Bell 206: JetRanger and LongRanger

[Colonal Mustard]

Originally Posted by Heli_Sticktime

Anyone have any comments or first hand gen on the testing that's been going on regarding the fitment of airbags below the fuselage of the 206 to take up the brunt of impact in a crash, see page 12 of the Feb Rotor & Wing mag

Oh great......survive the impact only for the blades to kill you...discharge those first me thinks

[albatross]

"So Capt, can you explain what happened after the engine quit?"

"Well things were going great up until that first big bounce! It got a little weird after that!"

[nigelh]

I am not aware of any reason not to fit Agusta parts to a Bell outside USA , certainly they can be sourced at far lower prices. Eastern Atlantic at Shoreham have got a hangar full of 206 parts including c18 and C20 engines. My old 206 was an AB very reliable and a third of the price of running an AS350, thats for sure !

[McGowan]

Any pruners going to the Bell CTA 20-24Mar06?

Anybody out there going to the Bell Customer Training Acadamy at Alliance Airfield the week of the 20th to 24th of March06?
I'm doing the 407 pilots course.
Be great to catch up with like minded people for a couple of thousand beers...........

[canterbury crusader]

B206 problems

Has anybody ever known the cyclic in the B206 to stiffen up, not a hydraulics problem but to do with the teflon uni ball?
any help would be appreciated

[Arm out the window]

If it was the uniball, wouldn't the hydraulics isolate you from it? Maybe it's just something in the control runs from the stick itself up to the servos, or in the cyclic friction.

[canterbury crusader]

I am 100% positive it is in the uni ball but unsure why. It developed rather quickly, you can just feel it starting to grab (ever so slighty, not silky smooth as is normal with 206) with the hyraulics on.
PS. Not flying it until I have had a chat to the engineer just seeing if it has happened to anyone else

[munchkins]

Normal wear and tear requires the uniball to be checked for "breakaway" and the shims adjusted accordingly. If this procedure has been done recently, you could experience a stiff cyclic with the hydraulics off, but highly unlikely with the hydraulics on. If you have had an engineer/mechanic make an adjustment on the mixing bellcrank, you will definately experience feedback through the cyclic. Ask me how I know. To the best of my knowledge the mixing bellcrank rarely requires any maintenance,

[canterbury crusader]

the reason im not to keen to fly it is because i can barely move the cyclic with the hydraulics off. there would be almost no chance of keeping it upright if the hyd fails. with hyd on it is almost normal, almost.
thanks for the help

[HeliEng]

I would like to say that your swashplate needs re-shimming, but usually they go slack not tight.

How quickly has this come on? Do you fly this particular machine a lot???

[sprocket]

The uniball can stiffen up if the friction has been set on the 'high' side of the limit, particularly with the newer type matarial used in later balls (going back a few years though).

While you are flying the ball heats up normally with use causing the friction to increase markedly (I believe up to 80lbs breakaway). If the friction has been adjusted recently (300hrly) it may need rechecking.

... and yes, noticable even with hydraulics on.

CC When do you notice the stiff cyclic? Is it after flying? Or during start? Do you have the normal few millimetres of loosness in the stick before you start?

[munchkins]

I have seen the teflon on the uniball worn to the point of bear metal. This was due to incorrect adjustments to the shim pack. The shims are "pealable" and it's very easy to peal more from one side than the other, thus ending up with more friction on one half of the uniball. When your engineer checks the shim pack on both sides make sure he has his micrometer handy. This is critical!

[beetlenut]

Had something happen like this on a 206b3. First thought I was imagining things as the effect was of such a short duration. Especially on transition to the hover and heavy the hydraulics would become "transparent" and loads on the cyclic and collective made things exciting. You could pick up fly a circuit or to another airport and nil probs, all hyd checks would be without issue. Make a faster than normal app or be heavy and the fun would start.
Engineers traced to a dirty hyd filter that would intimitantly block/unblock meaning the bypass would open/close and the hydraulics would work/not. One of those wonderful faults that our engineers had never seen before.

cheers

[canterbury crusader]

relatively new to this machine but not to the B206, Im not moving the cyclic enough to heat anything up but its probably worth looking into. unsure of machines history. the cyclic isnt stiff at any stage with hydraulics on but you can just feel little jolts as it catches and releases as it is moved. I have noticed the problem worsen in about 40 min flight time.

[munchkins]

Originally Posted by canterbury crusader

relatively new to this machine but not to the B206, Im not moving the cyclic enough to heat anything up but its probably worth looking into. unsure of machines history. the cyclic isnt stiff at any stage with hydraulics on but you can just feel little jolts as it catches and releases as it is moved. I have noticed the problem worsen in about 40 min flight time.

Now you have confused me. You say the cyclic isn't stiff at any stage with the hydrauilcs on and then mention the problem is worse after about 40 minutes of flight time??

[canterbury crusader]

My appologies,

I should have said the problem developed in about 40min flight time, and yes it is not stiff with the hyd on, It feels like the cyclic is binding (although not stiffening or affecting control in any way). After turning the machine off i moved the cyclic around and you can hear rubbing noises coming from the uni ball,

Im trying to descride this as best i can, just feel sorry for the engineer

[munchkins]

First thing is not to feel sorry for your engineer. His job is to ensure that the 206 strapped to your a$$ is 100% airworthy. If you can hear noises coming from the swashplate/uniball, get your engineer to pull the unit apart and check it out thoroughly before your next flight. Please let us know what you find.

[canterbury crusader]

will do,
I feel sorry for him trying to work out what im saying, the noise is the same noise i have heard after a new uni ball has been put in on another machine and described as "tight but will loosen up" which is what has got me concerned.

thanks for the advice

[GLSNightPilot]

The uniball is on the pilot side of the hydraulics, so it can cause stiffness problem unrelated to the hydraulics. I've seen this problem several times, almost always related to buildup of dirt and crud in the joint. The teflon may be in good shape, but the crud in there can cause stiffness in the cyclic. It shouldn't be dangerous, because you can overcome it, but maintenance should be able to clean the joint easily enough.

[BlenderPilot]

If the tightness is even in all the range of movement disregard this, but if the bumps into something moving the control sideways and then it gets stiff, but the rest is kind of normal, then it's the mixer at the bottom of the "broom closet" behind you, one of the bolts is too tight.

Either way, don't fly until you figure out what is going on, even if the problem might not be critical, you will be distracted by it an it will get your thought process thinking of something else.