected Raven2. According to your argument, the ancillary benefits are increased power, altitude performance, payload, speed etc etc. And this was all part of some conspiracy to avoid litigation from icing victims and their families. Right?

Well, if that was so, WHY IS THE CARBURETTED RAVEN1 STILL AVAILABLE FOR SALE?????


And if I may also answer one of your points to headsethair:
But educating pilots to follow a well-worn, effective procedure is easy. Yeah Right. Thats why this is the first R22 carb icing incident ever. Well, unfortunately, there are still a lot of stupid/forgetful people flying helicopters. :sad:


Fly safe,

B73

[212man]

So, hands up those that think injected engines don't suffer from icing! I think you just substitute the words 'carb icing' for 'intake icing' (albeit without the refrigeration effects).

[Gaseous]

B73. Enjoy your trip abroad.

I try to know about what I write.

Quote
"I haven't got an engineering background but higher compression pistons implies to me greater pressures in the cylinders. This, in turn, would require either a more substantial block to withstand these pressures---."

Er no, actually. Lycoming do make a variety of castings and forgings but basically they don't beef up the higher output engines by much in terms of weight. They do certainly alter them with modified oil systems, pistons, bearings and different ancillaries but the big lumps are basically the same. I seem to recall that since the crank fracturing episode a few years ago all 540s now use the strongest crankshaft. Im sure someone will correct me if this is not so. If you're really interested I could dig up some weights for different output 360s & 540s.

quote:
or reduced reliability.
Whats the difference between taking more power by adding FI(if that is what gives more power - see below) or changing the valve timing. Both increase volumetric efficiency and in lay terms, cylinder pressures. If you take out more power by whatever means, there is a penalty whatever Robinsons design ethos is.

Incidently, Lycoming do not cite increased power as a reason for using injection. They suggest lack of icing and fuel economy.

quote:
"Have you got a link?"
have you got a search engine link on your PC? I'll assume not so I have done it for you.

Its at the bottom.

quote:
turbocharging is still susceptible to a loss of performance with altitude. To avoid this, you've got to look at supercharging:

Er no actually.
From Lycoming flyer Page 62

In simple terms, the turbocharger provides an air pump which allows us to supply the engine with dense air not only at sea level, but also when operating in the thin air at altitude.

In a standard atmosphere at 10000 ft you aint going to get more than 20 ish inches of MAP without forced aspiration. FI doesnt help this and is no better in this respect than a carburettor.

quote
WHY IS THE CARBURETTED RAVEN1 STILL AVAILABLE FOR SALE?????

For how long?

What I do know is that society is getting more litigous. Vapourisation carb ice is a known problem that can cause death. It is avoidable by changing to fuel injection. Will these 3 facts kill off carburettor equipped Robinsons?

That was the point of my original post.

Personally I would like to see an injection equipped R22. It would then continue to be the world beating aircraft it has been for the past 25 years. The rotary world would be poorer without it as costs for training will soar.

Quote:
According to your argument, the ancillary benefits are increased power, altitude performance, payload, speed etc etc.

No, because none of these are as a result of simply adding FI according to Lycoming. The benefit is better mixture distribution giving better economy and no vapourisation icing. The 540 in a Raven2 must have more tweaks than just FI to get significantly more power.

Conspiracy?
No. I see it as sensible business practice to eliminate known risk where possible by product improvement. Robinson are a reputable company and I would expect no less from them.

Quote:
Well, unfortunately, there are still a lot of stupid/forgetful people flying helicopters.

Yes and I'm one of them. Thats one reason I bought a fuel injected helicopter.

212 man. True.

According to Lycoming (PP48 of Flyer)

"In the case of fuel injection and pressure carburettors, it is the IFR type of flight condition which generally causes induction system icing. "

I agree, fly safe

Phil


Seriously, all users of Lycoming engines would benefit from reading their Flyer series. There is a lot of information on carb icing, maintainence, engine managment and a whole lot more besides. I have the original paper prints but its all available at:


http://www.lycoming.textron.com/main.jsp?bodyPage=support/publications/keyReprints/index.html

[headsethair]

Gaseous: adding FI to an R22 would have many problems - and I don't think anyone outside the Robinson factory has the qualification or experience to comment. Including me. I'm sure if you email Pat Cox or Frank, you'll get an answer.
But - cost, certification, weight, space are all on the menu I'm sure. The Raven II engine is very different from the I inside.

But it's this "automation" thing that gets me. If we were to follow your idea the whole way, we would have a fully-automatic helicopter which required nothing from the pilot other than, possibly, flight control input.

We have developed cars along these lines. Owners are coddled by technology - they don't need to scan instruments because there aren't any. They don't need to chnage gear, because they've got an auto box. They don't need to check any fluid levels because the car will tell them when it needs something. In safety, we've surrounded them with airbags and ABS.

Has this made motoring safer ? No. For some drivers it puts them into a "sitting room" environment and they stop paying attention. They get bored - so they fill their time making calls and listening to the ICE. They think they're bombproof with their safety devices - so they start to drive beyond the limit of their capabilities, thinking that the car will rescue them. People truly believe that airbags will save their life.

Transpose this to helicopters and lowtime PPLs and you have a recipe for disaster. Carb heat requirement means that a pilot has to do a regular instrument scan to check for the "yellow" arc. And he may spot something else going on. Additionally, awareness of carb heat requirements means that a whole string of information processes through the pilot's brain - OAT, MP, governor, aircraft performance. It keeps the mind on the job of flying.

I reinforce this argument with the CAA's argument on power failure. A battery must be capable of supplying the aircraft with full power for at least 10 minutes - because the CAA think thats how long it would take a PPL to spot the alternator fail light.

If all the instruments were simply reduced to an "on report" status, I'm not all certain that the cockpit would be a better place. (Yes - I know that's the way it's gone at the expensive end. And don't they all just love their FADECs and EFISs ? No.)

[Gaseous]

HS Hair
I suppose you think that the governor is a sissy device not for real pilots.
Take it off, chuck it away. That'll make those low timers work!

edit 1/2 hour later.

Sorry, a bit low that. However the point is valid . What is an acceptable degree of automation?
I happen to think carb heat is one task too many because it catches one out badly when under pressure. It has put a lot of aircraft into the ground over the years. I dont want self flying helicopters either.

Phil

[212man]

(Yes - I know that's the way it's gone at the expensive end. And don't they all just love their FADECs and EFISs ? No.)


Actually we do! (and the FMS too)

[headsethair]

212man "Actually we do!"

I don't think you are the elcted spokesperson for everyone. The HEMS unit I have contact with would dearly love to stuff their EFIS right up the ar5e(s) of the inventor(s).

Gaseous : "I suppose you think that the governor is a sissy device not for real pilots.
Take it off, chuck it away. That'll make those low timers work!"

I hear the sound of a foot being blown off. And it's not mine. The governor is a well known masker of engine malady. Some of the carb heat incidents have been made worse by the governor's ability to keep opening the throttle until there's no more. Of course, a pilot flying to the POH with a hand on the throttle would feel this happening.......but again, because there's a governor, they don't think they need to keep their hand on the throttle.

[slowrotor]

The report cited at the beginning of this thread stated "caused by carb ice after a descent from 2000ft to 1500ft"
I do not see how a carb venturi can be blocked with ice in a descent from 2000 to 1500. In less than a minute.
It takes time to accumulate ice, layer upon layer, then the power starts to go down.
Disclaimer: The comments here are MY opinion only, based on my experience and thoughts only.

I flew an O-320 lycoming powered Piper cherokee for years in Alaska without ever getting carb ice.
I quit using carb heat on descent. In fact the Piper PA-28-140 owners handbook states: "Carburetor heat should not be applied unless there is an indication of carburetor icing, since the use of carburetor heat causes a reduction in power which may be critical in case of a go-around. Full throttle operation with carburetor heat on is likely to cause detonation." (quoted from the Piper manual)

So how is this relavent to the R-22 you might be wondering.
The carb on the O-320 is bolted to the oil sump and therefor gets heated to some degree by conduction from the oil sump casting.
Why would the R-22 experience carb ice in one minute while the Piper with the same engine almost never does?
Maybe the engine fan on the R-22 cools the carb more than the Piper. Just a thought.
Maybe a little more heat on the carb casting would be an alternate remedy, rather than conversion to injection. Heating the carb casting(instead of the air) does not cause detonation.

So in conclusion, I do not see how a R-22 could experience carb ice in less than 10 minutes as stated, and if it did, then the carb needs to be heated continuously to prevent further problems. Application of carb heat after the fact may not help in time and it certainly is a distraction from flying in a most stressful situation just before impact. Even for a well trained pilot.

slow

[ShyTorque]

The likely reason carb ice doesn't form as quickly in Alaska is down to low relative humidity and temperature giving a lower overall water content in the air. It's possibly not valid to compare rates of ice accretion in dry arctic air with much wetter, warmer air of temperate climates.

Carb heat is best used as a preventative measure because the process of clearing intake / carb ice is likely to cause the power situation to get worse before it gets better, due to the ice melting, disturbing the airflow in the intake and then going through the engine.

Certainly the aircraft I used to instruct on was fuel injected but had an induction air heater. As far as the go-around was concerned, to avoid detonation, RAF teaching was the phrase "RPM - MAX (CS prop), Mixture - FULLY RICH, Carb Heat - COLD".

Bring on the Diesel engine - definitely no carb icing, mixture leaning or detonation problems then :ok:

[Flingwing207]

Personally I would like to see an injection equipped R22. It would then continue to be the world beating aircraft it has been for the past 25 years. The rotary world would be poorer without it as costs for training will soar.

Actually, for operators who fly their aircraft a lot, at 2200 hours, the 300CBi and the R22 are pretty much even in total cost per hour, and at 4400 hours the 300CBi is cheaper. The only way to make the R22 noticably cheaper to fly is to use Pathfinder insurance, and with that, you get what you pay for (i.e. it's great insurance until you actually USE it).

The mandatory overhaul is much more expensive than the quoted cost - you lose the use of the aircraft for up to three months, you may have to ship it across the country, and there is almost always things needing to be done which aren't included in the "list price".

There's no question that the R22 introduced the concept of (relatively) low-cost helicopter flight and flight training. However, Schweizer has more than caught up. Frank Robinson is glad indeed that they build 'em slowly in Elmira, because I suspect you'll see CBi's replacing a lot of timed-out R22's.

[Bravo73]

Well Gaseous/Phil, you don't really seem to be open to a reasoned discussion so I'll try one more time. Hopefully it'll be the last.

Firstly, have you got a search engine link on your PC? I'll assume not so I have done it for you. Well, strangely enough, I am aware that you're able to search for things on the internet. It's just that it's recognised good practice and common courtesy to include any references within your text. (Incidentally, I found the Lycoming website (using something called Google) and tried using Lycoming's own search function to find 'Flyer'. It came up blank).

But thanks for the pointer to the Flyer articles. When I've got a spare week or two, I'll plough through them. But I did have a quick look through a couple of them and there didn't seem to be any reference or mention of helicopters. Hmmm, I wonder if that's important...:hmm:

quote WHY IS THE CARBURETTED RAVEN1 STILL AVAILABLE FOR SALE????? For how long? (Blimey. Here we go again with the conspiracy theories.) For as long as Frank's customers want to buy them, I imagine...

Will these 3 facts kill off carburettor equipped Robinsons? Who really knows (apart from FR)? But I can tell you that the Raven2 is offered IN ADDITION to the Raven1. If there was some grand plan to get rid of carburetted machines, then the Raven2 would've replaced the Raven1 (in the same way that the R22B replaced the A, HP etc). But there isn't, so it hasn't.

For the last time, the Raven2 was produced for hot and/or high operations. IN ADDITION TO THE RAVEN1. (Sheesh, you've got me sounding like a Robinson salesman. I'm not even Robinson's biggest fan).

Like I've been saying all along, I'm by no means an expert on this subject but as I alluded to in my original post, it's amazing what you learn (and what myths are 'debunked') on the Robinson Safety Course.

If you haven't already (but I suspect that you have), can I suggest that you attend the course? If you have, then maybe a refresher might be in order (unless of course you're worried that it might just be a load of Robinson corporate propaganda/brainwashing/the lawyers are going to get us blah blah blah...)


Over and out,

B73



P.S. Out of interest Phil, are you a successful businessman (possibly self-made), PPL, owns his own aircraft which is kept at home? Because you seem to be exhibiting some characteristics of a particularly dangerous subset of this 'breed'...

[helicopter-redeye]

The thing that will 'kill off' the Raven I (as we know it) will be a move by the oil industry to kill off 100LL.

Jet fuel in lower cost (now) and the rise of the JetA1 eating internal combustion engine is just beginning.

Whaddyathink to the 12yr/ 2200hr rebuild gradually re-engining the 44 fleet with a diesel buring Jet A1.

No carb there, either ....

:8

[Gaseous]

B73
Blimey, who's rattled now.

Your reasoned discussion was full of technical inaccuracies which is why I suggested Lycoming as a source of accurate information on the subject. You dont need an in depth knowledge of your engine and engine operating principles to fly but it is my opinion that it helps. It sure helps when engaging in technical discussion.

Search engine? Sorry, I take your point.

Conspiracy? No. dealt with that one.

I didn't start the story that the R22 may well be killed off. I think I read it first in Pat Malones article when he interviewed Frank Robinson in the AOPA magazine. Frank Robinson takes safety very seriously and he has said before that accidents affect him deeply. It is with this in mind that I wondered if yet another carb icing incident would affect his decision to continue production or not, or for how long. Availability is not up to the customer who wants to buy a carb equipped heli. It is up to Robinson if he is prepared to sell them.

Yourself and Headsethair have argued eloquently for the retention of the status quo (carb). I happen to think its time has passed. Can we agree to differ with good grace?

The reasons for putting injection on the Raven2.

It has the same continuous rating as an Astro of 205 BHP . The 5 Minute rating has been increased to 245 BHP from 225
The Original Astro engine was derated from 260 BHP so technically only needed less derating to give the same performance as a Raven 2 engine. Hot and High? Fuel injection really does not help. Rating the engine at 245BHP does, but the limit of density altitude is the same for carb and FI. The Raven2 engine may have beefed up bearing surfaces to keep Franks reliability reputation and it may be more efficient, but FI is not required to get 245BHP out of an O540. Bear in mind that the original carb Astro engine is rated at 260 BHP by Lycoming.

Robinson may market it as having greater altitude performance but it aint the fuel injection system that allows that. Its the extra 20 BHP. Their website does not explain that. If injection is not required for the extra power- which it is not, and it doesn't help hot and high - which it doesn't, and leaning is not recommended - which it isnt, there aren't too many reasons left to use it.
In fact, only two. Fuel economy and icing resistance. These are not my opinions. They are technical facts.

Dangerous, moi? Funnily enough I think of myself as very safety aware. I try to learn as much as possible about what I do cos I think this helps reduce risks.

Lighten up, we're on the same side. I didn't mean to p*ss you off. (but I cant resist just a bit of sarcasm now and again)

Phil

Helicopter redeye
Diesel, yep, like it. But I dont think it will affect my flying career. (which is likely to be short and messy according to B73)

Flingwing 207

It is some time since I did my training but 300 and Enstrom was significantly more expensive than R22 here in the UK. I wonder if they now cost the same if costs have equalised?

Tch, there I go again, wondering. Look at the crap that gets me into.
:}

[VeeAny]

Just in case anyone actually wants to see it flyer is available at

http://www.lycoming.textron.com/main.jsp?bodyPage=/support/publications/keyReprints/index.html

Not immediately obvious but several flyer articles on the first page of the lycoming search results page if you search for flyer !

Its well worth a read although sifting through it for heli specific bits can take time.

Gaseous sorry, just noticed you did post a link to this earlier, It just got lost in the argument while I was trying to keep up.

For what its worth, I think you should agree to differ, there is no right answer, just like there is no H300 / R22 winner. Both sides of the argument have some validity. Horses for courses and not all the courses are the same !!!

Safety is all that matters at the end of the day, how we actually achieve that is another matter.

V.

[Bravo73]

Oh my god. I can't believe that I'm biting again. But seeing as this will effectively be recorded for posterity, there are a number of inaccuracies and mistruths that need to be corrected (again). (Apologies to everyone else for having to drag this out slightly further. It's beginning to feel like pulling teeth...)

Right first things first. You dont need an in depth knowledge of your engine and engine operating principles to fly but it is my opinion that it helps. I accept that my technical knowledge isn't as in depth as it could be on this subject (as I've been saying all along with the references to 'I'm no expert'). I now certainly know more about the internal machinations of a Lycoming engine than I did at the beginning of this 'discussion'. And I've got you to thank for that, Gaseous. However, I still stand by my original (and in hindsight, grossly over-simplified) assertion that 'by and large, a FI version of the SAME engine will produce more power than the carb version'. (It certainly applies to auto engines). However, we now know that Fuel Injection is only one very small piece of that puzzle.

I didn't start the story that the R22 may well be killed off. I know. Neither did I. Heck, I haven't even mentioned the R22. (Ooops, there was the one brief mention of the R22B replacing the A and HP. Nothing to do with their use of carburettors though). All I did was try to explain why the Raven2 uses Fuel Injection.

Yourself and Headsethair have argued eloquently for the retention of the status quo (carb). Are you sure? Are you really sure? Can I suggest that you go back and read my posts again. Properly this time. Like I've already said, all I was trying to do was to explain why the Raven2 uses Fuel Injection. It seems that you and headsethair have been running with this pro/anti carb debate.

Now, if you'd asked me what I felt about this personally, then I would've told you that I'd quite happily see all carburettors replaced with injectors. But you didn't so you presumed that I was 'pro-carb'. And I can even give you a real world example - I much prefered flying the CBi version rather than the CB model of S300. The extra power (whether real or perceived) and the use of fuel injection were only a couple of reasons. So you were more right than you realised when you said Lighten up, we're on the same side.

(And before you accuse me of some sudden New Labour-esque U-turn, go back and read my posts again. Maybe you'll even notice that I haven't re-edited any of them after the initial posting, even if I did change my mind).

A final thought regarding carb heat - have you actually considered that there are plenty of places on this planet where carb ice is never, or at least very rarely ever, a problem? (Anywhere with very low relative humidity for starters such as the outback of Oz or even maybe somewhere like Torrance, California....:hmm: ) No carb ice obviously = no need for carb heat. Why, otherwise, is there the carb heat locking mechanism on R22BIIs? (And no, this is not some pro-carb argument. Just an appreciation that we don't all live in cold and wet P******, Lancashire).

And do I think you're Dangerous? No, probably not. You seem to be more concerned about the details than most private owners that I've come across. But once again, you mis-interpreted what I was alluding to. The characteristics that I was talking about were being stubborn, obstinate and having a 'I'm always right' attitude, even in the face of irrefutable evidence. These characteristics alone aren't necessarily dangerous but can be a pointer to more worrying practices. I just hope that you don't take this attitude with you into the cockpit...

You also said that I try to learn as much as possible about what I do cos I think this helps reduce risks. Quite right. But the photo of your site looks pretty tight. Is this the level of risk that you're willing to accept? Or to put it another way, would a commercial operator expose themselves to a similar level of risk in a single engine machine? (These are rhetorical questions. I'm not expecting an answer. Actually, I implore you not to answer so that this thread can die the death that it deserves). (And apologies in advance if the photo doesn't show the football field size area that you might use for approaches and departures. Still quite tight for parking though).

(which is likely to be short and messy according to B73) Bit of a low blow that one. I genuinely don't want Mr AAIB to be telling me about BDKD in one of his reports. And I don't think that he will do in all honesty. But there's always room for more refresher training.

And that, I hope, is my last word on the subject!


Regards,

B73



PS I've ranked this whole thread as '1 star ...Worst' in an effort to discourage people from wasting their time reading it.

[helicopter-redeye]

You must be having a really rotton day 73.

Right about the carb heat in Oz. Why I flew out of Bankstown, carb heat was never rated as a hazard by JF (Australia does not have clouds, except during the bushfires...)

;)

[Flingwing207]

Hi Bravo73,

According to Lycoming, the HIO-360G1A in the 300CBi produces the same amount of power as the HO-360C1A fitted to the 300CB. If you look at the respective POH's for the helicopters, you will see the same performance charts - the only difference is that the CBi does not have a "mixture leaned" page.

I have never flown a CBi with more than 450 hours on it, and I have never flown a CB with less than 1,800 hours on it, so I cannot make a subjective comparison. Our CBi certainly performs better than our CB, but it weighs 100 lbs less, and is three years and 1400 hours newer.

Aircraft FI systems are not like current automotive FI systems, they are like FI systems fitted to cars in the 1960's - continuous flow, no electronics, and in the CBi, metering via a mechanical mass-airflow system. An aircraft like the Enstrom 280 or the 300C has pilot-controlled mixture which is set using EGT as a gauge.

You are likely to get better performance out of a FI engine, as the fuel metering is usually more precise - however, I suspect that similarly equipped and equally fresh, a properly leaned CB would perform very close to a CBi (even at sea level, the CB is usually running a bit too rich - try the leaning procedure from the POH some time). The R22 would benefit from the FI system fitted to the CBi, as currently there is no leaning procedure for the R22, nor is it fitted with a vernier knob - once you are operating above 3,000' MSL, that O-360 is definitely running rich with the mixture knob fully in.

Remember that the bottom line on engine power is the amount of fuel the engine can burn at the optimum fuel/air ratio. As long as the induction system is capable of flowing air freely, and the fuel system is capable of fully atomizing the proper amount of fuel, it doesn't matter how it gets to the cylinders.

It's easier to efficiently get the optimum mixture to all the cylinders with FI, so it's easier to get the engine to deliver its rated power. However, all other things being equal, you are talking about a relatively small gain. Since the R22 already has "too much" engine power, it would only gain a little performance at high MSL altitudes - which could also be realized by fittting it with a proper mixture control and devising a leaning procedure.

However, for a training helicopter, the FI in the CBi is a great safety feature - it only takes one actual case of carb ice to make anyone a believer!:}

[Head Turner]

How I hate those who pull their baseball caps hard down on their heads and say that IF the training is correct then the student will never make a mistake 'cause he/she is trained to do the correct thing. OK that works BUT why the hell cant the rotary winged technocrates do some proper reasoning and come up with a modification that will not require the pilot to FORGET.
Yesterday I was walking and was passed by two horses pulling a small carrage. Who was the bright spark that designed this modern form of transport?

It's call PROGRESS and that means seening that there is a BETTER way of building things.

So R22 are modern helicopters! Rubbish, they are ancient and frightenly under engineered to do the job that they were supposed to have been designed for. Surely safe flight characteristics encompassed engine systems and Carbs are unacceptable under the safe flight characteristics heading.

No amount of special briefing seminars and courses will replace good design.

I'll duck now as the air will be filled by the Robbo supporters club defending their corner, but they have to or they would be out of work!

Ducking for cover.

[headsethair]

HeadT : "Rubbish, they are ancient and frightenly under engineered to do the job that they were supposed to have been designed for."

It was going well until you wrote that. What a statement - no factual foundation whatsoever. And if I was FR I'd track down your IP address and whip you with a writ.

In what way can you prove that they are "under engineered to do the job that they were supposed to have been designed for." ??

You're shooting from the hip with your keyboard.

The R22 was designed as a personal transport helicopter and has a certification for that purpose. (Most of the accidents happen in training flights with an instructor onboard.....) The design is based in the mid-70s - but that's the case throughout aviation.

If there's a problem it's with the certifying authorities who make it prohibitively expensive to upgrade aircraft.

Presumably A-B would love to make a new Jetranger with FADEC etc - but they can't without putting up the price considerably due to re-certification.

I wouldn't be at all surprised in RHC are looking to replace the R22 with another 2-seat trainer using a newer engine, some EFIS and all-round better performance. But it won't be anything like the price of the 22.

[Gaseous]

Sorry I didn't get back sooner. Ive been on my hols. B73, if you're still reading this, sorry for getting back at all.

In response to B73s reasoning for Robinson adopting FI for the Raven 2, I attach a section of Lycomings article on the choice of carb or FI. Make your own mind up.

Since the fuel injector is more complex and expensive than a carburetor, why should it be considered? Because the fuel injector has its own set of advantages which in some cases are worth the additional cost.

First, the fuel injector causes air and fuel to be mixed at the cylinder intake port. Therefore, the refrigeration type icing that occurs in a carburetor venturi when fuel vaporizes in moist air cannot happen when a fuel injector is used for fuel metering. Many pilots consider this to be a significant advantage.

The primary characteristic of the fuel injector is improved fuel distribution to each cylinder. This feature reduces the possibility of one cylinder operating at a very lean air/fuel mixture while another may be operating near the rich end of the mixture scale. The improved distribution allows leaning that results in slightly lower overall fuel consumption. This is of particular value in the higher horsepower engines where saving a small percentage of the fuel being burned may result in a significant dollar savings.

. :

Full article at

http://www.lycoming.textron.com/main.jsp?bodyPage=support/publications/keyReprints/general/fuelInjector.html

I believe this supports what I wrote in my earlier posts.

Headturner, I have to agree with headsethair about the R22, in that it is well suited to its purpose and is a remarkable piece of engineering. It does have the flaw which led to this thread in the first place but the villain is not Robinson. It is the crappy regulation and certification requirements in this industry which stifles progress. If this wasnt the case then I'm sure you could buy an injected R22 if you choose to live in wet Lancashire.

Danger, opinion coming up.

I think that the regulatory system actually causes some of the accidents it is meant to prevent.

Finally, as the size of my LZ has been questioned this is another view of my landing site, as taken from where my Enstrom is parked. Rather bigger than a football pitch.

http://myweb.tiscali.co.uk/avenuedentistry/balloon.jpg


edited for spelling/typing only