What compass?

[Bryan Cotton]

I am somewhat of an anorak regarding the regs.
§91.205 Powered civil aircraft with standard category U.S. airworthiness certificates: Instrument and equipment requirements.
Charlie is right, we don't have a standard airworthiness certificate.

[fjdoug]

Well, hush my mouth!

hey Charlie, no need to, all good stuff and interesting....

for Aussie builders; i guess this is why VH reg. aircraft don't need a (direct reading) compass, not sure about RAAus...

1. Duplication of instrumentation in LSA and amateur-built experimental aircraft.

Legal determination confirms that CAO 20.18 applies to all Light Sport Aircraft (LSA) and amateur built experimental aircraft that are registered with CASA [but not those registered with an approved recreational aviation administration organisation such as RA-Aus].

The effect of this legal determination is that many of the EFIS panels similar to and including the Dynon range which are being installed in ever-increasing numbers by LSA manufacturers and amateur builders are not CASA approved.

CAR 207(2) implies that the owners could be required to either supplement or replace the panels with CASA approved navigation and flight instruments thereby adding to the cost of compliance without providing commensurate safety benefits.

A further effect of this interpretation would be that these classes of aircraft be required to have a direct reading magnetic compass in addition to any other device that performs the same function, such as a Dynon EFIS panel.

This is not consistent with the intent of CASR 21.186 in that an LSA compliant aircraft is regarded as meeting a stand-alone set of standards [the most common of which is the internationally accepted design standard (ASTM)] and is therefore entitled to a special certificate of airworthiness under CASR 21.186 without further design criteria being imposed by individual NAAs.

The additional CAR 207(2) requirements are also inconsistent with 21.191 and an unnecessary imposition on amateur built experimental aircraft which are fitted with one of the modern EFIS panels, and which are restricted by CAR 262AP(6)(a) to operations by day under Visual Flight Rules unless otherwise approved under CAR 262AP(6)(b).