Removing the cowling for preflight inspection

I removed the cowling to find this.


It was a lesson learned for me to pull cowling more often. I sensed something was wrong due to last flight on run up the aux charge was a negative. It had been approx 15 hours since I had cowl off and no indication of a issue as I was next to the alternator changing the oil filter. The fact that the alternator had come apart was not as alarming as the fact it was resting on the oil filter and on its way to wear a hole into the the oil filter. I have not looked at what caused it to come apart but I suspect either loose internal bolts or possible thread strip.
Thought I would share as something to look for

Good catch.

I looked at the picture before reading the rest of the post and it took me a moment to see the b/u alternator. A habit I have always done is when I check the oil on pre-flight I look through the door for a visual of anything that can be seen. Two reasons; first to see if anything is out of place, missing, or sprayed and second to see the oil filter and the hours visibly written on it for when it needs to be changed.

I always do a sniff test in addition to see if anything like oil or fuel is particularly strong smelling under the cowling.

Who was the manufacture of your standby alternator?

I always liked the idea of a direct drive alternator. I never liked the center of mass so far from the mount.

Please let us know how the manufacturer responds.

Perhaps a little off topic, but has anyone modified the top cowl on an RV to allow it to be quickly and easily opened on one or both sides for a quick look as a part of every pre-flight?

My current airplane is a Grumman which allows me to pop the cowl with just 2 latches and open it on its top hinge to inspect the engine. I was taught to do this every time as part of my pre-flight, and it does allow me to confirm no oil or fuel leaks, no hoses rubbing or other possible problems.

I would like to have a similar ability in the RV-10 I'm currently building, rather than just the small oil door opening. However I haven't determined if this is practical. My current thinking it to build it per the plans for now, and then perhaps try to modify it after Phase 1 when I have a flying aircraft and time to experiment.

Gary Newsted

Gary Newsted has/had an RV-9 with a cowl that opened - it was really well done, and allowed easy inspection. He had a Subaru in there, so didn't need the baffles - that might have made things a bit easier. I think this would be a very nice mod, as I find removing the cowl to be a bit of a pain now, and I'm sure once I paint, it will be really tricky.

rv8ch said:

Gary Newsted has/had an RV-9 with a cowl that opened - it was really well done, and allowed easy inspection. He had a Subaru in there, so didn't need the baffles - that might have made things a bit easier. I think this would be a very nice mod, as I find removing the cowl to be a bit of a pain now, and I'm sure once I paint, it will be really tricky.

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Haven't heard that name for a while... And, a "lobster pot" for an air cleaner!

RV6_flyer said:

Who was the manufacture of your standby alternator?

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Looks more like a Plane Power http://www.plane-power.com/FS1-14.php than a B&C http://www.bandc.aero/alternator45ampshomebuilt1-2.aspx.

I could be wrong...

Yes it is plane power....I covered the label because I am not interested in negative feedback against the manufacturer...they have been good to me and it did have 456 hrs on it.
That is one thing with RV10 cowl is not much to see through oil door.

gasman said:

I always liked the idea of a direct drive alternator. I never liked the center of mass so far from the mount.

Please let us know how the manufacturer responds.

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ditto. no vibration analysis to support but it just doesn't look right with the large overhung mass.

Jim Barry in Denver built a large oil door that is about 1/4 of the cowl in his 10. I was going to do the same on my cowl but forgot about it till reading this thread.

You're not the first

My PlanePower backup alternator failed in the same manner a few months ago after 30 hours of flight. I've not posted publicly until now--it's really easy to damage a small company in these forums.

The cast (no inserts!) female threads failed in the nose adapter in mine. There is also very little thread engagement. It's really an under-engineered design.

Plane Power spent a lot of time analyzing and inspecting the failed unit I returned without results and without sending a warranty replacement while they looked the unit. I ultimately decided I didn't want another anyway.

Since I had purchased the alternator from Aircraft Spruce I gave them a call. They were fantastic! Due to the lack of appropriate response from PlanePower, Aircraft Spruce took over my warranty claim themselves and gave me full credit towards a B&C backup alternator.

It should be noted that the B&C unit is a one piece casting. A much better design. Installing the remote voltage regulator was a pain, but worth it in this case.

that is a poorly designed part. no more to say except that my 15 yr daughter could do better.

Just received email from manufacturer of FS1-14 that they denied the warranty and provided no options to fix the failed one. It is almost 500 hrs and 3 years old but I was expecting a " it is not under warranty but here is how we can help you and provide a solution" I think there is lack of engineering as the new one I installed looks as though the mating flange to the alternator is not machined precisely to mate the two together for the long term. Any one else have failure or experience with this unit?

I am attaching my top cowl with skybolt fasteners. It will take less than a minute to remove it single handed. I got the idea from a friend's -6. Not as clean as the hinge pin installation, but they do look nice and they are superior for maintenance and inspection. Of course that won't stop an alternator from falling off, but I might see it sooner.

Jackm said:

Just received email from manufacturer of FS1-14 that they denied the warranty and provided no options to fix the failed one. It is almost 500 hrs and 3 years old but I was expecting a " it is not under warranty but here is how we can help you and provide a solution" I think there is lack of engineering as the new one I installed looks as though the mating flange to the alternator is not machined precisely to mate the two together for the long term. Any one else have failure or experience with this unit?

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From the way the new parent company appears to be handling warranty claims on their all-too-often failing products, the last thing I'd do is throw good money after bad installing another one.

I know they're a forum advertiser, but come on!

DRMA said:

Perhaps a little off topic, but has anyone modified the top cowl on an RV to allow it to be quickly and easily opened on one or both sides for a quick look as a part of every pre-flight?

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There used to be, but I don't know if it's still available. Dave ? (I can't remember his last name) was selling a mod of the cowl that was just what you were looking for. But he sold the company a copy years ago. I don't know if they still offer the mod, since Dave was the driver for all the RV-10 mods.

Dave Saylor - AirCrafters

His -10 was at OSH last month, w/ the cowling mod. Don't know if he sold many - but it always looked like a good idea. Dave sold the company several years ago, but here is the current info - maybe you could call them and see what they say.

Aircrafters
140 Aviation Way
Watsonville, CA 95076

(831) 722-9141

HFS

This is scary. I have the same plane power alternator with 500 plus hours on it. I just had the cowl off a couple of days ago. I think I will take a better look tomorrow.

Bill.Peyton said:

This is scary. I have the same plane power alternator with 500 plus hours on it. I just had the cowl off a couple of days ago. I think I will take a better look tomorrow.

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If I had one, I'd pull it, dismantle, and install Time-Serts or similar in those threads. Time-Serts work very well.

http://www.timesert.com/

DanH said:

If I had one, I'd pull it, dismantle, and install Time-Serts or similar in those threads. Time-Serts work very well.

http://www.timesert.com/

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+1 Those are the best design of an insert I have ever seen!

Inserts, or at least put in a fastener with proper thread length engaged for aluminum. The one picture appeared to be about half enough threads engaged. ~ 2D is good for this situation.

I'll look today. Need to determine if there is enough meat to increase dia. Of hole. I noticed that the new alternators do not use fasteners and now use a solid casting. It would be nice to obtain the new casting and just replace the two piece config.

I spoke with Hartzell who claims that this is a rare issue, maybe just 2 or 3. I also confirmed that the newer version is the same as the older version.

I inspected my FS-14B alternator and did not see anything suspicious. The two casting are held together with 4 #10 screws, the heads are easily visible through the front casting without disassembly. All four of the screws appeared to be flush and appeared tight. The two castings were tight against each respective surface.

I chose not to remove it yet since I have a trip coming up. This unit has over 500 hours on it. If it were going to come apart, it probably would have. In my application, the field is not energized except to test it periodically, so there is no torque on the shaft or housing resulting from current draw.

I just wonder if a few of the units were assembled with the incorrect length screws?

Bill.Peyton said:

I just wonder if a few of the units were assembled with the incorrect length screws?

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It could just be an assembly issue, then it would be under warranty, no matter the hours.

Torque is irrelevant to this housing. Anytime accessories are bolted in line with the axis (in particular) of an engine they are subject to resonant vibrations. Diesel engines with rear drives and multiple hydraulic pumps will resonate like the prongs of a tuning fork. Aircraft engines don't have the high energy of a diesel, but far more than a typical terrestrial gasoline engine. This alternator does not look particularly stiff in a wagging direction. Looks can be deceiving, though. Only results count.

I decided to buy and install same model as I needed to keep flying at time. My concern is, it looked all normal 15 hrs earlier during condition inspection. I do run mine in flight as part of test to ensure I do have reliable back up if needed but out of 500 hours maybe only 25 hrs under load. Even the new one installed, the flange doesn't seem to have a precise fit but only way of telling is to disassemble. I feel another 10 hrs flying that way would have wore a hole in oil filter and turn into bad day. Also between ours and friends airplane ( new) we have gone through four of main alternators. Maybe we just hard on Plane power

Well I decided to disassemble mine and take a look. Like Jack, my unit probably had less than 1 hour of total run time with the field powered up.

The good news was no issue was found with the hardware attaching the front case halves. The brushes looked fine and had .38", well over the require .25" remaining called out in the ICA.

What I did find is that the rear protective shield was cracked all the way through in a couple of areas.

I also found that the rear support bearing has been spinning in the rear case to the point of wearing an approximate .020 delta between the OD of the bearing and the ID of the rear housing. The actual sealed bearing itself was fine, rotated smoothly, and wasn't leaking grease. I was surprised that the rotor had not yet contacted the stator assembly with that much play in the shaft/bearing.

After a long discussion with the Hartzell tech rep., he informed me that the front case was being redesigned into a single piece housing, similar to the B&C products, and the older style case was being assembled in a different manner with different fasteners. Also, found out that these units are not overhaulable nor do any parts exist for field repair other than replacement brushes.

Bottom line, this one is also toast, and failure was imminent. A new B&C is on the way!

Below are some photos of the disassembled unit.


[/url]IMG_1226 by Bill Peyton, on Flickr[/IMG]

[/url]IMG_1224 by Bill Peyton, on Flickr[/IMG]
[/url]IMG_1229 by Bill Peyton, on Flickr[/IMG]
[/url]IMG_1234 by Bill Peyton, on Flickr[/IMG]


[/url]IMG_1240 by Bill Peyton, on Flickr[/IMG]
[/url]IMG_1236 by Bill Peyton, on Flickr[/IMG]
[/url]IMG_1241 by Bill Peyton, on Flickr[/IMG]

You can see the wear in the casting bearing seat where the bearing has been spinning, along with all the metal dust that has accumulated on the housing

Alternators

"I spoke with Hartzell who claims that this is a rare issue, maybe just 2 or 3. I also confirmed that the newer version is the same as the older version."

That's interesting, maybe they just haven't heard about the 5 x PP 60amp units I am replacing (I have the serial numbers as I installed 4 of them) as a result of failures.
2 are due to the Volt Regulator (earlier models had them externally attached) falling off the back plates at 200-300 hours, the other 2 had max amp ouput (50-60) with 1 found with 4 diodes failed & mine has to be tested yet to determine the cause. As the fault happened outback Oz I flew back home on # 2 Alt (PP FS-14B) I am now really concerned about it too.

Denial by any manufacturer is something I can not tolerate especially when customers ask my opinion about a particular product, needless to say I have subsequently bought 5 x B&C units.

IMO we should be advising anyone we know of the reported proven problems with critical to flight/engine products.

Be careful out there.