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  Plane-Power 70 Amp Alternator Install Pirep

 

28 July 2022 News Flash:


On 25 July at EAA/OSH, I spoke with Plane-Power Support Rep, Allen Buffkin, who stated that Hartzell/Plane-Power have in development a one-piece machined mount to replace the welded bracketry that has been failing on many Beechcraft Bonanza engines. This new mount will only fit the TCM bracket PN: 628004. Hopefully, this will finally put an end to failing mounting brackets on Beech airplanes.


Allen also stated that they have alternator and generator replacement kits that now fit the original factory generator mounts, which presumably have survived the test of time on many airplanes. Click HERE for a link to their STC Approvals page.


Allen has agreed to provide his mobile number for anyone needing more info on this or other Plane-Power questions: (334) Three-Hundred  Six-Eight-Five-Nine.




 

 

OK, all you folks with Bonanzas with generator set ups and puny 50 amp alternators, check this out if you are looking for more juice to run your fancy new panel stuff or to stop brownouts during night ops with your incandescent taxi/landing lights running.

 

 

Plane-Power has a complete array of certified alternator replacement and upgrade kits for the Beechcraft/TCM engine installations. Check out Aircraft Spruce for pricing! 

 

 

Generator to Alternator STC Model Eligibility HERE 

 

IO-470N Alternator/Generator IPC Extract HERE

 

Gear Driven E-225 Series Fit Guide HERE




Check Out the Bracket Failure Pireps Below


 


 

Here is an install pirep from Stan S. the Bonanza man with an IO-470N:

 

We finished installing a new belt driven 70 amp Plane Power alternator on the IO-470 in the Deb today. It comes with a new mounting bracket, new stabilizing arm and belt tightening bracket. Everything fit perfectly. The Plane Power 70 amp alternator weighs 10 pounds, the same as the 50 amp InterAv alternator it replaced, but it has a state of the art small voltage regulator that replaced the InterAv's voltage regulator, over voltage relay and huge capacitor. The Plane Power kit also comes with an "ALT INOP" 100 milliamp warning light that must be mounted on the panel in the sight of the pilot and connected to a power source through a one amp fuse or breaker on one side, and to a terminal on the voltage regulator on the other. 

 

We fired up the engine to test it and put about a 45 amp load on it, and at 950 RPM it held 14.1 volts. The staff at Plane Power told me this alternator will deliver 70 amps at cruise RPM. Note not all 12 volt Plane Power alternators are 70 amps, the gear driven alternator that fits on the E series engines is 50 amps, and they also have some 60 amp models. If you have a belt driven alternator or still have the belt driven generator, this is a good option to upgrade to current technology, and I like the warning light that will illuminate if the alternator goes off line. Another Beech Boy recently installed the gear driven Plane Power alternator on the E series engine in his E35, replacing his old 35 amp generator, and is very happy with it, also. 

 

Picture of the installation attached, when the picture was taken we were not finished tie wrapping the wires, etc. The Plane Power alternator is physically smaller than the InterAv alternator it replaced, but weighs as much, 10 pounds, versus 17 pounds for the old 50 amp generator we removed about 7 years ago. We replaced the InterAv alternator because it failed, bad bearings probably resulted in physical damage to two of the three field/armature components or the brushes/commutator, it would only produce about 15 amps and upon removal the bearings were obviously worn out, the shaft had about 1/4 inch of end play.

We also replaced the drive pulley on the engine, the old one was a little dented. That job was a little tricky, using a puller to get the old one off and driving the new one on far enough to get enough threads on the shaft to move it the rest of the way on with the nut. Not much clearance back there, but far more clearance than Cessnas have!

 

Stan

35-A33 KSAC

 

Here is Stan's Plane Power Install

 

 

GBelow is more of what Stan has to say on 2/28/2024 about his success with the PP bracket:

 

"I will explain what I have done to successfully avoid a PlanePower alternator bracket failure (these bracket failures in this thread are referring to the belt driven alternator installations) and then I will explain why I have done it this way.

 

I adjust the belt tension looser than spec. Since the pulley on the PlanePower alternator is relatively large in diameter, the belt does not slip when adjusted fairly loosely.

 

I started doing this after replacing an InterAv alternator with the PlanePower alternator after the bearings failed on the InterAv alternator. I caused that bearings failure because I had to keep the belt tension very tight or the belt would come off. Then one day when trying to figure out why the belt kept coming off, Larry Gaines was visiting my hangar and noticed the pulley on the engine was warped! Got a new pulley and corrected that belt coming off problem but shortly after, the bearings failed on the InterAv alternator, and I upgraded to the superior PlanePower setup and kept the belt tension relatively loose so as not to wear out the bearings prematurely. 😊 Did this before I learned that the mounting bracket PlanePower supplied was marginal. With the looser belt tension, that bracket has lasted over 1,340 hours so far. 260 horsepower IO-470-N engine, similar to 260 horsepower engines in Barons with but with different intake setup."

 

Stan

35-A33 KSAC



 

The IO470 engine is known to dish out quite a bit of vibration.

 

 

 

IO470 owners continue to experience bracket failures through bracket Revisions, J, K and L.




 

HERE is a thread on Beech Talk going back to 2014 regarding Plane Power IO470 bracket failures.




The above picture is from David F. and here is his pirep on his experience:

"........in our case the mis-alignment at the green arrow was so severe (3 mounts so far) that it stretches the weld apart (the red arrows) causing the cracks. We re-welded our bracket and relieved the holes to achieve correct alignment of the bolts, correct alignment of the belt, and so far everything is working.

Our last bracket cracked within 10 flight hours before correcting the mis-alignment."




Below is a Plane Power bracket that lasted 85hrs before failure on Daniel K.'s K35 Bonanza.




 

N35 Owner Pedro G. says:

"I’m on bracket #9: changed engine mounts, balanced prop, shortened alternator belt, made sure bracket went in place without forcing it, and still no joy. Bracket #8 lasted 58 hours."



 

Below is a late model Baron Alternator bracket with very beefy gusseting. Perhaps Plane Power engineers might evaluate that design for a potential solution to their IO470 bracket failures????

 

 


 

Here is an install pirep from Baron B55 owner Joe B.

 

Put a pair of PP alternators on our Baron this year (2009) and love them. Very clean output and the pair was perfectly balanced out of the factory.

 



Below are pictures of Chris S.'s modified alternator bracket and comments on his Plane Power experiences. See the flex of his PP bracket in this movie HERE



Per Chris S.:

"Back in the days where Plane Power was Plane Power we ordered an alternator kit and they sent us the “gold mount”.  It required some Herculean efforts to install and we asked why they couldn’t simply install the new alternator on the existing mount.  So they made some changes and got it approved for us. 

 

The first rev had a design flaw and one of the alternator main pivot bolts departed the airplane somewhere between Tucumcari and San Luis Obispo.  The alternator hung by the tensioning arm and kept charging with belt intact.

 

We went to a single bolt through the alternator and spacers instead of two eliminating the hinge moment.

That worked well until the OEM bracket broke.  We reinforced and welded it along with a shorter belt.  Broke again and that’s when an intermediate arm was machined and welded in place.  Been going for a while now.

 

Our experience with the Plane Power alternators has been great otherwise.  The regulators and units work really well.

 

Last year end we purchased the Kelly Aerospace air conditioning system for the B55.  It requires a specific 100 amp alternator requirement that put out a lot of current at low RPM because ground operations are where the system is mostly used. The system is certified for all phases of ground and flight. Very likely we will be upgrading our alternators.


Use of a shorter belt changes the vibration characteristics of the alternator by moving the alternator mass closer to the engine. "