S-tec 50 upgrade to 55X

[femski]

I saw an yellow tag S-tec 55X upgrade kit sold on Ebay - its apparently nothing but the controller unit that goes in the panel. I hope with Avidyne launching its new digital autopilot that can fly indicated air speeds, more of 55Xes from Cirrus will be coming on the market.

I have an S-Tec 50 installed in my Comanche with not that many hours on it. Idea of adding intercepts, vertical speed control and glide slope capture - all seem interesting for IFR flying that I am gearing up for. So just in case another opportunity comes up I thought I will find out some more.

My questions are:

Is this true that you only have to replace the 3" controller of S-Tec 50 with a panel mount 55x controller to get intercepts and vertical speed/GS control ? It seems 55x pitch and roll servos are identical to that of System 50. Is there any other pitch or trim control needed ? I have electric trim but no auto-trim.

How big of an install is it ? Will I need further paperwork from S-tec (55x is STC'ed for Comanche). I believe they have been difficult in the past. But things may have changed.

Anyone experience with S-tec upgrade autopilot care to comment ?

Thank you,

-Sanjay

[Scott Ducey]

I am not sure if my response will be of help, as i upgraded from the Altimatic to the 55X. I think the 55X is amazing. it does so much. I am under the impression that you need to have auto trim in order to have the 55x if you want altitude hold, but I could be wrong. i also looked at the altitude preselect, however, give that it was an additional 7K, i didn't think it was worth the $$. this autopilot took away so much of the workload in ifr work, the preselect would have been overkill (for me).

the only downside to the S-Tec is if you ever want to move it to another airplane, i do not think the company will support it. i do not forsee that as being an issue for me.

Scott

[Scott Myers]

[Scott Grand]

[Scott Grand]