Bell 206: JetRanger and LongRanger

[mfriskel]

20 years ago I had an oil line from gearbox to compressor support hub break just forward of the B-nut at the gearbox end. This was a C18 engine and was found to be a high freq from the engine itself. Engine was removed for overhaul.

[sprocket]

Agree with mfriskel, check your engine for vibes. Also the T/R and main driveshafts if the eng vibe level is OK. It could be something as simple as a start/gen vibration. Good luck.
(EDIT)

[JerryG]

It's a bit long ago now for me to remember the details accurately but isn't there an air pipe that gets disconnected every time you do a comp wash in order to prevent water getting into it?

I have half a recollection of having to very carefully check that (a) it had been done up again and (b) it hadn't cracked with repeated daily on/off handling.

Please excuse if this isn't relevant.

Cheers
JerryG

[Mars]

If this is the P3 line in the Allison, it has been the cause of a number of engine failures over the years.

There appear to be a number of causes for the failure - two predominant ones are fatigue and maintenance error. The first is self explanatory; the second (and of course the first) can be caused by the frequent connection/disconnection cycles. As JerryC has mentioned, in the absence of an installed valve for the purpose, it is disconnected and blanked for every comp wash. There is an STC for the valve but it is not an 'approved' modification is some States (UK).

Some oil companies/operators replace the P3 valve at regular intervals - this appears to solve the problem.

[Vfrpilotpb]

Would some one explain what a " Chadwick Test" is?

Vfr

[sprocket]

The Pc (P3) line from the compressor scroll to the Pc filter does not appear to be the one mugsy has mentioned.

mugsy wrote:The cause appears to be a cracked air line between the governor and Fuel control unit
Although the Pc line has been a problem over the years.

Vfr: The Chadwick test is a vibration analysis check. Chadwick is one brand name of the test equipment that is commonly used and is also used a lot for rotor track/balancing.

[The Bogeyman]

On June 27 a Scweizer 269D made a hard landing after an engine failure. The Investigation reveiled a broken Pc line (compressor discharge pressure senseline to fuel control). Problem was probably too much tension on the line due to the fact that it misaligned. Misalignment of this line is not uncommon, but enough misalignment in conjunction with excessive vibration could result in a broken line. Rolls Royce has issued CSL A-1166 which advises to install the line without tension due to misalignment. Some extensive bending could be required!

[Newgen Jock]

Saw the same thing about 10 yrs ago while working for the (probably!) same utility company. If I remember rightly the eventual cause was routing/ clamping of the P3 line, which caused it to be IN TENSION all the time. It may also have been a (slightly) wrong part no, of subtly different length. ( was a long time ago!) With the natural hi-freq vibe of the engine/ MRGB, the line was vibrating which caused either chafing at a P-clamp and/or fatigue fracture, on a bend possibly.
Hope this helps Mugsy. Long time no see. Man those Line Audits were fun! (?)

[Thomas coupling]

VFR: It's the old way of checking whether the rotating blades (TR and MR) are in sync (tracked) and balanced. Very hit and miss affair, takes bloody hours.

New gen a/c have digital analysis plug in diagnostic kits, much more accurate and very quick (in the right hands).

[Captain Pheremone]

Hey VFR I'm not sure what side of bed Thomas Coupling woke up on cos he does not like Chadwick but his answer is wrong.

Chadwick is the name of the system designed by Mr Chadwick (of all people) from California to balance any rotating system. It is a digital analays system and is used throughout the world on blades turbines shafts etc etc.

On a helicopter the time comes in setting up sensors on the frame, main blades, TR blades, tail boom etc. Then you simply fly the helicopter in the regimes of normal operation, the computer does the rest and tell you where to place balance weights.

You land put the weights on where needed and voila.....a smooth chopper.

Other sysems such as strobe or bamboo and paint also work well!!!!!!!!

[mugsy]

Thanks for the input, folks.

Subsequently found out that a Jetranger went down in RSA with the same problem. That makes 4 in this neck of the woods.

Seems to me that if the tightening of a nut can stress the flange, or that a slight misalighnment of a pipe can keep it in stress, then you can bet that we'll have more failures.
That sound like poor design to me.

Incidentally someone in the industry sugested that when we tried to find high Fx resonance with a Chadwick we were unlikely to find a problem because it is not designed to pick up a turbine bearing going pear-shaped. It is better at medium frequencies such as props, rotors, drive-shafts. He sugested something called " microvib" (I think that's the spelling) Any comments?

[Alfa Hotel]

Occurrences with aircraft powered by an Allison 250 engine in which Pc line fatigue was a causal factor:

13-09-1984 Denver USA Bell 206L-3
05-10-1985 Islamorada USA Bell 206L
30-03-1989 Vallejo USA Hughes 369D
08-12-1989 Waimea USA Hughes 369 HS
21-04-1990 Williamsport USA Bell 206 B3
09-09-1990 Kokhanok USA Bell 206 B
11-07-1996 Pigeon Forge USA Bell 206 B
27-06-1998 Assen Netherlands Schweizer 269D
13-04-2000 El Paso USA Hughes OH-6A
21-08-2000 Dartford Marshes UK Hughes 369E

I wonder how many others there are besides these and how long is this problem going to continue before anything is done about this?

[mugsy]

Great info Alpha Hotel. The plot thickens. Now we know of 14 power failures in about the last 10 years

[Choppersquad]

can anyone tell me where i would get extension pedals for a jetranger, i know paravon do them in the states .is there anyone in europe who supplies them.also same again for the md 500

cs

[Gymble Stop]

Maybe you should look into purchasing a pair of “extension legs”.

No TSO required.

No W & B calculation required.

Probably cheaper??

And the girls might begin to notice you at the aero club Bar.

[belly tank]

Gymbal stop!

C'mon, that comment was a bit below the knees! :}

Chopper squad, i know im a bit vertically challenged but those pedal adjustments come back a fair way, are you really that short!!...can you see over the top of the panel at least :)

[Choppersquad]

they keep calling me a bum .now i know why.thanks guys
your the best.

by the way its for longer not shorter.i no you ausi jocks
think shorter ,so the girls say..........................

cs

[kopter]

Can you mix and match M/R blades for a B206?

Part numbers are:
206-010-200-033 (single tab) and 206-010-200-133 (twin tab)

Some say you can others say not?

As far as I know the only difference is is single tab vs. duel tab.

Thanks in advance... :ok:

Ps- If you can, is their any negative aspect to doing so?

[sprocket]

Yes you can mix them. Provided that you can statically balance them.

[Banzai-blades]

You can definitely as I have been flying a B206 BIII for a long time time with a mixed set.

Rightly mentioned that the static balance is bit tricky but patience does it.

We have found that during blade tracking in flight always do the setting on the blade with the twin tabs first and then "fine tune" from there.

[spinwing]

Mmmm ..... putting my engineers hat on for a moment ...

I would have to suggest that the static balance would be the least of your problems when mixing blades sets .... depending on how many hours the "old blade" has when fitted up with its brand new mate! ...

I have many times tried to do this (at the bosses whim) and we always had problems trying to get a good (smooth!!!) in flight track... the reason being ...with an old (high time) blade we seemed to always have a "soft blade" Vs "hard blade" mix which causes all sorts of flying track and vibration problems ..... most of which can only really be fixed by matched blade sets.

Yes I know its expensive .... but there you are?

:{ :{ :{

[av8rbpm]

Just send Bell product support an email at the following address. (Assuming you are operating a ship with a valid s/n, not some destroyed and rebuilt "project" ship, they will be more than glad to answer your question.)

email to : [email protected]

[that chinese fella]

One of the problems with a mixed set is that any call for inboard tab has to be doubled if only 1 dual tab blade fitted.

This can lead to excessive tab which tends to reduce ride quality overall.

[HeliEng]

In the dregs of my memory, I seem to remember that a different tracking chart was issued for the two tab blades.

If I am correct, and you have a mixed set, which polar chart would you use?







"They say that the early bird catches the worm, but it is the second mouse who gets the cheese!"

[206 jock]

I have an early 206 A/B with a mixed set - both blades have been modified with the stainless steel leading edge.

Every pilot who flies it comments that it is the smoothest J/R they have flown! Both have over 4,000 hours left so that may be a more important factor than the dash number itself.

They were tracked and balanced by a good engineer which may help too.

[3top]

Hi everyone,

looking for a quick info:

Bell 206B3

a) What is the OGE performance for a 206B3 loaded with
3 pax - 175 lb average
1pilot - 175 lb
cargo - 100lb
fuel - 45 min, incl reserve

OAT at 11000 ft +10-15 deg C

b) Same machine:
What can I do, weight-wise at 11 200 ft OAT +10-15 deg C.


Fact: Resently we had a "hard landing" in our neck of the woods, at "around" 10000 ft. Reports of the actual site would indicate an actual elevation of 11000 or 11200 ft. I recently over flew the area with direct climb from sealevel to that place - flying alongside the destination I indicated 11200ft - +12C. (....with a R44-Clipper II - never below 50kts!!)
Landing site is such that an approach into Groundeffect is not possible, thus I need OGE performance for a landing - and even there groundeffect will be marginal - narrow pinacle/ridge.

I was asked to bring some insurance guys to the site with a EC120B. Now we all know that the EC120 looses quite a bit to the 206 at that altitude. I read the performance charts (EC120) to no more than 320 kg payload at that altitude incl. fuel, pilot, pax. at OGE.
Which means it would have been a 1 pilot +1 pax and fly twice with a fuel stop.

Some friendly discussions about 206 versus EC120 prompted me to post this question.

I don't remember anything from my short stint in a 206, but I "feel" that the 206 was doomed the moment the pilot tried to land at that altitude with the load as estimated....

So how about some W+B practise for on the edge flying? :D


Thanks in advance,
3top
:cool:

[407 Driver]

I believe that you are quite correct in assuming that the pilot was "Doomed" in attempting a landing at that estimated weight/temp/altitude in a 206B3.

My initial W&B & performance calc shows that the max HOGE weight at 11,000 +10C is approx 2700 lbs.

The scenario that you explained works out to be approx 2966 lb (given a 1,900 lb airframe, and 38 USG - 266 lb fuel). I don't have a 206B3 RFM on the Base, but used www.bellhelicopter.com to get the performance information.

I would suggest that flying an approach to 11,000 at +10 to +15C to a spot that may require HOGE performance at a weight which is possibly 266 lb above the manufacturers RFM limitations may certainly result in "doom".

My personal expericence with the 206B3 is that it will certainly perform at or above the RFM charts.

[George Semel]

Well I don't have a AFM for a 206B3 handy. But if that one was anything like the last one, I flown, he was to heavy by at least 300 to 400 lbs. Not knowing the condition of the aircraft, is hard to really give an answer. You know what he had for power? There are a lot of 206's that are a bit on the weak side of the Power Assurance Chart. So not knowing the hard facts for that helicopter, its really not fair to guess. Now your load in a 407 would be no problem.

[SHortshaft]

Using 3top’s scenario and based on a machine I know, which has a basic weight 1988 lbs, I would estimate that the stricken machine had a weight of 2917 lbs. (I have used less fuel than 407 driver reckoning 18 US gallons would meet the ‘45 minutes including reserve’).

From the RFM I calculate the max weight for an OGE hover in the vicinity of the LZ would be 2650 lbs for an aircraft without a particle separator and 2620 lbs for one with a particle separator.

So I would concur that the machine would probably be 250 to 300 lbs overweight.

If a ‘hard landing’ was the result then they may wish to regard themselves as lucky. The last case I was involved with that had a similar scenario the engine topped out, and the helicopter suffered rotor rpm decay, loss of directional control and caused multiple fatalities.

[[email protected]]

Are you talking Altitudes based on 1013 or heights based on QFE/QNH?

The elevation needs to be converted to a Pressure Altitude and then a Density Altitude to sort out performance.

[BlenderPilot]

The only thing you need to land or TO at in those conditions is a field (half a soccer field for example) and to carefully watch the wind or you will use all you power in your feet.

Anyway, landing shouldn't have been the problem, but unless he had a large flat field I don't see how he was going to take off.

[3top]

Okay guys,

the actual altitude was/is 11200 ft, temp was based on my own overflight of the site 3 weeks ago. Temp hardly changes around the year. I don't know how much temp changes over the day, that's why I stated 10-15 C.

Blender, there would be fields that are bigger than a soccer field, but you have to go down into a narrow valley like chute to land and then there is no go-around (...nor would you ever get out of there with the same load).
This is on the top of a volcano (non-active).
Anyway the plan was not to land on any of the fields but directly on one of the ridges around the crater where TV/Radio/Phone has a lot of antennas.
HOGE-performance is a must to approach/land, especially as there was hardly any wind that day.

The owner of the "incident" (actually the 206 is scrap metal, luckily only light injuries to the pilot) was sampling our EC120 two days ago, and will probably go for a new one. I warned him about the performance difference of the EC120 versus 206 at these altitudes, but he generally doesn't go there, so it seems the EC will fit his user profile just perfect. (I know the 206 beats the EC hands down up there....)
He was flying with his 2 sons who are both low time private pilots.
They basically confirmed my suspisions: 4 persons on board, average 175 lb + 60 gallons of fuel.
They indicated that the wreck is at around 10000ft, but from their discription "it" started to happen at the antennas (11200 ft).
The pilot was an "experienced" veteran - so experienced he never bothered to check performance-charts in the POH.....

As mentioned I was asked to possibly fly insurance personal to the site. The EC-performance-chart for HOGE gives me roughly 300kg over emptyweight - fuel-pilot-cargo/pax for the same conditions - so it would be one pax only, little fuel job.
Still I would check that with an HOGE in free air if the flight ever comes through.
In this case complacency killed the cat!

Thanks for all your inputs!

3top
:cool:

[407 Driver]

SHortshaft, please explain your 18 USG thoughts?

I'm assuming that you'd use 15 USG as a minimum (I have for my career) then a burn of 30 USG / Hr x 45 minutes = an additional 22.5 USG. The total adding up to 37.5 USG.

Crab, Bell HIGE / HOGE charts are based on Pressure altitudes.

[[email protected]]

407 - I guessed they were since most performance graphs are but I wasn't sure how 3top was assessing the altitude - did he climb on QNH and note the reading or did he have 1013 when he did the flypast? I think from his answers that he had 1013 set which at 11200' gives a DA of 13200' with +10 degC and 13840' with +15degC.

[SHortshaft]

407 Driver,

Thanks for the explanation of your fuel plan.

I was calculating on the basis of my understanding of the statement of the fuel on board being ‘45 minutes including reserve’. From that I calculate at a consumption of 24 USG / hr the fuel required was 18 USG.

As I see it the minimum planned fuel for landing is 20 minutes. Obviously depending on the type of operation (e.g. Part 135 equivalent) we may be required to carry an extra 10% variable reserve and an additional fixed reserve of 30 minutes (company requirement), but that was not stipulated in the original post.

I see that you are using 30 minutes fixed reserve at 30 USG/hr + 45 minutes at 30 USG /hr. Fair enough, but I query the fuel consumption rate you have chosen. As I read the graphs I would expect a lower fuel flow given the scenario quoted.

I didn't want to exaggerate in my post; I wanted to give the pilot of the incident aircraft the benefit of the doubt.

Happy Landings!

[vortexstate]

Channel Nine News in Sydney had a human interest story tonight, reporting that the NSW police today retired their last Bell 206 from service and are placing it into the museum for all to enjoy. The government has placed approx $M2.8 aside to replace the aging relic...... gunna miss seeing the old girl beating the skys, but I spose there are enough other aging relics (like the ones i fly) still around!
Do we have any idea on a replacment, and will they paint this one ship side grey?
:yuk:

[rotorque]

An AS350 B2 at this stage.....

The old Jetranger is 500 hours shy of 20,000 hrs. Not bad for one owner and only flown to the church on Sundays.

Cheers

[fullflaps]

It would have been a great feat for the boys to continue running it for another few months to hit that magic milestone.
It had to another AS350 to keep the maintenance streamlined....:ok:

[Shawn Coyle]

Highlights the problems with civil performance charts - they only give 'hover capability' and not power required to hover vs. height AGL like the military charts do.
Couple that with less than perfect knowledge of the power available from the engine (was this engine passing the power assurance check?), and you have the recipe for this accident to be repeated.
Subject of my next article in Rotor and Wing...
(and unless there is a large difference between the altimeter setting and standard pressure the actual altitude is close to the pressure altitude - but 10-15C is nearly 20C warmer than standard day for that altitude)

[Ascend Charlie]

Those machines were worked hard, around 100 hours per month each, with almost every takeoff at max weight. They performed pretty well, considering what we asked of them and the multiple roles required.

Hoisting a stranded policeman and his dog (part of a team trying to rescue a dopey bushwalker) off a cliff face in pouring rain and desperately low fuel was one of the fun memories. Specially the look on the dog's face.....

[tusker]

Do not forget the LTE folks, even slightly overweight, as bad as it is, may tempt the high time one into the IGE approach, but if you are in the mountains you do not always have the luxury of into the wind, and the cross wind at max all up plus some, at 10000 plus feet plus some, gives you the ideal LTE situation. We have had a couple of those of late and when you chat to the pilots the common denominator is, " I dunno what happened, it just ran away on me", and with a Vortex in the tail rotor no graph in the world is going to help out. Old 206 problem that most times gets swept under the carpet and the driver takes the rap. As for the EC120, dont forget that in thr EC120 VEMD you get the calculation on the screen in front of you and even if the POH was used for emergency toilet paper you still only have to know how the VEMD works and it will tell you what you can and what you can not do. Unfortunately in the 120 the red line is not as wide as in the 206 and that horrible announcement on the VEMD, "Parameter Overlimit" or "Exceedance" tends to make the driver a little more honest than he would have been under the Bell rules. Besides, both the 206 and the 120 are really magic helo's and driven between the correct lines make for really safe ops. I have flown a 120 from France to South Africa, 54 hrs ferry, and can assure you that the numbers in the book are quite conservative,
Cheers
Tusker

[Go Smoke]

Hi I'm fixed wing only but I would be interested to see what you guys think of the video link below.

LINK (http://www.airviolence.com/download.php?view.178)

It directs you to a page where you can download the short video.

Makes my hair stand on end seeing this - 10' less and I'm thinking that would have been it.
Cheers,
GS

apologies if this is old hat.

[UwantME2landWHERE!]

Apology accepted ;)

[Bravo73]

It has come up before, in a thread named 'Stupidly lucky....or luckily stupid?' (http://www.pprune.org/forums/showthread.php?s=&threadid=158788)

The title kinda says it all. :\


Regards,

B73

[Go Smoke]

Thanks for the link Bravo73, I had tried a search but didn't come up with anything.

Thanks again,

GS

[Kruger63]

I would say that the tail boom has a ripple underneath now....I dont what happened to him as he went off the end of the strip....I was waiting for the smoke

[giveitsome]

Look closely and you'll see pax in the back. It's one thing to have no idea about energy management and knock off heights ref aeros and wing overs by yourself, but to fly into the ground (and he did) with pax on board is unforgiveable. Guy will end up dead for sure, sad thing is he will probably kill other people as well.

The undercarriage and tail boom were never designed to take that sort of load and keep flying without some corrective maintenance.

The next video you see of this clown will probably be one where the tail boom comes off and the ACFT departs controlled flight.

Lets hope he doesn't pop up again.

If someone knows who this di - - head is-Do the right thing and put in a confidential incident report.


Give It some!!!

:*

[Wunper]

If this gets answered it should end up in the Jetranger thread

Does anyone have a good url to get an e-copy of the 206/206L series type certificate? I have googled myself into a stupor!

Many thanks in advance

W

[S92mech]

Here you go.
http://www.faa.gov/certification/aircraft/

[Wunper]

S92Mech

Many thanks a very useful link!!

W

[Lama Bear]

I'll bet you didn'y know that all the 206's including the 407 are on the same certificate. Makes the searching so much easier!

[S92mech]

No problem Wunper, glad I could help you.

[Choppersquad]

guys
iam looking for any good websites on the 206 jetranger.
ie general information on the machine
different colours schemes
part suppliers
range of accessories web site
is there also a 206 heliclub website etc

any thing that will give me knowledge and useful tips on the machine.

thanks in advance.

[Helinut]

Cs,

Try this one:

http://www.bellhelicopter.com/

Helinut

[Aesir]

CS

For accessories try:

Aero access (http://www.aero-access.com/)

However the accessories and options for the 206 is almost endless, don´t think you´ll find everything for the 206 on any one website.

Great helicopter : )

[ThomasTheTankEngine]

I might start flying a B206 L so im looking for some tips on diferance's from the 206 B (I have some time already on the B)

Thanks Guy's

[BlenderPilot]

Is it a "straight L"? or an L1,3,4? I have never flown a "straight L" and from what I understand its is extremely underpowered, now on the other L models . . . .

If you are going to fly an L3 or L4 watch your wind, weight because at higher weights and altitudes you will run out of pedal completly in calm wind with about 85 percent torque and begin spinning, if you don't watch the wind you will spin with less than that. Know your Critical Wind Azimuths. Forget the above if you have an L with a High Altitude TR kit.

When starting an L3 or L4 don't "crack" the throttle below or above what the manual says, do it at exactly what the manual states, I usually go at 12%, if you wait until say 14% it will usually lead to a delay in start and when it does it will be more of an "explosive start" in which the initial TOT rise will be more difficult to control.

Its extremely easy to autorotate but if you do autos to the ground do not ever pull back on cyclic past neutral because you will chop the boom or at least hit the fins with the MR.

Remember to check you forward fuel, and don't forget to shut off your fuel valve (or pull the pump CB's) or you will run you battery down even with the BATT switch OFF.

Overall its smoother, faster, more stable, than the JetRanger. Its my definition of a reliable and safe helicopter. I don't climb on these so often now but I used to everyday and I still feel its more reliable than the 407, and feel more confident in it, sure the 407 is more powerful, bigger, faster but I still see many things that need fixing in it, not so with the L models, THEY ARE PERFECT.

[The Rotordog]

Agree with nearly everything Blender said...except that bit about straight-L's being "extremely" underpowered. Don't know that I'd go that far. Then again, I flew 206A's, Franklin-powered 47's and A-model F-28's. (I know about underpowered.) As a matter of fact, those old straight L-models were actually faster than the L-1's with their wider engine cowlings.

Watch the fuel c.g.! It varies as it burns. If you happen to be lifting off with just yourself onboard at the most-aft fuel c.g., the nose will come up and up and up before the heels of the skids leave the ground. Keep this in mind when coming back in for a landing. Terminate to a hover a little higher than you normally would to keep the stinger well clear of the dirt. (Watch other L-models hover in this condition for enlightenment. It'll make a believer out of you.)

Similarly, you don't want to have someone in the copilot seat, two in the aft-facing seats and no one in the forward-facing rear seats, especially with an empty baggage compartment. Unlikely combination, you think? I've had it happen when shuttling passengers around to different destinations within a small area (Read: oilfield).

I've always felt that 206's in general have unresponsive, "squishy" feeling controls in flight because of the loose way the transmissions are mounted. The L-series is worst of the bunch. The transmission is suspended from the Nod-a-matic beam, which can cause some "interesting" flight characteristics. First is "nodal bounce" in which the airframe will sometimes jump up and down vertically as it would with an out-of-track rotor. Only it goes away! Secondly, when doing practice EOL's from cruise flight, if you lower the collective pitch before feeding in aft cyclic, the hammering from the nodamatic beam will give you nightmares. Remember: Aft cyclic FIRST, then down on the pole.

In a hover, the L-series seems more laterally unstable than the B. At least to me. Don't know why. And the pedals will seem like they're mired in molasses compared to the sporty pedals in a B-model. And when operating in close quarters don't forget, that tailboom is looooooong.

Like Blender, I think the L-models are just about perfect. The L-3 was my favorite. Once you get used to them you'll never want to go back to a harsh, slow, rattly old B-model.

Have fun!

[rotorboy]

Yeah, and once you get out of the L and into a Astar youll never want to fly the 206 again:ok:

rb

Oh and I whole heartly agree about the straight L being extremely underpowered.. Thank goodness the one i flew had H2o Alch inj.

[hihover]

I have operated the same 206 BIII for 8 months. In the past 2 months I have noticed an increased tendency for the main rotor blades to lock-up after about an hour from shut-down.

I understand the drill of moving the blades through 180 deg in the "wrong" direction before the next start and this clears the lock-up just fine, however, I have the following questions for you technical experts and would appreciate your help:

1. Could I be doing something that is causing this problem or is it quite normal for an engine with 400 hours to a mini-turbine?

2. Is there anything I can do to fix the problem without an engine strip?

3. Each morning, I am having to put quite a force on the blade tie-down in order to break the carbonisation. At what point should I say....ok, lets get it fixed?

Thanks for your time.

[Steve76]

Hi all,

Recently got to play in a Longranger LR model. Giddyup.

Had a discussion with a bloke that confused me and left me a little bit skeptical.

Apparently a C20R engine fitted to the LR is automatically given a +7% addition to its power assurance check. This was introduced during a discussion about the additional weight that can be calculated in the FM while working out your HOGE weights.

IE: if you are landing at 5000ft you might be able to carry 3500lbs of MAUW. Should you be flying the LR model, at that temperature and height you might add another 250lb of weight as per the FM chart.... no problem.

However, the reason for this is supposed to be that the C20R model is given a +7% rating to the PAC.

I find no mention of this in the FM and wonder if it is just more "Rotor Legend".

[TheFlyingSquirrel]

Was the water/meth injection system factory fitted or did it come as part of the C20R engine ? Thanks guys.

[Steve76]

Stock. No water or meth injection.

[TheFlyingSquirrel]

So why am under the illusion that all 206Ls have water/meth injection?

[albatross]

The only longranger with water injection was the original with the C20B engine.
I seem to recall that it was not standard kit. Perhaps someone has a copy of the RFM supplement.
I have heard that there were 206A's with the C18 that had it too but never saw one.
Bye the way - yes someone once actually did grab the wrong jerry can and fill the resevoir with jetB.
Upon injection the torque available was considerable - the TOT did however exeed all limits. It actually expanded the burner can and turned the outside of the turbine section a pretty purple colour! What it did to the burner can, nozzle and turbine wheels was impressive.

[John Eacott]

Albatross,

Yes, Water-Alcohol Power Augmentation System is FMS-1 in the 206L manual, not a standard fit. Kit part number 206-706-400 :8

[Airmech II]

Pah site sucks and took ages to login but .... What oil do you use in your engines, if it is not Mobil 254 or equivalent generation with high temperature qualities then this is normal & you will end up reducing the HMI time of your turbine. If you are using Mobil 254 then send me an email.

[hihover]

Thanks for taking the time to reply Airmech. Actually I am using Aeroshell 500.

Do you think that could be the cause?

[S92mech]

Have you done an oil flow check? How much oil flow do you have?
The only good way of fixin this problem is to split the turbine and clean the coking out.

[hihover]

Thanks for the replies chaps. Looks like I'll try and nurse it to the miniturbine.

[Bell 206]

Hi Fellow Ppruner's,

Hope there is someone out in our big wide helicopter world that might be able to help us.

We are looking for Sprag Equipment to fit a Bell 206 Long Ranger.
Used if possible.

Regards

Bell 206

Many happy landings to you all!:ok:

[rotorboy]

ISOLAIR try google, they make the tank and the micro foil boom.

Contact AGROTARS in PA (usa ) been spraying with 206's for ever.

RB

[quichemech]

It would also be the best time to switch your engine oil, the 254 may cost a bit more but it will be worth it.

[Bell 206]

Thanks Rotorboy,

will try them.

[overpitched]

Someone a bit closer to home is South West Helicopters at Cootamundra. They operate a spray 206. Terry McKenzie is the owner from memory.

http://www.southwesthelicopters.com.au/index.php

[hihover]

I'll look into that, thank you.

[Phoinix]

Can someone explain to me the difference between Jetranger II and III. Was there a "I" too? I would like to know more about it's history of development. Some www site where this data is available (google didn't bring much), or your pure experience. Thanks!

[helicopter-redeye]

I think the II had smaller tail rotor blades

[Brilliant Stuff]

And bigger Engine on the three. you also have the difference between the A model and B model.

I only remember that the III has a 420shp and maybe the II only 400shp and the I was 380shp don't quote me on that though. Someone will surely come along soon and give all the right in's and out's otherwise have your tried Heli Links (http://www.helikopter.li/) ?

[rotornut]

The 206A had an Allison 250 C-18A with maximum output of 317 shp. The "B" had an Allison 250 C-20 with 420 shp. However, I believe the maximum take off power of the C-20 in the "B" was limited to 317 shp, the same as the "A" model. These are the main differences, as I recall. I'm sure there's someone out there who can fill you in on the others.

[paco]

As mentioned, the A model had a 250-C18, which wasn't cycle limited, and a 3000 lb MAUW. The II and III have a C20B engine, and the III has a 92 gallon tank, which has been subject to a 50-ft drop test with all that fuel in, which the ordinary 76 gallon one with a range extender hasn't.

Otherwise, there's not much real difference, aside from styling and looks inside, except that the III has a higher internal MAUW of 3350 lbs (as opposed to 3200) if the 65" tail rotor is fitted, together with a placard or two. I think the II can have the same mod, but I'm not sure.

Phil

[Phoinix]

So, the only difference between II and III is the tail rotor. No structural difference in the tail boom?

The whole thing came up on our two jetrangers. S/N around 8400, almost one after the other. One has a sign (just FWD of front door) Agusta-Bell Jetranger III, the other just Agusta Bell Jetranger. And I was wondering if the other might be something else than a III, and how can you tell. Nothing about "JetRanger ??" in the manual.

From what i can tell, both have the same tail rotor. Only difference is that one has leather seats. :suspect:

[goaround7]

IIs or IIs converted into IIIs have the fuel pump/filter in a different position on opposite side.

Also check door latches - IIs had square ones, IIIs aerofoil shape (unless they went to the trouble of changing them when they upgraded a II to a III).

[The Nr Fairy]

If you're a low time pilot, or inexperienced on JetRangers, then a checkout on an A model if you've not flown one before is a must.

A company I do ad-hoc work for had to lease in a 206. Only one available was an A model and I had to get checked out on it specifically before flying it. It turned out to be the hottest day of the year as well, so an A model which hits the TOT limit first, not a torque limit, was interesting.

What did I learn, both from the checkout and the day's flying ? Don't have loads of fuel, make sure the ground staff load pax to a MAUM well below the max authorised for the a/c (in this case MAUM is 3000 lb, I kept it with 25 USG and asked for a max of 2800lbs max). Worked a treat.

[Phoinix]

In our country we have no A models. TQ is defenetly the first to reach the limit.

@goaround7:

Fuel filter is located on the port side.]

[overpitched]

From memory all the A models I have flown have had hydraulic pedals. Also most jetranges I have seen have a small tag attached near the drivers side pedals that gives serial number and model type.

[Phoinix]

No **** :}

I already know S/N and AB-206B, only "Jetranger [?]" is missing.

[shorthorn]

The information for converting a Jetranger from a 11 to a 111 is contained in Service Instruction 112. From memory the items that require changing are the larger (wider) oil cooler which also requires strengthening of the deck which it sits on.

The tail rotor gear box output shaft on the 111 is also different (larger). The tail rotor gear box housing is the same but the cover plate, output shaft, bearing etc are different.

[Ascend Charlie]

Isn't there also a difference in the main Xmsn, one having 3 spur gears and the later models having 4?

Instrument panel clusters varied from a B47 layout, to a curved panel like a Huey, to a flat rectangle.

Where's Giovanni Cento Nove when you need a techo answer like this? Swanning around somewhere in the Med on his yacht, probably.

[Jed A1]

Phoinix,

I thought your two Jetrangers were SN's 8643 & 8646. Both manufactured in 1981. That would make them both BIII's. See the approved flight manual.

Bell started production of the Jetranger in 1965. The first civilian model was the 206A, with the Allison 250-C18 which produced max 317shp. This was and still is the transmission limit. Engine TBO was 1,500 hrs - no cycle limit. MAUM 3,000lbs.

In 1971 the 206B started production, the engine was changed to the C20 with a 3,500 TBO (but cycle limited). The panel was changed and MAUM was increased to 3,200lbs.

You can convert a 206A to B spec's and this is known as a 206A/B.

In 1976 minor upgrades were introduced and the was known as the BII.

In 1977 the BIII was introduced with the C20B 420 shp engine and 2" larger tail rotor for more tail rotor authority. Transmission limit still 317shp. Factory new BIII's are SN's >= 2212.

In 1982 the BIII (SN's 3567 onwards) got better seats, 91gal tank, improved latches, wedge windows, harness changes and the C20J engine (with minor changes over the C20B).

Agusta license built virtually all models of the 206 for sale outside of the US.

All of the top of my head ;)

[trackdirect]

Jetranger III has

* Bigger air vents positioned lower on nose
* Double latch doors
* C20B eng (later models have W,J or R)
* 4 pinion planetary in transmission also oil filter housing instead of screw on filter.
* Beefier MR blade grips, different blade bolts.
* Rods and bellcranks for N2 system (instead of flex cable)
* Heavy duty Main driveshaft
* Bigger oil cooler (Deck under oil cooler is replaced with honeycomb deck)
* different oil cooler cowling (Mainly length and vent differences)
* TRDS cover different fasteners (camloc instead of DZUS)
* Segmented TRDS ( some late II's had this though)
* Bigger TRGB output shaft
* Bigger TR span
* Two piece aluminium TRGB cowling
* Different servo mount on top deck (lifed to 10000hrs)
* Air scoop on eng cowl for starter gen

The TR servo was phased out sometime during the BII production.
Also some other cosmetic changes in the interior with plastic changes and fwd seat belt shoulder harness mounts.
Later model III's have added rear shoulder harness and different door handles, similar to Longranger style handles!!

The fuel filter position was only changed when the alisons were having problems with turbines letting go.... with the filter on the port side next to the turbine it tended to get taken out when the turbine wheels flew out the side resulting in a fire to deal with as well as no engine.... so they moved it to the stbd front of the engine bay to give you one less thing to worry about if the turbine blew up!!! once this problem was solved they went back to thew old spot.


Any more questions???:ok:

[overpitched]

Well there you go. I thought that fuel filter relocation was a mod performed on media 206s as a result of an accident in the states.

[trackdirect]

From memory, many years ago there used to be a placard on 206 N2 gauges that said "Avoid continuous ops between 90 - 98% N2"
There was a yellow arc and it was advised that ops were either at idle or 100% with smooth acceleration to be carried out between 90-98 and no ops in that range due to a harmonic forming in the #3 wheel. The harmonic would cause blade and shroud separation, this is why bell moved the filter.
Allison beefed up the wheels and this problem was cured. The filters were then put back in their original place in later models.

Besides it was a bit crowded up front maintenance wise if you had to remove a driveshaft with a fuel filter in the way, especially if there was a rotorbrake fitted, I much prefer the filter up the back end of the engine instead of the front!!!

[rotornut]

Don't have loads of fuel, make sure the ground staff load pax to a MAUM well below the max authorised for the a/c Oh yes, and make sure your compressor isn't worn out. Ours certainly was and until we replaced it it would hardly lift off with just a pilot and passenger and not even full fuel.

[Phoinix]

Jed A1, you are correct. My bad on S/N. How did you get the data for our jetrangers anyway? :8


You guys are amazing, thanks for the info! :ok:

[vaqueroaero]

OK so here's the situation:

Doing track and balance in a refurbished 206 A model with a C18 motor. When the throttle is rolled off to ground idle, the N2 stays in line with NR.

Initially if NR increases then N2 will follow it with an increase, but then slowly it will start to decrease, but N2 never gets to the idle position of around 60-65%.

So is this normal for a C18, all other 206's I've flown when the throttle is closed there is an immediate needle split.

Is it a problem with the sprag clutch (that's we think) or something else.

Aircraft grounded until we have an answer.

Thanks in advance.

[NickLappos]

The condition isn't normal, I think. The clutch is the first suspect. How does it behave manually when things aren't running? Any noises or funny business?
Sounds like it is partially hanging up, which is a sign it could fail in either direction, potentially leading to a de-clutch under power, which looks like an engine overspeed combined with an engine failure. Not good.

[PPRUNE FAN#1]

The condition isn't normal, I think. The clutch is the first suspect.Despite what Brother Lappos says, this is completely normal. It is the sure sign of an inexperienced turbine pilot when he complains that he doesn't get any "needle-split" during a practice auto. (Here's a hint: it's called a free-turbine.)

vaqueroaero:Initially if NR increases then N2 will follow it with an increase, but then slowly it will start to decrease, but N2 never gets to the idle position of around 60-65%.And it won't. The N1 will surely fall to it's idle range, the but even at "idle," the 250 engine is putting out somewhere around 18 horsepower- enough to keep the unloaded N2 wheels spinning at their governed rpm.

Governed?

Yup. Just because the fuel control lever (that "throttle" thingee) is in "Idle" doesn't mean that the governor isn't still working. And yes, it will keep the N2 from overspeeding if the NR increases above 100%.

Many new turbine pilots are confused by this. They do not understand that the N2 needles WILL NOT necessarily split like a recip in a practice auto. One fatal accident occurred because during the practice auto the two pilots were more concerned about the lack of a needle-split than what they were doing. The Rolls Royce engine manual even states that some "N2 instability" is normal. Yeah, once in awhile I've seen a little "hunting" of the N2 needle in a practice auto (especially with a C-30), but most of the time the N2 stays right up there at 100%. In fact, in practice, there is very little difference between flat-pitch "full throttle" and flat-pitch "flight-idle." Even the N1 readings may be similar.

But just for argument's sake let's rule out the freewheeling unit! When you shut the engine down, do you get a needle-split then? (Go to cut-off from 70 or 80% NR if you have to.) When the ship is shut down and you turn the rotor in the direction of rotation, can you hear the N2 wheels turning?

If the answer to those two questions is "yes," then there is no reason to ground the ship. Fly on, hombre.

[NickLappos]

Wow, do we need a course correction or what?
How many things did pprfan#1 just screw up? Let me see:

1) When the throttle on an Allison/RR is rolled to idle, the governor is put to bed, out of the picture. I could draw the schematic for ppf if he'd bother to read it. At idle, the CECO fuel control metering valve is pulled back to an essentially fixed position, which allows the engine to barely run. On an S-76A the idle will be about 65 to 70% if the throttle is pulled back, with the rotor at 100%.

2) The needles will split, virtually all the time, when you command the engine to idle with the throttle while the rotor is at 100%. If you just let the collective down and the rotor builds upward, the engine will still be governed, and will creep up to about 103%. This is called updroop, and is built into the governor for stability purposes.

3) If you do not get a clean needle split when you roll the throttle to idle and the rotor stays at 100%, then land the aircraft and give it to pprune fan #1. He deserves it. In Sikorskys, including RR equipped engines (S-76A), it is a maintenance check that you MUST get a split. If not, suspect the clutch.

In my turbine flying, I have seen a few clutches that hang slightly, enough to prevent a split when the throttle/speed levers are pulled to idle. These clutches had bad rollers, and in one case, the clutch was about to fail. I also have a few patents on these engine control characteristics, I think I understand it a bit.

I really do not know what is up pprune Fan #1's butt this week, but I hope it crawls out and leaves him alone!

[Red Wine]

Number 1 Fan....

What a dangerous series of one liners that you have quoted.

If any younger aviator listens and remembers your obviously incorrect statements then they may put your advice into action with serious implications.

One piece of advice to all:….

If you roll the throttle off in flight and there is no Split between the NR and N2 on a RR, then put the machine happily on the closest hard ground and yell for help.

You have a Clutch Free Wheel Unit problem…..

[ThomasTheTankEngine]

Its been a few years since I flew the 206 in flight in autorotation we always had a big needle split.

On one 206 I flew there was no needle split in autorotation when the throttle was closed so the aircraft was grounded and repaired, Sorry but I don't know what the problem was it was some time back.

[maxtork]

I would have to agree with Nick's camp on this one as well. You should get a needle split. However before I started looking at the big spendy parts like the sprag clutch I would check to see if the aircraft is lying to us. If memory serves me correctly the NR/N2 gauge has two cannon plugs on the backside one for each indication and it is very easy to reverse them. I have seen this before and it isn't always caught early on. I would expect if this was the case that you would still get a needle split but it would be reversed (NR would drop off and N2 would remain) but stranger things have happened. Just a thought worth considering but above and beyond that the freewheel clutch it is.

Max

[NickLappos]

good idea, Max, and less expensive! Not likely, if the gauge has behaved right otherwise, but still a good idea to check.

Bad clutch rollers can sometimes be flet and heard when the shaft is rotated by hand in the hangar. Sort of ratchety feeling and a snickity sound.

[S92mech]

Years ago I had a 206B have a clutch failure. Pilot reported a noise when the main rotor blade was rotated forward by hand. We rotated the main rotor forward and the power turbine turned with the blades. I removed the sprag clutch and found the cage of the clutch broken with a piece of the cage jammed in between the sprags.
Fly at your own risk.

[BlenderPilot]

My old job at a Bell CSF involved doing a Maintenance Flight before and after a helicopter was recieved for maintenance, we would take all paramenters, idle, hover, flight, power check, control rigging, and Autorotation RPM, etc. etc. I have probably flown 40 different JetRangers and some get a needle split in Auto but some don't, at first I thought that wasn't right, but the mechanics said that it was ok as long as when you where on the ground, when you shut the engine down the needles would split, if they didn't then there were problems, but this was on engine shutdown.

In flight we have never made a discrepancy of the needles not splitting.

[Fatigue]

Gentlemen, I have to agree with Blenderpilot on this one, at mother rucker ,we do autos everyday and while the N1 goes to idle, we do not get a needle split between the N2 and nr , only on the shut down there is a positive split......

[PPRUNE FAN#1]

Wow. Darn. Now I'm really confused. And I mean scratching-my-head-confused. I've flown a 206 or two in my day. And I say: No definite N2/NR needle-split in a practice auto in a 206. Then people, including the "esteemed" N. Lappos jump down my throat and call me incorrect. Maybe I've only dreamt my career, that it didn't really happen? Perhaps.

N.L. sez:1) When the throttle on an Allison/RR is rolled to idle, the governor is put to bed, out of the picture. I could draw the schematic for ppf if he'd bother to read it. At idle, the CECO fuel control metering valve is pulled back to an essentially fixed position, which allows the engine to barely run. On an S-76A the idle will be about 65 to 70% if the throttle is pulled back, with the rotor at 100%.Hmm, the N2needle goes to 65%? I've never flown an S-76, but this statement does surprise me. So what you're saying is that once the FCL is brought back to "idle," the governor is completely out of the picture, hmm?2) The needles will split, virtually all the time, when you command the engine to idle with the throttle while the rotor is at 100%. If you just let the collective down and the rotor builds upward, the engine will still be governed, and will creep up to about 103%. This is called updroop, and is built into the governor for stability purposes.Well I have to admit that I do not understand this statement. If we retard an FCL on an engine to "idle," then as you say that engine's N2 will go to 65%. Okay...but...how will lowering the collective cause that engine's N2 to go to 103%? Furthermore, why will that engine's N2 be "governed " to 103% if the governor is completely off-line? Maybe I better have a look at that schematic, Nick.

I think two things are happening here. Either Nicky is confusing N1 and N2 or he has forgotten how an S-76 flies. Hey, let's not be too hard on him- that's what happens when we get old.

I will admit that since I've never flown an S-76A, it is entirely possible that if you pull an FCL lever back, that engine's N2 might go to 65%. I doubt it, but it's possible. But I can say with confidence that the N2 needle of a 206 will definitely *not* go to 65 or 70% in flight with the throttle at "idle." Anyone who says otherwise is either fantasizing, doesn't understand how free turbine engines work, or has never flown a 206.

I guess I'll just wait and see if anyone else weighs-in on this topic. Maybe a former Bell Helicopter CSF pilot or a guy who flies at Rucker will shed some light on this and prove me wrong once and for all.

[skitzs]

In PPfan1 defence.

I dont know what im talking about but i have a couple of thousand hrs in 206 and do autos at least 2/3 times week and never seen a needle split more than 8% or so, i just put it down to the lack of load on the N2 during auto, even the N1 idle sits a bit higher at times in auto than at ground idle, either the same or 1% more.

I also presume the free wheel unit aint so slopy so im guessing may be it will drag the N2 up a little, its bound to. Cant see this as a malfunction,

These are only my observations and are also recorded during test flights by maint: we run quite a few B206 and are all exactly the same give or take 1% or so.

Like i say, just what i see, never seen it any other way, maybe all our 206 should be grounded, ( i need a vacation ) :D hope this helps.

Will certainly dig a little deeper now. cheers. ( edit for my bad spelling)

[Arm out the window]

To maybe cloud the issue a bit, in the 205 when we did maintenance test flights that required autorotation, we would for the first one lower the collective fully and look for a needle split (N2 vs Nr); then, having proven that it would autorotate, wind the throttle to idle from the cruise for subsequent entries, giving a marked needle split when the collective was then lowered, Nr recovered and N2 stayed down (can't remember the value it went to, but definitely below the governed range of 6000 to about 6700 from memory).
Going out in the 206 tomorrow so may get a chance to check the occurrence or otherwise of needle splits when the collective is lowered fully to enter the auto profile (won't be rolling the throttle off though).
Can I also put in a request for the maintenance (pardon the pun) of a non-bitchy forum, as we usually enjoy.

[eagle 86]

Wasn't going to get into this but I will. As an ex-mil instructor with not an inconsiderable number of hours (and subsequent EOL's) on many Brit and US machines it is my experience that, almost always, the split between N2 and NR in stable autorotative flight is minimal,not so N1.
In the machine I currently fly and do autos in for Base Check/ conversion purposes, powered by a single PT6, the manufacturer saw fit to overlay the Mechanical Engine Control with an Electronic Engine Control to ensure an N2/NR split in auto. Not so the N1 which can hit a Flight Idle RPM in auto 6 or so % below the on ground, flat pitch Flight Idle - low enough to bring the ENG OUT warning on!
In a hard flaring manouvre the N2 will follow the NR up.
GAGS E86

[chester2005]

I would be grateful for some recommendations for Jetranger type conversion training in the UK.

Preferably the cheapest one:O

Also preferably in the North or Midlands, however if the price was right i would travel. (its only a 5 hour course isn't it?)

Is 5 hours realistic for conversion from R22 and R44? or should i budget for more?

I will be flying one in the USA later in the year so to be able to log the hours (JAR logbook) i need to be type rated on my JAA licence.

If someone knows a way around this please let me know. I believe that the UK CAA can be really picky about people hour building in USA in helis that they are not rated for but still trying to log P1 hours .

Thanks in advance :ok: :ok:
Chester

[oldrotorhead]

mmmmm.....methinks most of you have little idea about how a free turbine engine works, including the governor, except for Nick Lappos and a couple of others above!!

PPN#1F..where did you get the impression that Nick said any thing about the N2 being at 70% at idle? Come on now, you must be aware he was referring to the N1.
And by the way, if you are in any doubt as to whether the governor on an Allison or RR 250 is working when the throttle or power lever/s is or are back at idle (in autorotation of course), try pulling the bloody lever up climbing away and see how quick your "governed" N2 gives up. Haven't ya noticed what happens to the N2 during the terminationof a practice EOL, even at the hover?
Defence rests, yer honour.

[The Nr Fairy]

I did mine at Alan Mann - expensive, but there was a reason for it. I can't recommend any schools up north, but I'd ensure you ask to be shown:

[list=1]
Flight with limiting conditions (TOT, torque, and N1 if possible) - preferably also at MAUM or close to it.
Flight in an A model (severely TOT limited).
Crosswind / downwind operations when OGE and heavy. Beware gusts !!
[/list=1]

If you're switched on, converting across in 5 hours is not an issue.

And BTW, learn about the torque / TOT limits - not just temporary exceedances, but what exceeding the limits means for maintenance action.

[paco]

chester2005 - give me a PM!

Phil

[Bravo73]

chester2005 - give me a PM as well!

Also, check out this thread (http://www.pprune.org/forums/showthread.php?s=&postid=1450966#post1450966) for some handy JetBanger tips. It's a great machine.


B73

[ThomasTheTankEngine]

The Helicentre at Liverpool. Sorry I dont have the website address.

[MGT727]

Heard a Jetranger crashed today in Angola killing 1. Anybody with more info on what happened?

[i2gofly]

My good ole' friend vaqueroaero....just have the master, Mr Krauss take a look at it! :)

[Hippolite]

MGT

This one took some finding out but details are as follows:

Owner is a company called Inter Transit. They are in the construction and transportation business apparently.

The company has had the 206B for about 10 years.

My informants tell me it was an engine flame out but the landing caused damage and injuries.

Passengers included the Vice Minister for Public Works, his ex deputy and the ex minister for social integration.

Some have had to be flown to South Africa for treatment.

HH:cool:

[Matthew Parsons]

As many have indicated, there is a possibility that there's a clutch related problem. The results of that can be quite nasty, so it's a good idea to confirm whether that is the case.

If it's not the case, it could be that the idle setting of the throttle is providing enough non-governed fuel to allow an unloaded freewheel to spin at N2=100%. If N2=NR then the clutch should engage so you wouldn't expect to see N2>NR (that's bad). If the rotor increases slightly, then N2 may be able to increase as well, but just to the N2 that is possible with an unloaded freewheel.

Because you said that the N2 will drop below 100% once it splits from the NR, then it seems that the rotor is driving the freewheel to an extent.

In any case, ensure the clutch is working properly.


As far as the 103% NR after a collective drop that Nick mentioned, I don't know the S76 system, but other governing systems that are not isochronous (maintain exactly 100%) will exhibit similiar behaviour. Rather than reacting immediately to small changes in NR or collective position by providing less fuel, a reduced power demand will cause the rotor to increase. Once the increase is large enough, then the fuel flow is altered.

Maintaining the NR slightly high following a reduced power demand has the benefit that if the power demand is soon increased, then the rotor only has to slow without changing the fuel flow again. This means that the engine runs at a constant power when there are quickly changing loads in the rotor. Or as Nick said, it improves the stability.

Of course, engine and rotor governing is much bigger than what I've mentioned, this is a simple explanation of why higher rotor speeds can result from collective lowerings in some systems. Experts, feel free to tear this apart.

Matthew.

[PPRUNE FAN#1]

oldrotorhead:PPN#1F..where did you get the impression that Nick said any thing about the N2 being at 70% at idle? Come on now, you must be aware he was referring to the N1.Yes, leave it to a "test pilot" to complicate the issue. Vaqueroaero never mentioned N1. He was referring only to the apparent lack of N2/NR split in a practice auto. Which is normal. He said he (erroneously) expected that the N2 needle would drop to 65% "idle" position. Others chimed in with similar (and similarly wrong) expectations, and then our boy Nick sez that when you pull the throttle back on an S-76A the rpm goes to 65-70%. Oh yeah, he fails to mention whether that's N1 or N2. Hey, even I was confused by that statement, so I *KNOW* that vaqueroaero, who was expecting "65%" N2 during his practice auto, is too. The other thing I question is, if the C-30 idle speed is set properly (59-65% according to the RR manual), then why, with the FCL on the idle stop, is the N1 65-70% in an S-76A? In my C-20 equipped ships, rolling the throttle to idle gives me 62% N1, just like on the ground. Do S-76A pilots not pull all the way back to the idle-stop?And by the way, if you are in any doubt as to whether the governor on an Allison or RR 250 is working when the throttle or power lever/s is or are back at idle (in autorotation of course), try pulling the bloody lever up climbing away and see how quick your "governed" N2 gives up. Haven't ya noticed what happens to the N2 during the terminationof a practice EOL, even at the hover?Lord, some of you are dense beyond belief. Here is what I have observed: Sometimes in a practice auto, if I make a turn or a flare, the NR will increase above 100%. The N2 will start to follow the NR up, but it will *then* split and go back to 100% or so. Governed? Maybe not, but the N2 for some reason does not always follow the rotor up to the 107% limit.

And in fact, this is *exactly* the situation vaqueroaero described.

Matthew Parsons says:In any case, ensure the clutch is working properly....Which would be good advice, IF THERE WERE A CLUTCH. But there isn't. It's called a "freewheeling unit." And calling a FWU a "clutch" is like saying there's a clutch on the back wheel of your bicycle. Which we don't say. There is no clutch on a helicopter with a free-turbine engine. If the NR goes above the N2, either in practice autorotation or upon shutdown, then the FWU is working properly. According to vaqueroaero's original post, there was never any indication that the FWU was doing anything other than what it's supposed to.

Some of you people really need to learn more about how 206B's behave before spouting off about stuff you do not know. But that is a constant source of irritation on this board. Someone will ask a legitimate and specific question, then he'll get responses that start out, "I don't know the answer to this, but I think..." Hey, if you don't know the answer, why not leave it for those who DO?

Live and learn, boys, live and learn. And hopefully, vaqueroaero has learned...well...*something*...from this thread and is back flying his inappropriately-grounded 206. (I'd love to see the write-up and sign-off on the maintenance log on this one!)

[Quick Release]

Yes it is quite interesting seeing some of the views on this one,

Im still with PPF.! on this one regarding N2 split,

the B206 has a FWU which is a "sprag bearing" and is a nice tight fit, it has to be other wise when it comes to drive it will slip when engaging and wouldnt be healthy, so" there is drag on that "sprag bearing" when free wheeling, when the rpm rises, flaring lets say, there is a slight increase in N2, be it only small,
Balanced decent in an auto with a flare at the bottom and the nose Yaws left, transmission: drag. same kind of thing.
It ain't broken......:*

[fostaire]

It is really enlightening to see the varied opinions from so many people. Let me put in my 2 cents worth. Before I get drilled from the other highly regarded participants, I am going to give what I know to be a likely possibility from years of maintenance experience as well as flying experience in the type.

This applies to a Bell 206 and the RR 250 engiine.

First: when the twist grip is rolled to flight idle the governor is out of the system.

Second: Once the twist grip is in the flight idle positionwhile in flight (autorotation), the N2 RPM will be TOTALLY dependant on what maintenance has the Fuel Control (N1) IDLE setting at. If the FCU idle is on the high side, there will be NO needle split in autorotation. For training ships, it is generally a good idea to set idle on the low side to get a good needle split in autorotation.

Third: Don't ever fly a machine if you suspect the freewheeling unit to be defective. The life you save may be your OWN! You can check it on the ground as others have stated by rotating the rotor both directions and listening/observing the 4th stage turbine wheel in the exhaust stack. Rotate the rotor IN the direction of rotation and the turbine should NOT rotate, and there should not be any rubbing/chattering noises. Rotate the rotor opposite the direction of rotoation, and the turbine SHOULD turn, and you MAY get some additional "whirring"noise from the engine.

Most importantly what I have drawn from this thread is if you have a maintenance question, ASK A MAINTENANCE TYPE!!!! Pilots are notorius for trying to baffle with BS when they aren't sure. Yes, I am an ATP. :-)

[anjouan]

fostaire,
How nice to see a civilised, knowledgeable reply without a hint of condescension like those from PF#1.
Naturally, there is a clutch involved. In simplified terms, a sprag clutch is a freewheeling clutch which through a system of roller bearings allows a drive to be transmitted in one direction whilst, through its freewheeling mechanism, in the case of a helicopter, it allows the engine to run down to idle whilst the rotor RPM are not dragged down with it.
Nick may have omitted to mention that it is the N1 which go to idle, whilst the N2 stays loosely at the same value as the Nr, but be assured that his observations on PPRuNe will always carry more weight than those of PF#1 because we all know where Nick is coming from - after all he posts openly under his own name, unlike either PF#1 or myself and Nick is not insufferably pompous, arrogant and overbearing in his replies :}

[Matthew Parsons]

Clutch: noun "Any of various devices for engaging and disengaging two working parts of a shaft or of a shaft and a driving mechanism."

Live and learn PPF#1.

[PPRUNE FAN#1]

anjouan:Nick may have omitted to mention that it is the N1 which go to idle, whilst the N2 stays loosely at the same value as the Nr, but be assured that his observations on PPRuNe will always carry more weight than those of PF#1 because we all know where Nick is coming from - after all he posts openly under his own name, unlike either PF#1 or myself.And so by that standard, anjouan, we shouldn't pay any attention to anything you say either, eh?

I really detest this site and the way some of you gits get. You feel that it's okay to say anything at all (even if it's incorrect) as long as it's veddy, veddy polite. After all, if it's not said with just the proper temperament, then we don't want to hear it, eh what? Which is why, I guess, Nick Lappos can make conflicting and contradictory statements but nobody dares say anything.

Vaqueroaero posted his little issue. Nick replied with, "The condition isn't normal, I think." Later on, he sez, "The needles will split, virtually all the time, when you command the engine to idle with the throttle while the rotor is at 100%. If you just let the collective down and the rotor builds upward, the engine will still be governed, and will creep up to about 103%."

Let me see if I got this right: So the engine is not governed but then again it is, and the N2 will definitely split but will stay up around 100%, maybe as high as 103. According to Nick.

Oooookay. Clear as mud now!

Nick again: If you do not get a clean needle split when you roll the throttle to idle and the rotor stays at 100%, then land the aircraft and give it to pprune fan #1.

In other words, give it to a pilot who's actually qualified to fly it, knows something about it and knows improper conditions from proper ones. Yes, I'll buy that.

Here's a scenario for you self-appointed experts out there: What if you're solo and have minimum fuel when you do your auto rpm check? Even at flat pitch, the NR will decay from 100% to where it ought to be for that machine. As will the N2. Definite split? Not. Nope. No way.

And Matthew, every helicopter has a sprague clutch (FWU), that is a given. Pistons and fixed-turbine ships have other clutches that actually allow the engine to rev above the NR upon start-up. I have met many RR 250 pilots who really, truly thought that their steed had also had such a "clutch" in addition to the FWU. I was afraid you were one of them. See, we turbine pilots do not refer to the FWU as a clutch except as a conjunctive term.

Threads like this are actually a lot of fun. I'm sure there are a lot of pilot-readers out there going, "You mean turbines *don't* have clutches?" "You mean the N2 needle of a free turbine won't go to idle when you roll the throttle off in flight?" "You mean the N2 needle in a free-turbine engine might not even split in a practice auto?"

[NickLappos]

pprunefan#1,

It is clear from your adrenalin-fueled rants that whatever crawled up your butt remains there. I do think most readers will get more out of this with less storm, and more discourse.

Regarding what someone with an open mind could have learned here:

1) The engine is NOT governed when the throttle is at idle. It is set to a relatively fixed fuel flow. (BTW - For CECO fuel controls, it is an absolutely fixed fuel flow, changable only by maintenance setting. Once, 25 years ago, we had to shim the idle metering valve, because we ran out of turns on it, and could not get a start.)

2) The Nr/N2 needles will split most of the time in a 206, and MUST split all of the time in a Sikorsky, when the rotor is at 100% in auto, and the engine(s) throttle(s) are at idle. SOME 206's might not show a split if their fixed idle settings are on the high side.

3) If you don't get a split while at idle in an auto, ask questions, because it could be a bad thing in a 206, and always is a bad thing in most other helicopters.

4) If you want a clean, carefully thought out answer, don't ask Pprune fan #1. He doesn't like to share his info, he likes to whack you in the head with a shovelful of it.

[anjouan]

PF#1 is the only person who in his rantings will eventually be ignored just because of the unpleasantness of his manner. If you detest this site so much I suggest you stay off it in future - you will not be missed.

I did not say that posts from anyone who posts anonymously should not be paid attention to, merely that we all know who Nick is and that, therefore we know where he's coming from and how well qualified he is when he makes his informative comments on technical matters.
The main one who is confused around here seems to be you. For example
IF THERE WERE A CLUTCH. But there isn't.
every helicopter has a sprague clutch (FWU), that is a given. . So there isn't a clutch, yet every helicopter has one?! :confused: Oooookay. Clear as mud now!

A clutch is merely a device for connecting two rotating shafts of which there are, of course, many in a helicopter. A sprag clutch is a clutch mechanism which incorporates a freewheeling unit so that the two rotating shafts can be disengaged if the inner one slows down. In a turbine, this allows the engine compressor and it's associated gas generator to be at idle, without dragging down the rotor. Naturally, on the ground the rotor will slow down if it is not being driven at a flight rpm power setting, whilst its rpm in autorotation will vary depending the factors altering the autorotative force. So as fostaire and Nick have pointed out, the N1 and N2 will depend on the maintenance settings on the CECO FCU, whilst the Nr will vary depending on whether the aircraft is in a steady state autorotation or is being manoeuvred, which could cause an increase or a decrease. If the steady state auto are too low, they can be increased by engineering making adjustments to the blade pitch.

Naturally PF#1 will now write a 10 page rant explaining how all of the above is rubbish, especially as I really detest this site and the way some of you gits get. , or maybe Threads like this are actually a lot of fun. . Confused? You will be :ok:

[PPRUNE FAN#1]

anjouan, you have contributed exactly ZERO to this thread. I suggest you simply stay out of it unless you have something positive to contribute.

There. Short enough for you?

EDIT: Oops! I just went back and re-read your post, old bean. You wrote:A sprag clutch is a clutch mechanism which incorporates a freewheeling unit so that the two rotating shafts can be disengaged if the inner one slows down. In a turbine, this allows the engine compressor and it's associated gas generator to be at idle, without dragging down the rotor. See what I mean about people who don't know what they're talking about? Let's go back to Turbines 101. Sonny, the COMPRESSOR/GAS GENERATOR can speed up and slow down at will with absolutely no effect on the NR. It is only "gas coupled" to the rotor.

It is the N2 shaft that is the one connected to the trans. The sprague clutch allows the N2 wheels/shaft to do slow down without effecting the NR. (Not exactly ten pages but it will have to do.)

Don't you people understand this subject? I thought you guys were smarter than this. Guess I was wrong. Gosh I hate that.

Oh Nick!2) The Nr/N2 needles will split most of the time in a 206, and MUST split all of the time in a Sikorsky, when the rotor is at 100% in auto, and the engine(s) throttle(s) are at idle. SOME 206's might not show a split if their fixed idle settings are on the high side.Nick, you ought to stick to Sikorskys. Or Gulfstreams. Or Mooneys. Or whatever it is you're flying these days. You evidently don't know much about 206s if you say something like getting a split "most" of the time in a 206. Wrong!3) If you don't get a split while at idle in an auto, ask questions, because it could be a bad thing in a 206, and always is a bad thing in most other helicopters.It is not *always* a bad thing in a H-500. It is not *always* a bad thing in an E-480. It is not always a bad thing in a S-333. It is not *always* a bad thing in a Twinstar. It is not *always* a bad thing in a BO105. Did I leave any RR-250 ship out?

If anyone is doing anything with a shovel, it ain't me. But yeah, there sure is a lot of shovelling going on here.

[anjouan]

PF#1, you really are a most obnoxious person and it's not surprising you were thrown off when you were using your other name. I am not, nor ever will be any b*astard son of yours - I'd kill myself if I were, but as I'm almost certainly older than you I think it unlikely. What exactly, pray, do you feel you have contributed to this thread? You spotted my small error (freely admitted) and then rant on and on in your usual arrogant and condescending fashion. Yes I'm human, I make errors, but you just hate to be wrong don't you? Wow, a perfect pilot - you must be the first one ever then. You wind yourself up so quickly, it's probably just as well you're a manager now - someone as unstable as you would probably be a danger to all when flying. Your English, which unlike mine is probably your native language is not much better either. It's a sprag clutch SONNY

IF THERE WERE A CLUTCH. But there isn't. The sprague clutch allows the N2 wheels/shaft to do slow down without effecting the NR Okay.... so there isn't a clutch in there, but the one which isn't there allows the N2 shaft to do slow down without affecting the Nr.

So have you decided yet whether there is or isn't a clutch in there somewhere? You're such an obnoxious git, it's not worth commenting further. I'll leave you to finish off with another of your tirades.

[SASless]

Something I used to do before doing an autorotation in a strange aircraft......while setting on the ground at full chat....pull an arm full of collective...getting the aircraft light on the skids....then roll the throttle off....checking for the right indications which included a needle split. Alternatively, a hovering auto will do the same but requires you to be "airborne".

[PPRUNE FAN#1]

anjouan:as unstable as you would probably be a danger to all when flying. Your English, which unlike mine is probably your native language is not much better either.Oh anjouan. If it makes you feel better...superior?...makes you feel like MORE OF A MAN to criticize my spelling/grammar, then have at it. Frankly, I would have expected more maturity from the PPRUNE group and only expected such childish behaviour from that from the bunch over at Just Helicopters but you have proved me wrong. AGAIN! Good job, old sod! It is interesting though that you harp on *my* alleged mistakes whilst seemingly glossing over your own as if they were inconsequential. Curious, that. But there you go.

Oh, and you call yours a "small error?" Son, confusing N1 and N2 is not a "small error." It shows a real, basic, solid lack of understanding of how turbine engines work.

Any why you keep harping on my previously getting banned is also curious. Wishful thinking on your part now? Would you prefer that all people with whom you disagree be somehow banished from your lofty presence? That posters whom you deem "unpleasant" be permanently removed from this board? Get off the banning issue, you Board Nazi. The mods know full well that if they ban someone, that someone will just change identities and come back. I've got more email addresses than Frank R. has lawsuits.

SASless:Something I used to do before doing an autorotation in a strange aircraft......while setting on the ground at full chat....pull an arm full of collective...getting the aircraft light on the skids....then roll the throttle off....checking for the right indications which included a needle split. During such procedure, performed in a 206, the MR decay will be too fast to notice any N2/NR needle-split, so I'm not sure what good that would do. BZZZZZT! But good try, thanks for playing.

So at the end of the day, what have we (vaqueroaero) learned from this thread? Well, according to people who actually fly them, 206's do *not* always show a definite N2/NR needle-split in a practice autorotation. In fact, *most* times they won't. There is hardly any noticeable difference in a 206 between flat-pitch/full-throttle and flat-pitch/idle-throttle. Which is what I've said FROM THE BEGINNING. Any questions?

pprune fan #1, your personal attacks and general manner are not what we all want on pprune. I must caution you about this. None of us want this site to go the way of others. Behave or be gone.
PedalStop

[chuckolamofola]

From and ole mech's point of view:

1. I don't mean to be critical, but I wouldn't ground or unground an aircraft based on information from the internet. Suggest you consult your local Bell CSR or Product Support Engineering if you are that concerned.

2. Nick's wrong and PF#1 is correct, though Nick did relent and say they may not split: There won't be a split as there is enough airflow from the engine at idle to keep the turbine up to rotor speed during an auto. The only time that I can remember seeing a split is after shutting down the engine you will see a split if you don't use the rotor brake and let the engine spool down.

3. PF#1 is wrong and Nick is correct: At idle the N2 governor is inoperative. Don't believe me, use the N2 governor beep switch to beep up or down, note the N2 doesn't change. I've disconnected the N2 beep actuator to adjust the rod end and moved the N2 governor lever back and forth, it had no effect.

4. Regarding N1 idle speed setting, we always set the idle speed to the max side due to the fact that when operating in hot weather, if the idle speed was on the slow side we would sometime get a flickering Xmsn Gbx Oil Press. light

5. As mentioned before, if you rotate the rotor by hand in one direction and it turns the turbine and then in the other direction and it doesn't you don't have a stuck clutch.

6. The 206 has a free wheeling unit that allows the rotor to turn free in one direction and locks the shaft in the other direction. Inside of that free wheeling unit, is a "Sprag Clutch". So yes there is a clutch on the 206, but it is not a series of roller bearing. It's hard to explain what the Sprag looks like but they don't roll, but act more like wedges so that they lock the shaft to the outer coupling when the engine is producing more torque than the rotor. If the rotor produces more torque, such as in an auto rotation then the outer coupling can rotate freely around the engine output shaft.

So after all this diatribe, what did "vaqueroaero" do with his aircraft, did he change the free wheel unit, call Bell PSE or just keep flying his aircraft? Stay tuned folks for tomorrow there will be a new episode of "As the Rotor Turns" :\

Chuck

[PPRUNE FAN#1]

pprune fan #1, your personal attacks and general manner are not what we all want on pprune. I must caution you about this. None of us want this site to go the way of others. Behave or be gone. Oooooh, now I'm really quaking in my boots! Not. Oh wait...I can talk in colors too! Oh, the ignominy, getting banned from PPRUNE. Oh please.You know, I really wouldn't care. It would tell me that you "professionals" really care about decorum MORE than truth. Take this little thread. Poor vaqueroaero, an obviously inexperienced 206 pilot, reports something he did not understand. Then the supposed "experts" all told him that his ship was probably one step away from utter destruction. Trouble is, the situation he described is COMPLETELY normal. And vaqueroaero would have learned that...eventually. But not by reading PPRUNE!

So go ahead, ban me if you want. Yep, you sure wouldn't want to criticize Nick (LAST NAME DELETED) for putting out bad poop and then clouding the issue by bringing N1 into it (sort of). Oh nooooo. Meh- this thread has run it's course anyway, who really cares.

Wait- I mean ban this SN. I'm shortly going to be switching internet providers at the house anyway. So in the words of the great Ah-nold Schwollenpekka, I'll be Bach.:ok:

pprune fan #1,
This is a moderated group, either conform or get out. Your choice. I find others who can disagree with each other and not use the same rude and denigrating manner. This is not a warning, it is a 3 day ban.

PedalStop

[Big_Johnno]

I have noticed that most accidents relating to Loss of Tailrotor Effectiveness (LTE) seem to involve the Bell 206. It is not very often if at all that i have heard of an LTE accident involving any other type. Is there a reason for this or is it my imagination. Are B206's more susseptable to this condition than other types.
John

[diethelm]

Fan #1

No one has a problem with the fact that you disagree or agree with anyone else. It is your delivery.

Vaqueroaero is not some helpless idiot. He is not going to go out and ground a machine because of one person's opinion. Nor is he going to go fly around on something he is questioning becasue you say it is ok. He is looking for some opinions or maybe some input if others have had a similar experience. With this input, and the advice of others he trusts, he will make a decision. No different than decisions people make every day.

[Skycop]

I've learned something really useful from this.

My CV that would have been addressed to PHI is now going in the bin.

If Prunefan#1 is typical of the management attitude prevailing there, I want no part of it. :mad:

[rotornut]

We used to own a Hughes 269B. It could be very short on left peddle authority. In a strong wind near max gross you couldn't do a 360 in the hover using the left peddle. The Schweizer/Hughes 300C is a much different beast however and has lots of tail rotor effectiveness.

[Matthew Parsons]

Theoretically, any helicopter could experience LTE. Modern designs tend not to experience LTE in typical flight conditions.

Jetrangers are high in numbers, have been around for a while, and are used in places where maximum power is frequently demanded. Because of all this, I'd expect to see more LTE problems with a Jet ranger.

And yes, they are more susceptible compared to many types.

[notnoz]

Big_J,

You'll find that the majority (if not all!) of 206 LTE cases are in the earlier models with the smaller tail-rotor. There isn't alot of authority there especially at or close to max gross and you really have to be on the ball. Found it most dangerous when scanning fires, not a pleasant feeling when the tail steps out when you're heavy low and slow!

[NickLappos]

over 95% of all LTE mishaps involve bell 206's because the tail rotor is much more marginal on a 206 than most helicopters.

The term LTE is a misnomer, as I have posted an pprune many times. Most single rotor helicopters have never experienced an "LTE" mishap.

Short of left pedal is far different than approching to a hover and spinning until you crash. If the 206 had a large enough (satisfactory) tail rotor, it would not experience LTE any more often than other types. I will post a study I did a few years back that shows its propensity.

[heliguy50]

I have been working on B206 for about 10 years, the governing range does not start till 70% and has absolutly no effect below that. You will not get a noticeable split in the needles in autorotation because the 'free turbine' is no longer loaded and the idle gas flow will keep the N2 at roughly the same sped as NR. The gas turbine engine is a very simple beast so never compare it with how a piston engine and clutch works. Piston engines mechanically drive the gearbox through the clutch. Turbine engines pass air over the free turbine which then drives the gearbox through the freewheel unit. In theory you could hold the blades of a free turbine while the engine is running, impossible on a piston engine. In practice anything above ground idle and the torque is too high and something would break.

Of course the terms ' ground idle' and 'flight idle' confuse lots of people depending on your country of origin. 'Ground idle' is when the engine is running at around 62% or so, 'flight idle' is when the engine is running at max goverened rpm, it means you can commit avaition, notice I sayed 'GOVERNED' rpm. The governor is there to control engine rpm as compared to rotor rpm, so if you pull collective lever the rotor rpm drops and the governor tells the fuel control to chuck in more fuel to maintain rotor rpm.

I am not trying to teach pilots or others how to suck eggs, but some people are not taught correctly or get on the wrong track at an early stage! I am not criticising any of the previous posts but there does seem to be some bad feeling about a subject that could potentially kill people, we are all professionals be we engineers or pilots and can all take advice and accept it without abuse. Wether you are right or wrong we are here to learn and no-one is ever too old to learn, if so, it is time to retire from the industry. Happy flying one of the safest and most reliable helicopters in the WORLD!!

[vaqueroaero]

Talk about ask a simple question!

As I seem to have started a slanging match, here are a few more details.

Yes I'm inexperienced on the 206, maybe 180 hours or so and 2 sessions of Bell school under my belt.

I have maybe flown 8 or so 206's and every single one, including those at Bell, during an autorotation showed a definite needle split.

So here I am flying an aircraft that has just been rebuilt, yes I'm being cautious.
I do an auto and something that I personally haven't seen before happens: the needles don't split. So we decided to call it a day because we had has some other teething problems and make some calls. Simple safety in my book.

The next day we were out again after our more experienced brethren assured us that all was well.

The reason for posting it here: I know that some very experienced people frequent this board. Judging some of the answers to my query I'm glad I did.

Quite why it degraded into the thread that it did I don't know, but now I'm the wiser: Sometimes they split and sometimes they don't!

[Aesir]

All helicopter types have their little idiosyncrasis that the pilot has to be aware of!

The AS-350 has the Jackstall
The R-22 has the low-G mast bumping thingy
& The JetRanger has the LTE risk.

It´s no problem, the pilot just has to be aware of it and it´s not going to happen to you!

[spinwing]

Yeeeup ... they all have their little peculiarities ...

The Hu 500A&C models as well as the Bo105 and the Bk117 will run out of left pedal on takeoff at high weights and DAs, albeit in a very benign fashion.

The AS350 will run out of Ng and right pedal at altitude.

The BH412 will let you know it doesn't appreciate slow flight with a right crosswind and can be very naughty to you if you try a high gross wt takeoff from a turbulent deck!!!

And the PUMA will put your passengers to sleep if you fly at 14000' (just be careful you don't go to sleep as well!!!!).

;) ;) :ok:

[PPRUNE FAN#1]

pprune fan #1 said:

but that's got to say something.

Yes, a three day ban from the moderator. Defy further, you are history. This will be a civil web site, Mr. Fan.

PedalStop
Rotorheads Moderator

[mickjoebill]

Do you have any data on what type of missions they were flying?

Mickjoebill

[Skycop]

Thank goodness for that!

Is this person REALLY employed as a man manager of professional pilots? I find it hard to believe, in all truth :suspect:

[Aesir]

I know where you are going Nick and I agree that designers of new helicopters should make them better than the old one´s!

But the JetRanger is hardly a "flawed" design for a well trained pilot to fly.

There have been manufactured 7300 JetRangers that have flown 38 million hours (and still counting). The JetRanger’s history of reliability and flexibility, combined with the best safety record among all single-engine aircraft make it everything but a "sub-standard aircraft"!

There may be newer better aircraft made but they are perhaps not economically profitable for all operators.

And operators are using these machines to make money and not just to drill expensive holes in the skies.

So for us "Brave" pilots that dare to fly the JetRanger we will just have to keep on and hope the best ;)

[tommacklin]

Nick,

I think you are wise to suggest that we insist on a better standard with each generation of aircraft, however, what makes the big picture quite different from cars is the level of training and awareness that any pilot should have before going off in a different aircraft type.

LTE does not just happen, it is well documented and a known phenomenon that can occur when the conditions are right.

Gentle aircraft handling and an awareness of the immediate environment regarding LTE should stop the problem.

Now, how do you make pilots aware without a demo?? I think it would be a good idea to have an LTE awareness video, something along the lines of the Robinson Safety video. Something that all pilots of 206s should watch every year or so. It may already exist.

I had been flying for 7 years before I heard of LTE. Granted, I was flying Gazelles and LTE was something that only happened in the US....not!

I was a passenger in a Gazelle that did 5 or 6, 360 deg turns, undemanded, caused by a clumsy pilot in a strong wind.....and the yaw stopped only when we crashed. That was my intro to LTE and I am certain that awareness is the key.

[notnoz]

l think Nick has a valid point! We should be expecting more from aircraft manufacturers and striving towards safer more user friendly aircraft and not accepting flaws and/or inadequacies as part and parcel to the industry. What happens when a car manufacturer discovers a flaw in their design, they recall 'all' the affected vehicles and make the necessary changes at 'their' expense. Why, because if they don't they know they'll get their arses sued the next time an accident can be attributed to that problem. With aviation, firstly they don't admit any flaw on their part as that would be an admission of guilt, rather they provide an 'optional' alternative at the owners expense!

The reason jetrangers have so impressively sold X amount of units and flown X amount of hours isn't necessarily because they are such a great aircraft it's because they filled a large hole in a market that had very little competition. Why are they still being used in such large numbers, because safety and technology advances come at a cost that most operators aren't prepared to entertain! Thankgod times are a changing and there are a few better options out there today!

Granted, better training and awareness of things like LTE will prevent accidents but maybe we should be looking at the root cause of these kinds of problems and address them before blaming the pilot who may or maynot have known as much as he should have.

[BlenderPilot]

The normal 206L4 tail rotor is so "underpowered" that at altitude, you can hover 70% Torque with the pedal against the stop, if any light breeze comes from the wrong direction it will just weathervane you into the wind and there will be absolutelly no pedal to stop it from spinning, and no mention of the interesting possiblilites of what could happen when you take off in these conditions.

The 407 on the other hand could probably hover on TR power alone if you could point the thing down!

[407 Driver]

A Bell 206B may have less than adequate tail rotor authority, but a 206BIII with the 65" T/R has enough control for most situations. If you hit the stops with a III, then you are definitely doing something out-of-the-ordinary. In my 5,000+ hrs on III's, I can't recall ever hitting the (L) stop.

Blender, Yes, the 407 pedal control is superb :ok:

[Quick Release]

Helly guy50.

Well said. :ok:

[that chinese fella]

It is often "quoted" that the Bell 206 helicopter is the safest single engined aircraft in the world. Usually reference to FAA statistics is made to qualify this statement.

Can anyone direct me a link etc. where this "quote" comes from.

(If indeed it was ever the case!)

[Aesir]

"The JetRanger’s history of reliability and flexibility, combined with the best safety record among all single-engine aircraft"

From BHT (http://www.bellhelicopter.com/en/aircraft/commercial/maHLS206B-3.cfm) webpage.

I have heard this and read for many years. I remember reading a booklet from the NTSB about single engine aircraft accident statistics where where it was clear that the B 206 was safer than other single engine aircraft. You could try to search www.ntsb.gov also!

It is amazing if this still holds true with all the single engine turboprops on the market like Cessna Caravan, Malibu Mirage, TBM 700 & PC 12 that a helicopter would be safer considering the much more dangerous nature of work that a helicopter will perform.
I remember though reading somewhere that Cessna claims that the PT6 in their C-208 has the best reliabilty record for an engine.

[Ascend Charlie]

I heard this claim, but couched more in terms like these:

"It is the aircraft least likely to have a problem which results in a crash. If it IS involved in a crash, it is the one in which you are most likely to survive." When you consider having to maintain 50 knots in a plank when you dig into the hardwoods, the idea of an auto into a clearing sounds more inviting.

That sort of stuff makes the apprehensive grandma, about to go for her first flight off the ground, more likely to get on board. Could also be Bell Bull5h1t.

[albatross]

It has been a long time since I flew a 206 - but If you are conducting a power assurance check as per the flight manual and you are 18% low you have a major problem.
When was the last time you did a power recovery wash?
Next suspect the bleed valve is not closing.
Next suspect would be the compressor and hot section.
Best of luck!

Remember a power assurance graph is basically a paper engine.
The chart says a spec engine at a given Alt. (29.92inches or 1013) and temp. that a given N1 and ITT should give you a specific torque.
If your real installed engine produces less torque for a given N1 and ITT then it is below spec and if it produces more torque then it is above spec - whch is a good thing!
I only say this because I have seen a few folks who have a hard time fiquring out what the chart is telling them.

[sprocket]

Mr Shellfish, get that engine to a doctor before it's affliction spreads to the rest of the fleet.

1. Ask yourself, 'when was the compressor last inspected? (case halves)'

2. Has the power deteriorated gradually, or overnight? (bleed valve failure will increase TOT by about 20-25 deg at those settings)

3. N1 seems to be high for the torque (only memory ) and will usually point to a front end problem.

[the coyote]

Could also be the torque indication is in error.

[Geoff Williams]

Before you start pulling the engine down, check you have the right graph. If you have a particle separator fitted, there is another graph in the applicable RFM supplement.

[BlenderPilot]

How are you performing the Power Check, are you at an OGE hover, or 52 knots? You are supposed to reach a limit first (TOT, TQ, N1) and then take readings, if you don't reach a limit you can't be sure how the engine will behave when you really need the power. Make sure you use the appropriate chart, Particle Separator or not.

[Steve76]

BP is quite correct. You MUST reach a limit to access the engine correctly. Usually 100%TQ. Make sure the heater and anti-ice are off as well and set 29.92 on the altimetre.

Remember, when you read the chart you are looking for the torque percentile that the engine should AT LEAST produce.

If you are pulling 100% TQ and the chart plots out at 85% TQ, then the engine is actually producing MORE power than spec.

Therefore a +15 engine.

[overpitched]

Just putting the technical stuff aside for a minute. From a practical point of view I've never flown a 206 with the N1 & TOT so high at 77% Tque. For the conditions you describe generally the N1 would be 90-91 % and you certainly shouldn't be up on max continuous TOT.

[John Eacott]

Mr S,

I'd certainly follow all the good advice here, but if a power assurance comes in negative, carry out instrument checks first before you start (expensive) work on the engine. Dead-weight test on the torque indicator, Barfield check on the ToT indication, calibration on the Ng gauge: even a pressure test on the altimeter could be worth the effort if the engine is actually healthy, and the instruments are wrong. Has this engine always given these figures, or has there been a noticeable deterioration over a period of time?

Mind you, it can sometimes work the wrong way: some time back we had an S76A with a negative engine. After a Barfield calibration, Chief Engineer decreed that all 6 ToT indicators were to be ignored for both engines, and revised manually by some 20C. Needless to say, the Barfield was out of whack, and we still had an engine change :rolleyes:

[belly tank]

Mr Selfish,

You should be getting in the order of 90-91%N1 650 TOT FOR 75%TQ @ 20 DEG C OAT @1500'

Hope this helps

[Aser]

Chief Engineer decreed that all 6 ToT indicators were to be ignored for both engines

I don't know nothing about a S76 but 6 ToT indicators for 2 engines? :E Are you talking about the thermocouples?

Regards.
Aser

[John Eacott]

Aser,

Two analogue, 2 digital and 2 sets of LED's = 6 indicators for two engines.

Alas, we simple pilots spent some days convincing management that we couldn't quite understand how they could all have the same error ;)

[Wunper]

Don't forget about proving the calibration & innocence of the OAT gauge whilst on the instrument witch-hunt.

W

[NickLappos]

As a rough rule of thumb, the power loss below spec can still allow "airworthiness" if the cause is known (ie, a dirty engine or one with a worn compressor and not one with internal cracks) and if the power loss is reasonable.

Some maintenance procedures for military turbines allow one that fails power assurance (HIT check) by -10% torque to be flown (Black Hawk for example) , some even allow -15%.

Is a low power engine more likely to quit? Probably not, if the cause of the power loss is not an internal mechanical failure.

Is a low power engine less trustworthy? Not necessarily, but a dirty engine or a worn one is more likely to stall, and more likely to accelerate more slowly when called on for power.

[albatross]

One thing you must remember is that all the performance charts are based on a "SPEC" engine.
Therefore if you have an engine that is failing the power assurance check the durned thang ain't going to perform as advertised.
Not a big problen going from A to B at the same altitude but you could have a problem going to a higher altitude or in such things as OGE hover.
I have seen the result of a compressor stall on short final and it was not pretty - the 206 was definitely not serviceable afterwards! It was even less serviceable after it was dropped from 2000 ft by the 205 slinging it out of the bush!
I think it would have been cheaper to replace the engine after it failed the power check.

[loachboy]

G'day all,

Nothing overly exciting, but currently OS and in need of a standard (well layed out if possible) Bell 206 Checklist.

If anybody can assist please PM me.

Much appreciated in advance.

Regards

Loachboy

[BlenderPilot]

Bell 206 JR A/B, II, III, 206 L, L1, L3, L4, or maybe even an LT ? They all have differences between them.

[IHL]

If a power check is marginal use a crayon instead of a pencil.;)

[Disguise Delimit]

Arrange all the switches in a pleasing and eye-catching manner, and start the engine.

Start at the top overhead panel, go front to back, top to bottom, left to right. Look at every switch or button, determine whether it needs to be on or off. For a JetBanger, you need Batt ON, Gen START, boost pumps ON, fuel valve ON, throttle OFF. Everything else is as desired.

After start, turn on what you need. Test the controls and hydraulics and fail-safe.

Pre-take off VAs are the same for most helos, works for everything from an R22 to an S76, and are borrowed from the venerable Huey:
Hatches
Harness
Heaters
Electrics
Fuel - quantity, pressure, selection
Instruments in limits
Lights out
Audio
Auto (autopilot and/or/auto governors)
Full throttle
Top of green

Blast off.;)

[paco]

PM me with your real email

Phil

[John Eacott]

Loachboy,

Google is a wonderful thing :rolleyes:

This took 1 minute: Bell 206 checklist. (http://www.hovercontrol.com/artman/publish/article_36.shtml)

;) :ok:

[skidbita]

How about trying the RFM!!!

[albatross]

I notice that in the checklist John Eacott posted that the prestart has "HYDRAULIC SYSTEM (Control boost ): off" and the engine shut down has
"CYCLIC & COLLECTIVE FRICTION: hydraulic switch off
BOOST PUMPS SWITCHES: off
TOT: stabilize for 2 minutes
CAUTION SWITCH: off
THROTTLE: close
TOT and N1: decreasing
FUEL VALVE: off


Not taking John to task at all for posting the site. It is, after all, not his checklist.
I have a few hours in 206s and I do not agree with starting / stopping with the hydraulics off. In fact I would say that except for testing the hydraulics should be on if the blades are turning.

Also why turn off the boost pumps before shutdown? Remember that the engine driven fuel pump is lubricated by fuel.


Have things changed since I flew 206s? It has been a while! I fly 212s and we start and stop with Hydraulics and boost pumps on.
Just curious.

[albatross]

Good one IHL - only a fellow Canadian would say that ! :ok:

[The Rotordog]

It is always dangerous to post a checklist that is either not in line or differs with the AFM. The "checklist" referred to by John Eacott is one that I look at skeptically. I don't know why he would recommend it.

In the first place, we're not sure which "206" the checklist refers to. I can tell it is for a B-model, because the described technique would certainly not work on my L-3. But it does not specify. I have a few other gripes too:

Why start with the hydraulics off? The AFM does not say to do this. I'm tempted to think it's a typo, because the "Run-Up" checklists has us turning the hydraulics off again, with no interim step that ever turned them on! Also, at my outfit, we do a preliminary check at Flight Idle - just shut the switch off and check for anything unusual, then turn it back on. The "real" hydraulic system check is done at 100%, where it needs to be done.

And what exactly is the "Caution Switch?" Is this a field mod? Also, this list calls for the pilot to check the overhead panel circuit breakers, then go *down* to the fuel valve, then back up to the roof to check Rotor Brake-Off. Not good. But remember, a checklist is not a "do-list." As long as all those things are accomplished prior to punching the starter, who cares?

During shutdown, my current employer insists on turning the generator off BEFORE killing the engine. And we never turn the gyros off while the blades are still turning (hard on the bearings, so the avionics guys tell us). Stop throwing switches unnecessarily! Just leave the switch on.

I actually like Disguise Delimit's version. I would only add two things: 1) "All Tiedowns - OFF." Failure to ensure this can range from the embarassing to the fatal. I know we're supposed to check it before climbing in, but it doesn't hurt to put that item on the Pre-Start. 2) "Control Friction - Adjust." I've know pilots who've tried to take off with the cyclic frictioned down tightly.

Lawyers can complicate anything, and they've surely had their hands in the 206 checklist. A 206 needs only four things set correctly to start: 1) Blades untied, 2) Battery On, 3) Fuel Valve On, 4) Throttle at Shut-Off. That's it. *EVERY* other switch, circuit breaker or control can be in any position and it won't affect the start. (Well, with the exception of the TOT indicator c.b. which I have never, ever seen pulled in my entire career.) The rest of the few things that need checking or adjusting can be done during the one-minute warmup.

When in doubt, go by the AFM. When using anything else, be very wary.

[VeeAny]

As you will all no doubt have noticed the checklist linked to by John is for MS flight simulator and not a real 206.

Probably why it refers to switches not cbs and hydraulics off for start, coz it really wouldn't matter.

V:D

[LGNYC]

You might not have noticed, but the link posted by John goes to a FLIGHT SIMULATION website. If I'm playing on my PC and do a start up with hydraulics off I probably wont hurt myself. So I'd rather not use a checklist developed for/by somebody playing on their computer.

On a side note, you can find a lot of useful information on the jetranger from Bell's "product data" document. This is like a marketing book (300 pages or so) that explains how the machine is built, what options exist and how they work, etc... in more detail than the flight manual. Personally, I found that a very good read in conjunction with the POH. Really, there is a lot more in these documents than basic marketing pitch.

see
http://www.bellhelicopter.com/en/aircraft/commercial/pdf/206B3_PDB_low.pdf

for the jetranger

and
http://www.bellhelicopter.com/en/aircraft/commercial/pdf/206L4_PDB_low.pdf
for the longranger (havent read that one)

[Revolutionary]

This question pops up on this board from time to time, people asking for a checklist I mean. Most of the time it's someone inquiring about a checklist for an aircraft they are not currently flying and wish to learn more about, which makes perfect sense.

Loachboy however seems to suggest that his aircraft is out of service (OS?) because it is lacking a checklist. I don't know where he's located and I don't know what the aviation laws of that place may be, but presumably one would be required to carry a current RFM -including the Normal Procedures section- on board the aircraft.

If the aircraft is lacking an entire RFM then you could order another one from Bell. I would be wondering however what other records may have gone missing from this aircraft...

I'm puzzled...

[Bravo73]

Revolutionary,

Considering that Loach is an Aussie, I suspect that the OS might mean OverSeas (hence unable to access his stuff...)


Just a thought,

B73


PS How's the cricket going, ya 'Strines? :D

[John Eacott]

The point I was trying to make, on a cold and boring Sunday with nothing to do but watch the snow fall, was a reference to using Google. About 128,000 hits were shown, so I chose one at random without reading it: silly me :O

Here is a better (proper) checklist (http://www.helicopterflight.net/turbine_transition.htm), about two thirds of the way down the page, after what seems a fairly well composed article on turbine transistions.

Now, back to watching the snow and hoping enough will fall to justify getting the snowmobile going :p

[Revolutionary]

Bravo 73

Australian... fair enough but still: if you need a checklist because you're going to go flying and you need to start 'er up, there should be an RFM somewhere in the aircraft. Anyways I better shut up as I don't seem to understand loachboy's question.


PS How's the cricket going, ya 'Strines?

I was puzzled before and now I'm baffled. English is not my native tongue: 'ya 'Strines?'

I'm Dutch. Forgive me...

[Tickle]

Hi everyone,

I've always wondered about why the Longranger has fins on its horizontal stabilizers and the Jetranger doesn't? Does anyone know?

Something to do with its longer body?

Regards,

Tickle.

[TheFlyingSquirrel]

and those funny little moving tail plane thingys.

[paco]

From my TRI handout:

"The horizontal stabiliser has a movable rear elevator connected to the cyclic to provide greater authority. The side fins stuck on the ends are offset by 5° to the left, at the opposite angle to the vertical fin (the stabilizer also protrudes more one side than the other), because the vertical fin tries to turn the tail too much to the right at higher speeds, being stuck on the end of a longer tailboom. An increased tail rotor pitch travel is provided by the rigging procedure for greater authority."

Phil

[Tickle]

Thanks for the info - it makes sense now. :) Such a delicate controlled balance, helicopters are.

[The Rotordog]

LongRangers are faster than B-models. The very first L-model produced had no endplates. Squirrelly bastard! Very unstable in roll, especially if you had a speedy one on low skids. (By the way, "straight" L-models were faster than later models due, possibly, to the fatter cowling needed for the C-28 and C-30.) Then Bell added the endplates and smoothed out the cruise. Then we all started installing those cool wedge windows in the back, which disrupted the flow over the aft fuselage and tailboom. Some of the squirrelliness returned. It's worse if you have one wedge window and one non-wedge.

[that chinese fella]

It is my understanding that the Engine driven fuel pump is not reliant on boost pump pressure for lubrication. The EDFP is capable of drawing the fuel up from the tanks on its own and it effectively lubricates itself.

FYI, after fuel system maintenance there is a 2 minute ground run carried out @ 100% with boost pumps off to ensure the integrity of all connections (ie none are loose and sucking air).

Although not a FM item often I will pull the boost pump CB's during the 2 minute cool down to check the integrity myself.

BTW I have a basic dislike of using CB's as switches.

[SASless]

Gee, and there I was thinking they helped streamline the aircraft into wind when they go topsy turvy after they ditch in the Gulf of Mexico.

Seems they probably do as much of that as anything else with the number of them that wind up in the briny down there.:uhoh:

[Bravo73]

No worries, Revolutionary. 'Strine' is what our Aussie cousins are actually speaking when they think that they are speaking English! (Google has more on the subject...).

And as for the cricket, can I suggest that you have a quick look at BBC News (http://news.bbc.co.uk/sport/default.stm)...? Think of a World Cup final between the Netherlands and Germany and you'll come close to how important this game is for both sides. We (the Poms) have got a slight advantage at the moment but there's a whole day's play left to go...



PS And there's no need for forgiveness - your English is way, way better than my Dutch! ;)

[loachboy]

Thanks Bravo 73, Paco and John,

Probably should have mentioned Overseas rather than 'out of service'. Forgot Australia wasn't the only Country in the World !
Didn't realise such a simple request would cause so much narkyness amongst the ranks.

Currently overseas and going flying in a few days time. As I don't have much time in 206's, and don't have my 'stuff' with me.
I wass interested in gaining as much knowledge from the flight as possible.

Thanks to all of those who helped.

Be gentle boys.

Loachy.
XO

[nimbostratus]

As an examiner, I have to assess the applicant's ability to follow the approved checklist. The majority of checklists in the UK include the instruction to start the engine with only one fuel boost pump operating (this is not what the RFM states). This was the way that I was taught when I first started flying this type, but I seem to recall an instruction from Textron/Lycoming quite a while ago that stated that both boost pumps must be used. Does anyone recall this instruction, as it has got the potential to cause problems at the 'debrief' stage.

[paco]

If you started with only one operating you would fail your PPC in Canada. the idea of starting with one is allegedly to check for leaks from the A/F fuel filter, but I've never seen it officially anywhere.

"They can also mask an air leak in the airframe fuel filter - if one is sucking air, you can confirm it trying to start without the boost pumps engaged. If there is a leak, the engine will sign-off around 45-55% N1. You are also likely having problems with the governor, which may be indicated by the N2 not maintaining 100%."

For the record, the FM says that boost pumps shall be on for all normal engine operations, which when you consider they started out with none at all says a lot!

Phil

[trackdirect]

I have PM'ed an Excel program to MS that is put out by standard aero, It covers quite a few models of helicopter with A250's in them. I don't have the facility to post it to PPrune but can email to someone to host so everyone can download it, It makes powerchecks that much easier. No more reading graphs.

Heliport?? let me know who is avail to host the program....

[Aser]

If a power check is marginal use a crayon instead of a pencil :D
Thanks for the smile at 03:20 am

[BlenderPilot]

I have PM'ed an Excel program to MS that is put out by standard aero, It covers quite a few models of helicopter with A250's in them. I don't have the facility to post it to PPrune but can email to someone to host so everyone can download it, It makes powerchecks that much easier. No more reading graphs.

Heliport?? let me know who is avail to host the program....

I can host it, send it here,

[email protected]

[trackdirect]

Blenderpilot, I just sent it and it bounced back saying your mailbox is full... I will try later

[NedRex]

With that N1, TOT and Torque you appear to have a massive compressor inefficiency.

1. Look to a heavily erroded compressor case half set (been in the dust?). Have you had a history of case half errosion? Remember after about the third set of cases, the rotors are so thin that you will generate an impressive compressor stall as the pressure waves roll between the efficient stators and the inefficient blades of the compressor rotors.

or

2 An air leak from the Bleed valve not closed. Remember at 94%N1 you will still be in Bleed Valve modulation range. Get up to about 5000' PH and try it again. Your N1 should be higher than 95% to be sure that it is closed.

or

3. Look for a split in the armpits of the combustion outer case, a split in the discharge tubes , a popped seal in either of the ends of the discharge tubes or the burner drain valve wide open. If these are the cause you should also experience a significant delay in the acceleration schedule after the first peak in TOT.

or

4. The anti-ice valve or bleed air heater valve is leaking badly.


Good luck

Ned

[turboshaft]

A belated response from the Model 250 support team in Indy:

By the Bell flight manual, power assurance chart, these readings should yield a torque of 85 - 90%. However, neither the Bell manual or our OMM instruct for the engine to be removed. Best answer is one of the two following:

1) Get in touch with Bell light helicopter product support, since it is the airframe manual that determines the airworthiness of the complete aircraft,

2) Although the numbers do not indicate a spec engine, there are many factors that could effect the performance, some as simple as washing the compressor or determining whether the bleed valve is completely closed, maybe even check and verify the calibration of the TOT system. The real question is whether or not the aircraft will perform its mission, which is the ultimate decision of the pilot.

You can contact the team via [email protected].

[Shawn Coyle]

My understanding is that in order to get the LongRanger IFR certified, it needed the fins on the horizontal stab. (There actually were some that were certified for IFR).
But a very light Longranger with high skids with fairings and end plates would be very squirrely. Take off the fairings and it was OK. Sort of 'who's in charge of directional stability and who is in charge of dihedral effect?' discussion.

[Arm out the window]

Regarding the pitch side of the story; as far as I understand the situation, the moving trailing edge on the horizontal stab is like the Huey/ 204 / 205's 'sync elevator' - moves in response to a linkage in the cyclic control run to provide more control of fuselage pitch attitude through the airspeed range, a kind of precursor to the massive stab angle changes used in machines like the Blackhawk.
Like Paco said, provides 'greater authority'.

[cpt hobbs]

i am looking at both a 206 and the ec120 to buy for a business man to travel around ireland. Please express pros and cons for comparisson and your final choice. $1 mil budget. thanks.

[SMOUFW]

For 1 mil Aus dollars you could get two pretty good second hand Jetrangers-not to sure about the price of a used ec-120- would imagine though a little bit more.

To compare them operationally-if you looked up the word reliable in the dictionary you would find a photo of a jetranger-they just keep going. Ofcousre you'll always find the knockers but over a ten year period we operated up to 4 206's and other than the routine maintenance I can remember a couple of t/r chip lights, 1 eng chip and a couple of gauge failures.And i'm talking about 600-800 hrs per year per machine. The other consideration is support and parts....do your homework there....again I don't know what eurocopter/Bell have in Ireland.

I was fortunate to operate a EC-120 on trial for around 3 months and in that time had great feedback from pilots and passengers. Someone with a lot more time on the ec would give you a better appreciation however I loved flying the machine and the pax loved it. Bigger windows and a lot more comfortable.If your planning to have a full ship expect a lot of negative comments about the back middle seat in the jetranger...it's a F#$%^. Every day people would complain about having to sit there. We called it the TFC,(Thanks for coming) seat. Atleast in the EC everyone gets a great seat and no arguements.

The luggage compartment on the ec is little more generous than the jetranger however as all 206 drivers know it's amazing what you can fit in a jetranger boot.

Thats my 3 cents worth-to answer your question if it's just you and/or your pilot criusing around Ireland with regards to price take the jetranger option-maybe a few ec operators could add some pointers to even the debate.......Have you considered a R44?

SMO

[blade771]

This could start quite a debate!!

Would probably go for 206 myself, however do agree that the 120 has better alround visibility for the pax however have heard some stories of problems with the 120 i.e. c of g - this may have been corrected now.

Otherwise both lovely machines.

[KikoLobo]

i fown both of them, both as a pass and as a pilot, 206 its a work horse. True ec is more confortable for the pass, but 206 its so reliable and its so a noble machine and a joy to fly. Its slower though but its a very safe 'the safest single engine aircraft in the world' and it keeps its record for a long time. Maintainance its not hard and well documented, your mechanic can do a lot more to it than on the EC to fix it on the field.

More technology on the EC, quiter for sure, but the penalty for it its power. Although jet rangers are not a loader heli, it can carry more weight and be more forgiving in altitude and hot wx.

Its just my POV.
I flown both of them to see what i would buy, and got a 206. Ohh, operation cost is also lower. (at least in mx)

[headsethair]

The budget is $1m - US I assume ? That won't get much of a 120......

[rotornut]

Do a search on EC-120. There have been a few threads on their maintenance and reliability problems.

[Thomas coupling]

It's not just about operating costs etc, is it.
We are living in the 21st century now and things such as duty of care/risk assessments etc have to be considered.
I would seriously also look at crashworthiness issues.
The 206 has that woefully inferior tail rotor authority issue hanging over it too.

On a separate note: bear in mind the spares and servicing scene.

A helo sat on the deck waiting 4 days for a replacement part for instance, is just scrap metal:ooh:

[and Tompkins]

A few other things to consider:

Autorotation - ever seen an EC120 auto from about 10-15' AGL? Talk about slamming you into the ground! You'll find the 206 offers much more margin than the EC120 due to the nature of the rotor system. Much more inertia in the 206.

Useful Load - Don't get hung up in EC telling you that the 120 has a greater AUW. Once you load it with the necessary equipment and fuel to fly it away, you'll have more UL in a JetRanger with the same equipment. This is especially easy to see when comparing Bell and EC's HOGE and HIGE charts from their technical specs. You'll find a tight race, but I suspect EC would tell you differently.

Having flown in both, I would not take an EC120 above 110-kts. It seemed like everything was about to shake loose in the cabin.

I'd take the JetRanger. :ok:

[belly tank]

Thomas Coupling wrote:
"The 206 has that woefully inferior tail rotor authority issue hanging over it too."

Thomas...in my limited experience in helicopters to date which includes 1000+ hours in jetrangers ive never had any problem with tail rotor authority..and ive done most hovering ops that require alot of pedal....treat it right and think about what your doing and you should never have any tail rotor authority / lte or whatever they call it tommorow problem :ok:

[Aesir]

The 206 has that woefully inferior tail rotor authority issue hanging over it too

Belly Tank..

That is exactly what I was going to say, you just beat me to it!

This LTE "Problem" on B206 is a non issue.

[IHL]

Belly Tank & Aesir:

I disagree. I know several pilots that have experienced it. It is real and it is out there but it can be managed.

When I fly a Jet Ranger I am always very cognizant of wind direction and the conditions that can lead to LTE.

[belly tank]

IHL,

I didnt say that it its not an issue, maybe my wording was a bit obscure, however as you say with proper management and decision making it is overcome.

and i think this applies to most if not all aspect of flying.

cheers!

[leemind]

headsethair - US$1m ~ £570k

You'll easily get an EC120 for that money. Quick search of the 'net or look in Helimart found several. e.g. 2002 with 1,000 hrs for EUR870k (£558k)

[Thomas coupling]

Belly Tank / Aesir:

Ignorance is bliss....I suggest you get to know your a/c a little more:

NickLappos said:


posted 3rd October 2005 11:03
--------------------------------------------------------------------------------

rotorboy,

In an LTE study I did about 7 years ago, based on worldwide accidents of all helos, using four different data bases, this is what it showed:

95% of all LTE accidents involve Bell 206 models.

Virtually 100% of all LTE accidents involve Bell helicopters (one Robbie in UK was reported as LTE, but was probably over pitching).

My conclusion was that the inadequate size of the Bell 206 tail rotor was the principal cause of its LTE woes.
A second finding is that all tail rotor authority events were being called LTE because the marketing campaign conducted by Bell was effective on removing the heat from their design.

LTE really does not exist, it is a label used to blame the pilot when a marginal helicopter loses yaw control within its approved envelope. That does not mean that a 206 can be milked by an experienced pilot to not lose tail authority.

LTE cannot be experienced by any helo built to modern standards (larger tail rotor). It is impossible to get LTE in a Black Hawk, Apache, S76, H-500, EH-101, Lynx, etc because they have adequate tail rotors.

[John Eacott]

TC,

Beg to differ: maybe with the small tail rotor, but the 206 with the later tail rotor is quite manageable, and we operate frequently hot and high.

I'd be making more of an issue of the EC120's low inertia main rotor system, and the R22-like autorotation characteristics :eek: I'd have grave reservations using an EC120 for low level operations that wouldn't cause any concern in a 206, because I'm not sure that I'd get away with a survivable auto. Apparently the factory pilots prefer to run on around 40-50kts in the 120, maybe for a good reason!

[belly tank]

Thomas Coupling wrote,

"Ignorance is bliss....I suggest you get to know your a/c a little more:"

I think i have reasonable knowledge of My aircraft the 206 in this case, ive done most ops that require the use of alot of pedal mainly OGE hover work etc etc hot and as high as you can get here in australia!. and as i said in my limited experience on Jetrangers 1000 + hrs on type to date ive never had a problem or accident, and as i mentioned before its managable if you treat your aircraft with respect it deserves.

so your statement above is totally ignorant about the fact you should give a bit more credit to your peers before you make assumptions on their ability :8

[B Sousa]

IF you have a Million to play with and look around just a bit I think you can get a pretty nice B206L4 and have some spare change for cockpit toys.
Give it some thought.

[Aesir]

NickLappos said:

Thomas coupling..

Ohhohh.. If Nick said it then it MUST be true :rolleyes:


The original question was:

Please express pros and cons for comparisson and your final choice. $1 mil budget. thanks.

In my opinion the perceived LTE "Problem" of the 206 is not an issue in choosing which aircraft to buy! If properly flown it´s not a problem!!

Like was said for $1 mil you can get a nice 206L4 which is certainly a much superior aircraft to the EC-120.

I have a friend who operates EC-120 and from talking to him he seems to have unusual problems with parts availability and cost :{ Don´t get me started there..few months ago he had to replace the flashing beacon at a cost of $9.000.- The whole thing had to be replaced as a unit, not possible to change the bulb!

He fly´s his EC-120 about 350 to 400 hrs a year. I fly my AB206B a 1971 model with.. yes you guessed it, the small diameter tail rotor.. I fly about 150 hrs a year and guess who takes more money to the bank after all costs have been figured in? I do.

Needless to say his EC-120 is for sale.

When comparing the two EC-120 & B206 one should consider the autorotative characteristics as well of both aircraft. Since they are single engine I would much rather be in a B206 following engine failure, both aircraft do have engine failures like any motor vehicles and the outcome of such a failure will be more likely to be succesful in the B-206.

Unfortunately it´s difficult to do a "Study" of succesful outcomes of engine failure landings comparing aircraft since many countries do not require any reports to be made if the landing was succesful with no damage.

Here is my suggestion for the original poster:

"Be Smart, Fly Bell"

[Thomas coupling]

Belly up: I wouldnt brag about a 1000hrs on type if I were you. There are people on here who have flown that on type in only 18 months, that is not a lot of experience:8
And you are not my peer...you can't even spell Chief Pilot in your profile never mind act like one:uhoh:


Aesir et al:

Join the real world eh? You can't keep flying a 40 yr old design forever....one has to move on and invest in technology with all its merits. Safety is the industry mantra now.

Aviation news comments (http://www.aviationtoday.com/cgi/rw/show_mag.cgi?pub=rw&mon=0203&file=0203ec120.htm)

Just another view..................................

Aesir: interesting web site.

[Dynamic Component]

I have a few hours on the EC120 and 206.Each has its own role.For pax work I would choose the 120.For anything else I would choose the 206.I would prefer a 206L4. Just keep in mind that you cant load 4 adults and pilot and use all the baggage space in the 120.

TC- who pis*ed in your porridge? SO what if belly tank can't spell. And they are entitled to their own opinions.(I can't spell either:} )

[belly tank]

Thanks DC!

See TC i do have a peer!..your words were the last straw i have now enrolled in spelling classes, ill let you know how my progress goes:8

As for the thread...you will like this TC i also have limited experience in the 120 and have found it to be a nice aircraft for pax work as DC has stated, nice open cabin etc etc, its horses for courses what are you planning on doing with the machine you choose CPT Hobbs, is it mainly going to be used for the business man alone or will most of your loads be with a full compliment of passengers.

as DC has stated have you looked at a L4!

[Aesir]

Thank you for your view Thomas..

You said:

Join the real world eh? You can't keep flying a 40 yr old design forever....one has to move on and invest in technology with all its merits. Safety is the industry mantra now.

That is exactly why I fly B-206..SAFETY! Get it?

I want to be in something that can land safely if I have engine failure which we all know can happen in all helicopters anytime and if I don´t have two engines then for sure I´m going to be in a helicopter that can autorotate safely.

I know why LTE happens and some other things that could happen to B-206 in flight and I know how to avoid those situations..! An engine failure I have no control over, it could happen when I least expect it.

New helicopter designs do not necessarily mean that they are safer in all aspects. Manufacturers do try to make them more economical to operate than the competition so customers will buy them. And boy did EC get the DOC´s wrong on the EC-120, they can say whatever they will about how economical it is but ask any operator in the field who will give you a straight answer and then find out how much it costs to run. There are loads of 120´s for sale now, I wonder why?

But don´t get me wrong, like someone said if you don´t worry to much about engine reliability and perhaps fly all the time over land and non-hostile terrain then the EC-120 is fine for passenger transport for someone who has the funds to run it. There is lot´s of people who don´t really care if it cost´s $300 or $500 pr/hr to run.

I like the B206 because it cheap to run which means I make more cash and it´s safer to fly in my area of operations.

I´m guessing that the original poster has probably gotten tired of reading the bull that´s been posted but please keep us informed what you end up buying whichever way you decide!

[blade771]

I guess $1m is about £700K, you could of course go for a twin (AS355) wouldn't be brand new of course probably F1 / F2 but you could probably get something reasonable for that kind of money.

[B Sousa]

You can't keep flying a 40 yr old design forever....one has to move on and invest in technology with all its merits

If I was a Playa........I would have bought a 407 when it first came out. Since I have a saying etched in my brain. "Never buy an A model of anything" I waited to see how many of the "Rollers" paid for the ADs that would surely come out, and they did.
Now its a bit better, someone else suffered the problems and its a great purchase......
Same thing flys with the EC-120. Let someone else do the testing and since I see a few more buying the farm recently it is not over yet. Then maybe.
As to purchasing "new" only a proven aircraft and only then if I cannot find a clean machine that someone else has eaten the initial depreciation.

If I had the ability to purchase anyway...........

[BigMike]

Horses for courses I guess. Jetranger if want to do a wide range of work, 120 if you mainly fly pax. 40 year old design vs new one? Who cares. Which one makes the most commercial sense, thats the bottom line. Second-hand L-4 would be much better than either.

TC, I think you will find that the tail-rotor is not an issue in the B III Jet-ranger.
I would consider someone with 1000 hours on type to have a bit of an idea. What do you consider experienced on type? Just remeber its not always total hours on type, but what you did in those hours...

[B Sousa]

tail-rotor is not an issue in the B III Jet-ranger.

Are we talking an LTE issue here?? I have heard this song before. Personal opinion is Pilots are the problem. If any aircraft is prone to doing something out of the ordinary it should be addressed in the intial training and etched in the pilots gray matter. If done correctly problems should not occur OR if Murphy is flying then the pilot will be able to correct things before a disaster occurs based on his awareness in the seat.

Im Still voting for an L-4

[BigMike]

As it was when I first flew a 206 a long while ago. I was warned to be carefull with pre-BIII Jet-rangers. Something to simply be aware of.

[B Sousa]

Something to simply be aware of.

And it appears you have not forgotten, good.. Another good example, if I can drift a bit, was the Huey. Many variations of it but as there are also different UH-60s, the one big difference was that the Huey used two airframes.
UH-1B, C, M etc. had the B204 airframe, wheras the D,H,V etc. had the B205 airframe.
When I transitioned from the H to the M, the first thing the IP did was take me way up in the mountains and do a 360 turn at a 50'OGE hover on a hot day (in a big LZ) Dam thing ran out of pedal. Lesson there was although it was a Huey with an L-13 etc. The tailboom was still smaller and the tail rotor cannot handle things, Hot, Heavy, High........

Back to reality, Im still voting for the L-4.........

[Choppersquad]

gents
wondering has any one come across the tot gauge in the 206
jetranger in flight going from normal needle setting eg straight and level flight setting on the gauge,needle passing through the
red to the maximum for approx 2,3 minutes and then resetting it self back to normal reading based on normal flight.
there is no increase or decrease in engine output while this is happening.
is this a common problem with tot gauges in the 206.
regards
cs

[B Sousa]

Through the red as in through maximum temp?? 2-3 minutes.
Yikes thats scary and should also be a reason to put the thing safely on the ground. In all odds the guage or sending unit may be bad, but thats a big no fly either way.

[NickLappos]

The gage actually reads resistance thru the thermocouple sensor in the engine, and can often fail by going to ground some other way, leading to sky high readings.

You are right not to panic, but B. is right, don't start that puppy again until someone has put a tester on the thermocouple loop.

[Disguise Delimit]

I saw one do 2 clockwise laps of the gauge - must mean a TOT of around 4000 degrees!

[diethelm]

Nick is correct, check the thermocouple or the block where the ship wiring connects to the thermocouple. Not a Jet Ranger issue but a C20 issue.

[rotormatic]

There are two types of TOT indicators in the Bell Jetranger.

The basic system is comprised of an engine thermocouple harness, junction block, airframe thermocouple harness and an indicator.

Early serial number ships used a self contained system that did not use any aircraft DC power to operate. The TOT indicator used the current produced by the thermocouples to move the needle.

This system required the airframe thermocouple harness, along with the engine thermocouple harness, (wired in series) to be calibrated to eight ohms, using a barfield test set, which is basically a wheatstone bridge. This test set allows a very accurate harness calibration. The resistance spools used to trim the thermocouple harness are mounted in the instrument panel. With this system, the resistance of the thermocouple harnesses is critical to the accuracy of the TOT indicator.

This early system was maintenance intensive, due to the calibration requirements needed during an engine change, and scheduled checks of the system. The thermocouple harness required calibration at each engine change, due to the manufacturing tolerances of the engine thermocouple assembly.

The only way this system would read high would be caused by loss of resistance in the thermocouple harness, or a faulty indicator.

Later serial number Jetrangers upgraded to a servo type indicator. This indicator only uses the voltage produced by the thermocouples as a reference value to measure the engine turbine temperature... Aircraft DC power is used to move the indicating needle.

This later system is more reliable, and requires less maintenance, because thermocouple harness lead resistance is not critical, since the indicator does not draw current from the thermocouples (no voltage drop). There is no requirement to calibrate the thermocouple harness when a servo indicator is installed during scheduled inspections, or engine changes. Also, with the servo system, resistance spools are not installed in the thermocouple circuit.

Situations that would make an indicator reading go high with the servo system would most probably be limited to the indicator.

[KevinLonghurst]

Hi

I'm sure I might as well be asking for the proverbial 'Hen's teeth' or 'Rocking horse s**t'.....but here goes....

Does anyone know of a 'defunked' Jetranger fuselage located in England....tucked away in a yard or field somewhere..maybe slightly damaged...covered in green mould etc.......??

Many thanks

[Aesir]

Old JetRanger´s never die, they just get better :D

[Big_Johnno]

Make a great realistic cockpit for flightsim. hope you find one.

[alouette]

I might know of a mothballed JetRanger on Vanuatu...but perhaps this one could a bit too far for you...

Alouette:O

[rotorboater]

Theres one at the following link

Jet Ranger (http://www.applesalvage.com/aircraft/jetranger.htm)

[KevinLonghurst]

Thanks RB....seen that one.

K

[DBChopper]

Rotorboater,

Is that the remains of G-JWLS, taxied into by the Spitfire at Duxford a few years back?

[rotorboater]

It has the same serial No so I suppose it is.
I know you can't see much from the cockpit of a spit but surely a JR is pretty big!

Carolyn Grace Spitfire
Carloyn Grace's Spitfire (ML407) was involved in an accident when its propeller blades struck a helicopter as it was taxiing to a halt at Duxford airfield on the afternoon of 31 March. No one was hurt in the accident but the helicopter, a Jet Ranger (G- JWLS) was badly damaged.

Theres your answer - Women Drivers!;)

[Simon853]

Kevin,
Is it for a simulator?
If so I spoke to a guy recently who'd done just that and said it was actually a good deal more difficult than he anticipated and the cockpit needed so much remodelling and metalworking he might as well have started from scratch and fabricated his own - which is exactly what he went on to do.

Si

[Barndweller]

Kevin

Know where there is one that you might be able to get. Private mail me with an email address and a little info about what you want it for and i'll approach the owner.