Jim Burns wrote:
: To the group: At how many hours do you rebuild or replace your mags? or do
: you wait for a problem to arise first?

My airplane has Bendix mags, which as Jon pointed out have a recurring
AD for impulse coupling inspection. I think it's every 400 hours, though, but
I can't remember. So, every 400 hours the impulse mag gets an internal
inspection. I have the non-impulse mag inspected at the same time, although
not strictly required. It makes me feel better while I'm flying night IMC over
the Chesapeake Bay. Most of the time nothing needs repair, although the
first time we found some "superceded" parts that were replaced.

If I notice different mag drops and the plugs are OK I have the mags looked
at, as the timing may have changed. Every 100 hours I check mag to engine
timing when I clean the plugs.

Keeping the mags well tuned makes the engine start much easier, too.
--
Aaron C.