AS350 Astar/Squirrel

[Auscan]

Good Morning All,

Just wondering if anyone out there knew of any good low time AS350B2 or B3's for sale. Looking to purchase ASAP. Thanks in advance.

Cheers

[Talk Turn]

Sorry Auscan not much help to you but looking for a B2 in the UK and looked in all the usual places.

[CyclicRick]

Try ringing +49 2382 82082. they have just bought a B3 with good hours and I KNOW he always likes to sell his helicopters, nearly got a 212 rating until he sold them all from under me...drat!
Don't buy it too quick though, I might still get to fly it :E

Sorry, slip of the keyboard it\'s a B2 NOT a B3

Rick

[chopperdr]

auscan: pm me if your interested in a b3 in north america
dr

[Cyclic Hotline]

http://animalpicturesarchive.com/animal/Animated_GIF/Squirrel/sqtiny.gif

[nigelh]

Does anyone have any information about the Arriel 1b engines in the AS350 BA. Apparrently a small piece of metal has fallen off the shroud on module 2 and has gone through the whole engine causing total destruction......engine write off 240,000Euros !!
To make it better , this probably happened 2 years ago and it has been flying around on public transport all this time....like a time bomb. Turbomeca deny there is a design problem but how many engines have had this happen and how many crashes ??? Any info really appreciated.

[SawThe Light]

Arriel 1B huh? Now that seems to be one damned fine engine if it has tolerated FOD some two years back that has apparently taken out the interior of the engine, yet no-one has noticed it.

No vibes? No power loss? Just kept on haulin' a*s.

Doesn't seem that there's any design problem if the chain of events are as written.

I saw a copy of the IFSR for the Arriel a few years back and it was impressive for its reliability. If I recall correctly I could expect an in-flight shut down from all causes (fuel exhaustion, false indications, minor fault precautionary included) each 100,000 or so hours and a catastrophic type engine event each 500,000 or so flight hours.

Going on the data I saw it seemed that I could expect the thing to go BANG once each couple of thousand years at the rate of effort I was doing. Then again, it could be tomorrow, couldn't it?

I still feel real comfortable with them though.

(O.K you guys, I know it's French)

STL

[Bell_Flyer]

Does anyone have experience on a good replacement unit for the AS350 airconditioner? Specifically, the electric blower motors are hideously expensive for what they represent and they seem to only have a short life.

Is there a modification that can be made to a Squirrel to make the air vents as good as the Bell air vents (on the 206/407 models).

Many thanks.
:cool:

[widgeon]

What system is fitted ? Aero AIre , or Integated ( jack keen version).

http://www.maverickhelicopter.com/

If you talk to these guys I think they have had experience with both versions.

http://www.platinumaviation.com/
now sell the integrated flight system.

http://www.aeroaire.com/ is now run by enviro systems.

I think the french factory installed system was based on Aero aire .

[Phoenix Rising]

Integrated Flight Systems, owned by Platinum Aviation are the best in the business for air con systems for the AS350. Give them a call and talk to owner Leroy Aday.

www.integratedflightsys.com

and

www.platinumaviation.com

Cheers

Ned

[Bell_Flyer]

Thanks Widgeon and Phoenix. What the Squirrel needs is better air vents like the Bells and then there's no need for airconditioning (unless in extremes of temps)!

rgds

[Jack Carson]

Has anyone experienced either abnormally high cruise fuel consumption or problems with the accuracy of the fuel indicating system on the AS-350 B2 or B3?

[rotorboy]

There have been some problems and possible related accidents in regards to accuracy of fuel gauges in the older B2' and BA's. They had a float type fuel senseing sytem that would stick when it wore and got old. I believe there was a SB or an AD out on it. All the new A/C have a capacitance system and you can buy the kit for 11k to replace the old one.

The B3 sucks alot more gas than a b2, and the b2 more than the ba. Noticeably so.

RB

[Jack Carson]

Thank you for your rapid reply. This is a brand spanking new B2. The fuel consumption appears to be closer to a B3.

[Big Beres]

Having some time in both, here is my 2 cents worth.

180-190lts/hr or 30% per hour for the B2 and 220-230lts/hr for the B3.

Beer in mind that is just what I have experienced

[Dynamic Component]

Big Beres,

Not picking a fight, but 30% of 540Ltrs is 162Ltrs/hr.We burn about 168 Ltrs/Hr on our B2:}

[Devil 49]

Would appreciate a Eurocopter citation for securing the rotor.

I'm having a technical disagreement- one party is concerned about the starflex, the other with the blades and the effect of unrestrained flapping. Specific issue- The blades must be immobilized, braced and tied above "x" windspeed (40 knots?)? Up to that point, autorotation is the only issue?

I believe this is addressed in the maintenance manual.

[Lama Bear]

10% = 20 minutes
10% = 40 miles
10% = 100 pounds

The higher you are the better these numbers. But for anything between 3,000 ft and 9,000 ft thes numbers have been very constant fo me.

[Droopy]

This is purely from memory, and I'm assuming the 350 limits are the same as the 355; beyond 20kts tie downs required, beyond 60kts hangarage is recommended. I could get you a maintenance manual reference in a few days if no-one else comes up with it.

[Rotorbee]

I remember having several AS355 in for an overhaul and all the blades where scraped, because they where never tied down. I can only suggest to tie them down all the time.

[Devil 49]

Droopy, the maintenance manual citation is exactly what I'm looking for- if and when it's convenient, I'd appreciate it. The aircraft subject to this disagreement is a B2, same head and blades as a 355.

Rotorbee- It's an EMS A/C, so time is important, the tie-down kit we're using is horrible and prompted the discussion. Specifics motivating change and supporting documents...

[4Rvibes]

I have never split a starfex head using tie-downs. Here is the method taught in Donouworth and Marsaille.

Tie the main rotor down at it's median point..ie leave it where it is when no wind is blowing, let it jerk all over the place all night, check it in the morning before you fly, 99 percent of the time it will be worth flying.

If you tie it down FFS don't drop it two inches as you might on a different head you will bust that starflex and that equals an expensive repair.

Para 2 applies to factory courses as taught on As350, As355, as365 and EC135.

Talk to the guys who design and build the things if you don't believe me.

I have been fixing these types for over 20 years,some just happen (no wind, no flex), some are engineer/pilot/handler lack of knowledge), most are avoidable.

Take care

4R

[Giovanni Cento Nove]

In my experience, with the B model STA 1000 cracks occurred due to not tying the blades down in even the slightest amount of wind. The cracks are on the lower side from compression.

The 355 grey blades tend to crack on the upper side at about mid point. Why - who knows.

IMHO Starflex damage comes from droop stop pounding on shutdown with the cyclic not centred.

Not a definitive answer, just personal experience.

[rotorspeed]

My experience over a lot of hours is 180L/hr on a straight 350B, (ie not B2/3) 235L/hr on the 355N at S/L, 210L/hr 5000ft, all at fast cruise.

[Jack Carson]

I thank one and all for your responses. I did a fuel consumption check of the subject aircraft and found that it agrees with your inputs. It appears as if we had a pilot experience issue. Your responses will help with our training.

[MBJ]

Jack

I gave myself a surprise on a long ferry flight in a B2. Experience was an issue then as well since I had 1:30 on type when I left UK. Cruising at 1000ft through Europe was giving me 35-36% per hour (instead of the 30% I had been expecting) and an endurance of 2:35 to chicken fuel. Later, through Egypt I was up at 11,000ft and it was around 24% per hour and I was staying up for 3:25. Subsequently I did some graphs for my own use in Ethiopia which was very helpful.

The fuel consumption presentation in the flight manual was not very useful on the subject.

Great aircraft though, I wish I had one now!

[[email protected]]

Over the 12 years of operating the 350, we have had great success using blade stands when ever the helicopter is on the ground, in a hanger or otherwise (under all wind conditions). The blade stand consists of an adjustable aluminium pole with a blade cradle which slides over the end of the blade, and then is adjusted to unload the starflex whilst supporting the blade at the end in a lightly loaded configuration.

We started doing this religiously following some blade and starflex issues and we have never had a single problem since (over 10 years). Our starflexes always go to SLL and the first problem we suffer with the baldes shows up in paint erosion, no delaminating of leading edges or anything else. It works extremely well.

Hope this helps.

[Jack Carson]

MJB,
I believe that we experienced the same situation that you described. The long leg was flown at 1000MSL. If he had climbed to 7K or 8K, he would have had plenty of fuel. You are right the AS 350 is a sweet aircraft to fly. That comes from an old S-76 pilot.
Thanks Again
Jack

[IHL]

The Transportation Safety Board of Canada recently released the report of a fatal AS350 accident.

Report:

From the report:...
3.1 Findings as to Causes and Contributing Factors

After experiencing a hydraulic system failure, the helicopter departed controlled flight and crashed while manoeuvring for landing. The reason for the departure from controlled flight could not be determined.


It is likely that the hydraulic pump drive belt failed in flight, precipitating the hydraulic failure.


It is likely that the hydraulic circuit breaker was in the tripped position in flight, rendering the hydraulic CUTOFF and HYD TEST switches inoperative. This would result in hydraulic pressure from the main-rotor servos being depleted asymmetrically

Report (http://www.tsb.gc.ca/en/reports/air/2003/A03O0012/A03O0012.asp) http://www.tsb.gc.ca/en/reports/air/2003/A03O0012/A03O0012.asp

[Outwest]

I agree completely with 407D, don't ever think this is somthing that will give you warning. I consider myself VERY lucky to be able to describe when I first experienced this situation. I was in cruise flight, no pax, looking for an oil rig in northern BC (this was 1980, before GPS) I got down low over the trees to see if I could see the derrick over the tops, there it was a mile away. I stayed low and once over the rig started a what I would not call an agressive cyclic climb to the right. The cyclic froze in my hand, the next few moments seemed like an eternity, really maybe 2 or 3 seconds but something I will never forget.
Don't get me wrong, I love the Astar, one of the nicest a/c I have ever flown, but as in all a/c treat it with respect.

[FlyingHead]

Hi gents, the freezing control problem with the Astar, from what I have been teach during my initial, can be created by negative G because of the pump. I have experienced it in that situation and it is not really confortable situation.
Cheers
FH

[Brian Abraham]

An interesting discussion. Our company employed a few senior ex army Blackhawk instructors and jack stall was a frequent topic of theirs and related a number of accidents which were a result of the phenomema. Until their employment I had never heard of the term. They also told of how it was demonstrated to pilots under going conversion onto the Blackhawk. In light of your comment Nick it would seem that an educational program may be in order.

Brian

[What Red Line?]

As you say Brian, very interesting indeed.

This is new to me and I suspect most others. Didn't think it happened with Blackhawks. Any chance of it with the S92?

Were there Blackhawk jack-stall accidents in Australia? I seem to recall reading that a couple of Aus BH's had a night mid-air but haven't heard of other accidents down there.

[SASless]

What Red Line,

From an earlier post in this thread by Nick Lappos, now ex-Sikorsky....but still somewhat knowledgeable about the issue under discussion......

"I know that Sikorsky would deem that behavior unacceptable, and require stronger servos (and swashplates, if the parts could be bent in maneuver!) I believe it is a governing philosophy of US manufacturers (certianly Sikorsky) that the controls must not lock up and the rotating control system not be damaged by virtually any maneuver the pilot can conceive, and it is a strong requirement in US Military regulations. I am also quite certain that the FAA would not approve such behavior, absent the bi-lateral agreements that make it necessary to overlook some things from foreign certifications."


Now we hear that this did occur in some Australian BlackHawks? Or is there some question as to whether it did for sure happen? Or what actually happened? I cannot imagine the Oz Blackhawks are any different than the original marks in that regard anyway.

[NickLappos]

Brian Abraham said:
"An interesting discussion. Our company employed a few senior ex army Blackhawk instructors and jack stall was a frequent topic of theirs and related a number of accidents which were a result of the phenomema. Until their employment I had never heard of the term. They also told of how it was demonstrated to pilots under going conversion onto the Blackhawk. In light of your comment Nick it would seem that an educational program may be in order."

OK, Brian. Let the education begin here. There is NO Jack stall in any Black Hawk, nor in any modern Sikorsky type. There are NO accidents caused by, related to or involving jack stall.

Maybe you could have those guys who you think said this log in and share their thoughts, I would like to discuss it with them and clear up the misunderstanding.

[Steve76]

Nick, the guys Brian is mentioning learn to fly in Astars through the Australian military. I think there has just been a misunderstanding.

While on this subject: Does anyone remember the accident in the US where the Astar on a news job ended up crashing onto a rooftop with all of us trying to decide whether it was hydraulics or a tail rotor failure?
We all watched the footage and I was today just thinking if there had been a resolution to that accident.

[Brian Abraham]

Nick and Steve,
The individuals have since left and returned to the army but they were definately talking about the 'Hawk. Would seem perhaps to be one of those urban myths that develops some where and has a life of its own although they did talk of demonstrating it to students. Will try and contact one of them and see if they will post.

Brian

Nick,
An after thought. The guys mentioned read the list so your emphatic reply should give them the message.

Brian

[Bomber ARIS]

Steve76,

I had heard rumour that the A-Star news copter was subject to the pilot mistakenly selecting the hyd test button rather than the collective mounted switch he had hoped for.

I stress that this is rumour. I have no AS350 time so am unfamiliar with the exact hyd set up on this machine, but seem to recall other A-Star incidents of a similar nature due to poor ergonomics by Eurocopter.

[SawThe Light]

C'mon you guys, don't get too deep into this thing. Leave it as one of those mysterious things that can still be used as the probable cause of those un-explainable accidents that happen from time to time. You know the story, "Musta been jack stall, couldn'ta been anything else. He's too good a pilot".

On the other hand, if someone can provide real evidence that boosted flight controls commomly lock up while the particular type is being operated within its certificated flight envelope, then we need to ask some really serious question to the various airworthiness authorities who have certificated it. I would think that the FAA for example would cancel that ship's type cert in a heart-beat if this were the case.

'nuff said.


STL

[Steve76]

Brian; that's interesting. I will be enlightning to hear what they have to say if they bother to post. I think Nicks position is pretty clear and I understand the S70 variants to have similar hydraulic pressure to the S76, (I think it's the S92 with 5000 psi?) so a jackstall situ seems surprising. Hey! next time you are at FSI, see if they will let you have a pole of the Blackhawk sim... that will put a grin on your face :)

STL - read this thread from start to finish and then re-think your post. See the light...

[Devil 49]

As to accidently engaging the hydraulic test switch:
Boost disabled, controls stiff;
Caution panel segment illuminates;
The horn blasts.

I find it hard to believe that disabling the control boost inadvertently would be more than a transient problem. The aircraft would tell you in many different ways, that the button you'd just pushed wasn't the landing light.

Had an occurence of servo transparency yesterday- cruise flight, vulture sails into path, left bank and descent, resistance to roll back to horizontal. This was not an aggressive maneuver. It's so common I barely recall the circumstances.

[NickLappos]

Devil,

Were that "engine transparency" the howls would start. That it is "servo transparency" makes it ok!

I think it is properly labeled "servo inadequacy".

[SASless]

Earlier in this thread I posed the question...."Why would I want to fly an aircraft that had this problem?" I also asked how the FAA granted an airworthiness certificate knowing this occurs?

Nick, you said you did not think the FAA would go for such a thing as I recall.

Does that mean the FAA is unaware of this event in the 350 series and thus the aircraft can continue flying?

What happens if someone complains to the FAA about this....will they jerk the C of A of all the 350's in the USA?

[Shawn Coyle]

Part of the problems with servo transparency is the bilateral airworthiness agreements under which the helicopter was originally permitted to enter the country.
The helicopter was certified originally in France, and because of a bilateral agreement between France and US, if it is certified in France, then it is accepted with minimal fuss in the US for Part 27 helicopters. For part 29 machines, the process is a bit more rigorous but not much different.
The French seemed to have few problems with the servo transparency in certification, and the US was relatively powerless to not accept it (or they may not have seen this during the FAA familiarization flights).
Things like this that are discovered later in life become more a political issue than a technical issue - and political issues are nearly impossible to solve any time.
As an example of this - there is no such thing as night VFR in Europe for single engine aircraft. So the EC-120 didn't have much beyond a single wander light to light the instrument panel when it was first certified. That was caught in the approval for use in North America (both FAA and Transport Canada caught the problem) and the EC-120 had to have the instrument panel lighting changed significantly for N. American sales.

[paco]

That must have been what happened with the electrics, then.

Phil

[IHL]

SawThe Light: have a read of the accident report I posted, link is on page 4 of this topic.

[SawThe Light]

Steve76 & IHL

Took your collective advice and re-read the entire thread, my post and the TC report.

What I see is that the post is still headed "Astar jack stall" .

In my post (slightly tongue in cheek if you didn't note) I made an apparently simple observation that "if someone can provide real evidence that boosted flight controls commomly lock up while the particular type is being operated within its certificated flight envelope, then we need to ask some really serious question to the various airworthiness authorities who have certificated it." I also went on to say that the regulatory authorities would take appropriate action if someone could provide real evidence etc etc.

What's difficult to understand about that? Have you any real evidence that this has occurred while operating within the certificated flight envelope?

In the matter of the TC report here are a few notable points as follows:

- The hyd CB was likely out in flight and probably un-noticed by the crew

- The hyd belt apparently failed in flight

- The hyd test switch was activated

- The M/R accumulator pressures were less than 50% of normal pressure

- No other anomolies were noted in the hyd components

- Para 2-3 said in part "As a result of not slowing the helicopter to the recommended . . . . "

- The report said in part " The reason for departing controlled flight could not be determined. . .

Don't see anything anywhere relating to jack stall (The thread title).

STL

[sandy helmet]

I had heard rumour that the A-Star news copter was subject to the pilot mistakenly selecting the hyd test button rather than the collective mounted switch he had hoped for.

In subsequent interviews the pilot maintained that he had lost his tail rotor, or control. If you look closely at that crash you can see where he tried to fly it into vertical stab control, realised it wasn't happening, and deliberately flew it into the chimney to stop the whole thing in its tracks. A brave thing he did and lucky that it worked, seeing the built-up area he was over.

An AStar is quite controllable without hydraulics, and you can pick up, hover and land without them. I find it funny that there is so much criticism regarding this "servo transparency" issue as being
a failure of the French to build an adequate or safe machine, while the issue of LTE with certain Bell products is still ongoing. To be honest, I think I'd rather have jack stall than LTE any day. Until the perfect helicopter is built, there will be flaws, quirks, etc to be taken into consideration by those that fly them.

I think that the point here is that until as Nick says the problem is addressed by the manufacturer, there can be no substitute for knowledge and training.

Regarding the Limit light on the 355/365, as I understand it it is there primarily for when the machine is on the ground with no load on the head to alert to excessive cyclic displacement. You would have to be pretty severe in your maneouvring in flight to get that to light off.

[Devil 49]

The "Limit" light- at least on the 355- mirrors the servo transparency on the 350. It's not uncommon in flight.
The difference between the two situations is important. In a 350, you have inequality in control forces, and thus compromised control at an unexpected, unplanned and potentially dangerous time.
If you're in the 355, the same situation results in a light on the caution panel, and the controls remain fully effective. Hmm... so much for the blades stall and mechanical control issues....
The airframe differences between the two types are minimal beyond the power plants, electrics, and tankage. The biggest difference is the 355 has dual hydraulics and direct drive pumps. The vert stab differences probably aren't germaine.
My guess is that the servos and the hydraulics just aren't robust enough to overcome flight loads in the 350.

Regarding the hydraulic system circuit breaker- in 17 years I've only flown one (of dozens) that had CB's in place of the factory fit fuses. Remember that it requires electrical power to disable the boost...

[407 Driver]

Excellent dialouge Gents.

Here's a line from the report that may be of importance to the outcome...just as important as C/B's switches and procedures...


"There were good visual meteorological conditions at Mekatina, with clear skies, calm wind and a temperature of -30ºC.

The elastomerics tend not to be quite as "elastic" at minimum temps...giving much stiffer than normal control forces with out HYD assist.

Just my thoughts...

[NickLappos]

407,

The elastomers are not any stiffer while in flight, because the internal heating from the flexure is quite sufficient. In any case, the stiffness of the elastomer is a very tiny force compared to the stall forces from the blades as they produce high thrust.

The stiffness of the elastomers is high during warmup after cold soak, that is why many helos have warmup procedures for the rotorhead, and restrictions on the amount of flapping until a few seconds of running has passed, allowing the internal friction to warm up the elastomers.

As a recap for this thread (and a chance to awaken the arguments!):

The "transparency" is experienced when the rotor pitching moment forces (blade stall forces) become great enough to overcome the hydraulic forces of the servo. It is not actually caused by low hydraulic pressure, it is a function of the design being so marginal that the servos are too weak to push the blades around as the helicopter gets near stall. The maneuvers that cause "transparency" are often quite normal, and sometimes the effect is alarming and dangerous.

The limit light on the 355 is second cousin to "transparency" in that the servo forces trigger the light when they get large enough to signal impending loss of control. However, the 355 seems to have less propensity to enter jack stall, mostly because it has a more capable servo design than the 155.

NO US helicopter, civil or military, can have such "transparency" issues, since these signal that the controls no longer are controlling, and the pilot is a passenger. I also wage my friends at CAA would have similar thoughts, were they able to post here. Only the weakness of the bilateral regs (Shawn's excellent post above discusses this) allow such marginal controls to be put into service in countries other than France.

Why do the French approve such marginal systems? Je ne sais quoi! Perhaps it is because the French government owns the manufacturing company, the design engineers, the test engineers and the approval agency, and they dislike arguing with themselves. It is so unseemly to actually regulate yourself, n'est-pas?

[407 Driver]

I stand corrected, thanks Nick

[sandy helmet]

It does beg the question why has the limit light not been fitted to the AStar - does anyone know if it was a post - FAA/TC mod on the 355/365?

[NickLappos]

Sandy,

Good question! Any EC people out there who can answer?

[Matthew Parsons]

There's a Limit light in the AS355F-1 I'm flying right now. Don't have the manual here, so I'm not sure if it's a mod or if it's original.

We flew an intentional jackstall on the Gazelle. It takes quite a bit of effort to put yourself into that condition. I agree that if it could be designed out of the system without consequence then it should, but it's not as if there's a very large accessible and easy to use "DO NOT TOUCH THIS" button in the cockpit.

Like many things helicopter, it does require the pilot to understand and be aware in able to prevent and if required, recover.

[SASless]

Nick,

The French may not have a fondness for arguing amonst themselves...but they sure enjoy arguing with everyone else. Eeeet issss Lodgeek!

[Grey Area]

Let’s not turn this into a Francophobe forum.

As anyone in the business knows that the design and certification of any helicopter is a series of trade offs. In a good design everything is sized perfectly, keep the weight down is the battle cry in any helicopter design office, US, UK, France or where-ever. Each manufacturer has a different take on how to design a helicopter and how to achieve compliance, were that not the case then every helicopter would be the same. In the same vein safety cases rely on different mitigations; you can keep the pilot alive by making the crew station survivable in a 30 g impact but that is costly and heavy, alternatively you can reduce the risk of such an impact in other ways that do not necessarily make the aircraft less safe. Each design must be taken in entirety and a direct comparison between manufacturers design priorities in a single area will not result in an objective comparison.

Eurocopter will argue that the hydraulic system is designed to ensure that the rotor head cannot be overstressed. Something that in the early days of the Starflex head was paramount given the lack of operational data associated with any new technology. The fact that technology works and other manufacturer use elastomers is testament to a successful technology. In later Eurocopter models the Limit light is an indication that the head is close to its limiting stress loading, just as mast bending moment is displayed in other semi-rigid designs (BO105 for example). As an aside there are many in the Eurocopter who believe that hydraulics should run at the lowest possible pressure in order to minimise the safety implication of leaks and minimise weight, as SASLess put it.

Be in no doubt that the French take civil certification very seriously, in fact unlike the ETPS & USNTPS the EPNER Rotary Syllabus is based on US FAR certification and not European military compliance. After all Eurocopter has worked very hard to break into the North American and international markets and has had considerable success, they can’t be doing things too badly.

We are all different and from differing backgrounds, to really know your aircraft you need to understand the philosophy behind it not fight against it.

Fly safe chaps.

GA

[Shawn Coyle]

I don't want to turn this into a Francophobe rant either, but....
It does make one wonder when the hydrualics off control forces on the AS-350 series are huge (a technical term we use in flight test) and others (like the Australian military) found significant problems with the handling hydraulics off.
I remember instances of 'there is no problem with the helicopter, it is how you are flying it' on more than one model of helicopter from this manufacturer, which does lead one to wonder about the politics of the situation.
I think it will also be found that as a result of the cold weather re-test, several changes were made to the AS-350 series hydraulic systems.
Don't get me wrong- there are some wonderful design features in French helicopters, but like everything else in this world that is designed by man, they ain't perfect.

[Grey Area]

I totally agree, and if there is a flaw in the helicopter I would certainly expect Eurocopter to sort it out. My point is that if the product flys as designed then there may be a transatlantic training/philosophy issue that needs addressing.

Lets face it no manufacturer wants the users to lose faith in their product, look what the DC10 tail engine issue did for MD sales.

GA

[Collective Bias]

There are two types of servos in the 350, Dunlop and SAMM.

On the types I have flown there have only been Dunlop servos, and these are "easy" to demonstrate "jack stall" on.

Anybody out there that knows if the SAMM servos are the same, or better than the Dunlop. Dunlop seems to be more common.



CB

[NickLappos]

Gray Area said:
"Eurocopter will argue that the hydraulic system is designed to ensure that the rotor head cannot be overstressed. Something that in the early days of the Starflex head was paramount given the lack of operational data associated with any new technology."

Balls! Stated another way, you contend that because the rotor is so very structurally inadequate (that it can be damaged by pilot maneuvers,) thus it is a good idea that they weaken the hydraulics so that the pilot instead loses control in the critical maneuvers!

How about simply building a helo strong enough to start with? And if it isn't strong enough, how about fixing it?

I think it is not a Gray Area. Your profile says that you are a RN TP. Is this something you think the UK military would buy?

[Grey Area]

Nick

It is your contention that the rotor is "structurally inadequate" not mine.

The fact that you so strongly disagree simply supports my argument that there are cultural differences and different design philosophies.

I simply do not believe that bigger is always better. Whilst in military applications there is a greater need for redundancy, in the civil sector, particularly the light single market, weight eats payload and payload pays the bills. How many successful overweight or overly complex helos have there been in the civilian market? None, WG30 is a great example of how a complex military design does not necessarily translate into a commercial success.

FYI Single Squirrels operate at RAF Shawbury primarily in the Basic Helicopter Training role but also used for QHI training and misc tasks. Twin Squirrels are operated by 32 (The Royal) Sqn in the VIP role. So in answer to your last question yes, I think, in its time, the AS350 was a good design compromise. Although the Gazelle is much more fun!

GA

[MightyGem]

The British Army has always known about this with our Gazelles. When carrying out any hard right turn, I would always reduce collective a little bit to reduce the load on the servos, and never had a problem.

Is it a design fault? Possibly, but the aircraft concerned are fairly light aircraft with generally light control forces. Therefore the pressure within the hydraulic system only needs to be fairly low in order to control the aircraft. Hence the ease with which this pressure can be overcome.

Larger, heavier aircraft have heavier control forces therefore require higher hydaulic pressures. The Lynx hydraulic system is at around 3000psi and doesn't have a jackstall problem, but you can't really put a 300psi system on a 350/355.

Of course, all of the above could be b****ks. :D

[SASless]

Nick,

Remind me of my hydraulics theory....something about pressure...ram diameter....and cams....could we not get the same snoot out of two systems with different pressures but different sized components? The compromise is not just operating pressure but the sheer size and weight of the rams we would need....low pressure on the bulldozers....but really huge heavy metal bits...and higher pressures on smaller lighter bits?

Say what you want to about yer 350's.....if the rotor forces can overpower the flight control hydraulics....it seems a bit daft to me to say it is okay so long as you are aware of it. When I holler whoa....I want some thing to move besides my butt in the seat as I slide forward while pulling back on the cyclic.

Seems to me...if I put the controls to the mechanical stop...collective full up....cyclic full over and forward...and pedals full right (in the french model)....I want the hydraulic system to cope with that....full flow, constant pressure, and no feedback or "jacque stalling".

Anything less than that is sub-standard engineering design.

Before anyone says anything about...."come on...no one does that....they have not seen me flying an underslung load!" I scare myself sometimes.:uhoh:

[NickLappos]

Gray Area,
Inadequate is the definition of a rotor that can be bent by the pilot during relatively normal maneuvers. This is not hypothetical, it is (according to you) why the hydraulics were weakened to the point where the control of the helo is sometimes removed. This is not cultural, it is engineering, and we are not dealing with beliefs, we are dealing with hardware.

Sasless,
The issue is not hydraulic, it is rotor structure. The Squirrel can bend and break its rotor if handled near stall. Weakening the hydraulics is the "fix" according to Gray Matter.

MightyGem, The thread was about another model, not the Gazelle. Read the first several posts to see. In my understanding, the Gazelle is very much less prone to jack stall than the 350 series, which has relatively normal maneuvers causing loss of control (a cultural problem, according to Gray Area.) I agree, because if control is lost close to the ground, the pilot will end up looking like cultured yogurt.

Also, the hydraulic pressure is applied to a piston area, so that almost any hydraulic pressure can be used, if the piston is properly sized. It is not a pressure issue, it is a design issue, where the designer has chosen a servo that gives up during some maneuvers, and the pilot becomes a passenger as a result.

[paco]

The difference is that, with the gazelle, it's reproducible in similar circumstances almost every time, whereas in the 350 it can catch you any time. Thus, with the gazelle you could call it a limitation, and with the 350 a design fault.

Phil

[Arm out the window]

Rumour network, indeed!
Shawn, what's this about the Australian military finding significant problems with the hydraulics off handling?
AS350Bs and BAs were operated for years with few dramas and lots of practice hydraulics off landings. Very predictable and easy to handle, once the 'fault' was detected and the hydraulic isolate switch operated.
'Jack stall' was a discussed and demonstrated phenomenon in training courses, but I never experienced it or heard of it being a problem in normal aircraft use, and they got a bit of a caning manoeuvre-wise, much more so than the teetering-head types that were also used by the Aussie forces, because they could take it!
To paint this phenomenon (which certainly does exist but is only in my experience a problem if you like to throw the controls around like a gorilla, although to be fair, I don't know much about how they respond in extremely cold conditions) seems to be hysterical over-reaction based on a lot of hearsay.
Over...

[Devil 49]

Collective Bias:
The present aircraft I'm in is the only one I've ever flown any significant time in that has SAMM servoes. There's no apparent difference as to jack stall.
The SAMMs have other bad habits unique to the type- they "kick" when the pressure comes up. It's in the RFM....

[sandy helmet]

First of all we need a EC tech rep on the line who actually knows what is going on - anyone, anyone?? Ken where are ya?

Secondly, has this phenomena ever led to loss of control causing an accident? Not that I am aware of, so is it really a design flaw or structural inadequacy? - Most incidences of jack stall that I have heard about have involved aircraft close to MAUW and close to Vne. Are those "normal" operating conditions?? Generally accepted procedure is to back off collective and cyclic, and control is regained. Why would you want to be in a full speed cyclic descent anyway????

And Nick - is it really a structural issue as opposed to hydraulic??

The issue is not hydraulic, it is rotor structure. The Squirrel can bend and break its rotor if handled near stall. Weakening the hydraulics is the "fix" according to Gray Matter.

Because if this is the case, wouldn't one expect to see cracked blades, splintered stars, or bent pitch links?? I have never heard of this happening as a result of jack stall.

The aircraft has been designed to be flown with out hydraulics if necessary, and is controllable at speeds of up to 70 knots, without damage to the rotor system. If you are incredibly strong and willing, probably more - you just aren't getting any help from the hydraulics.

I believe it is more of a 'characteristic', that perhaps should be investigated a little more thoroughly, same as LTE for the 206 series, the T/R problem with the 407, or the phenomena of mast bending in the 204,205,and 412 that led to the RIN and limited torque settings in the RFM limitations.

Is it necessary or practical to change a major design feature such as the hydraulic system?? I think I can answer for Eurocopter.
Knowledge and training I think are the key to this "issue".
After all its not what you know that will kill ya...........
Arm out the window...I'm with you on this one

[Grey Area]

Inadequate is the definition of a rotor that can be bent by the pilot during relatively normal maneuvers.

Nick that is plain spin - In the world of the articulated head that may be true but any rigid or semi-rigid design can be damaged by a pilot if he does not adhere to his limitations - mishandling the cyclic on the ground being a prime example, rapid manoeuvres at high speed another. Depends how you define normal. Put an unbriefed 206 driver in a Squirrel and get him to land on a decent slope and I'll give you good odds that he'll over-stress the head. I've seen it, or rather prevented it, many times converting pilots to Lynx.

All that aside this is a not a real issue. The recovery from jack-stall is simple, ease the manoeuvre. It is not a safety issue if the pilot flys within the capability of the aircraft - just like any aircraft there are manoeuvre boundarys.

The argument from SASLess that he should be able to "put the controls to the mechanical stop...collective full up....cyclic full over and forward...and pedals full right" is frankly daft, at low speed you might get away with it but in the cruise or faster,with the contol authority of a semi-rigid head you would end up in a very hazardous situation.

GA

[SASless]

Gray Area,

I think you are missing the point....we are discussing the 350, not the Bell two bladed head. Not withstanding that, there are things that I will not do in various helicopters for various reasons. In any Sikorsky I or Bell helicopter I have flown....the hydraulics always kept up with the control inputs...take from that what you will. In the MBB products....except for some roll coupling...the hydraulics keep up with control inputs. In the Boeing-Vertol products I have flown...the hydraulics keep up with control inputs....it is only on the 350 we hear of this "Jacques Stall" event.

Yes, in the Bell two bladed heads...if you show your butt you can snap the mast off at the top....yes, if you enter negative "g" you can get into mast bumping and snap the head off...or lose control. Yes, in really aggressive maneuvering you can get yourself into a pickle in very high speed, high "g" pullups following a gun-run in a Cobra. Yes, you can over stress the Mast on the Bell 204-212 series if you pull too much power at too high an airspeed....but in all of these events...the hydaulics work with full control authority.

Your question "why would anyone want to operate near Vne at max weight?" Everyone of us who fly these things for a living will do that at some time. As long as the power utilized remains within the set parameters....we usually go for whatever speed we can get on long distance flights....Vne is the limit.....not near Vne....otherwise the Vne would be lower than it is.

There is no denying the fact....the controls should not enter "Jacques Stall" and remove the control of the aircraft away from the pilot. It is poor engineering at best in my humble opinion.

[sandy helmet]

SASless

Applying that line of reasoning then to other aircraft...............
You should be able to be low and slow and heavy in a 206............
You should be able to punch in as much pedal as you want in a 407......................
You should be able to push over a teetering system into low G.........
You should be able to fly into icing conditions.....................
Is fuel REALLY necessary??................................

Point is, every aircraft has its deficiencies, quirks, characteristics etc etc, and granted some are of grave enough concern that they eventually find their way into RFMs as a pilot procedure, or a limitation, while others remain as a known phenomenon to be discussed, taught, trained.

Vortex ring state, or settling with power, doesn't imply a design flaw on a particular helicopter (or does it???)

I do see your point on a system that maybe should perform better, but if it is a known characteristic, isn't the first and obvious fix not pilot technique?? As in not pushing over a teetering head, not putting yourself into LTE, or getting into settling with power?

[matador]

I've been flying, among others, A stars for 18 years now and have to say that I've experienced jackstall only twice on B models and when I was doing quite an agressive flying. Never had any more on twins (F's and N's) although I have to say that it's been a long time since I don't fly the hard way anymore. So for me it has not been an issue but I've never flown them -25 ºC and it seems that some pilots have encountered that situation in normal flight envelopes:confused: , if really so it should be something to take care of.
I fly my AS 355 N with total confidence in flight controls. Just my 2 cents
Buen vuelo

[SASless]

Sandy,

In response....in each situation you mentioned...the pilot has the control....not the aircraft. When the controls quit working...the pilot does not have control.

LTE...the aircraft is fully functional...the controls work...might be the tail rotor does not have the ability to cope with the yawing moment but the controls are working. Judgement is the main issue there....keep your nose into the wind...don't let a yaw rate develop.

407 and its tail rotor....seems like the controls work too good there.

Bell Helicopters and their tail rotors are much akin to the "Jacques Stall" issue. Thus you will not get much argument from me about those issues.

Zero "G"....again the controls got you there....judgement is the issue.

Icing....the controls are working....judgement got you into the ice.

Low, slow, and heavy in a 206.....again...judgement got you there.

Fuel....pilot judgement again.

In the 350....with "Jacques Stall"....too many reports of it happening for it to be a simple judgement thing....gets back to engineering and the controls not working all the time.

[Arm out the window]

I got hydraulic feedback in a Huey once while manoeuvering 'positively' to avoid hitting someone else in a formation, which felt just like the dreaded Jack Stall - unusually fast and large cyclic movement leading to forces through the controls which went away as soon as the severity of the manoeuvre was reduced.
That's the same thing as we're talking about with the Squirrel, isn't it?

[SASless]

For sure hydraulics or pylon mount issues that felt like feedback...or mast bumping....? Used to get hydraulics failure on the Alouette III in severe turbulence....hit a real down draft...all the fluid went to the top of the resevoir....pump cavitated....feedback in the controls...till the down draft was replaced with more normal forces.

[Jack Carson]

During testing at Patuxent River we experienced a form of Jack Stall in the AH-1T (PT-6 powered AH -1 with a 214 rotor and tail rotor). Even with a 3000PSI hydraulic system the servos were not able to react the flight loads during a symmetrical 3 g pull up. During this maneuver we experienced significant levels of control feed back in pitch. Review of the data also revealed that we exceeded test cards imposed limit of 3 g's. I do not believe that the weak hydraulic system is actually capable of protecting the airframe. Limitations do that.:E

[Nev Bartos]

Can someone help me with the specs of the AS350D and its differences compared to the B series?

Thanks

NB

[paco]

It is powered by a Lycoming engine that had nil respect in the early days, but is now workable. It is not supported by EC

phil

[rotornut]

The "B" series used to be called "Falling Stars". However, paco is right: the newer version of the LTS101 is apparently much better.
See:
http://www.pprune.org/forums/showthread.php?s=&threadid=18877&highlight=lts101

[widgeon]

SO who knows what the AS350C was ?. One of the early Canadian ships shows c to d to b on its registration.

Mark C-GMEY Serial No 1004
Common Name Aerospatiale Type Certified Model AS 350B
Identification Plate Model AS350C TRANS D TRANS B
Base Of Op. - Country CANADA
Base Of Op. - Province Quebec
Base Of Op. - Location Les Cedres
File Location Dorval Basis for Eligibility for Registration Type Certificate - H83
Type of Registration Commercial
Category Helicopter Weight (Kgs) 1950
Manufacturer Societe Nationale Industrielle Aerospatiale
Year of Manufacture 1979
Country of Manufacture FRANCE


Link to all you need to know about AS350 models

http://www.aviationtoday.com/cgi/rw/show_mag.cgi?pub=rw&mon=1003&file=1003as350.htm

[rotorboy]

Rotornut,

I believe the "D" was the falling star, otherwise known as the Death Star.

RB

[OCTANE100]

I read somewhere recently that a soloy conversion is on the way for the AS-350 using the updated LTS engine with much increased output and twin channel fadec which will give even the B3 a run for its money with MUCH lower DOC's.....would be a great conversion.
With regard to the AS-350 series all the basic airfames are more or less the same not including the engine / airframe interface parts, the t/rotor compensator fitted from the B1 onwards and some minor frames added to the underside of the tranny deck for a/frames modded from B upwards...... The vertical and horizontal stabs are a little different for almost all models. There is a fence on the tailboom of the B1 and B2 that must not have achieved a whole lot because it is not to be found on the B3....

[belly tank]

OCTANE100,

I beleive also that Bell will introduce a version of the LTS 101 into the 407 from 2006 thereabouts!..should be interesting.

Here in NSW the National Parks have a 350BA with a C-30 Fitted to it

[Fun Police]

apparently, the b3 doesn't have a strake because it doesn't need it as it has enough tail rotor authority as it is.

[rotorboy]

Soloy (pappilon ownes the soloy/ STC ) does have a STC for the LTS101, they are calling it a B2 101 or someting. They had one at the show this year. Supposedly the 101 is a super eng now. One thing about the 101 in the d model is it burns dirty, turns the tailboom black in a hurry.

The 101 DOC is a fair bit lower than the french eng.

rb

[GLSNightPilot]

Someone (the name escapes me, but was located in Broussard, LA) had an STC for a conversion of the D model to an Allison C28 or C30 engine. I can't remember if there was a model change or not. It never became very popular.

When I transitioned into the AS350D I thought it was heaven at first - a heater, 3.5 hours fuel, fast, comfortable, roomy, and very responsive. The B206 paled in comparison. And it was a nice ride as long as everything worked the way it was supposed to. When things started to go wrong, it could be a handful. I still recall doing a postflight and wondering where the water on the engine deck had come from. Turned out to be kerosene, and the fuel manifold that was mounted behind the combustion chamber, in a circle around it, had sprung a leak, spraying fuel directly onto the combustion chamber. The good news was that the leak was large enough that the amount of kerosene being sprayed provided cooling, and was too heavy to ignite. :eek: :yuk: :ooh: :ooh:

[Giovanni Cento Nove]

AS350C was the first with a LTS 101 600A and preceded the B model in being type certified.

AS 350D came after the C with LTS 101 600A2.

AS 350D1 is the same as the D with a LOWER MTOW.

AS350B came along with Arriel 1B engine.

All of the above have "Blue" MR Blades.

AS350BA is a "B" with 355 "Grey" blades and 355 TR blades and a few mods to the transmission deck.

AS350B1 is like a BA except with a Arriel 1D engine and TR compensator and boom strake.

AS350B2 is as above with a Arriel 1D1 and different tailpipe.

AS350B3 is basically a B2 with an Arriel 2 engine (FADEC) VEMD and NO boom strake as it has the TR off a 355N Model.

EC130B4 is EC120 at the front, B3 in the middle except with Dual hydraulics and EC135 in the tail although a mirror image due to direction of rotation.

There is/was a Soloy conversion to install a 250C30. Ones I have seen have some probelms with exhaust re-ingestion and if you look at the installation it is very "draggy" compared to the Lyco or TM.

There is a "Super D" with an LTS 101 750 and effectively B2 running gear.

Some people who have stuck by the Lyco love them. Low fuel burn and the engine can be operated "on condition". You can do a lot on the Lyco yourself. TM are very reluctant to let people outside their organisation mess with their engines.

And there is an odd one out there - AS350BB UK Military training aircraft (HT1) which I think is a BA with a 1D1 in it.

[Nev Bartos]

Does the LTS 101 600A2 have all the problems soughted out or is one to stay away from and stick with the Arriel donk ?

I am looking at a machine with an approx 2500 hrs TSN.

Thanks

NB

[Giovanni Cento Nove]

Judging by the terminology you are using - look to the East of you. There are a few operating and there is a bit of experience there.

Talk to someone at Airwork (NZ) they look after 350D's and BK's with similar engine.

One O Wonderful's have some form in NZ. The Cresco Ag machine had the LTP although now carries a PT6.

[widgeon]

Be aware of the component times , between 2500 and 3000 hours most of the dynamic components need major overhaul or replacement.

[Nev Bartos]

ENGINE (Lycoming LTS101-600A-2 with 2,491 hr TSN)
GP Rotor Assy 5000 3837 77%
GP Disc 5000 3837 77%
GP Spacer 15000 12617 84%
GP Sealing Plate 15000 12617 84%
Impeller 15000 12775 85%
Axial Rotor 15000 14485 97%
Compressor Shaft 15000 13362 89%
PT Rotor Assy 12000 12000 100%
Fuel Control 2400 397 17%
Fuel Pump 2400 1625 68%
T1 Sensor 2400 2221 93%
O/S Limiter 1800 1760 98%
PT Governor 2400 1430 60%
Air Flow Modulator 2400 1742 73%
Fuel Manifold cyc 2000 1821 91%
Start/Gen 1200 1200 100%

[widgeon]

Should also pay attention to Starflex , upper and lower sleeves MGB and Epicyclic module. Starflex was abour 3000 hr retirement ( If I recall correctly though it is more for the D now I think about it )

[Giovanni Cento Nove]

If you change your mind later I think it is still possible to convert from a D to a B via SB.

[nigelh]

ANY engine would be cheaper than turbomeca, their service is **** and they when you bend down to pick up the penny they left you with they **** you again.!! I had small part of mod 2 go through engine and it cost E250,000., all i get is a Gallic shrug!!

[rotorboy]

Anyone know of weight and balance software for a PDA? Any other good PDA software (aviation) that you guys can recomend?

Thanks

RB

[Gordon Bennet]

There's a spreadsheet at www.electrocution.com/aviation

GB

[Devil 49]

I made an Excel S/S, converted it with "Documents to go" to run on a Palm OS. It does every thing I need in EMS- existing W&B and compares it to fore and aft limits, computes max wt on the stretcher with exisiting crew and fuel, and a very few other conveniences...

If you'd like it, PM me, I'll send it on. It's not fancy...

For more general computing, I use CoPilot on the same Palm OS unit, and like it great deal.

[rotorboy]

Ok 350 guru's I have a question?

I have a fair amount of time the in the 350, but recently have been working it at a Pa of >7000-12K. I have noticed that starting the initial light off tends to be pretty hot and requires maniuplation to keep it in the 700-750C range, even bringing it back just a hair to mudulated it, cause it to flame out (0ver 9000 pa). EC want you to immeaditly induce fuel when you hit the starter. Just as an experiemnt I waited unitl 10%n1 before I came forward with the FCL and got a much cooler light off (as expected) .

Anyone else seen anything like this. Tips for running these things up high?

RB

[Firepilot]

Are you, as a standard practice, introducing fuel at the same time as you press the start button? The only time you should use that particular technique is when the OAT is below freezing. (As per the flight manual) Standard start procedures for the B-2 are:

"-When the Ng reaches 10%, move fuel control lever forward
about 1/3 of its travel range (When OAT is below 0 C, open the
fuel flow control at the same time the start push-button is
pressed)"

[Steve76]

Firepilot is correct mate... as it reaches 10% then introduce the gas. On the 1S1 arriels you can intro from initial igniter activation.

Should it not be modulated at 650 - 700 degrees?

Smell burning yet? :)

[katismo]

Check your battery, Rotorboy. If you have bad battery, you need to move your fuel control more forward during start. It great's of course T4. Be aware it. Change your battery ASAP if it's the fault.
(That you need to do only if you are in the middle of nowhere!.)

Normally I'm doing my starts like this: Move forward fuel control when it's front edge is front edge of the hole. (I mean hole where fuel control is during flight) Then push start button and t4 rise to about 670 degreeses after Ng is thru 10%. You dont have to move fuel control before t4 is going to fall. Keep t4 between 650-700 degrees during start. That is easy way. It works our As 350 B and B2 helos. (Still monitor T4 all the time!!.)

(hope thet you are understand what i'm trying to type) Languages are not my best part.

[Felipe]

Dear aviation friends

I was wounder if someone have an information or where can I find about dual belt hydraulic pump for the 350B3.

Thanks for the info.

FELIPE

[Revolutionary]

I believe Eurocopter offers the hydraulic backup as an option on the B3. It's listed as such on the spec sheet.

[OCTANE100]

Felipe,

I can't help but wonder why you would go to the expense of adding that option when a simple daily check will show the condition of the single "uprated" belt...ie the vee type, they are very reliable...

Not trying to second guess you but the only real reason for the change from the original green flat hyd belt on the earlier AS-350's in my humble opinion was the lack of regular "condition" monitoring which led to the inevidable......There are plenty of other areas a B3 could do with a little work/modification....

[goose boy]

all As350's( Both twin & single) with auto pilot have been grounded worlwide.

Eurocopter have discovered a defect with the weight & Balance issues and have declared them grounded.

The only way you can fly them is if a fully certified engineer, who has been certified via Eurocopter to carry out these check's, carries out a check A before if flies every day.

This is regardless of whether the flight is classed as a private or commercial.

Intill Eurocopter come up with a solution this is the procedure you have to comply with.

Can anybody shed some light on the situation.

As always I stand to be corrected.

[SASless]

Could you provide the details from whence that grounding order comes.....Emergency AD's or something maybe?

[widgeon]

IS it all autopilots ?. ( 2 axis , 3 axis , coupled )
For the twins it would probably be more significant . I would guess that less than 5% of singles have autopilot .

Nothing on federal register .

[Heliport]

goose boy

Is this rumour or news?

[goose boy]

WIDGEON

As far as I know it is all.

SASLESS

I dont know the answer to that question.

HELIPORT

My source is from a very well know maintanaince company, I dont want to mention there names for obviouse reasons but the company begins with M.

Also I have had first hand dealings with a AS350 owner who is currently dealing with the situation.[

[SASless]

Heliport...I went to faa.gov and checked for AD's in both Emergency and Past 60 Days catagories and came up empty handed.

[ShyTorque]

Seems a strange thing.

What has the check "A" got to do with weight and balance?

If it's a secret, it shouldn't be!

[goose boy]

Sorry When I say Check A it's more of a engineers check A ( totaly irelavant to a pilots check A)

More of a certificate of release to service for one day

[Heliport]

goose boy

"very well know maintanaince company."

If your info is kosher, what's the problem about naming it?

You may be right - I don't know - but "AS350's Grounded Worldwide" is an eye-catching headline. You got the wrong end of the stick on another thread you started recently - and since removed.
I'd be much happier if we had a checkable source to confirm what Eurocopter has actually said.


Heliport

(I've changed your title for the moment, and will change it back if what you say is confirmed.)

[SASless]

Heliport,

It would seem there would be lots of response to such a situation....here and other web sites.....but other than the original post....there seems to be no smoke signals from any fires showing.

But then....maybe there are not all that mamy 350/355 aircraft with autopilots out there to be affected.

[ShyTorque]

"Sorry When I say Check A it's more of a engineers check A ( totaly irelavant to a pilots check A)"

??

Is there a difference? There isn't on the aircraft type I fly and hold a check 'A' qualification for. We use the same checklist as the engineers.

[Fortyodd]

My sources tell me that it originated from a faxed warning from Eurocopter concerning a cracked vibration absorber. Requires checking daily by an engineer due to the need to take the belly panel off.

[CRAZYBROADSWORD]

news to me my company operates both and they where both flying today as where a number of other 350/355s.

[widgeon]

If the belly panels had hartwell latches could the pilot carry out inspection ?. If i recall correctly if the panel can be removed and installed without the use of a tool then an engineer is not required, is this correct . If it is a cracked vib absorber then to me it sounds like an isolated installation problem , I recall the sfim/sagem system had one of the computers mounted adjacent to the vib absorber. Can't see how a W and B problem would cause damage to the vib absorbers .

[verticalhold]

Eurocopter issued an alert telex on 9th June to inspect the right hand cabin anti-vibration damper. The inspection has been included in our Daily Mandatory Inspections. All the pilot does is drop the right hand side of the belly panel to check the damper. If it breaks it could foul the trim actuator. Our engineers showed us in a few minutes what to look for. No fuss, no drama, no grounding.:ok:

[SASless]

VH....but if it breaks in flight then what? Possible for it to foul the control linkage and thus be a bit bothersome?

[verticalhold]

Sasless;

You are absolutely right. Sorry, I meant no trouble about groundings or complex inspections. If it did break in flight it could cause a serious buttock clenching moment. I haven't heard if this fault has actually happened or whether someone has realised the possibilities and reacted accordingly, if so good on them.

VH

[SASless]

If this slight irregularity is of enough concern to require a daily visual inspection....one would assume the FAA, et al....would be issuing an Emergency AD on the issue. Another argument for operators to buy bare bones helicoters....see what happens when you add fancy avionics...nothing but extra costs and inspections!!!

[NickLappos]

SASless, you used to complain about barebones aircraft flogging around the patch at night, now you say that barebones aircraft are better (is that a gotcha?)

[SASless]

Nick,

Sorry old boy...that is not a gotcha....just another chorus of the same refrain.

I said....yet another excuse for operators to argue against buying the fancy kit....citing the increased costs of yet another inspection.

If the aircraft did not have the servo....and the chance of interference with it....would it be a "daily" visual inspection vice a periodic inspection as are a multitude of other things?

A question is begged here....did the engineers drop a clanger on this one by not anticipating the conflict?

[jayteeto]

Just revising for my 355 OPC next week and the anti vibration resonator is not part of the autopilot. It just reduces vibration around the cabin floor area. The aircraft has to be checked once a day by a qualified engineer (not the crew) and details are available from macs

[oldbeefer]

Yes, the problem is that the antivibrator could detach and fall onto an actuator. The check is a one-off, and not required daily.

[goose boy]

thats not what I have heard from 3 different owners now as they all have to get it checked off by an engineer daily

[TheFlyingSquirrel]

For us barebones chaps, What kind of device is the AntiVibrator, how and where is it connected and what effect does it have in real life?

TFS

[chopperdr]

squirrel: pm me, have some very detailed jpegs of the anti vibe weights if your interested.
dr

[oldbeefer]

Goose boy - we operate 27 AS350s with 2 axis autopilots, and that's what my chief engineer told me a couple of days ago.

TheFlyingSquirrel - as I understand it, the Squirrel was found to have numerous vibe problems. Some were removed/reduced by the antivibrator on the rotor head - some ground resonance (or something similar) difficulties were reduced by adding the springs on the back of the skids and dampers to the skid mountings. The anti vibration units under the floor are lumps of lead on flat springs and are mounted one under each pilot's seat. They are tuned in the factory to reduce the vibration levels felt by the front crew (engineers speak of 'nodes' whatever they are). It's probably the size and weight of the lead that makes them a problem if the spring or mounting fractures in flight!

[TheFlyingSquirrel]

Thanks for the reply Oldbeefer - how effective are the lead devices? A little or loads?

Thanks.

[widgeon]

I have been told that they reduce vibration substantially , they were not going to be installed on EC120 but after first flights they changed their mind , with a 20 to 30 lb weight penalty there must have been good reason.

[The Nr Fairy]

A "node" is a stationary point in a vibrating system.

Visualise a skipping rope, or tail rotor drive shaft. Start shaking it at one end, keeping the other held firm. As it vibrates, one part of the rope/shaft won't move - that's the node. Shake it / turn it faster, the node moves.

The lead weights I assume move the nodes in the AS350 cabin to near the seat attachment points - less movement, less bounce in the pilots' step when they get out.

[John Eacott]

AD's just issued here in Australia: AS350 (http://casa.gov.au/airworth/airwd/ADfiles/ROTOR/ecureuil/ecureuil-112.pdf) and AS355 (http://casa.gov.au/airworth/airwd/ADfiles/ROTOR/as355/as355-088.pdf).

[MightyGem]

Hmmm...how can it not become effective until the 20th, or have I misread it??

[TheFlyingSquirrel]

Thanks for the pics Chopperdr - know I can see what everyone is yappin about. I personally can't see how a dumb piece of lead can have any significant advantage - but I presume it acts as a counter-balance? I've glued it up if you don't mind - i'll remove it if you like - thanks again. Also, how can it fall onto an acutator?

TFS

http://img.photobucket.com/albums/v650/theflyingsquirrel/Dsc01283.jpg

[rotorspeed]

The relevant Eurocopter Alert Telex equires a visual inspection at the next, and each, ALF check (after last flight of day) until they introduce a modification to prevent any interference with the trim actuator rod in the event of failure of the vibration damper blade.

No mention of engineers needing to do it. Extension of Check A, so effectively daily.

Anyone ever come across such a damper blade crack/failure or know the TT/history of the incident that triggered this?

[oldbeefer]

rechecked with techies - you're right. A daily visual inspection is required. Seems a bit OTT?

[Heliport]

So, can we take it that AS350s are not 'Grounded Worldwide' and all that's happened is Eurocopter has issued an AD requiring an additional check to be added to the other daily checks?

[rotorspeed]

Heliport

Yes, at least seems clear to me.

Oldbeefer

Tend to agree it is OTT, which is why I'm interested to try and find just how many incidents anyone knows of. What worries me is the added risk of finger trouble on a pretty big cowling that I reckon could cause some serious damage if it came undone.

OK it's got 3 latches but it is not light and a bit awkward. History tends to prove that if pilots (and engineers) open cowlings, sooner or later they'll forget to close them properly.

Balance of risk then. And allocation of responsibility!

[NickLappos]

TheFlyingSquirrel-


That thing is a vertical vibration absorber, designed to "twang" probably at 4 per revolution frequency, kind of like a person standing on a diving board can make the board bounce at its natural frequency. It is resonant at the frequency, and so it absorbs those vibrations from the surrounding structure. It is very effective, that kind of absorber is used in the industry quite a bit. If it is not tuned right, that area of the cabin will feel like a rocky road. Two absorbers like that are located in the UH-60L near the pilot's step. The stiffness of the diving board and the amount of lead are selected to make it "like" the 4 per rev (which is probably about 21 to 25 Hz).

The place near its mount that is to be inspected is where the vibration gets passed through, so it is subject to high stresses, and thus the crack inspection.
I think I see a place on the weight for a vibration pickup to be mounted (the circle with a hole). If so, this is probably used at the factory to fine tune the absorber by reading how much it shakes in flight, and adding or subtracting weight until it is peaked out.

[chopperdr]

nicks correct, you can see the cross hairs where the 6 attach bolts p/u the airframe, that is the pickup point. also note the washer glued to the hammer weight, this is very common to see washers or various amounts of loose change glued on the hammer face to fine tune the airframe.
dr

[NickLappos]

chopperdr,

If that loose change are Franc coins, it means someone has found a use for the Franc!

If you guys would like, I can post some comments on the type of absorbers commonly used.

[SASless]

Nick,

Please do provide us a topic for some vibrant discussion....hopefully the frequency of posts in reply will vary with the source. Maybe that bit of information will dampen any misunderstandings and smooth any inconsistencies.

[chopperdr]

nick: your correct, however if you order by part no. from eurocopter, the face value increases by a factor of 4, lead time approx 90 days and the service bulletin requires that the head side is up : )

[Hilico]

What, even for that hose that is plainly labelled 'Made in USA' in the picture?

[chopperdr]

hilico: for that a/c hose your okay, in stock, ready to ship, reasonable price, call platinum aviation.
now if i can just figure out how to finance an stc installation of PW207E engine we would really be cooking with gas.
dr

[widgeon]

CD I thought first plan was a RR250 in EC120 , surely with all the disposable income on this site we could raise enuff capital !!! As350b207E is a bit long , any shorter names ? Is Jack K still around talking of platinium ?.

[chopperdr]

widgeon: so many more eligable airframes with regards to the astar. the 120 is ok as long as its kept light. as for jack K not sure if he is still involved.
will be at ecl monday

[Oogle]

Gents

Are there any AS355 operators still having problems with this inspection?

Anyone know of the pilot being authorised to conduct said inspection or does it still require an engineer?

Thanks

[EESDL]

Right pain in the preverb.
We're lucky that aircraft is based where gingerbeers work but the flexibility of the beast is hampered for 'overnights'

Pilots are not auth'd to carry out the additional check - unless they're also a certified engineer

[Droopy]

I was told this morning by a CAA maintenance surveyor that the decision of whom to authorise [pilot or engineer] was being delegated to the maintenance organisations...

[Oogle]

Cheers guys.

I will chase it up.

Now....... where did I put that number.....

:O

[goose boy]

I got told by a little dickie bird that the whole reason why this check can not be carried out by a pilot is because the A.D that was sent out did not say to be carried out by engineer's & crew on it like all the rest and it was supposed to be on there.

which mean's this whole knightmare is all down to a typing error.

[goose boy]

They are now letting pilot's carry out the A.D check if you get certified from a maintenence organisation.

I know McAlpine's are certifieing people to carry out this check

Hopefully no more messing around and that we can all get back to haveing a social life again .

[EESDL]

Yep, likewise, back to auth'd pilots carrying out the check!
Not a good advert for EASA, CAA, Blah

[goose boy]

EESDL

So True

[goose boy]

As far as I understand Eurocopter have Given all operatores a choice.

You can either check the damper daily before first flight or you can have the damper removed all together.

It's only taken them over a month to come up with this solution.

They must of had half a dozen monkeys working around the clock on this one

Any opinions on this

[Felipe]

I am looking to buy a set of floats for the 350 B3 model. If you have any ideia of who may have one available for sale, please let me know. this is hard to find and to expensive if you buy new at Eurocopter. Any ideia!!!!!:(

[rotorboy]

Air Curiser and Apical. The advandage with the aircuriser is they pop on and off and the gas is in the float itself vs the aricraft. The Apical's are retty much permantly mounted on the skids, configured with several differnt bags.

good luck,

just remember never trust the floats, the electrial firing and alwys double check the rigging on the MANUAL release. Nothing more nerve racking than pulling the T handle and not hearing the floats go when your falling from the sky

rotorboy

[Graviman]

Anyway these could be automated, in a similar manner to airbags, to save pilot workload?

The simplest system would be a float in a small chamber, that triggered a fast inflation. OK it wouldn't stop partial submerge, but it would stop it becoming a more serious situation like inversion. Once the pax and pilot had walked away, the heli would also be recoverable.

Maybe even link it into the hard landing airbag system suggested in an earlier thread, although airbag/float shape might not be compatible.

Mart

[rotorboy]

That really isnt practical. Most floats I have flown on an astar are fired by a trigger on the cyclic, that shoots a charge into the mechansim that inflats the floast (rather rapidly). There is usualy and secondary failsafe system ( I have seen fail) which is a mechanical linkage to the float firing device.

I as a pilot would rather have control of when the floats fire. Condiser the Autorotational charectaristics change dramatically with two huge airbags on the side. mo drag!

Floats may get you on the water but most of the time the a/c is lost due to capsizing.

rb

[Mars]

There have been a number of accidents where aircraft have impacted the water in an uncontrolled manner, the flotation equipment has survived the impact but has not been manually activated by the crew. Research carried out by Westland Helicopters in the UK and independently in the USA on behalf of the FAA has identified drowning to be the major cause of loss of life. Aircraft occupants having survived the initial impact then failed to safely escape from the hull.

In March 1992, an AS332L crashed into Sea State 7 conditions during an offshore night flight. Only 6 of the 17 occupants survived. Although the impact was severe, post crash investigation indicated that the flotation system may have survived and been at least partially available, had it been activated. The crew did not have time to manually activate it and there was no automatic means. The accident investigators considered that inflated flotation bags would have prevented the hull from rapidly sinking and assisted passenger evacuation from the inverted cabin by allowing it to float higher in the water.

In September 1996, an AS350B1 was carrying out low level overwater filming with 2 persons on board. For reasons unknown, but suspected to be inadvertent closure of the fuel control lever, rotor rpm dropped and the aircraft descended into the sea. Although the pilot attempted to, he did not have enough time to manually activate the emergency flotation equipment. The helicopter impacted the sea, inverted with the subsequent loss of the passenger.

Provision of a means to automatically inflate both ditching and emergency floatation equipment could have prevented loss of life in the above accidents.

Most helicopters working offshore in the North Sea now have automatic inflation of floats.

[widgeon]

ADvantage of apical floats is you can take off again ( get a bit of spinning happening until the TR gets thrust ). The floats are fairly easily removeable it is just those pesky skid extensions that take some time. Phoenix in NWT are using them on their EC120 to land on lakes to collect water samples. I am not sure if any flotation system can recover a helicopter once it has ditched. ASide from the Sea king there are not many that will float for any appreciable time after impacting the water. Flying at high speed close to the water I do not think even automatically activated floats would be of any use

[chopperdr]

widgeon: your correct, with the apical emergency floats you can land and take off as they have enough bouyancy to keep the tailrotor out of the water. ditching floats are approved for water landing only. operators must be careful to make sure they have emergency floats vs ditching floats, if they decide to alight from the water.
with regards to the extensions, have seen a number of operators keep the extension installed and just remove the bags when not flying over water.
one more advantage to apical floats on the astar is the mechanical pull system, no electrical system. apical also has the astar floats available with the liferaft built into the float bag, thereby freeing up cabin space.
dr

[erchie]

Who or what is the best thing to use to get accurate operating costings for UK aircraft? Is there anything like C&D or who are the best to speak to? The a/c concerned is an AS350B2.
Any advice from them older and wiser greatly appreciated.

[nigelh]

I operate a BA and all i can tell you is...............A LOT !!! About double that at least of a 206 , and when it comes to the engine side.....well you are bent over and R****ed by Turbomeca....circa £200,000 if you are unfortunate enough to have FOD damage and have to have an exchange !! I can buy around 7or8 allison C20 engines for that. I cannot imagine a B2 will be much different.........great machine though!

[greenthumb]

Just confrontated with an AS 350 BA accident i'm interested if anybody of you guys have experienced a LTE on a AS 350. I have a few hundred hours on this type of helicopter but never encountered such a problem.

The ship was taking off with an external load on a 50ft rope when suddenly in 100ft it began to spin to the left. At this moment the IAS should be round about 10-20kt. There is no indication of any technical malfunction. The helicopter was short before the MTOW but not overloaded.
LTE would declare the reactions of the ship seen by the witnesses.

[rotorboy]

the As350 has tremendus t/r authority but altitude and high Gross Weights you can get your self in real trouble.

I had a 350B2 swap ends on me picking a sling load at nearly 10K. The load wasnt that heavy. light and varible winds 0-5 from every where. I went to pick the load up vertically at 75-100 feet the thing just swapped ends , weather vained into the wind and stopped. My heart went in to my mounth and I was nano seconds from punching the load off.

A good friend an someting similar happen on approach to land , near MGW at altitude, real light squirrely winds, shallow approach 10-15 off the ground swapped ends and stopped.

I have a heard a few other storys , all at alt near mgw.

hope this helps

RB

[B Sousa]

The ship was taking off with an external load on a 50ft rope when suddenly in 100ft it began to spin to the left

Need some numbers here. Like What was the Aircraft Weight, Altitude, Temperature and what was on the end of the 50' rope.

After you get those, Im sure you will see what makes the world go around............

[NickLappos]

Most LTE's are due to rotor rpm drooping when too much power is commanded. Lowering the rpm reduces the available tail rotor authority, and is really not LTE, but rather over-pitching, a good British term. What was the power/rotor rpm during the incident?

[imabell]

thank you nick, thank you,

overpitching at last, instead of more of this crap about lte.

obviously if you run out of main rotor rpm you will lose tail rotor effectiveness. if the wind changes speed you get loss of tailrotor effectivness.

the chance of weather cocking with a heavy load load at altitude is to be totally expected and not a consequence of lte but a case of no more power available, something has to give.

i know why pilots like to think lte was to blame, it's because it is a good excuse for bad handling or inattentiveness.

better than telling the boss that you overpitched his machine and bent it.

"it had nothing to do with me boss", "it was that bloody lte phenomena", or "I could still pull pitch so i must of had more power left, then it started spinning all by itself".

thanks again nick for the reality check. :ok:

[rotorboy]

Imabell,

if the wind changes speed you get loss of tailrotor effectivness. or perpahs direction.

Ok explain to me your deffenition of LTE.


When you have a light varaible wind, you position into the current/ most prevenlant wind direction, then wind shift slightly and you are at a high power setting and you "weathercock" or have an uncommanded yaw. Recoverable or not, how is that not a symptom or byproduct of LTE?


So all these 206 accidents at altitude with uncommanded yaw on short final to spots are all over pitching? not lte? Tailrotor authority has nothing to do with it?

rb

[helmet fire]

Terminology: the bane of understanding!

Rotorboy, I see your points, but I think you are mixing the terminology between LTE, Authority and perhaps not understanding imabell's oevrpitched call. So we are all singing from the same sheet of music, I suggest the following terminology cut and pasted from another thread:

Loss of tail rotor control: You are not able to control the tail rotor pitch mechanism.

Loss of tail rotor thrust: Little spinning thing at the back stops spinning or falls off.

Loss of tail rotor effectiveness (LTE): "Newly" discovered and named in the 80's after many (in particular OH-58/B206) accidents. Although somewhat awkwardly named (as the tail rotor is still effectively working and must be providing thrust) LTE refers to what is thought to be an ingestion of main or tail rotor vorticey through the tail rotor which causes an onset of yaw in the direction induced by torque that cannot be overcome by the application of full "power pedal". The yaw rotation can build up quickly enough to fool most pilots into believing they have experienced a loss of tail rotor thrust. The concept has come under fire lately because of the early thoughts that the tail rotor enters vortex ring state being a little hard to prove. Oh - and then there is fenestron stall that possibly fits into this category too, although strongly denied as a possibility by the manufacturer whilst allegedly being strongly experienced by the pilots!

Loss of Tail Rotor Authority (LTA): Also a new term to make the old Huey war story of "..and then I ran out of left pedal and..." sound a little more sophisticated and technical. In this situation, the tail rotor does not produce enough thrust to counteract the torque/crosswind combination you require, your power pedal hits the stop, and around you go - though often quite gently when compared to LTE or loss of thrust. A lot of aircraft are susceptible to this, but the UH-1D/H Huey is famous for it - and many people have had the earth come up and smite them as a result.

This is somewhat semantics, but the reason I used the term Loss of Tail Rotor Authority instead of “Over pitched” is that it confuses the situation a bit. Over pitched infers that the blade pitch angle is too excessive either for the engine power to overcome the induced drag, or that the blade may be in some sort of stall condition. Most commonly, over pitching refers to the main rotor case (as Nick says below) causing a RRPM droop and therefore LTA, or it could mean a T/R blade overpitch causing LTA. Either way, both manifest in a LTA situation - not an LTE.

But not all LTA is caused by over pitching. LTA also covers the other conditions where niether the M/R or T/R blade is over pitched but the T/R still cannot produce enough thrust to counter act the yaw. IE the T/R blade pitch angle is at it's max, but the resultant thrust is insufficient to overcome the yaw conditions caused by power, DA, adverse wind, pilot handling, etc.

So in green thumb's case, I don’t believe that the tail rotor or main rotor has “over pitched”, although as imabell points out, this common term has been clouded by the LTE hysteria, and somewhat forgotten - and with the forgotten term comes a forgotten condition and a forgotten recovery technique - and I share imabell's concern with this. Fly a UH-1H and you will be forced to remember.
:oh:
In the AS 350 case, though you have yet to provide weight and DA details, I think an LTA case can be made: the T/R was unable to provide enough yaw authority for the power/DA/wind combination. Given that it was an AS 350, it is unlikely that the T/R blade was over pitched/stalled, and unlikely to be a main rotor droop – though the term over pitched certainly describes the aircraft reaction accurately, and the recovery actions are the same. (Unlikely does not mean impossible!)

edited to include corrections by AOTW!

[Arm out the window]

Overpitching (as I understand the term anyway) is when you pull too much collective for your engine's available power to overcome the drag, so the rotor system slows down; it doesn't necessarily imply a stall (even though I guess you could say that bits of the blade are stalled all the time). The only way to recover would be to lower the collective.

What I'm getting at is that in an 'overpitched' situation you'd have drooping Nr and the associated loss of main and tail rotor thrust, not necessarily the case in these so-called LTE situations.

As you say, helmet fire, the 206 LTE situation as we have had it explained to us is a rapid onset yaw probably caused by vortex ingestion.
I think that tends to support the Huey 'running out of left pedal' case being different to that, because you can sit there in the hover with the pedal bouncing off the stops but not be scared of whipping around to the right at a great rate - it feels controllable, while not necessarily comfortable.

[imabell]

thanks again nick, "lte does not exist".

but its not a way to blame the pilot it's a way for the pilot to move the blame to the helicopter.

only ' thought' to happen to the bell 206.

and your right too arm out the window, when you demand more power than any helicopter engine (piston included) can supply you end up with full left pedal and no tail rotor authority, ergo loss of tail rotor effectiveness.

fly the aircraft properly and it won't happen.

[greenthumb]

Thanks for your answers. I will try to describe the accident better.

An AS 350 BA (converted from "B") hauling loads with a 50ft rope in 3000ft PA, OAT 20°C, light and variable wind. Take off weight seems to be round about 1950-2100kg. (the load is destroyed and it's not possible to determine the weight of the load exactly) The >5000h experienced pilot lifted the load without problems and began to climb and to accelerate when suddenly the ship turns to the left. The left spin accelerated and wasn't to stop, even not with lowering the collective or full right pedal the pilot later explained. The ship and the load turned around the heads of the ground crew some full 360's and chrashed 50m ahead into the ground. The pilot doesn't opened the hook and released the load because he afraid to hurt someone on the ground.
As i wrote before there are no indications of a technical malfunction. The experienced ground crew reported the tail rotor was turning all the time. I' m surprised because the whole thing seems to me to be a kind of loss of directional control. That's not easy to understand because i thought LTE is a problem of the 206 or 500 series. Of course a loss of directional control is also possible on a AS350, but i have never heard about such a problem on AS 350 and never experienced personally on this type of helicopter. But i believe the pilot is really experienced on this kind of work, doing such flights a lot of years and will not loose the a/c out of control on such a "simple" flight during accelerating. But we are all humans and nothing is impossible.

Good to say the pilot isn't to bad injured and we all hope he will made a good and fast recovery.

[Flingwing207]

Would it be better to explain the "overpitch vs LTE" in this fashion?

It takes a fixed amount of horsepower to keep a helicopter hovering. For any horsepower, as RRPM goes down, torque (as expressed about the rotor mast) goes up. This demands more thrust from the tail rotor to maintain heading.

At the same time, the tail rotor RPM drops, therefore demanding a greater AOA just to maintain thrust. So you have two factors demanding left pedal, and there's only so much left pedal...

However, for most helicopters, the tail rotor is able to effectively counter any torque the engine/main rotor can develop as long as you keep the RPM in the green (and under most flight conditions). So for most helicopters, "LTE" can only happen if you overpitch, and droop the RPM while pulling a lot of power.

A few helicopters (B206, H269A) can, with RRPM in the (normal) green, regularly produce more torque about the rotor mast than the tail rotor can counter. So even if you are doing nothing "wrong", at high power settings you can find yourself running out of left pedal because the tail rotor is incapable of sufficient thrust even when operating at full RPM.

[helmet fire]

Thoroughly agree with Nick here about the procedure on how to baby the aircraft and blame yourself when it all goes wrong! It was the same on the Skycrane thread: LTE is thrown about with such misunderstanding that it has succesfully hidden a design flaw in a shroud of aerodynamic faux-legitimacy! (I think I shoud resume drinking after that phrase - sorry!).


What green thumb describes is most assuredly not LTE, but that is the only one we can rule out from the description thus far. Without more info, we can only rule out LTE, we are left with Loss of tail rotor thrust, Loss of tail rotor control and LTA. We have a high power demand, with adverse wind direction ?? at relatively high DA (approx 4560 ft - plus humidity?) More questions are still required: was there any rotor droop? If so, was this due to N1 limiting, or governor malfunction? If not, was the tail rotor being driven (or just windmilling? The tail rotor was spinning - but was it powered? Were the t/r control mechanisms functioning? Was it a hydraulic event? Sounds like he held the load and crashed the aircraft? Was he able to move the aircraft away from the ground people, but not the load? Did he have the cargo release system active?

And others will bring more to the table I am sure.

[Flingwing207]

Hi Nick,

Yep, I'm just a poor ol' head CFI trying to thread the briar patch between reality and what's printed in the textbooks we still have to answer to come checkride time. Since it was OVC002 all day, I got to engage a couple of my instructors in a discussion of this very subject, trying to find the balance.

We decided that if you get the "uncommanded yaw", you have just that. a yaw. If you react promptly and correctly and stop the yaw, it was not LTE. If the yaw stops on its own, not LTE. However, if you respond promptly and correctly but cannot stop the yaw, you have LTE (this still keeps us safe with the FAA). If you don't respond promptly or correctly, then you goofed - and the result cannot be truely classified as uncommanded (even if the first bit was) - hey you had your chance, Tex.

So if Sammy Schweizer gets his tail pushed around by that 12G20 tailwind, but ends up facing the wind going "wha'happah?", not LTE.

Rebecca Robbie gets sideways on a steep approach but stomps the left pedal and stops things, not LTE.

Joey Jetbanger starts seeing the word go 'round while OGE and downwind, and full left pedal won't stop it, LTE.

I agree that it is not altogether appropriate to call low-RPM induced "unstoppable yaw" LTE, but at that point, it ends up the same - (even if you initially screwed up by drooping the RPM).

[Arm out the window]

Nice work with the names there Flingwing!
Considering the start point of the thread, you'll have to come up with another one like 'Simone Squirrel' or 'Etienne Ecureil' now - or 'Anatole A-Star' for the Americans.

[SmashTheVSI]

O.k

So L.T.E may or may not exist, but whats it called when you stick in the left pedal on a AS350 on take off? Is that L.T.E as well?

[helmet fire]

wow flingwing - you really an instructor?

wow flingwing - you really an instructor?
I strongly suggest you review those text books with your mates. Perhaps you could quote them here because your conclusions do not match current aerody theory. There is a real difference between LTE and rotor drooped LTA, Loss of control or loss of thrust.

And guess what - they all have different recovery requirements, no matter how much you and your buddies decide it is all so simple.

Smash -
Mate that is not LTE, though let me assure you, LTE does exist. If you are putting in left pedal, that is due to streamlining unloading the T/R by enabling the vertical fin to provide some thrust and translational lift reducing inducd power, nothing to do with LTE, LTA, etc. The T/R is working too well, not well enough. Call it translational lift.

[Flingwing207]

Well, helmet fire, here's the FAA line (AC 90-95).

THE PHENOMENA OF LTE.
LTE is a critical low-speed aerodynamic flight characteristic which can result in an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, can result in the loss of aircraft control.

When they say "does not subside of its own accord", does this mean "without pilot input", or "even with the proper input"? So, Sammy Schweizer;s yaw stopped as soon as he was into the wind. He was just slow on the pedals. LTE?

Rebecca could well have just applied insufficient left pedal as she passed through ETL and raised collective. LTE?
Joey on the other hand experiences a rapid yaw, and even WITH application of the corrective action, is unable to stop it. What else to call this? LTE?

So when you droop your rotor RPM, and then you experience an uncommanded yaw rate which does not subside on its own accord, AND you can't stop it with the pedals, by the FAA definitions, you are experiencing LTE. The low RPM might have gotten you there, but you are there all the same.

The Rotorcraft Flying Handbook and AC 90-95 both describe low RPM as one of the contributors to LTE, along with hot & high, heavy GW, low speed, downwind ops, and right turns (in a CCW rotor helicopter). I didn't write the books, but as a CFI in the USA, I am bound to work within their guidelines.

You might be able to educate me here - if I am losing T/R thrust due to rotor droop, and I start yawing, would I not lower collective (as much as able), regain airspeed (as much as able) fly into the turn (as much as able) while applying opposite pedal?

[NickLappos]

Flingwing207,
Your logic, if carried to extreme:
If you bash your tail cone into a mountain along the right side, and your aircraft yaws right and "does not subside of its own accord and, if not corrected, can result in the loss of aircraft control." So I guess if you hit a mountain, you experience LTE!

If you pull the rotor rpm down to your socks because you requested too much power, and you are too numb to the cues that your aircraft is screaming at you, you have LBP, loss of brain power. If you treat it as a yaw problem, you have so purely missed the point contained in "pilot in command" that perhaps it is time to hang it up.

The reason why the distinction is made is that the causes and cures are different, as is the aerodynamics. If you blur it all together, you will never actually understand nor control your environment. I know of pilots who lost roll control due to rpm droop, should we call that LCE loss of cyclic effectiveness?

[Arm out the window]

Can I have some confirmation or denial of the following, which summarises what I've read and heard about the phenomenon known as LTE:

a. Is associated with the Bell 206

b. Happens in a high left pedal demand situation at low speed

c. Is thought to be 'set off' by the not-very effective tail rotor operating at normal rpm encountering dirty air from either the main rotor vortices, or ingesting its own vortices

d. Is more likely when the relative wind comes from certain critical directions (ties in with 'c')

e. Is characterised by a very rapid right yaw that can't be stopped with left pedal

f. Can perhaps be flown out of as described by flingwing, given room to lower collective and gain airspeed, but will probably only be stopped by rolling off the throttle or crashing, or both.

Lots of definitions and acronyms being thrown around in this discussion; are these points a fair summary or not?

[zdfwflyer]

Anyone care to anal-ize this report?

KAUAI News

Helicopter crash report a case of 'he said, he said'



By Andy Gross - THE GARDEN ISLAND

The circumstances surrounding the fatal Heli USA Airways crash Sept. 23 off the Ha'ena Coast remains a "he said, he said," situation.

According to a preliminary report issued Tuesday by investigators with the National Transportation Safety Board (NTSB) and compiled by lead investigator Debra Eckrote, Heli USA pilot Glen Lampton told investigators the Heli USA Airways Aerospatiale AS 350BA, N355NT (registered to Jan Leasing LLC, of Las Vegas, Nevada) was at 2,000 feet flying along Na Pali Coast toward Kailiu Point. Lampton said he had encountered some weather in Waimea Canyon.

According to the preliminary report, as the flight approached Ke'e Beach, Lampton noted rain showers which appeared to be offshore. As he came around the point, Lampton said he "suddenly saw a MD500 coming straight for me." He made a left turn to avoid the traffic, and as the helicopter leveled out, it encountered heavy rain.

Based on interviews, other pilots, including Ian Bagano, who was at the helm of an McDonnell Douglas 500 (MD500, or Hughes 500D) owned by Inter-Island Helicopters, were at about 300 feet above sea level, getting out of the weather.

Bagano said he was well below 2,000 feet during this course reversal, and it wasn't until he was near Hanakapi'ai Beach, several miles to the southwest of the Kailiu Point, before he heard Lampton's mayday call.

Eckrote said she had no hard data to support the eyewitness accounts of the pilots. She said there was no radar operating in that area.

The preliminary report is a narrative, and does not draw conclusions. It is based upon interviews with pilots and other personnel, none of whom are identified in the report.

Eckrote said she hoped to have the final report finished in three to six months.

According to NTSB officials, the preliminary information is subject to change, and may contain errors which will be corrected when the final report has been completed.

During preliminary interviews and a subsequent written statement, Lampton reported that, at the completion of his lunch break, he spoke with a representative at the Princeville Heli USA Airways base, who reported no adverse weather conditions.

Preliminary interviews with other air-tour-operator pilots in the area reported that the weather off of the Kailiu Point had been building all day.

Eckrote said that, because there is no weather station in the vicinity, pilots had to depend upon each other's reports.

Lampton told NTSB investigators he could still see down and to the right to the coastline. The pilot opted to reduce airspeed to 60-80 knots, and started a 15-to-20-degree right turn over the beach. The helicopter got about 160 degrees into the turn when the airspeed went to zero and the aircraft started to rapidly descend. Lampton attempted to control the helicopter with control inputs, which had no effect.

The pilot stated that he realized that they were going to hit the beach, and applied full power. The rate of descent suddenly stopped, and the helicopter went back up in the air momentarily, and entered an immediate hard spin to the left. According to the report, Lampton instructed the passengers to open the doors, and he transmitted a mayday call as the helicopter impacted the water, bounced back into the air, then impacted the water again, still spinning, but remaining on the surface for a short time before it eventually rolled to the right.

At approximately 2:15 p.m. the Heli USA copter hit the ocean several hundred yards off the coastline at Ke'e Beach, near Ha'ena.

The flight encountered instrument meteorological conditions just prior to the accident.

According to Zoe Keliher of the NTSB, Lampton was not instrumentrated. A company flight plan was in effect. The pilot and two passengers received minor injuries. The remaining

three passengers were fatally injured. The flight departed from Lihu'e Airport at 1:54 p.m. for the intended 45-minute tour.

Lampton reported that the weather was good until he reached Waimea Canyon. Clouds were present in the canyon, therefore he exited the area at the lower microwave station, near the entrance to the canyon, and proceeded to Na Pali Coast.

The pilot flying a tour about 15 minutes prior to the accident said that he encountered the rain at the Kailiu Point and made a gradual descent to about 300 feet above ground level. The pilot was able to maintain visual reference with the coastline, and continued on his tour route.

According to the NTSB preliminary report, this pilot reported no encounter with turbulence, downdrafts, lightning or windshear, while maneuvering through the rain. One other pilot in front of the MD500 and doomed Heli USA craft also reported that he entered the rain shower and descended to 300 feet just past Ke'e Beach before he made a course reversal due to deteriorating visibility.

According to the preliminary report, Bagano also reported encountering the rain showers, and he too made a controlled descent to a lower altitude to maintain ground reference. The visibility decreased to a point where he, too, opted to reverse course.

Based upon earlier reports, the two surviving passengers, Karen Clifton, 44, and her husband Bill Thorson, 48, said they didn't believe Lampton had to maneuver to avoid hitting the other helicopter. They said they saw a helicopter below them.

[helmet fire]

zdfwflyer: i would care to comment....that report is totally irrelevant to the thread, however i am sure that flingwiing can safely conclude it was an LTE event that caused the accident, after all, it hit the water and spun uncontrollably left.

AOTW,
Some points on your summary;
95% of LTE have been on B206, as Nick points out. Bell claim it is not limited to the 206, but few other types have had a record of the event. This ties in with the claim of "a new aerodynamic theory or phemomena" rather than any acceptance of deisgn flaw.

re your point 'f", the recovery technique was as you say. A 1995 ish B206 accident in the Australian Army was an LTE event and the pilot did just that - he tried to lower lever but had insufficient height, and then rolled the throttle off in accordance with the checklist procedure, writing the aircraft off and sustaining injury to himself and his pax. The checklist actions were reviewed and the recommendation was to lower the lever if hieght permits, otherwise attempt a flyaway using out of turn cyclic rather than roll the throttle off, particularly when faced with adverse terrain. I dont know if Bell ratified this recommendation, but it certainly makes sense. The danger is trying to discern LTE from Loss of T/R thrust whilst you are spinning around madly staining your shorts.

As a sideline, senior pilots very unfairly critised the junior pilot involved who carried out the taught checklist procedure to perfection in harrowing circumstances. well done that man. He did what the senior pilots had taught him, and what Bell recommended. Where do they get off??

[headsethair]

In the UK the CAA released a FODCOM (Jan 04) after 2 "LTE" filming incidents in 03. The FODCOM of course made no reference to the facts that the two machines involved were 206 models.
A year later (!!) the BBC released an internal Health & Safety Alert to all production departments, referring to the CAA alert and stating that all productions must ask any helicopter operator they book a series of questions about LTE.
What a mucking fuddle that caused. It flashed up on the BBC internal email system as a major alert making everyone drop their media glasses onto the tips of their noses and panic. Suddenly, all helicopters were going to kill you.
God save us from the clipboard and box-ticking mentality.
LTE isn't a cause of accidents. It's a symptom of bad driving.

[Thomas coupling]

Ok, Ok.....now that everybody who is visiting this thread for the first time, is thoroughly confused with:
LTE / LTA / LTC / overtorqueing etc etc...would anyone out there who thinks they have a handle on this, care to summarise for the benefit of many ab initio pilots and 206 drivers...what, IN VERY BASIC TERMS is LTE.

So they can go away and log it ready for easy recall when needed:

I thought I had this nut cracked...now I'm not too sure?

[Arm out the window]

Thanks, helmet fire.
The revision to the recovery technique of trying to use out-of-turn cyclic sounds a bit dodgy to me, gut-feeling wise; I'd be more inclined to cyclic into the turn slightly, or at least keep it centered (given the room to move) and try to do some kind of an ugly ascending, accelerating and hopefully slipstreaming climb out.
Using a heap of left cyclic as the machine was spinning rapidly right sounds a bit like a recipe for rolling it over or mast bumping -as I say, gut feeling, so maybe the test pilots can comment further.

Thomas coupling,
as a relative newcomer to the 206 I was keen to find out what this LTE business was all about, and the summary I wrote above is about the best I've been able to glean.
We all know about the obvious things that can happen to any tail-rotored helicopter, such as loss of tail rotor drive, or damage to the tail rotor itself; as has been mentioned, machines like the Huey can get short on tail rotor authority (ie high power hover, left pedal banging on and off the stops, but not whipping around to the right), but when I started flying the 206 people would talk about this LTE thing; apparently a rapid right yaw in high power low speed situations that can be brought on when the wussy tail rotor gets dirty air and can't cope, exacerbated by winds from certain directions (must check the chart again, the 8 o'clock springs to mind).

Hope this is of some use.

[headsethair]

Nick, "If it is not possible to get LTE in a Black Hawk, nor in a Lynx, nor in a H-500, nor most helos. How is it purely "bad driving" if you get it virtually only in a Bell 206?"

There are many ways that many machines can be made to kill or maim people. In helicopters, a lot of machines have their own - er - characteristics. Whether it's carb heat or "once only" autos in an R22 - or apparently LTE in a 206.

My point is that if you know a machine has a characteristic, shouldn't you do everything possible to avoid aggravating that area ?

We all know that helis can get into vortex ring on the main rotor - so we avoid getting into that situation. Why can't a 206 pilot have the same attitude to LTE ?

I am delighted to note that your company's Blackhawk products do not get LTE. Neither does my R44. When it comes to rebuild, I'll consider replacing it with a Blackhawk. I quite like the one G Bush had at G8 in Scotland.....is it leased ? Might it become available when he's finished with it ?

[NickLappos]

headsethair,

You are certainly right that there is lots of middle ground, and one should fly appropriate to the type he is strapped into.

I just want to be sure that we don't tar all helos with the brush invented to excuse the bad behavior of a few. While a test pilot for a manufacturer, I had to stop an effort by the FAA, fueled by Bell, to have that LTE Advisory Circular regurgetated into the flight manuals of all helos. This would have been the ultimate victory for the apologists, and a defeat for those who think we might actually try to fix the helo instead of blame the pilot, even if only on alternate Tuesdays.

[Flingwing207]

Nick, h'fire, whups - I guess you missed the part where I agree. As an instructor operating under the auspicies of the FAA, I am forced to reconcile the party line with reality (the party line being the RFH, and AC). BTW, the AC eliminates mechanical issues as a cause of LTE.

Anyway, as to what I think and teach as far as LTE versus all the other reasons a helicopter might go 'round on you - my (personal) definition of LTE is when the main rotor is creating more torque than the tail rotor can counter (at full pedal). All the other stuff (weathercock, vortex, MR vortex) are ways to experience unanticipated yaw, but not LTE.

Nick, I'm not trying to debate your point that letting RPM droop is a pilot error, and I agree that if you keep RPM up, there are very few helicopters that will experience LTE. However, once the pilot MAKES that error, you may reach the point where the tail rotor cannot overcome the torque of the main rotor. You yaw, and no application of pedal can stop it. Physically, aerodynamically and result-wise, the only difference between (shall we call it B206 LTE?) and low-RPM LTE is how you arrived. Important difference to be sure.

Anyway, I think the frustrations lie with having to toe the FAA line while trying to teach new students what's really going on. If I tell a pre-private student "there is no LTE except in a Jet Ranger", they aren't going to have a good time defending that statement with a DPE holding a copy of the Rotorcraft Flying Handbook or the AC. Better to have them understand the principles and mislabel them as LTE.

[PPRUNE FAN#1]

In defense of the 206, I can't recall ever hitting the left pedal stop. But I certainly can vouch that I have done that in other helicopters. It's never a comfortable feeling.

My one and only encounter with "LTE" was in a LongRanger. Up high, photography flight, hovering downwind. Pullling more and more power to hold position, I had "some" left pedal in but didn't sense that I was about to hit the stop and in fact had not. Suddenly...snap!...around she went. In the happy comfort of retrospect, I guess the vertical fin just blocked off enough of the tail rotor's inflow (or something) that the T/R just couldn't hack it at the high power-setting.

The rotation was so abrupt that I thought I had a tail rotor failure. Alternatively, had I known more (but not enough!) I might have assumed that the tail rotor had "stalled" like the wing of an airplane gives up the ghost. Having all of 1,000 big hours, I was bamboozled and pretty much just along for the ride, thrown sideways against the front seat passenger who was likewise thrown sideways against his door. I uttered an expletive phrase that began, "What the...?" Luckily we had plenty of altitude. I do remember lowering the pitch and banking into the spin. We did fly out of it. I thought to myself, "Don't do THAT again!" And I did not.

Sometime later I read the FAA Advisory Circular on the subject. I was surprised to learn that the tail rotor is *not* stalled during the event, and is still producing thrust. The recommendation was to go to FULL left pedal and hold it there. In my own experience, I do not remember doing that. I vowed to not make that mistake again. And I wonder how many "LTE" accidents occur because the hapless "low-time" pilots, like me, failed to stuff the pedal all the way in quickly enough because they were already low, down near the trees, concentrating on something outside the aircraft, something other than the theory of tail rotor inflow versus huge, blocking vertical fins.

So now when I'm operating in situations that demand high power and a wind off the tail, I'm very, very careful about yaw rates. And now I know what to expect if it snaps again.

Do I believe that the 206 tail rotor "stops working" and/or will spin "out of control" in an LTE event? No. It will spin until the pinhead at the controls (me) pushes in and holds the left pedal and perhaps reduces the torque if possible until a) the weathervaning tendency takes hold or b) the tail rotor gets a good "bite" again.

I laugh at that LTE Wind Chart that Bell puts out. According to it, you're susceptible to LTE with wind from virtually every quadrant except a tiny slice of area to the front right. Silly me! I didn't realize you could get into LTE with wind off the left. But Bell wants to have ALL their bases covered, I guess. And truthfully, as I've admitted here before, all of my helicopter flight time is at relatively low altitudes - below 5,000 feet. So I cannot comment on the 206's tail rotor performance at altitude. But down here in the thick air, I do chuckle when flying in a 206 with newbies who seem preoccupied with LTE when making an approach with a wind from the left-front. "Heh, go fly a B-model offshore," I tell them. "Offshore, where you'll be making max-gross landings to confined-area drilling rigs and the wind will be nowhere NEAR that little slice of clear area on the LTE chart." You'll be flat-out amazed that 206's aren't spinning out of the sky all over the place and falling into the water.

I kind of agree with headsethair. The phenomenons we ascribe to the main rotor as VRS or SWP can be excited while operating inside the flight envelope. Military OH-58 accidents aside, it seems to me that the number of civilian accidents attributable to "LTE" are small. I'll accept that, like the main rotor, the tail rotor has some performance limitations too, even considering N. Lappos' contention that this is unacceptable. (Listen to Nick screech on this subject long enough, and you get the impression he wishes that the FAA would just ground the Bell 206, that unsafe P.O.S. and be done with it.) You know, all things considered, for a helicopter that was designed over forty years ago, I believe the JetRanger ain't half bad.

Your mileage may vary ;)

Afternoon Edit: What was I, sleeping? Happened to crack open a 206 AFM today and what to my wondering eyes should appear, but the Critical Wind Azimuth Chart! The "avoid area" is much smaller than my memory lead me to believe: only extending from 050 degrees (relative to the nose) then back around to about 210 degrees. For some reason, I thought it encompassed the entire left side of the a/c. Ah, the failing memory of old age.

Apologies.

[helmet fire]

Flingwing, I do see your point, and know it is difficult to translate official stuff into student speak to get the message across, however, I think perhaps you are slightly missing the point: LTE is not the correct term for all T/R problems. LTE relates to a specific aerodynamic event that has a history of association with B206 models.
Your personal definition of the main rotor producing too much torque for the T/R to counter is, unfortunately, wrong. And it concerns me you are teaching another generation of pilots that definition of LTE. Look how you have even confused poor old PPRUNE Fan. lol.

Look back over the thread (you too tc) for the simplified LTE v LTA v LTC definitions. All different. All require different reactions to rectify, and all are derived from "official" theory. That is what you can teach to your students.

BTW PFan, a stalled aerofoil still produces lift, and it may be because you have never hit the left pedal stop that you got to experience LTE. So did I for the same reason.

[spag]

The danger area for LTE in the bell 206 is in the sector from approx 240 - 280 degrees relative bearing at wind speeds of 10 to 25kts. This is where the tail rotor can experience vortex ring state. LTA is different as stated above.

[PPRUNE FAN#1]

helmet fire:BTW PFan, a stalled aerofoil still produces lift, and it may be because you have never hit the left pedal stop that you got to experience LTE.In my LTE event, I got the impression that the tail would have spun around even *if* I was at full pedal. It was that abrupt - bordering on violent. I doubt that even full pedal, had I utilized it, would have had any appreciable effect once the yaw rate got started. But back in those days I was so far behind the aircraft that I could barely keep it in sight on a good visibility day.

spag:The danger area for LTE in the bell 206 is in the sector from approx 240 - 280 degrees relative bearing at wind speeds of 10 to 25kts. This is where the tail rotor can experience vortex ring state. LTA is different as stated above.I've met and flown with pilots who've said this very thing, in a very worried tone of voice! It's humorous, in a way. Those of us who've got lots of 206 time know...we KNOW that 240 to 280 is not the dangerous place for the wind. In fact, wind off the left assists by providing increased weathervaning stability. Anyone who gets a 206 to actually spin with the wind at 280 just isn't pushing on the left pedal hard enough and that ain't the fault of the aircraft.

Sure, wind from that quadrant will force your feet to dance on the pedals to keep the nose straight as the downwash from the main rotor impinges on the tail rotor. But that's no big deal. It's when the wind gets behind you in a 206 that you are flirting with disaster, especially if you're down low, over the trees and slow.

It provokes one to wonder: If flown in the Scout role, would an Agusta 109 be having LTE accidents since it's got a similarly large vertical fin? Enqiring minds want to know!

[greenthumb]

...it is not possible to get LTE in a Black Hawk, nor in a Lynx, nor in a H-500, nor most helos...
LTE relates to a specific aerodynamic event that has a history of association with B206 models.
Interesting discussion but i'm afraid i'm personally on the same place.

Should it be possible on AS 350? And how can an experienced driver, after more than xx rotations on the same the day, on the same route, on the nearly same weight, suddenly loss the a/c directional control?

[NickLappos]

Two comments:

Use the controls to the fullest. It is not LTE if you don't use the pedal all the way, it is "shy pilot". I have tested helos for 30 years, and hit every stop on every control at one time or another. You must use your machine, not ride in it, if you expect to earn your pay.

greenthumb, you have few facts, and many assumptions here. Without knowing what torque he pulled, and his Nr, you do not know what he did to the machine (he might not either!). OGE, with a sling load literally calls for over pitching as a possible cause. Was the 6th time at higher OAT? Where are the facts, not just the broad circumstances?

[Flingwing207]

First off, thanks everyone for your interest and input in this - these discussions are why a lot of my non-flying (or fixing, or ground-schooling) hours are spent on-line!

OK so here's where we are (or I am, anyway):
=================
Nick Lappos:
Most LTE's are due to rotor rpm drooping when too much power is commanded. Lowering the rpm reduces the available tail rotor authority, and is really not LTE, but rather over-pitching, a good British term.

LTE is... <snip> ...how a helicopter can lose control while within its normal envelope. In contrast, if a pilot takes on an excessive crosswind (beyond the flight manual limits) or is he pulls too much torque or operates at too much gross weight or pulls the rotor rpm down below normal, the resulting loss of yaw control is not really LTE, it is LTA.

It is not LTE if you don't use the pedal all the way, it is "shy pilot".

helmet fire:
LTE refers to what is thought to be an ingestion of main or tail rotor vorticey through the tail rotor which causes an onset of yaw in the direction induced by torque that cannot be overcome by the application of full "power pedal".

There is a real difference between LTE and rotor drooped LTA... ...let me assure you, LTE does exist.
======================
So let me make sure I've got this. LTE is when you get a yaw when everything else is OK. It's NOT when M/R torque overcomes T/R thrust - that would be LTA.

So we get LTE because of a disturbance in airflow, then the yaw starts, and only when when we can't stop it with full pedal it's LTA?

(BTW, I'm not sure when the topic of loss of thrust (as in something breaks) or loss of pitch control (stuck pedal/busted linkage) got mixed into this - certainly it wasn't in anything I posted. I realize that you would react differently if the T/R stopped turning or the pedals no longer controlled T/R pitch.)

Bottom line, I am actually concerned enough to be asking for clarity from you guys on a few things:

1) Is the basic FAA description of LTE correct - as a definition of LTE ("LTE is a critical low-speed aerodynamic flight characteristic which can result in an uncommanded rapid yaw rate which does not subside of its own accord and, if not corrected, can result in the loss of aircraft control.")? IOW, the aircraft yaws while in a "normal" flight envelope, and if the pilot doesn't respond properly, the yaw can go out of control.

2) LTA is when full (power) pedal won't arrest a yaw? This could be due to any number of reasons, including low RPM, high density altitude, high gross weight, big crosswind, OR an undersized/underpowered tail rotor.

3) For LTE to become an emergency, does it have to become LTA? I would think so, or else you would arrest the yaw, at which point you are no longer experiencing LTE or LTA. If the Bell issue is due to an undersized/underpowered T/R, I would think it would also be more susceptable to LTA, which is the real emergency.

4) If 1) is true, are you then more susceptable to LTE (or can non-Bell helicopters become susceptable to LTE) if operating near or beyond the edges of the flight envelope as described in 2? Or is it simply that ALL helicopters become more susceptable to LTA, but Bell helicopters have the additional gremlin of LTE which increases the chances of LTA?

5) Since the FAA doesn't single out make/model, is it fair to allow a student to go to a checkride with the following: all helicopters are susceptable to LTA if you push things enough. The "phenomenom" of LTE is the susceptability of a helicopter to enter a uncommanded rapid yaw while still in a "normal" envelope - while all helicopters are susceptable to uncommanded yaw, certain makes/models will yaw earlier, faster and further than others. Certain makes/models can also experience LTA while in a normal envelope. If you experience a rapid uncommanded yaw which then leads you into LTA, the amount of trouble you are in is inversely related to your altitude, but it is trouble no matter what.

[NickLappos]

Some explanation of how LTE occurs:

1) Every tail rotor has minor variations in its thrust output, based on the precise flow it is experiencing. If you put some turbulence into a rotor, the thrust will drop a bit. I have experienced this thrust change in every helicopter I have flown.

2) When you are operating at peak thrust, (max pedal angle) there is no more yaw control available. Should any turbulent flow enter the tail rotor, there is no more thrust available.

3) Main rotor torque is big, tail rotor thrust is small. A 5% increase in main torque can completely swamp a tail rotor that is at maximum thrust, and therefore at its control margin. A 2% increase in main torque beyond maximum yaw control will look like a wild ride, with the tail whipping around.

4) Most helicopters have excess tail rotor thrust, so that small thrust changes do not unleash the beast. A tail rotor that is very marginal will experience the same slight loss of thrust, but is more likely to experience LTE because it is riding on the edge and has little to help recover.

5) Sometimes the main rotor wake slips into the tail rotor, it can be heard and felt, and it can cause a 5% loss in tail thrust. That is why the azimuth diagram exists on the Advisory Circular, to help show where this occurs.

6) If the helo has little extra tail rotor thrust and collective is misused slightly at the bottom of an approach, so that the torque is somewhat above hover torque at the bottom, LTE can occur. The best way to make LTE occur is to make the approach too fast, so that you make a quick stop at the bottom, and suck in a lot of collective to stop the descent. That is precisely where most LTE's occur.

LTE occurs when a marginal helicopter runs out of yaw control while inside its envelope, LTA occurs when a proper helicopter is pushed outside its envelope. Both have run out of yaw control, but the LTE bird is in far worse shape, because there is nowhere to fix it. The LTA bird asks that we lower the collective, stop pulling too much power (stop climbing, usually) reduce the engine power, and all gets right.

[BigMike]

Nick, did the larger tail rotor Bell fitted to the BIII fix the problem or just patch it?
Is "LTE" just a pre Jetranger BIII problem?

[George Semel]

Boy this one has become a bit of a contest. The 206 has some things about it that you just need to be aware of, one of the things that has kept me out of trouble, is the slow application of collective, no need to hank pitch, also I have found that just use enough power to do the task you need to do, Ie why pull in 100% when you can do it will 89% for example. A lot of this LTR stuff is to much pitch, to fast, the gov can't keep up, you then get a little rotor droop, and well you get the rotors slowing and you still have all that power pulled in, you get a yaw. Every time I got into one, mostly doing power assurance checks, the yaw would stop as soon as I reduced the power a little. Is the TR on the 206 little on the small side, yep, so you fly knowing that. As for the numbers well yea the 206 is going to be in more accidents and such, because there are a lot of them flying around, Bell sold something like 5000+ of them. All in all the 206 is not a bad helicopter, yes it has some quirks, but all and all if you take good care of it, and fly it well with in the limits rather that at the limit stops, and just don't push it. You could spend the next 20 years flying one and never raise a sweat. It also helps to keep the wind on the nose, but that would be true of any helicopter. Now from what I understand the UH-60 dose loose TR effectiveness ever now and again. Of course you have to have it shot off first.

[NickLappos]

BigMike,

I really do not know of any 206III LTE events, perhaps the redesign did help. It could be that it only covered the power/gross weight increases, however.

Please do not misread me on this, I have personally recommended the 206 to at least two folks who became operators, so I have no "agenda" with it. I do believe if you nurse it in the tight spots, it will work. But I am concerned that we decide it represents a good 21st century standard, which is not what I would envision handing to my son.

The situation is so bad that the FAA has approved 412's, 212's and 430's with NO pedal margin, and NO crosswind capability, using a Cat B, 9 passengers or less approval. They undertook this based on the success they had in teaching us to nurse our aircraft, and blame ourselves when our aircraft bit us while in its normal flight envelope. That concept truly concerns me, and is not where we want our industry to go, in the future.

Some lame poster above said I "screached" too much about this, but that is because he hasn't had his helicopter kick his ass, and then have some official with the correct rubber stamp and Advisory Circular tell him it was his fault.

[Flingwing207]

To distill:
It's LTE if the helicopter is within its operating envelope, a yaw develops, you run out of pedal and can't stop the yaw.

It's LTA if the helicopter is outside of its operating envelope, a yaw develops, you run out of pedal and can't stop the yaw.

??

Perhaps this is why the FAA has elected to roll it all into the moniker "LTE" - while one is design induced and the other is pilot induced, the results are the same, as is recovery (full pedal, reduce power/torque, get airspeed, fly with the yaw).

[NickLappos]

the difference is very important:

In a helo prone to LTE, the machine screws you

In a machine experiencing LTA, you screw the machine.

Recovery from LTA involves reducing power (torque) down to normal, thus generally reducing from a climb to level, with ground strike as much less probable. Aircraft that experience LTA almost never crash due to it.

Recovering from LTE involves reducing the power from normal to descent, thus almost always assuring that you and the ground can become one. Aircraft that experience LTE often crash because of it.

that being said, if you find yourself spinning to the right, put in full left pedal, carefuly reduce torque, and try to accelerate out of the mess you are in, no matter if you call it LTA, LTE, MTA or FTA (SASless, tell them what FTA means!)

One thing I learned from this thread: there are pilots out there who would allow their helo to spin out of control without putting in full opposite pedal. For what reason would one allow loss of control without fighting the situation with all the tools at your disposal?

[3top]

I like Nicks definition about pilots screwing machines and machines screwing pilots!!

Didn't have the privilege to get my hands on a Blackhawk (or any derivative) yet, but I am still hoping!

When I started to fly the 206 I had about 1400 hrs on the Bell-47 and about 2000 on the R-44.
Generally I am slow to get used to a new machine, but after about 35 hrs I started to explore the limits of the machine ( or rather MY limits in the machine!)

It took me about 500 hrs to get to the edge in the R-44.
It took about 5 hrs to find the limits in the 206. Still I liked to fly it, until part of the compressor let go - down it went, it flew again 2 weeks later, but I prefer the EC120 hands down.

Back on track - LTE:

Nick talks about the upper edge (economically) of good TRs.

Let me give you a sample of the lower edge:

I don't know wether it still gets demonstrated, but at my first Robinson Safety Course the instructor would demonstrate
(albeit light wind, half fuel, 2 persons on board) a 1 foot hover at 75% RRPM!! This was not to show how a R-44 still stays aloft when RRPM is 29% below nominal ( R's fly at 104% RRPM), but to demonstrate the TE (Tailrotor Efficiency). He still could do a complete pedal turn either side!
He never demoed it at 70%, but would confess, that it gets hard to control there and he would run out of pedal at times!
The same demo in a R-22 is done at 80% - well it is a little more sensitive!
Now when I loose a little MRRPM a times when external cargo is heavy and Density Altitude is high - LTE is no concern EVER!!

If you can't afford a Sikorsky, go for the Robinson - LTE is NOT in the Robinson Vocabulary!

3top:cool:

[NickLappos]

good story, 3top!

the maximum rotor thrust drops by the square of the rotor rpm, so that at 70% rotor, the max thrust is about half what it is at 100% (0.70 x0.70 = 0.49).

[helmet fire]

I like that screwing definition too!!

3top, good demo. We use it often with the UH-1H during stuck left pedal forward situations.
But please note that you are describing LTA, not LTE when you use that demo to illustrate a point.

[Squirrel]

In the EC130 and as well in the new production AS350B3's, there is a potentiometer which monitors yaw movements which will increase the RRPM (thru the fadec) when T/R limits are being reached (when the 10% control margin is getting close). It is increased to something like 402 from 394 for the purpose of providing more T/R authority at those critical times, such as lifting heavy loads in the hover at altitude. Density altitude is also factored into the equation.

To me this supports Nick's comments that overpitching at altitude likely could lead to reaching or exceeding the 10% control margin for the 350's and thus insifficient T/R thrust.

[Arm out the window]

Interesting idea, squirrel. There must have been some decision making required in the design of it, for example, does it still act if an overtorque, say, would be needed to increase the Nr by the required amount?

[NickLappos]

Squirrel and Arm,

The use of the governor to help controllability is a great idea, much in keeping with the idea that the total machine should respond to the mission.

I have personally worked three similar ideas into production, and on them, the overtorque issue was built into the logic, so that the uptrim of Nr was slowed down to match the torque limits available. For those who are wondering what we are talking about, the upbeep of Nr causes a torque increase, so that an overtorque is possible if something is not done to prevent it.

The three areas that I worked on were the Comanche load factor enhancement, where the main rotor is sped up if the aircraft is maneuvered so that stall is prevented, and controllability/maneuverability is enhanced. Another is the use of Nr to trim the best range solution, automatically. The third is the "blow away" limiter on the 76C+ and S-92, where the torque limiter is varied as the rpm droops, so that constant power is available, thus preventing the spiral decay that occurs when a dumb constant torque limit is imposed on the aircraft. If the helo has a constant torque limiter, any hover overtorque is liable to result ina ground contact as power is being reduced by the limiter. Because torque times rpm is power, if the torque is limited and rotor rpm decays, the power is being reduced, so the helo starts a descent, making the pilot pull more collective so that the rpm decays further, and so on, until the ground comes up and smites the helo.

I would bet that the EC people worked the overtorque issue into the logic, perhaps with a slow uptrim rate, or even a limiter to prevent overtorque.

[3top]

Helmet Fire,

of course you a right!
There is no LTE on a Robinson, well maybe at 60% MRRPM.

At some extreme flying (filming - sideways, etc....) I do run out of pedal, but there is never any loss of TR-power anywhere.

It is fun when one goes sideways (anywhere from 100º to 30º),
once you are all up on power and run out of pedal, you reduce power just a smidgen and the helo has TR again!:O

I can control the angle at full pedal just by changing the speed a little, playing with the collective just so little...

Okay to the TR-demo, PLEASE don't do this to your students or yourself!! It was a factory designed demo to show the great power of the Robinson TR and I think part of it (as a side benefit) to demo the helo won't come falling as a rock just because the low rpm warning starts to yell....

I use 85% at 1 foot hover, light load, If I have to do recurrency training with oldtimers that HAD to change to the R brand - especially if they come screaming down at 110% - 2000' VS in an auto, because of "fear of death by low RRPM!"

I was in a R-22 when it was shown to me (80%RRPM), and I observed it done at 75% in a R-44.

The blades start to cone at an obscene angle!!

Thanks to the coning hinges the stay pretty much straight though!

3top:cool:

[Arm out the window]

Thanks, Nick. Sounds like some great ideas for making use of newer technology to take the load off the pilot and make things generally more safe and efficient.

[212man]

Nick,
pity you didn't work for Bell; they could have used some of that logic themselves (along with the "let's save the MGB rather than the airframe" logic!)

[NickLappos]

212man,
No pity here, Bell uses a different philosophy with everything, consistent with holding down the lower cost end of the market (that is not a slur, someone has to fill that market slice!)

The S-58T had the simple torque limiter, it was once all we had. New integre=ated systems allow us to mix variables from all over the aircraft, making it far easier to tailor the behavior more precisely to the need. Ofter, the trick is to think of what the pilot now does, and do that, automatically.

[BlenderPilot]

All I know is that in the normal Bell 206 L4, if you are not careful about your weight, and you try to take off into a hover too heavy at a high DA, you will find yourself spinning as soon as the skids leave the ground with the pedal all the way to stop, and with about only 80% power applied (TQ), bringing it down again becomes very tricky, if you try to do anything but roll the throttle off.

There is a beautiful video of this, pilot who is taking off from high mountain, starts spininng a foot off the ground, doesn't have TR authority, but has enough power to climb vertically (while spinning of course) then he dives it, recovers control for an instant at about 50 feet, only to loose it again and crash.

Don't know if you can call that LTE, LTA but whatever it is its a very dangerous if you are not careful.

The 407 TR, well that is a completely different story, it will get you out of most trouble, but it will also reach it's limits at altitude if you are not careful.

[3top]

Hi all,

Nick said:"No pity here, Bell uses a different philosophy with everything, consistent with holding down the lower cost end of the market (that is not a slur, someone has to fill that market slice!)"

Well Bell is not THAT cheap anymore either:
Someone local just bought a 206BIII with some minimum equipment for US$1.2 M, delivered in 2008!!

You get THREE R-44-II models for that and fly 9pax to more altitude than the good old 206, NEVER worry about the TR, now you even can get a A/C, delivery in 4-5 month....

And no I am NOT a Robinson Dealer or get any credits from Frank!

I love EC though! :O

3top
:cool:

[Aser]

BlenderPilot: And will you post the video..?

[Shawn Coyle]

In Bell's defence (or is it defense???) - the Bell 430 had suffienct tail rotor authority at the worst condition of wind at maximum weight at 7,000' Density altitude. (I did some flight testing with them when I was at Transport Canada).
And there is limit to what you can do with the tail rotor - put in such a big tail rotor that it really eats into payload.
There is, for example, no requirement in the regulations to be able to maintain heading while climbing vertically at maximum torque - should this be a requirement? Or should it be to maintain heading with winds up to 30 knots? or 20 mph as it currently is?

and Nick - I think you'd be surprised how many helicopter pilots never look at performance charts!

[NickLappos]

Shawn,
Actually, the 430 has twin sets of WAT curves, one set ( a pair of IGE and OGE hover charts) allows "wind from any azimuth" and the other set shows gross weights about 500 lbs more, and is for "wind within 45 degrees of the nose" for Cat B, 9 passengers or less.

This same travesty is published for the 212 and 412. I discussed this with the Ft. Worth ACO, and he told me that the zero margin yaw condition was used in the higher WAT because it was demonstrated and was safe, even though momentary contact with the stops was made, as long as there was measurable yaw rate in the direction of the input, there was still "control". Look at 29-2C page B-102 for a (ghastly) explanation of it.
See page 27 of the 430 product spec for the double line, one allowing hover with the wind off the nose only. I can email it to you, if you wish. Using this chart, the pilot can offload 600 lbs and have a good tail rotor, or gain the 600 lbs and lose yaw authority to fight a crosswind.

I have faced Bell 412's being sold to Saudi Arabia as SAR aircraft where that higher gross weight chart was used, with the words xeroxed out.

[anti-talk]

Trying to find information on operating costs and lease costs for an A-Star.
Not getting a lot of joy from net trawling - can someone please point me in the right direction. Approximate numbers are absolutely fine.
Thanks
Geoff

[BigMike]

As a matter of interest does anyone know the cost difference between running a BA vs the Super-D?

[widgeon]

http://www.aso.com/i.aso3/staticcontent.jsp?which=cda/main&iaso3sid=1

For 49.95 usd you get the single report.

if you have 515 USD you can get the complete database on CD.

http://www.gov.state.ak.us/omb/03OMB/budget/PublicSafety/proj35930.pdf

above source cites 495 USD per hour.

[Aesir]

I have always heard that the AS350 B2 costs about twice the DOC´s of a JetRanger to run.. The JR DOC is about $200.-

[BigMike]

For those who are interested these are the Bell Factory DOC's (2001):

206 $212
206-L4 $274
407 $352
427 $495
430 $511
212 $587
412 $736

[anti-talk]

Thanks Guys it was a ball park figure I wanted and 400 - 495 is good enuf for me - I had got a 206 at around 280 p/h.

[rotorboy]

Really depends on the model.

The B2 and B3 are way more expensive to operate than the BA. Figure a new 1d1 with all the trimmings is over 400k

A super D is a BA converted with a Lycoming Lts101. Better than a BA no where near a B2. advantage is the Lycoming is extrememly cheap to run, parts and support are in abundance. There is a new LTS101 conversion just certifed, that makes it a super B2, or something. Eagle in Spokane did a bunch of the flight testing on it for the feds. I hear it is a heck of alifter.

Why dont you call Eurocopter. I am sure they can give you the DOC's.

rb:ok:

[BigMike]

Used to fly a Super-D and a BA, and the Super-D was a better machine at altitude + burned less fuel. I knew it was cheaper to operate, just wondered by how much.
The new conversion to Super-D+ sounds real good. I heard Papillon were converting there Astars to this?

[Big_Johnno]

I believe A lot of operators still cringe at the thought of an LTS 101 engine. Apparently there is also a conversion from the LTS 101 to the allison c30 available for as350 astar. from memory Jayrow had a couple of AS350's with the C30 and i believe they were happy with them.

[BigMike]

The LTS-101 is now a very good engine and you also get the good customer support from the US. Having flown a good mixture of B, D, BA, and Super-D's, the 101 engines always seem to have that bit extra performance at altitude + the cheaper running costs.

[Aesir]

I agree the LTS101 very good engine now. I have about 1000 hrs with that engine and my ex-company has operated B 222 for thousands of hrs with the engine with no problems.

[Big_Johnno]

Can anyone please tell me what the difference is between an AS350B and a HB350 also an AS355 and a HB355?
Thanks John

[Ian Corrigible]

The HB350 and HB355 are simply Squirrels/Twin Squirrels produced by Helibras in Brazil (as the Esquilo). Other than customer-specific fits (e.g. for the Brazilian MoD's aircraft), the ships are identical to the various AS350 and AS355 variants.

I/C

[Big_Johnno]

Ian
Thank you for that, just goes to show you learn something every day.
John

[USACJ]

Does anyone have contact details for the people that do the Soloy/Lycoming Super D engine?
Thanks in advance

[Ian Corrigible]

Soloy Corp's website is here (http://www.soloy.com).

I/C

[BigMike]

An interesting read about the new "Super-D2"


Honeywell selects Soloy to develop STC for LTS101-700D-2 engine installation in AS350B2 helicopters

PHOENIX, February 6, 2005 -- Honeywell (NYSE: HON) announced today that it has signed a teaming agreement with Soloy, LLC to develop a Supplemental Type Certificate (STC) for installation of Honeywell’s latest LTS101 turboshaft engine upgrade for the AS350B2 AStar helicopter.

Papillon Grand Canyon Helicopters will be the launch customer for the new conversion.

“Honeywell’s LTS101-700D-2 turboshaft engine is designed to provide more than a 14 percent take-off power improvement at sea level and 18 percent more power in hot day conditions,” said Bob Miller, Director, Honeywell Light Utility Helicopter programs. “The improved power is generated by a new cooled gas producer (GP) turbine assembly that also increases GP disk life from 6,300 cycles to 15,000 cycles, helping reduce our customer’s operating costs. The LTS101-700D-2 also incorporates an updated and proven reduction gear-set that reduces accumulated power turbine cycles by 35 percent and increases torque limits by 6 percent.”

The engine footprint is identical to existing versions of LTS101 engines so current LTS101 operators can take advantage of the growth capability with no significant change to the installation or mechanical interfaces.

Soloy has already begun the new engine installation on a B2 Astar at its Olympia, Washington, facility.

Soloy has more than 30 years of experience in aircraft modifications and has completed numerous re-engine programs producing over 49 STC’s with certifications in 29 different countries.

“The Soloy STC, coupled with existing service bulletins, will allow operators of any model AStar helicopter to upgrade to the B2 configuration and then convert to the Honeywell LTS 101-700D-2 engine,” said David Stauffer, President of Soloy, “Our STC FAA certification is planned for early 2005.”

Soloy has begun taking orders for the AS350B2 upgrade, which they’re labeling the “Super D2”. Papillon Helicopters, who currently operate four “Super D” AStar helicopters with the LTS101-600A-3A engine, will be the launch customer for the new conversion.

“Our current LTS101 engines are burning almost 25 percent less block fuel per hour on our tour missions compared with competitive engine installations and are delivering significantly lower maintenance costs” said Dean Brandt, Papillon Helicopters Director of Maintenance. “We expect that same level of performance from these new LTS101-700D-2 engines.”

The LTS101 engine family has accrued more than 8 million hours of in flight operation. Honeywell has continuously improved this product through the infusion of recent technologies and upgrades. As a result, this engine family has demonstrated a four-fold improvement in reliability since 1996 and unscheduled removals and warranty claims have been driven to the lowest values in the history of the engine.

[David A. Stauffer]

The Soloy product line for the AS350 includes the following conversion kits:

AS350D, B & BA helicopters to the Rolls-Royce 250 C30M engine.

AS350D & B to LTS101-600A-3A engine what is often called a "Super D". This conversion STC was developed by Eagle Helicopters and is now owned by Soloy LLC of Olympia, WA.

AS350BA converted to the LTS101-600A-3A and also is sometimes referred to as a "Super D". Originally developed by Eagle Helicopter and now owned by Soloy, LLC.

Soloy is currently developing a STC to convert the AS350B2 to Honeywell LTS power using the LTS101-700D-2 engine. STC will be available the first quarter of 2006.

The Bell 407 is being updated to the Honeywell HTS900 which is a updated version of the LTS101 engine that includes FADEC controls. This engine will fit well in the AS350B3, wouldn't it?

[USACJ]

Thankyou David for the info.. What if I want to take a BA to a Super D-2.. Do you do the upgrade from the BA or does it have to be done by Eurocopter first??

[Hippolite]

I believe that Jayrow in Australia recently converted one from an Arriel to a Lycoming.

Apparently, its working very well. A competing company is looking hard at the conversion for their own fleet of 350s. It could become quite a fashionable conversion for older 350 aircraft with lower operating costs, better service and more power.

It is being considered for use as a "pricebuster" against the 350B2 and B3 and is considered the value solution.

[David A. Stauffer]

Currently the only way to upgrade the AS350BA to B2 configuration is through the EC owned facility network. I know that others have accomplished this upgrade but it is usually in close cooperation with EC. The technical data to upgrade is FAA approved and can be accomplished without EC involvement. However, as you know, EC can make this difficult if it is not involved.

It is our intentions to certify the AS350B2 to LTS power for now and how you get there is still under investigation.

[In2wind]

Hey was wondering what problems operators were having with their b3s and the fix. How do the computers and fadec perform?

[Head Turner]

Have you got a B3 or are you considering buying one and the answers here would affect your choice? Then why not an Agusta A119, better all round, best engine, beefy transmission, capable rotor head. Past problems have been sorted. Selling well.

[Aesir]

I have been flying the B3 & B3+ some.

I was not to thrilled with the idea that the company would be buying this modern fancy computer controlled equipment but they have actually performed really well with no specific problems to talk of. Some sensor faults and such but no real problems really.

My company operates 7 of them!

[Fun Police]

what's a B3+?????????????(for the benefit of the 15 character minimum :O )

[Aesir]

The B3+ is how my company refers to the newest model of the B3 with dual FADEC and no "MAN GOV" function!

I don´t really know if it´s an official name or just something my company uses for our latest aircraft!

[In2wind]

The throttle is an interesting one on the older model b3s. Just got to hope it hasnt been moved although Ive heard if you put it back to the vol postion it should be okay for a start. Heard anything on this one. Have also heard of problems with phones and wescams being operated in that it may effect the fadec?