EASA STC prop for PA28-181 Archer II
 

I just noted that we have a McCauley prop on our PA28-181 and it's been installed a few years ago on basis of STC no. SA779NE.

It was done before 2003 when EASA took over issuing STC's and accepted the old ones on a "grandfathers right".

I've been going through EASA websites, rules and regulations.... do anyone know if we are able to continue using the McCauley when it needs replacement, or do we have to change back to the Sensenich that the aircraft was originally approved with?

And out of curiosity, is the Sensenich and McCauley really the only propellers approved for the -181? If we want to go with the old fixed pitch ones (cheaper)... I know there are three bladed, and even electrical variable pitch, but that gets too expensive.

If the STC applicable to a propeller (or any mod) is appropriately installed on your plane, you can replace the same product (the prop). Think of the STC as a expansion to the type certificate for you plane to include the added change. The STC can only become invalid by AD, or unavailability of the mod part - which does happen. Note that for an STC to be valid on your serial number plane, you may require evidence that the STC was sold to you specific plane - some STC's come with a permission letter, or your registration on the copy of the certificate with the word "only". This is so the STC holder cat contact the airplane owner in the case of a problem - which also happens, I'm dealing with one now for a client.

Any other propeller change you desire for a GA plane will be in one of two categories: The is an STC already you can buy, or, don't bother. Noise compliance requirements have made prop approvals very complex and costly. I used to approve many such changes in Canada by serialized STC, but it's a problem now that noise is in the forefront of regulator thinking. I have done an EASA compliant niose test for an MT prop installation - it was a big deal!

Find a prop which is Type certificate or STC approved on your type, that's what to use.

File the ends of your McCauley prop until they are tapered and it will look like a Sensenich.

Ah, the benefits of living in Timbuktu!

Thanks, appreciated.