The only way I could get the altitude hold to work on the S-Tec
55 in the IVP was to set the Vertical Speed to “0”. When it lost or gained 50’
to bring it altitude again. The result was no proposing that I had every time
that altitude hold was used. (note: I was not using Blue Mountain, rather it
was driven by the artificial horizon.) My Epic uses a TruTrak Sorcer—what at
great autopilot.
Been fighting S-Tec for years on the
pitch sensitivity. Early on, a variable set of resistances worked for
several years using a gang switch from 17000 to 43000 ohms (depending on
load, altitude) This switch (on the panel) was thru two wires going out the
back of the controller... then the wires shorted out a pico fuse
internally for $150 a pop...several times.. now with a 33000 ohms
installed internally and no wires, it has worked one time. I suspect an
internal problem again... I could write a novel... Don Skeele
N320J 235/320