The original equipment Century II autopilot in my Cherokee is acting up again less than a year after I had it completely rebuilt. I really don't want to put another dime into a 42-year old A/P that is just as likely to go tits-up a year, or a month, after another rebuild. The much more costly Plan B is to spring for a S-TEC System 30 two axis (alt hold) unit.

From what I've heard from others (including my local instrument shop guy), read online, etc., the S-TEC is the superior retrofit A/P for older light aircraft.

Anybody with personal experience with these autopilots, I'd sure like to hear your thoughts on this investment. Including the GPSS roll steering add-on.

I have a S-Tec 50 in my 185 and it is ok on wheels but virtually unuseable on floats. Don't really know what the issue is but I have not been able to solve it. It also took me almost a year to get the bugs out of it and I used 3 avionics shops in desperation. I long for my old 400B in my 210, sigh.

nmflyguy wrote:The original equipment Century II autopilot in my Cherokee is acting up again less than a year after I had it completely rebuilt. I really don't want to put another dime into a 42-year old A/P that is just as likely to go tits-up a year, or a month, after another rebuild. The much more costly Plan B is to spring for a S-TEC System 30 two axis (alt hold) unit.

From what I've heard from others (including my local instrument shop guy), read online, etc., the S-TEC is the superior retrofit A/P for older light aircraft.

Anybody with personal experience with these autopilots, I'd sure like to hear your thoughts on this investment. Including the GPSS roll steering add-on.

What does completely rebuilt mean to you? Are you saying you had all the servos rebuilt? The switches changed? or Just the head repaired? The switches are usually the problem a can of contact cleaner and you may fix your problem.

I hear rumors S-Tec is on its way out

man, i hope they don't go out, the 50 in my 28 yr old T182 has been a live-saver more than once in wthr and smoke... and the gpss is awesome for a few hour flight south to vegas...mr scout is right, mine has had to be cleaned up a time or two, due to off-airport activity and dust, but a minor deal with an 18 pack for my fav mechanic...middle fork friends are valuable....!

A friend of mine is putting a TruTrak autopilot in the airplane he's building. Single axis- ailerons only, heading info taken off an electronic compass, either dial in the desired heading or slave it off the GPS. Nuce compact unit, but I think for experimental use only.

STec is rate based and is independent of your vacuum system. That alone makes it superior to the Century in my book.

once&futr_alaskaflyer wrote:STec is rate based and is independent of your vacuum system. That alone makes it superior to the Century in my book.

Responsiveness is the primary advantage of a position-based system. Attitude information is more advantageous for rapid recovery from in-flight upsets.

Most attitude-based autopilots are more responsivethan rate-based systems because they can correct the position-error
input more rapidly with less course / heading error during correction.The roll signal isn't influenced by yaw angle or rate. When the yaw angle and rate are combined, as they are in most turn coordinator based rate systems, they could diminish the effect of roll.

mr scout wrote:What does completely rebuilt mean to you? Are you saying you had all the servos rebuilt? The switches changed? or Just the head repaired? The switches are usually the problem a can of contact cleaner and you may fix your problem.

I hear rumors S-Tec is on its way out

ms scout - by "completely rebuilt" I mean that everything (main unit, servos, and DG) was removed from the airplane by the local instrument shop and shipped to Oklahoma for the autopilot shop to inspect, tune up, replace parts as necessary, and test out). Everything worked fine for about 6 months, then the unit started to drift - first it stopped tracking the VOR needle, then lately it's been ignoring the heading bug on the DG.

I'm pretty sure it can be removed again, gone through, cleaned and tweaked to work for another period of time. But I already spent $2,500 on that deal once, and my instrument shop guy warned me at the time that I could be doing the same thing again in a year or less ... and here I am, just as warned. For something on the order of $10K I can buy a brand new, new tech two axis A/P that should be good for many years. Or could do the Century II rebuild two or three more times in the next couple of years, and spend the same $10K for a 42-yr old single-axis, unreliable old tech unit.

If there are better units available than the S-TEC, I'd like to hear more.

We have a s-tec 50 in our 180, with the alt hold and gpss coupled to the 430w. It works great.

nmflyguy wrote:

mr scout wrote:What does completely rebuilt mean to you?

by "completely rebuilt" I mean that everything (main unit, servos, and DG) was removed from the airplane by the local instrument shop and shipped to Oklahoma for the autopilot shop to inspect, tune up, replace parts as necessary, and test out). If there are better units available than the S-TEC, I'd like to hear more.

To the point you had nothing completely rebuilt, you had it tested and repaired. Big difference between the two. I wasn't advocating keeping your old junk in fact the whole topic would be better served on the pipers owners website rather than this one. But in the interest of always trying to help when I can, you may want to fly it to a old guy avionics shop that understands the system you have rather than pay an A&P to take it all apart for nothing. You may find they can get it working for much less than you spent before.

If you have already decided on the change why even ask? Just make sure you buy the roll steering with your up grade it is magic.

mr scout wrote:

nmflyguy wrote:

mr scout wrote:What does completely rebuilt mean to you?

by "completely rebuilt" I mean that everything (main unit, servos, and DG) was removed from the airplane by the local instrument shop and shipped to Oklahoma for the autopilot shop to inspect, tune up, replace parts as necessary, and test out). If there are better units available than the S-TEC, I'd like to hear more.

To the point you had nothing completely rebuilt, you had it tested and repaired. Big difference between the two. I wasn't advocating keeping your old junk in fact the whole topic would be better served on the pipers owners website rather than this one. But in the interest of always trying to help when I can, you may want to fly it to a old guy avionics shop that understands the system you have rather than pay an A&P to take it all apart for nothing. You may find they can get it working for much less than you spent before.

If you have already decided on the change why even ask? Just make sure you buy the roll steering with your up grade it is magic.

mr scout - you seem a little argumentative, even asking why I bothered to ask my question.

Go back and read my opening post, and the title of this thread: I've decided to get a new autopilot, I've heard good things about S-TEC, and I was asking others with S-TEC experience to comment and let me know what their experience has been with that particular brand (and model, if applicable), as opposed to a different brand (like, uh, Century, or King). I didn't ask for advice about keeping the old unit going.

Also, this thread has almost nothing to do with Pipers - the S-TEC autopilots (and Century's and Kings too, for that matter) are STC'd for just about all certificated light aircraft.

And btw, the local instrument shop only pulled the autopilot, then put it back in the plane after getting it back from the autopilot shop, and then tested it out in the plane. With my consent, the local guy sent it to a professional autopilot shop in Oklahoma - AutoPilots Central. They run a nationwide business installing and servicing autopilots, all brands, and they recommended I go to a new unit. I suspect they know what they're talking about when it comes to autopilots.

I always am and your MS Scout didn't help , oh that's right the r is right next to the s on the keyboard . You asked about the investment so I mistakenly was trying to help you possibly save some money.

I wont let it happen again, the S-Tec 60-2 worked great in our 210

mr scout wrote:I always am and your MS Scout didn't help , oh that's right the r is right next to the s on the keyboard . You asked about the investment so I mistakenly was trying to help you possibly save some money.

I wont let it happen again, the S-Tec 60-2 worked great in our 210

sounds like ms scout is suffering a little pms (or is it pmr?) today

Have an S-tech 50 that came with the 182B. Alt hold, wing leveling and heading. Will track a vor. Don't have gps. Love it.

Having said that, the previous 182B that I had came with an old Britten auto pilot that seldom worked. Ripped it out and did not replace it. Better to hand fly than spend that kind of money.

Tim

nmflyguy:

I have an S-Tec 50 with GPSS coupled to a Garmin 530W. It's bloody magic. Ranks right up there with the Oregon Aero seats. If they haven't outright saved my ass, at least they have made it more comfortable on many occasions.

Fly an LPV approach with this setup and you get glideslope info on the approach. Hit one button at the DH to go missed approach and it will fly you to the hold, enter the holding pattern and fly a perfect race track for you all hands off. Oh yeah, you DO have to push in the throttle when you go missed.

Click off the GPSS, fly in hdg mode with altitude hold engaged and you can fly moose turns all day with the little steering knob. I loved it.

YB

Yellowbelly wrote:nmflyguy:

I have an S-Tec 50 with GPSS coupled to a Garmin 530W. It's bloody magic. Ranks right up there with the Oregon Aero seats. If they haven't outright saved my ass, at least they have made it more comfortable on many occasions.

Fly an LPV approach with this setup and you get glideslope info on the approach. Hit one button at the DH to go missed approach and it will fly you to the hold, enter the holding pattern and fly a perfect race track for you all hands off. Oh yeah, you DO have to push in the throttle when you go missed.

Click off the GPSS, fly in hdg mode with altitude hold engaged and you can fly moose turns all day with the little steering knob. I loved it.

YB

I want one for Christmas pleassssssssssssseeeeeeeeeeeeeeeeeeee

I had an S-Tec 50 with altitude hold coupled to the 430, in the 182 for years, it worked great. My 185 has a S-tec 55 with altitude hold coupled to the 430 and works good on both wheels and floats. Steve

Thanks, guys, I appreciate the input on the S-TEC autopilots .... sounds much like what I've heard from other sources.

This week I asked the local instrument shop guy, who's an authorized S-TEC installer, to give me a quote for the System 30 installed.

Was hoping the old Century IIb would hold out another year so I could put the Garmin GNS-430W in the panel this winter, so I'd be able to get my instrument rating in my plane learning to shoot WAAS approaches ... that dough will now have to go to the autopilot instead .... looks I'll have to save up some more to do the G430W later in 2011.

On the other hand, I'll be able to do those procedure turns and holds, etc. automatically on the A/P, once the 430W is in my panel.

Duane