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STEC-30
Thinking about putting a STEC-30 with the GPS Steer in our '79 Mooney
M20J. Anyone have one of these that would care to give a PIREP? We are located in the Inidianapolis area so fi yu know a good shop we'd appreciate it. Thanks!! Jon Kraus |
#2
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A student of mine has that setup in his Mooney. It's a hell of a seup
in terms of roll control. GPSS makes an autopilot behave the way you expect - it gets you on course and keeps you on course without a problem. Without GPSS, an STEC might as well be a decades-old Autocontrol/Altimatic - it will hunt so much in nav track mode that you will wind up just using it in heading hold mode. I'm not that impressed with the altitude hold function. The installation I've seen lacks auto-trim. I would say that if you have a Mooney without electric trim, the altitude hold is not worth buying. If the air is smooth, a properly trimmed plane will hold altitude anyway. If it's not, constantly retrimming when the thing beeps at you isn't any less work than just holding altitude manually. Michael |
#3
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"Michael" wrote: Without GPSS, an STEC might as well be a decades-old Autocontrol/Altimatic - it will hunt so much in nav track mode that you will wind up just using it in heading hold mode. Something's wrong with your student's S-Tec installation. Mine doesn't have GPSS, but when it's set to "Approach" mode and the CDI scale is set at one mile, it will hold me within 50' of my course line for 100's of miles without hunting. If I let the autopilot turn me to a new heading, it will hunt for a while. GPSS would fix this, but I can't bring myself to pony up the $1800 to add it. I'm not that impressed with the altitude hold function. The installation I've seen lacks auto-trim. I would say that if you have a Mooney without electric trim, the altitude hold is not worth buying. If the air is smooth, a properly trimmed plane will hold altitude anyway. If it's not, constantly retrimming when the thing beeps at you isn't any less work than just holding altitude manually. Once again, this doesn't sound right. Turbulence has to be pretty close to moderate before I'll turn altitude hold off. -- Dan C172RG at BFM |
#4
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If I let the autopilot turn me to a new heading, it will hunt for a
while. Well, that's the least of it. The real issue is when you change course, or just hit direct-to and nav. With GPSS, it gets on course and stays on course, smooth as you please. Without, you need to get it on course manually, set the heading bug correctly, then when all is good select nav track. And even then, you have a choice of hunting in enroute mode, or annoying wing waggle in approach mode. I suspect you have fewer issues with this because you fly a much more stable, solid airplane. The experience I have with these gadgets is in Mooneys and Bonanzas. I suspect the same issue applies to altitude hold. When I'm talking about smooth air, I don't so much mean lack of turbulence as lack of lift/sink. Your airplane doesn't have nearly the tendency to pick up speed when the nose is pointed down that a Mooney or Bonanza does, but the flip side of this is that lift and sink don't affect your airspeed (and thus your pitch trim) near as much. Thus you don't get beeped at to retrim every time the vertical speed of the air mass changes by 200 fpm - but in a Mooney without autotrim, you will. Michael |
#5
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"Michael" wrote: And even then, you have a choice of hunting in enroute mode, or annoying wing waggle in approach mode. If it does this, something's wrong. It's not a difficult control task. You should be able to pick a combination of approach/enroute mode and CDI scale that produces a smooth, on course track. Try approach mode with a 1-mile CDI. If that doesn't do it, I would suspect some binding in the aileron controls or a faulty roll servo. -- Dan C172RG at BFM |
#6
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If it does this, something's wrong. It's not a difficult control task.
I don't doubt it - but every installation I've seen does it. I know full well it's not a difficult control task, but I also know it's not the same control task for all airplanes. The more roll stability the plane has, the easier the task. A friend of mine who flew 727's for a while says that the autopilots on those were the same way - they never used nav track enroute because twiddling the heading bug (or even the roll trim) worked better. Michael |
#7
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I have the STEC30 in my C172, although no GPS steer since I doon't have
a GPS (that will be changing next month). As for the A/P I must say that it is fabulous, imho. I don't have any experience with any other A/P so I can't compare, but I can't imagine what more I could want unless it was one with alt preselect and some o ther bells and whistles. I figure I need to do some of the flying. I don't understand the other writer's comment about the alt hold. Mine holds flawlessly; no drift or variation at all, and it engages immediately. Whether IFR or VFR, I would recommend it without reservation. I also can't understand not having the alt hold; being able to rely on the A/P to keep the alt lets me be comfortable while I fold a map or reach in to the back seat without worrying that I'll gradually and imperceptibly descend or bust an IFR altitude while my attention is momentarily diverted. I agree that a perfectly trimmed plane will theoretically fly nice and straight nut there always seems to be something that changes what the trim should be as I fly along. Also, a you know, the STEC is based on the electric turn coordinator, so provides a huge safety cushion if (when) your vacuum system goes haywire. How nice it is to know that the A/P will keep me straight and level when the vacuum goes out!! |
#8
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Jon,
we have the 50 in our Tobago. Great unit! Trim on the altitude hold is a non-issue - you'd engage it only in trimmed condition anyway, so there never is any "constantly adjusting the trim". The "electric back-up" is reassuring. GPSS is nice to have, but once you have it you realize how few bends you have to fly anymore with GPS direct routings, so the thing rarely gets a chance to do its magic. When it does, it is great fun to watch. -- Thomas Borchert (EDDH) |
#9
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Jon Kraus wrote:
Thinking about putting a STEC-30 with the GPS Steer in our '79 Mooney M20J. Anyone have one of these that would care to give a PIREP? We are located in the Inidianapolis area so fi yu know a good shop we'd appreciate it. Thanks!! A number of my fellow Navion owners have that autopilot. I've got the 55X with GPSS. They're happy with theirs, I'm more than happy with mine. Can't help you with a shop in Indiana (got a good one here in Virginia if you want to come that far). GPSS is way cool. What do you have for a GPS? |
#10
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Ron,
We a Garmin 430 GPS in the Mooney. Now I am getting kinda excited about getting an AP installed. Whatever we end up with will have the GPSS installed. I figure that for the money the GPSS is a great deal. Jon Kraus Ron Natalie wrote: Jon Kraus wrote: Thinking about putting a STEC-30 with the GPS Steer in our '79 Mooney M20J. Anyone have one of these that would care to give a PIREP? We are located in the Inidianapolis area so fi yu know a good shop we'd appreciate it. Thanks!! A number of my fellow Navion owners have that autopilot. I've got the 55X with GPSS. They're happy with theirs, I'm more than happy with mine. Can't help you with a shop in Indiana (got a good one here in Virginia if you want to come that far). GPSS is way cool. What do you have for a GPS? |
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