GPSS with STEC 30
Jose Gibert
As anyone added GPSS to an existing STEC 30 install?
If so, describe the benefits of flying approaches with GPSS.
Jose Gibert
Grumman Cheetah / LoPresti GTO
Vero Beach, Florida
Mark Manes
I added GPSS to a System 30 in a Skylane I just sold. Had a Garman 155XL
approach GPS. The main advantage is in flying the new RNAV(GPS) approaches
(T-shaped approaches). It will let you pick the initial fix and fly direct
to it, turn to the final fix and make the 90 degree turn to final and do it
all hands off (and better than I can fly it).
Since I file direct to almost everywhere now it's not much advantage
enroute. It will do a good job if you fly a lot of arrivals. Anything you
program into the GPS it will fly using the roll stearing. With more of the
new RNAV approaches showing up all the time I consider GPSS to be an pretty
big advantage, with it I would rather fly RNAV approaches than anything else
other than an ILS.
Mark Manes
N28409
WC5I
"Jose Gibert" <vrbp...@bellsouth.net> wrote in message
news:HDIna.18551$eH6....@fe06.atl2.webusenet.com...
ArtP
<vrbp...@bellsouth.net> wrote:
>
>As anyone added GPSS to an existing STEC 30 install?
>
>If so, describe the benefits of flying approaches with GPSS.
>
I have GPSS on an STEC 55X, but the same benefit will apply to you. I
have an HSI. Since the GPSS function uses a direct connection from the
GPS to the autopilot, an HSI failure will still allow you to use the
autopilot in GPSS mode.
Ron Natalie
"Jose Gibert" <vrbp...@bellsouth.net> wrote in message news:HDIna.18551$eH6....@fe06.atl2.webusenet.com...
>
>
to do to add it?
Kyler Laird
>Gee, I didn't know GPSS was an option with the 30. What do you have
>to do to add it?
http://www.s-tec.com/products/gpss.html
http://www.seaerospace.com/stec/st901.htm
But a longer description (search for it) is here.
http://www.easternavionics.com/autopilots.html
--kyler
Ron Natalie
"Kyler Laird" <Ky...@news.Lairds.org> wrote in message news:oqh5n-...@news.lairds.org...
> But a longer description (search for it) is here.
> http://www.easternavionics.com/autopilots.html
Darn, I knew I should have looked at Jim's page first.
flyer
connects between the DG with heading bug and a GPS supported by STEC
and sends the required GPSS steering command. We have the Garmin 430.
The converter box has a pushbutton switch that allows you to select
either convential heading hold or GPSS. You must have the heading
hold option on the STEC 30 to use this, therefore. When there is a
flight plan entered into the GPS and your ground speed is above about
30 kts, and you select GPSS, the STEC 30 will fly the flight plan,
doing turn anticipation on all turns in the flight plan.
"Ron Natalie" <r...@sensor.com> wrote in message news:<DzTna.46352$6v1....@fe10.atl2.webusenet.com>...
Scott Moore
I think it probally depends on the GPS, since that is where the commands
come from. I have a 430, with that I get intercept ability (which the STEC
30 lacks completely), and better course following. For example, it will
handle a wind crab offset much better in GPSS.
I can't really compare it to normal VOR mode, because the times I tried
using that mode I was fairly disappointed in it. It is hard to set up,
you have to be dead on the VOR and trimmed out, and it can lose the
lock with enough wind.
You asked about approaches, but so far that is not that useful a mode.
Sure it flies GPS approaches great, but most of my approaches are
vectors to ILS, which use DG heading more than GPSS. On the occasional
GPS approaches I fly, it is nice to be able to leave the AP on. I have
tried the ILS AP, but am not satisfied with it, so hand fly those.
--
It amazes me that programmers feel the need to program in
the same language as others. The advantages of different
hair growing products are better established than the
advantages of any particular choice of language.
flyer
Scott's. It was not very good at flying a VOR radial or the LOC
signal. When we got it connected up to the Garmin 430 with GPSS, it
was night and day. It always weaved back and forth across the VOR
radial no matter how we had the sensitivity adjusted inside the unit.
(There is an internal adjustment that you can tinker around with).
But with the GPSS, it sets up a wind correction angle and holds and
flys the plane right down the magenta line on the Garmin map screen.
When we leave the GPSS on and fly an ILS approach to my home field, it
holds the LOC needle great (even though it is not using the LOC
signal). When we get close to the airport it sometimes flys back and
forth a few times across the course on rough days. My partner always
says "It's cuz we are getting close to the station". I still can't
get him to understand that there is no GPS "station" on the field and
distance from the waypoint means nothing since GPS is not an
converging angle system like VOR is. The reason the GPSS wanders in
my opinion during the last 1/2 mile of the approach is because of the
turbulence pushing the plane around when we are near the ground
upsetting the tracking.
Scott Moore <scott....@attbi.com> wrote in message news:<3EA4F626...@attbi.com>...
Mick Ruthven
Mick Ruthven
STEC 30. Our Bonanza 36 has an STEC 60-2, which is a much older autopilot
(installed in the early 80s), and it tracks the LOC and GS pretty much
perfectly using our King nav receiver. It never ceases to amaze us (a
seven-owner group) on an ILS coupled approach.
"flyer" <glasa...@yahoo.com> wrote in message
news:5e700d2d.03042...@posting.google.com...
ne...@dl.org
fiddle with the bug to have the autopilot intercept the course when tracking
in GPSS mode...It even plans the turns ahead of time so it doesn't
overshoot - It really is an amazing product well worth the 1000 dollars
extra (I think I paid 800) -
Paul
"Javier Henderson" <jav...@KJSL.COM> wrote in message
news:m11xztt...@prozac.kjsl.com...
> glasa...@yahoo.com (flyer) writes:
>
> > My experience with the STEC 30 in my Glasair is much the same as
> > Scott's. It was not very good at flying a VOR radial or the LOC
> > signal.
>
> Do you have a DG with a heading bug and set to the proper course, etc?
>
> The only time my S-Tec a/p wanders like that when tracking a LOC or
> VOR radial is when I screw up the DG setup.
>
> -jav
Mick Ruthven
"Javier Henderson" <jav...@KJSL.COM> wrote in message
news:m11xztt...@prozac.kjsl.com...
> glasa...@yahoo.com (flyer) writes:
>
> > My experience with the STEC 30 in my Glasair is much the same as
> > Scott's. It was not very good at flying a VOR radial or the LOC
> > signal.
>
Javier Henderson
Sure it should.It's used to compute the wind correction angle.
-jav
Mick Ruthven
the heading bug. Our heading bug doesn't do anything when the AP in in NAV
mode. Also, our course selector needle doesn't do anything on a LOC/ILS
coupled approach. And it flys a great LOC/ILS coupled approach, which was
the point of my original post.
"Javier Henderson" <jav...@KJSL.COM> wrote in message
news:m14r4n5...@prozac.kjsl.com...
Thomas Borchert
> Sure it should.It's used to compute the wind correction angle.
>
Huh? Not with our STEC-50. I can turn the heading bug all I want in NAV
(and GPSS) mode - no effect at all.
--
Thomas Borchert (EDDH)
Thomas Borchert
different planes, different servos, different friction in the control
system, different installer - all factors, I guess
--
Thomas Borchert (EDDH)
Dan Luke
> Sure it should.It's used to compute the wind correction angle.
No, it isn't. Why does the AP need to "compute the wind correction angle" in
NAV mode?
--
Dan
C172RG at BFM
Dan Luke
> > > Sure it should.It's used to compute the wind correction angle.
> >
> > No, it isn't. Why does the AP need to "compute the wind correction
angle" in
> > NAV mode?
>
> my plane, a Skylane with an S-Tec 55x.
Then it's very different from my S-Tec 50, which works just like an S-Tec
30. When mine is in NAV or APPROACH mode, you can put the heading bug
anywhere you want and it will have no effect on the autopilot.
> What heading will the ap fly after centering the needle, absent a
> reference from the heading bug?
In NAV mode, it doesn't consider the heading at all. It senses CDI
deflection and banks to correct as necessary. Once the needle is centered,
it operates the ailerons to maintain zero rate of turn. It will hunt back
and forth across the required heading a bit, then settle down.
> For that matter, what heading will
> the ap fly to intercept and center the needle without the reference
> from the heading bug?
If I try to intercept a radial from a big angle, my autopilot will do a lot
of overshooting back and forth before it finally settles down, but setting
the heading bug changes nothing. The autopilot doesn't know about heading in
NAV mode - it's all done with rate of turn and course error sensing.
Ron Natalie
"Dan Luke" <c17...@bellSPAMsouth.net> wrote in message news:valos9s...@news.supernews.com...
> > To avoid wondering back and forth. It definitely works that way in
> > my plane, a Skylane with an S-Tec 55x.
>
> Then it's very different from my S-Tec 50, which works just like an S-Tec
> 30. When mine is in NAV or APPROACH mode, you can put the heading bug
> anywhere you want and it will have no effect on the autopilot.
>
>
The 55x manual says:
If your aircraft is equipped with an HSI, your S-TEC autopilot will receive
both left / right deviation and course information. With an HSI, the heading
bug is not used during tracking. To intercept and track a VOR or GPS
course, select the desired course with the HSI Course Pointer and engage
the NAV Mode.
If your aircraft is equipped with a DG, the HDG bug must be set to the
desired course before engaging NAV Mode. The HDG bug provides course
information when using the NAV Modes.
I believe ethe distinction between the two units is that the 55x will intercept (i.e. can work
with the needle fully deflected) the NAV signal, where as the 50 you have to be pretty
close to on course to begin with.
Thomas Borchert
as Ron has pointed out, neither the 30 nor the 50 have NAV intercept
capability. The 55X has - and now we know how.
--
Thomas Borchert (EDDH)