Experimental Justification


So after investing more than 1,000 hours of building time and tens of thousands of dollars into building your new aircraft, you're thinking of going down to the local auto parts store and picking up an automotive alternator for your aircraft?  
We suggest you think twice.

The fact is, there IS a difference between automotive and aircraft alternators.  And some of those differences may mean the difference between you flying home with power to spare or preparing for immediate landing with that sinking feeling in your stomach after losing your alternator in flight.

You see, our very own alternator began life as an automotive alternator.  Sure!  Many years ago, we thought it would be simple: just reconfigure the mounting system of a typical Nippon Denso alternator and sell it to airplane owner/builders (in fact, some vendors do exactly that today!).  But for us, that dream lasted about as long as it took us to tear into a few alternators and do some real testing.  

What we found was most automotive alternators lack the proper design, composition and quality to be used for real aviation applications.  Among many other shortcomings, we found automotive alternators typically run counter to the desired direction of rotation on an aircraft.  Not necessarily a problem in generating power just the same.  However, the cooling fans would have to run backward as well.  That's workable, but not ideal. Also, operational RPM's would be significantly higher than the environment for which they were originally designed.  Again, workable, but not ideal.  At altitude, we found automotive brushes become fantastic abrasives!  Decreased moisture at altitude was no longer present to provide the requisite lubrication qualities.  And on and on...

We soon came to a hard decision:  Do we continue "tweaking" the automotive alternator idea, or should strive for more?  We chose the path less traveled and decided to design from scratch.  Yes, wherever appropriate, we would try to use existing automotive components (for instance, that is why you will find METRIC hardware on Plane-Power alternators).  But the critical features - all of them - stator, commutator, brushes, connections, cooling, fans - everything - would need to be rethought and reengineered to do it right.  

And remember, our goal all along was to manufacture an FAA-PMA CERTIFIED alternator for CERTIFIED aircraft.  So there was simply too much resting on anything short of doing things RIGHT.  It has taken years, but we think the results are well worth it.  

For current experimental aircraft owners, look at this table of side-by-side features comparing aircraft, automotive and Plane-Power alternators (you may click the image below for a clearer view if desired).  

You see, even beyond the alternator, we have put together a TOTAL solution for Plane-Power customers.  Everything has been revisited, reconsidered, and rethought: brackets, mounting hardware, belts - EVERYTHING!  And we put it all together in a simple turn-key kit that contains everything you will need to install the alternator on your Superior or Lycoming engine.  Considering all that has gone into getting it right, we believe most of you will agree - it is a heck of a good value for just dollars more than it would cost you to convert an automotive unit; and a heck of a lot better solution in the long run!  And we believe it strong enough to stand behind it for two full years from the date of purchase.

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