Jump to content

'Splain me about the Prop Hub "Eddy Current" Recurring A/D?


Mr. T

Recommended Posts

10 minutes ago, Andy95W said:

Exactly!  This AD originated with aerobatic airplanes, then it expanded to agricultural applications, then to over 300 HP applications.

Eventually, it was expanded to all Mooneys for some nonsensical reasons- probably partially so that Hartzell could sell more hubs and prop overhauls.

I hope I didn't just jinx myself for my next prop inspection 90 hours from now.

I kind of put it in the flying without a flight plan as far as causing accidents.

Link to comment
Share on other sites

16 hours ago, Yetti said:

It's like this

$3000 to fix with the old hub - $200 on a regular basis

$6000 to get a new hub

$9000 to get a new fancy prop

I asked the NDT guy if he had ever found one with an issue.   He said no.

 

15 hours ago, Andy95W said:

Exactly!  This AD originated with aerobatic airplanes, then it expanded to agricultural applications, then to over 300 HP applications.

Eventually, it was expanded to all Mooneys for some nonsensical reasons- probably partially so that Hartzell could sell more hubs and prop overhauls.

I hope I didn't just jinx myself for my next prop inspection 90 hours from now.

Just an FYI gents:

 

i cant vouch for the circumstances but one of the effected AC was an M20C. The poster has minimal content so I doubt he’ll make an appearance here. I don’t think these cracks are a common occurrence, but given that there have been cracks, it’s better to know. Catastrophic in flight failure would likely be disastrous. $200 is a small price to pay.

  • Thanks 1
Link to comment
Share on other sites

1 hour ago, Shadrach said:

 

i cant vouch for the circumstances but one of the effected AC was an M20C. The poster has minimal content so I doubt he’ll make an appearance here. I don’t think these cracks are a common occurrence, but given that there have been cracks, it’s better to know. Catastrophic in flight failure would likely be disastrous. $200 is a small price to pay.

Ross, I don't think either of us were saying it was nothing- I definitely get some peace of mind when I fly away from my prop inspection.  It's more a response to the OP who was asking how big of a deal it was.  

The guy from my local prop shop who actually does my ECI does the inspection very dutifully, but I get the impression by his demeanor that he really isn't expecting to find any cracks.

Now, if @Cody Stallings gets on here and starts saying he is finding a bad M20C prop more than every 2 years, I'll buy a new hub well before my next ECI, and probably within the next 2 months.  Maybe from Cody himself.

Link to comment
Share on other sites

34 minutes ago, Andy95W said:

Now, if @Cody Stallings gets on here and starts saying he is finding a bad M20C prop more than every 2 years, I'll buy a new hub well before my next ECI, and probably within the next 2 months.  Maybe from Cody himself

I’m actually thinking about contacting Cody and have him look for a used hub over the next couple of years. 

My thought when looking for a used plane was I wanted a prop that had been opened up recently and had first run blades in it. Do I care about $2 an hour for an inspection, nope. I might be able to run this prop for a decade without opening it up. 

With the weight of my turbo and extra remote filter up front I do not have the ability to run the new top prop or three blade. The pitch is also set differently vs stock so I’d rather leave it alone until it tells me otherwise. 

My prop guy at PTK said he has seen very few hubs have a problem. 

Link to comment
Share on other sites

44 minutes ago, Andy95W said:

Ross, I don't think either of us were saying it was nothing- I definitely get some peace of mind when I fly away from my prop inspection.  It's more a response to the OP who was asking how big of a deal it was.  

The guy from my local prop shop who actually does my ECI does the inspection very dutifully, but I get the impression by his demeanor that he really isn't expecting to find any cracks.

Now, if @Cody Stallings gets on here and starts saying he is finding a bad M20C prop more than every 2 years, I'll buy a new hub well before my next ECI.

My thinking mirrors yours. I would not put my family behind a prop that I thought was dangerous. That being said, the narrative that “my prop guy has never seen a failure”  only tells part of the story. My prop guy has never seen a Mooney failure but has seen them on 4cyl lycomings. He also mentioned the possibility of hubs that have had strikes making it back into service. 

Link to comment
Share on other sites

Welcome aboard ‘67.

Best regards,

-a-

 

The rest of this list was just some thoughts regarding broken hub challenges... they could be quite serious....

What could possibly happen if a hub breaks?

  • release a blade...
  • Imbalance of forces... quite large
  • broken engine mount... pretty serious
  • WnB change... depending on what actually departs the plane.

 

  • Losing a blade in flight puts a pretty close end to the flight...

 

Link to comment
Share on other sites

On 12/8/2018 at 9:13 PM, Cody Stallings said:

Yes Cody Has Found a Cracked Hub.

Havent scrapped a Hub in a long time, only a couple during inspection.

Mostly Corrosion an Pre-Load shelf damage puts the red tag on them.

 

I forgot to thank you for your advice on my prop and hub. I ended up keeping the blades and getting a new hub largely on your advice. No more AD for me, though I never found it to be a big deal, my overhaul was going to cost more than half the price of a new hub without the AD, so I went with a new B hub and existing blades. 

Link to comment
Share on other sites

  • 1 month later...

Another option is to contact a non-destructive testing (NDT) firm. I've had significant experience working with these firms in heavy industry. There is a "Level3" inspector who lives close by that I've worked with for years. When this AD came out I happened to bring it up while he was working in our mill. Turns out he was qualified for aviation work and did all of Net Jets NDT work. When I need the inspection, he comes to the hangar. My inspector works for Team Industrial. These guys travel all the time. If you call there might be someone in your area if your lucky. 

Link to comment
Share on other sites

14 minutes ago, PilotCoyote said:

Does changing to the B hub effectively change the red zone on your tach? My maintenance records show that when the B hub was installed the PO had the tach red zone repainted

No, the B hub doesn't change the tach.  You would have to change propeller types (such as a 3-blade or the scimitar Top Prop) to get rid of the red arc or change it.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.