Hartzell/eddy current

[triple8s]

I am coming up on annual time in a month or so and was wondering about the new hub that eliminates the eddy current on the Hartzell HC-C2YK-1BF/F7666A-2 as I understand it the new hub totally eliminates the need for eddy current inspection. Anyone running one of these??

Thanks, Mike

[GeorgePerry]

You are correct.  AD2006-18-15 spells out the specifics but basically as I understand it Hartzell props with a with non-suffix serial number propeller hubs installed on Lycoming 360 engines are affected.  This AD requires initial and repetitive eddy current inspections (ECI) every 100 hours.  The inspection looks for cracks in the hub.  ECI costs around $250-500 depending on where you go.

 

If your airplane has the improved design propeller hub (suffix SN ''A'' or ''B'') then the AD does not apply. 

 

Rather than dealing with the recurring inspection, a better way to go in my opinion, is get a "top prop" conversion. 

http://www.hartzellprop.com/top_prop/index_topprop.htm

 

Costs about $7-8K installed.  Most folks report slightly better climb and cruise speeds ta-boot.  I have a "b" hub prop with about 150 hours on it...but when it's due for a rebuild, I'm not going to...I'll opt for the top prop conversion.

 

http://www.mzp.gov.si/fileadmin/mzp.gov.si/pageuploads/DL_AD_NOTE2006/088_N-2006-18-15.pdf

 

Hope this helps  

[mooniac58]

I have a 2 blade top prop and LOVE it.  Fast and sexy.  Pic attached.

[GeorgePerry]

Nice!!...One thing that I did notice after looking at Hartzell's website is the placard for E and & F models that I'm not too fond of.

2 Blade Placard -" No cont. ops. above 24" btwn. 2350 and 2550 rpm" (M20E & M20F only)

Anyone have the top prop conversion on an E or F?  Any issues with this limitation?  Seems to me that it puts you firmly into one of two camps...full on economy cruse or bumping up against the 75% continous limitation.  Not alot of flexibility with the RPM's down low until the MP falls below the 24inch restriction up higher.

Also...I wonder why the restriction on E and F and not for the J?  Same engine, same engine mounts, same airframe F and J anyway.  Should the cowl make such a diffenence for vibration harmonics?  So one out there should know...

[airkraft]

I have the Scimitar Top Prop on my E model.  I've not yet had an issue with the MP/RPM restrictions.  Mooniac58 apparently does not either.  He's based near sea level, I'm at almost 8000 feet.

I worried about the new restrictions before opting for the Top Prop.  Now that I have some experience with it I find it may actually be less restrictive than the previous limitations (I can't recall exactly what they were).

Unless I'm missing something, the restrictions should only be a factor for normally aspirated Mooney's operating routinely below approximately 6000' DA'S where cruise MP's might be greater than 24 inches. Even there, wouldn't 2,350 RPM or less achieve 75% cruise power with WOT or less? 

Unless your sightseeing, on a very short flight or battling high winds aloft, I do not see why one would operate even a normally aspirated Mooney so low.  My true air speeds seem to max out around 10,000 feet.

Anyway, I'm very pleased with the Scimitar conversion.  I picked up a 2-3 knots TAS, perhaps some ROC.

[GeorgePerry]

Both excellent answers...thanks

[triple8s]

Anyone know of a close Eddy Current Inspection facility near DKX ? Yes I am gonna do it again, maybe I'll go the Top Prop route next year.

[triple8s]

Got the ECI done on my prop at southcoast propellors, cost 350$, while there I discussed the new prop option and the guy said he would trade my prop in and about 6 grand for a new scimitar 2-blade. I just keep asking myself when is enough enough, where is the point where you trade up?