REFLECTOR: Auto Pilots

[Ron Brown]

You don't need to throw the Navaid away.  While it is not as sophisticated 
as the newer autopilots, it does an excellent job of wing leveling.  In 
fact, I can turn the "turn" knob to 9 or 3 o'clock and I get standard rate 
turns or 1:30 and 1:30 gives half standard rate turns - so it does an 
excellent job controlling turns and holding wings level.

It does an acceptable job of tracking GPS and CDI courses.  I use mine 
regularly for doing localizer and GPS approaches.  However, it requires 
tweaking the "trim" knob to keep the CDI centered.  I have found this does a 
better job than hand flying the approach.  It gives me more time for 
scanning and I don't have to worry about the leans.  I use the CDI input to 
the Navaid (not GPS data string) to do this and it works well.

And once on course for long flights, an occasional tweak of the trim knob 
keeps it on course very nicely - especially in GPS/CDI mode.  Mine has the 
GPS coupler from Porcine but it does not handle track mode when using the 
aviation data stream from my Garmin 430 very well.  It works for about 5-15 
minutes then the Porcine drops out.  This data stream is different from the 
NEMA data strings produced by handhelds.  A friend had the Porcine coupler 
connected to his Garmin 90 and he said it worked extremely well, even 
handled course changes when running a flight plan in his GPS.

My Porcine/Navaid does however, handle the data stream from the Garmin in 
the heading mode.  I.e., this mode holds the current heading when the 
Porcine is using the GPS heading information.  A flick of the Porcine switch 
to the left or right adds or subtracts a degree from the heading.  Again, 
you may have to tweak the "trim" knob to get the heading just right - but 
this mode does work well for cross country work.  You may have to do some 
Porcine "gain" adjusting as described in the manual.

However, if I were buying now (instead of 4 years ago) I would definitely 
buy one of the newer digital units.  These weren't available and the only 
choice I had in a non-TSO (read inexpensive) autopilot was the Navaid.

Ronnie Brown
173 Elite RG