Monday, February 17, 2014

AerospaceLogic gauges!

Airplane fuel gauges are notoriously awful.  The certification rules are basically that they only need to read accurately when they are full and when they are empty, and barring that they can show whatever they feel like.  Most people pretty much ignore them, and use a totalizer on the engine monitor to make sure they don't run out of gas, but it's always bothered me that I have this incredible panel that's more advanced than many 747's, yet it has old and wonky fuel gauges.  Worse, the left one would sometimes suddenly go to zero in flight.  I wanted to get that fixed but Beech wanted some asinine amount of money for a new one, and to "overhaul" the little circuit board on the back of the unit was like $650...  so based on a recommendation I bought the AerospaceLogic unit dual tank fuel level.  For good measure, I never really understood what the ammeter gauges were trying to show either... they have a needle that shows a relative number between 0 and 1.  Anything positive meant charging but that's hardly useful.  AerospaceLogic has a proper ammeter gauge that shows battery voltage and alternator current, so I replaced those too.

These gauges are the small 2 1/4 inch that run along the bottom row behind the throttle quadrant.  Here is what was there before

The ammeter gauges are the two on the left center and the fuel gauges on the right center.

Here it is now.  No more post lights needed down there either.  The AerospaceLogic units combine both left and right for each function into one gauge, so four gauges became two and now I have two blank holes on the right.  That's fine with me for now, I figure I can maybe put a Dynon D2 backup AI there or else some more AerospaceLogic gauges for oil temperature and pressure.  The best part is, they work and are accurate to 1/10 of a gallon, and they look great.  The units themselves and installation for both fuel and ammeter cost me the same amount that one single new fuel gauge from Beech would have cost (about 2k).  Oh yeah and the super bonus... I gained two pounds of useful load.  It's amazing how heavy the old units are.  Anyone want to buy some B55 fuel and ammeter gauges?

AirTronics at KCPU did the work, great shop and they did a really nice clean install exactly on quote and also fixed one of my pilot mic jacks which was scratchy.  They seem to have a trick to the calibration headaches too and have done a number of these so if you're going with AerospaceLogic gauges give them a call.  I highly recommend the shop and super bonus #2 is gas at KCPU was $4.97 a gallon.


  1. Glad you had Jim do the fuels gauge, his calibration trick saves 4-5 hours.

  2. Thanks for the tip Kevin! Now I'm thinking I should do the oil temp/pressure gauges!

    1. That's what I did - trying to get the final FSDO work on whether or not the Insight G4 twin is in fact primary for both CHT / EGT ... then I can remove the cluster gauges.