« Archives in April, 2015

Avionics Master Switch

3 hours.

Originally when I built the electrical system, I was of a mind that an avionics master switch is a single point of failure and should be avoided.  I have since changed my mind.  First,  my comm2 radio has no off switch (MGL V6), second, I really want my comm and audio panel volume settings to be set and left alone.   Third, and this is the most important thing, I want to minimize the danger of transient voltage spikes damaging very expensive equipment when starting and shutting down the engine.

The simple fix is adding an avionics fuse block inline with the Endurance bus with a switch in between.   The EFIS has its own power switch and will remain on the E-bus.  So far so good, and the install went smoothly, except for the time I dropped the passenger stick through-bolt down the hole between the center section ribs.  That was fun, because my fat hand doesn’t fit past the stick through the access hole, and I wasn’t about to take the floor panel off.   I then fished around with a magnetic screwdriver bit holder, and that sort of worked, but then somehow, I dropped that in there too.   After a brief bit of grumbling (seriously, how long can you stay mad being at an airport), I was able to fish that out of there with a couple of long aircraft drill bits held like chopsticks.   After that, I got my bolt back.

I forgot to bring little zip-ties to re-secure the DB25 connector on the pax stick.  Also, I forgot to bring my little screwdriver so I could tighten up the connector on the back of COMM 2, which will get fixed tomorrow morning before work.

So now I’m less worried about blowing up my avionics than I was.  But the process was suspiciously painless, right up until that last bit.