PROP SPINNER BACKPLATE DISINTEGRATED - NEED MCCAULEY D-6502 BULKHEAD

[DCarlton]

Left SOCAL this morning headed to Willmar MN for fuel tank reseal.  Beautiful flight for the first two hours... then my prop spinner backplate started to disintegrate.  Fortunately I was only a few miles from P08 (Coolidge AZ).  First noticed a slight change in engine tone and vibration; then noticed a strange smell; thought it was burning rubber or an electrical issue (it was not).  Then a piece of the backplate quickly departed the airplane off the port side and the engine sound returned to normal.  Couldn't imagine what could have come off the airplane.  Started troubleshooting.  All the engine gages were normal; thought I may have lost an alternator belt but the alternator was still charging.  Landed uneventfully and then discovered the damage.  I believe the smell was the smell of shredded fiberglass from the cowling.  Found a team of very nice and helpful C-23 Sherpa mechanics on the field that will start searching for another backing plate for the three blade McCauley.  I've heard there may be composite options(???).  Would appreciate any suggestions to find parts quickly.  Took a Southwest flight back home from PHX.  Really bummed I didn't make it to Willmar as planned.  BTW, I think I've seen other photos of spinner backplate failures.  Is this a common problem?  It seems crazy to me now that you remove the spinner every annual and check the backplate for cracks.  If you have to look for cracks, it doesn't seem like a very robust design.  Thoughts / suggestions welcome.  So far I have not been able to find the P/N in stock new or used.  Thanks MS! 

 

Edited September 8, 2023 by DCarlton
Pics seem to have gotten hosed up.

[Bartman]

Wow !

I don’t have any insights on a cause or a fix, but great to see you are safe on the ground. 

[47U]

9 hours ago, DCarlton said:

Thoughts / suggestions welcome.

Sometimes mx induced.  There is a right way to add weight during a dynamic prop balance, and (in this case) a wrong way.

Good luck in your search for a backplate.  

[M20F]

Our 320 had a habit of shedding spinners on the right engine.  We finally changed the backplate after the 3rd one went over the side in 18 months, fixed the issue.  The old one looked perfectly fine but obviously had a bend in it somewhere.  

[mike_elliott]

3 hours ago, Bartman said:

Wow !

I don’t have any insights on a cause or a fix, but great to see you are safe on the ground. 

The inner ring of the spinner needs to be a very snug press fit onto the prop bulkhead, or this can happen. Tightness and integrity Should be checked at annual at a min, and to see if any play (IE cracks on backplate by grabbing the snout and checking for movement) during preflight.  The A1A engine and the 3 blade Hartzells seem to have a desire to shake some regardless of how well they are balanced, but that wasnt this combo

[DCarlton]

I've never had the prop balanced but it never seemed to need it.  The prop is not that old.  I think the backplate and spinner came with the new prop but I don't remember.  I'm pulling the log books today.  Looks like a crack may have started at one of the screw holes.  

Edited September 8, 2023 by DCarlton

[DCarlton]

Hi @Cody Stallings.  Sent you a message on Facebook too.  Looking for an in stock McCauley D-6502 bulkhead or D-6504 Spinner Assembly (new or used).  Appreciate your time.  

[47U]

5 hours ago, DCarlton said:

Looking for an in stock McCauley D-6502 bulkhead

controller.com

https://www.controller.com/parts/search?PartNumber=D6502&SearchType=Start

[DCarlton]

1 minute ago, 47U said:

controller.com

https://www.controller.com/parts/search?PartNumber=D6502&SearchType=Start

Awesome thanks!  Didn’t know you could search parts on Controller.  I’ll try them Monday.  I called a few places today showing parts on line and struck out. 

[Boilermonkey]

This happened to me after a engine and prop overhaul and install at Wilmar.   The "donut" that stabilizes the spinner on the nub of the prop hadn't been installed.  After 12 hours it fractured the bulkhead due to shaking and imbalance.   They came out and fixed it.  Replaced a few screws that were damaged in the process as well, one had to be drilled out.

Once you find the part, you'll need the local A&P to pull the prop off, install, and rehang the prop.  Takes 2-3 hours.

[DCarlton]

3 hours ago, Boilermonkey said:

Once you find the part....

Hopefully I'll have success Monday.  The only lead I have left is the one from 47U above.  Also have a prop shop looking and a mechanic.  I'm having visions of the plane behind grounded for six months while I wait for McCauley to make one; or having to trade in a good prop for a new one just to have a complete assembly.  

[DCarlton]

On 9/8/2023 at 8:56 PM, 47U said:

controller.com

https://www.controller.com/parts/search?PartNumber=D6502&SearchType=Start

Another bogus internet ad.  No stock.  This guy brokers used parts and doesn't want to get involve with cowl STCs and J spinner parts used on F model airplanes.  

[KSMooniac]

You can fly without the spinner, I believe.  You'll have to check your prop paperwork/Instructions for Continuing Airworthiness (ICA).  

[EricJ]

44 minutes ago, KSMooniac said:

You can fly without the spinner, I believe.  You'll have to check your prop paperwork/Instructions for Continuing Airworthiness (ICA).  

I don't think any Mooneys are approved for operation with no spinner.   Usually when it is approved for such it says so in the TCDS.    He has a J-style cowl, and I wouldn't want to experiment with flying one of those without a spinner.

[KSMooniac]

My J with an MT can fly without it a spinner. Maybe not without the backplate/bulkhead, though, now that I think about it more...

Sent from my LM-V600 using Tapatalk

[EricJ]

9 minutes ago, KSMooniac said:

My J with an MT can fly without it a spinner. Maybe not without the backplate/bulkhead, though, now that I think about it more...

Sent from my LM-V600 using Tapatalk
 

That's interesting if the MT STC lets you do that.   I'd still be a bit worried about the cowl/baffle behavior without a spinner and bulkhead.

[DCarlton]

1 hour ago, EricJ said:

I don't think any Mooneys are approved for operation with no spinner.   Usually when it is approved for such it says so in the TCDS.    He has a J-style cowl, and I wouldn't want to experiment with flying one of those without a spinner.

Agree.  A friend told me he operated his Piper without a spinner but I'd be afraid of unzipping the Mooney SWTA cowl mod in flight without a spinner. 

[DCarlton]

On 9/10/2023 at 7:37 AM, Boilermonkey said:

This happened to me after a engine and prop overhaul and install at Wilmar.   The "donut" that stabilizes the spinner on the nub of the prop hadn't been installed.  After 12 hours it fractured the bulkhead due to shaking and imbalance.   They came out and fixed it.  Replaced a few screws that were damaged in the process as well, one had to be drilled out.

Once you find the part, you'll need the local A&P to pull the prop off, install, and rehang the prop.  Takes 2-3 hours.

Looks like you have company.  The very nice mechanic that's working my issue called to tell me the forward "front support" (part #4 in the drawing) was missing when he removed the spinner.  I believe its press fitted onto the front of the prop hub and shimmed for a snug fit against the spinner.  It had been installed at some point because there is a visual ring inside the spinner where the "front support" used to make contact.  I've ordered a new Bulkhead and Front Support with Shims from Ottosen Prop in PHX.  Don't have an ETA from McCauley yet.  

[A64Pilot]

Airplanes will fly fine without spinners, but it is almost never allowed, because to make it legal to do so you would have to go out and do cooling climbs etc and Certify it without a spinner, and why would anyone spend that time and money to do so, remember it’s not just a flight, you have to write a test plan, submit it to the FAA, they will stuff it into some pigeon hole because frankly it’s not a real important test, then much later when they get to it, they will make recommendations, send it back to you and you’ll revise the test plan, and back it goes into the que at the back of the line and all this Engineering time writing and revising plans is money.

But they fly fine without one, just try to not get caught.

[DCarlton]

I don't have objective evidence yet, but rumor has it my parts have been shipped from McCauley.  I'm optimistic I'll be back in the air within a couple of weeks.  Definitely not gonna fly without a spinner.  I have visions of my cowl coming apart...