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

[Mr. T]

Can someone give me the down-low on the Hartzell prop hub "Eddy Current" recurring A/D?

* I understand the A/D must be complied with every 100 hours. Is that accurate? Is this like the seat rail A/D in a Cessna where you can't fly past the 100 hour point?
* How much does it typically cost to have the inspection completed?
* How often are problems found?
* What kind of shop can do the work? Do I need a specialist? Recommendations in or near the Kansas City area?
* What options are there for upgrading the prop hub and which option is "the best"?
* Anything else a newbie would need to know?

[MARZ]

Lots of info here.  Search for eddy current or check this

 

 

 

[gsxrpilot]

1 hour ago, Mr. T said:

* Anything else a newbie would need to know?

Don't buy a plane that hasn't had the hub replaced and the SB eliminated.

[Shadrach]

The AD is simple and inexpensive to comply with. It requires the removal of the spinner only. The cost in my neck of the woods is $150-300 depending on how proud the NDT specialist is of their work. The actual test takes about 5-10 minutes at most and involves running an ECT probe over the front half of the hub  It is mandatory every 100hrs, No, there have not been many failures, but there have been some. I did not replace the prop on my aircraft when the AD came out, because I know the plane and prop’s history. The blades have at least one overhaul left in the, likely two. At a cost of $200 done in my hangar about every 18 months, it makes no sense for me to upgrade at this time. If ai were in the market, it would not be a deal killer, but it’s obviously preferable to get a Hub that has no AD, at least for now...

[Guest]

From the AD,

 

[skydvrboy]

I found the prop AD no big deal.  I flew it to the prop shop and 15 minutes later their done.  Another 30 minutes later and they have the paperwork done and my $150 bill is at the front desk.

[MARZ]

There is also an “upgrade” that terminates the ad by resealing and filling the hub with a red dye oil.  This is the route I took.  IIRC it was @ 2 amu’s

[Shadrach]

30 minutes ago, Mike Ropers said:

There is also an “upgrade” that terminates the ad by resealing and filling the hub with a red dye oil.  This is the route I took.  IIRC it was @ 2 amu’s

My prop shop won’t do the red dye upgrade. They don’t like the modification.

[0TreeLemur]

When I first learned that my "new" M20C had this recurring AD I was concerned.  The prior owner flew with me to a prop shop that will do it on the a/c, and it went exactly as @skydvrboy said.    In fact just had it done the second time recently.  It is a pain once every 100 hours and adds about $2.00 per hour to the cost of flight.   No biggie.   The cost of a new prop without the AD will pay for a lot of ECI inspections.

According to the person who recently tested mine, there have been very few failures or detection of cracked hubs in the past few years.    In his opinion, all the hubs that were going to fail have all pretty much failed.   But once an AD is inacted, they don't go away thanks to bureaucratic inertia.   So, I'm waiting for somebody with a really awesome 2-blade scimitar Hartzell to upgrade to a reeeally awesome 3- or 4-blade prop, and sell me their 2-blade scimitar reeeeal cheap. 

[carusoam]

Check where you are going to get the test done...

Or who can fill the prop with the red oil...

For me, it was a half-hour flight away, using up a whole day to get it done...

All in, a couple hundred bucks, and a day off...

Just a drag, for a young guy, with little vacation to use, and only a few AMUs to spend...

Overall, the AD and the related crack, are less of a Mooney problem than the same prop on other planes... So it is a necessary homework assignment, but don’t expect to ever see a crack... bad news/good news...

There is a pic around here showing how serious a crack in the prop hub can be...

Best regards,

-a-

[Shadrach]

8 hours ago, carusoam said:

Check where you are going to get the test done...

Or who can fill the prop with the red oil...

For me, it was a half-hour flight away, using up a whole day to get it done...

All in, a couple hundred bucks, and a day off...

Just a drag, for a young guy, with little vacation to use, and only a few AMUs to spend...

Overall, the AD and the related crack, are less of a Mooney problem than the same prop on other planes... So it is a necessary homework assignment, but don’t expect to ever see a crack... bad news/good news...

There is a pic around here showing how serious a crack in the prop hub can be...

Best regards,

-a-

A whole day? How? If they knew you were coming they should have been under an hour from start to finish. It takes longer to R&R the spinner than to perform the test. 

Edited December 7, 2018 by Shadrach

[carusoam]

Ross,

This was the whole day that I took off from work...

Mostly because I didn’t have the shop, near the plane, near the work location...

Or MS to help with the logic, or detail, or advice, or MS friends to share the flights...

It was just a pain in the butt for about two years...

I used the hartzell(?) prop shop next to the MSC in eastern PA...

Hence the advice to know what to do, and where to go, before getting saddled with this less-than-challenging AD...

It took a long time to know I could have done much better!  

Best regards,

-a- 

[Shadrach]

7 hours ago, carusoam said:

Ross,

This was the whole day that I took off from work...

Mostly because I didn’t have the shop, near the plane, near the work location...

Or MS to help with the logic, or detail, or advice, or MS friends to share the flights...

It was just a pain in the butt for about two years...

I used the hartzell(?) prop shop next to the MSC in eastern PA...

Hence the advice to know what to do, and where to go, before getting saddled with this less-than-challenging AD...

It took a long time to know I could have done much better!  

Best regards,

-a- 

I think you’re referring to Sensenich in Lititz, PA (KLNS). I’d always heard they were fast and reasonable, but I’ve never used them.

[nels]

Typically if the plane has a three blade prop there is no AD. Just a tip while you’re hunting.

[0TreeLemur]

25 minutes ago, nels said:

Typically if the plane has a three blade prop there is no AD. Just a tip while you’re hunting.

To be clear, I don't want a 3-blade prop.  I want a real deal on a 2-blade scimitar from someone else who 'upgrades' to a 3-blade prop. 

[Ned Gravel]

2 hours ago, Fred_2O said:

To be clear, I don't want a 3-blade prop.  I want a real deal on a 2-blade scimitar from someone else who 'upgrades' to a 3-blade prop. 

I am not certain anyone with something like a Hartzell Top Prop would consider a three blade as a trade up.  

Just sayin'

[skydvrboy]

A local dentist has a b model hub sitting in his office as a conversation piece.  He told me if I wanted to upgrade to let him know.  The cost to overhaul and install the prop and hub alone would pay for 10 - 15 years of ECI's.  However, when my prop needs so much as a reseal, I'll be in his office!

[Mr. T]

Thanks for the good information.

One thing that I'm still not clear on -- is the 100 hour interval a "hard" limit, meaning the plane can't be flown past 100 hours without a new inspection? Any leeway at all?

[steingar]

2 minutes ago, Mr. T said:

Thanks for the good information.

One thing that I'm still not clear on -- is the 100 hour interval a "hard" limit, meaning the plane can't be flown past 100 hours without a new inspection? Any leeway at all?

I doubt it.  Those ADs carry the force of law, and the law is usually pretty picky on the details.  I ruled out one of the AD-ridden props in my search.  My worry is a mechanic unfamiliar with Mooneys could wind up taking a long time doing it, and thus cost me a lot of money.

[0TreeLemur]

2 hours ago, Ned Gravel said:

I am not certain anyone with something like a Hartzell Top Prop would consider a three blade as a trade up.  

Just sayin'

Ned, you can't stop me from dreaming.   That famous W.C. Fields quote is still true, but I'm not holding my breath.

[Guest]

5 hours ago, Mr. T said:

Thanks for the good information.

One thing that I'm still not clear on -- is the 100 hour interval a "hard" limit, meaning the plane can't be flown past 100 hours without a new inspection? Any leeway at all?

No tolerance is listed in the AD, so at 100 hours you’re grounded.

Clarence

[Yetti]

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.

[MIR2018]

anybody have a suggestion for a shop in the Charlotte, NC area that can do the ECI?  One that they have used before?

[kpaul]

1 minute ago, MIR2018 said:

anybody have a suggestion for a shop in the Charlotte, NC area that can do the ECI?  One that they have used before?

@AGL Aviation has a prop shop they use in the area that I would assume can do the ECI. 

[Andy95W]

1 hour ago, Yetti said:

 

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

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.