Robin wrote:

Hello Paul,

    I hope this doesn't immediately sound like a dumb question, but how can you find out exactly what the particular specifications for any given "AN" part is?  For instance:  Metallurgist typically say there is just about no difference between an American made grade 8 bolt and an AN bolt.  Well, that's fine and dandy and we all can see that relationship pretty well when you're talking about common fasteners,  but what happens when you begin to talk about other products?  How can you really make a sound comparison?

    Let's face it, we're building experimental airplanes and we do a lot of things that wouldn't make muster for what we consider "AN" standards.  Nothing points this out more than the fact most of us on this forum are working with rotary conversions.  Having said that, we all are trying to build the safest airplane at the lowest possible cost too, so how do we get the truth about the real differences between properties of different products?

    Collectively, we believe the rotary is superior to the Lycoming, and we can prove it a dozen different ways.  It's when we begin to get into the auxiliary systems that we always get into trouble.  Perhaps it's the way we're thinking Paul.  If we can find superior engines to Lycoming, then why isn't it just as probable that we might find superior "other" parts for our installations?  The trouble is we don't have a good way to realistically compare most of them.  Methods and materials are changing so fast we really need some credible way to compare apples and oranges so we know which one to put in the salad.  Some of the new stuff might actually turn out being safer than the old tried and true AN product, but I'd prefer to find out about it on the ground rather than in the air.  Unfortunately, it's likely to be we experimental guys who find out first, one way or the other.  --  What are your thoughts on how to compare apples and oranges in an evolving environment?

Robin

I have no idea Robin. The old NACA or NAA as I think they were called did that
in the old days.

Paul Lamar
 
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