B3e tail rotor spider assembly

[ktmnomad]

Hey guys,

I'm working in a 3rd world country and wanted opinions on the tail spider assembly.  

When I shut down the last days, I heard a clunking near the tail. After the blades stopped I saw that the spider housing or pitch link support tube has a fair amount of play. Obviously very technical terms here ha ha, can you tell I'm the pilot... 😂

Anyway let me know what you guys might think of this. The noise you hear in the video is the same I hear after shutdown with blades spinning. Dunk dunk dunk dunk kinda deal. 

 

Thanks. 

[GrayHorizons]

you need to change the split bush slider bushings in a bad bad way. 

350A33-2122-21 

might as well change the scraper seals too AUAS40-50-5-8

keep flying like that and you're through the chrome on the tail rotor output shaft and it'll have to be replaced too.... mucho more dollars for that.

[ktmnomad]

Thanks for that. Yeah I sent it to a few buddies and they said the same thing basically.

Mechanic here said it can go another 50 to 70 hrs with no problems... 😑

I flew it back to base today and said its getting changed and wrote it up in the book. Glad you confirmed my initial hesitation (conflicting answers) but then realistation that it definitely should be changed.

95% of my flying is slinging 6 to 7hrs a day with max loads at high altitude. Not something that should be left as is. 

Thanks. 

[GrayHorizons]

let us know if the TRGB gets sent out for overhaul too. I suspect it likely will require it for wear on the shaft. 

If I was you, I'd wander over and look at it yourself when the spider gets removed....I bet you're mechanic wont want you to see what he said would be fine for another 50-70hrs.

[ktmnomad]

The heli is still under warranty, there really is no reason why they shouldn't change everything that is needed so we see what happens. 

Yes! Im interested to see how it looks so I'll do that. I felt ”roughness” in the spider bearing at 2 different points while applying weight with my hand and turning the tail slowly. 

Thanks

[Bee3]

On 2/11/2019 at 2:47 PM, ktmnomad said:

Hey guys,

I'm working in a 3rd world country and wanted opinions on the tail spider assembly.  

When I shut down the last days, I heard a clunking near the tail. After the blades stopped I saw that the spider housing or pitch link support tube has a fair amount of play. Obviously very technical terms here ha ha, can you tell I'm the pilot... 😂

Anyway let me know what you guys might think of this. The noise you hear in the video is the same I hear after shutdown with blades spinning. Dunk dunk dunk dunk kinda deal. 

 

Thanks. 

 

Yellow Helicopters by chance....

[Heli500]

We just pulled a spider off our B3e with 2000 Hrs since new ( mostly people moving). Split bush bearings had broken free and been spinning for a while. Output shaft was still ok, but the spider was a mess. There had been issues of the bearings not bonded in well during production as explained by the Airbus Rep. 

Let us know what you find.

[ktmnomad]

On 2/16/2019 at 1:36 PM, Bee3 said:

Yellow Helicopters by chance....

Hey, ha ha nope not yellow lol. Trying to figure out what company that is. Have a couple in mind. 

[ktmnomad]

After I wrote up the movement in the book, I was happy to see them act fast. They changed the bushings and dust seals the next day and the following day was just waiting for it to set. 

They said the bearing was fine, unfortunately they did it all so fast I never got a chance to see it apart. Managed to get a few photos from one of the guys though. 

The roughness I felt on the bearing while applying my weight to the spider seems to have disappeared after they regreased it and what not. 

I really have nothing to compare this to so hopefully you guys can chime in. 

They didn't bother to rebalance anything and while its ”fairly” smooth at 100%, when I turn it to idle I get a lot of vibration briefly around 303-293rpm, the whole dash is shaking (3 to 4 seconds) until they drop further, doesn't matter what surface I'm on (mud, stones, concrete. Grass etc)

We are coming up on 1200hrs, seems they are trying to avoid ”little” things right now. Like the main seal or I think lip seal from MGB has been leaking the last 2 months and its starting to get really bad. They are delaying it until the 600hr. Its jetranger leaking right now, maybe more. 

Obviously if I was in a jet box I'd be less concerned lol. How bad is bad or at what point should I say this is BS and write that up? Was always told if the astar is leaking anything it's not good. The spill below the gimbal assembly after 5 hrs of flight is big enough that its running down the transmission hole to the fuel tank, so if you can imagine a pool of oil that big in circumference dripping from the bottom gimbal pin or close to it below the housing. 

Module 5 is also leaking but not much at all.

[GrayHorizons]

to answer the leaks, I've copied the criteria from the MM for your reference. I pasted it below.

The tail rotor balance should have at least been checked. If everything is marked correctly and re-assembled right, you can get lucky and avoid a rebalance, but it's a crap shoot. I just did one a couple weeks ago and the crew that checked the balance told me it was 0.4 IPS. SO even though I put everything back as removed, I didn't get lucky. they tweeked it down in several runs.

The Tail Rotor Output Driveshaft is clearly worn, thats indicative of that dark grey appearance. I dont see any breaks in the chrome in the pics though. But a quick rub of scotchbrite would remove some of the dark material and expose the blisters, bubbles or chips that may very well likely be there.

The next time they change the sliders, it may be more obvious. But at the very best you'll need a rechromed shaft at the next overhaul. 

 

Definitions:

Seepage:

Seepage is an imperceptible leak that cannot be measured.

The area in which you find seepage is "damp", but there are no oil "drops".

Doubtful leak:

There are signs of a leak and the quantity of oil is not negligible (as with seepage).

The oil may collect around the area but there are no other signs of a definite leak (no oil drops when the engine is stopped, no consumption that can be measured). It is possibly "accumulated" seepage or oil from another source.

Definite leak:

The signs show clearly that there is a leak:

After you stop the engine, you can see an oil flow (drops, a trickle of oil).

Oil collects and can clearly be seen to come from a point on the gearbox. It is also clear that it is not the result of accumulated seepage.

These signs are confirmed by a clear increase in the oil consumption.

Permitted leakage criteria for the MGB and the TGB:

The oil level must not decrease to become less than the minimum level:

• after 24 hours when the helicopter is on the ground,
• after approximately 1 hour when the helicopter is in flight.

When you add oil, the measured oil consumption must not be more than:

• 5 cm3 (.305 cu in) per hour of flight for the MGB,
• 2 cm3 (.122 cu in) per hour of flight for the TGB.