S-Tec 30 in the IFR world

smv

smv

Pattern Altitude
Joined
Dec 30, 2019
Messages
1,661
Display Name
Display name:
smv
Anyone successfully flying coupled approaches with the S-Tec 30?

I will be sitting behind one later this week with a GNX375 in the panel next to it and near as I can tell, the S-Tec will not follow vertical guidance, it will only hold an altitude based upon a baro sensor.

From everything I can find, the S-Tec 30 would make a wonderful VFR AP, but not so much for IFR operations. Better than nothing, obviously, if it will hold an altitude for you while monitor its progress then just fall back on stick-n-rudder (-n-throttle-n-trim-flaps-n-gear) to execute the vertical part of the approach.

Am I understanding this correctly or is there some magic way to actually have the S-Tec guided down by the GNX?

Edit to add: When I asked the avionics guy about this three months ago when it went in for a panel upgrade, he swore up and down that it would work just fine... I have found nothing since to support that claim.
 
Mine works well IFR. No vertical guidance, but will follow GPS, VOR or ILS laterally. Altitude hold also works well. Just fly the vertical axis by hand, it’s keeping you centered laterally.
 
Hang 4 said:
Mine works well IFR. No vertical guidance, but will follow GPS, VOR or ILS laterally. Altitude hold also works well. Just fly the vertical axis by hand, it’s keeping you centered laterally.
Click to expand...

That confirms what I have been able to deduce. Thank you.
 
kshaw said:
You really need GPSS to make it shine.
Click to expand...
True that. Holds are a great example of where GPSS really comes into its own. If you have your power settings for descents worked out, the vertical axis is pretty easy. I've thought about upgrading to the Garmin or TruTrack to get vertical, but I'm thinking I have better places to spend that kind of cash. I find mine to be an IFR capable autopilot. A GAD 29B will provide GPSS from a GTN or GNS navigator, not sure what's in your panel.
 
I fly approaches with my STEC-50 (same functionality as 30) and it's just fine. No vertical guidance but I just adjust the trim when needed and it's all good.
 
I have the STec 30 like it have done plenty of IFR flying with it. I have GPSS. I would like vertical guidance.
 
I have an S-Tec 30 but it also has the 60 PSS auto-trim that I had installed a number of years ago. Got tired of having to manually trim in turbulence. I also have dual G-5s to provide roll steering (GPSS). Prior to the G-5s there was an S-Tec ST-901 to provide GPSS. So the whole setup acquires and tracks LPV and ILS glide slope vertical guidance very well.
 
My S-Tec 30 works fine for hard IFR. As Hang 4 said, know your power settings and vertical guidance is easy. To be safe you need to be proficient at hand flying approaches. Autopilots are for convenience...not to be used as a crutch.
 
Arrow76R said:
I have an S-Tec 30 but it also has the 60 PSS auto-trim that I had installed a number of years ago. Got tired of having to manually trim in turbulence. I also have dual G-5s to provide roll steering (GPSS). Prior to the G-5s there was an S-Tec ST-901 to provide GPSS. So the whole setup acquires and tracks LPV and ILS glide slope vertical guidance very well.
Click to expand...
Are there any advantages to using the G5 GPSS rather than the S-Tec 901? I plan to do another G5 this summer but may stick with the 901 because it is so easy to use.
 
With the GAD29B and the G5 HSI, you can control the AP completely from the G5 HSI if the STEC 20/30 is in HDG mode. That is, you can fly a heading using the heading bug, or you can go into GPSS mode and track your IFR GPS, VOR, or LOC/ILS. I assume the STEC-901 does similar? If you install a G5 HSI, will the STEC-901 be able to pick off the necessary CDI data from the G5 HSI? (I don't know--that's an installer question.) When you put in the G5 HSI, the mechanical CDI is removed.
 
The STEC30 with GPSS does an awesome job on LPV approaches. Just manage pitch and power

kshaw said:
Are there any advantages to using the G5 GPSS rather than the S-Tec 901? I plan to do another G5 this summer but may stick with the 901 because it is so easy to use.
Click to expand...

The folks I know who have put in G5s in planes that previously had 901 GPSS say the STEC30 flies better on the G5 than the 901.
 
chemgeek said:
With the GAD29B and the G5 HSI, you can control the AP completely from the G5 HSI if the STEC 20/30 is in HDG mode. That is, you can fly a heading using the heading bug, or you can go into GPSS mode and track your IFR GPS, VOR, or LOC/ILS. I assume the STEC-901 does similar? If you install a G5 HSI, will the STEC-901 be able to pick off the necessary CDI data from the G5 HSI? (I don't know--that's an installer question.) When you put in the G5 HSI, the mechanical CDI is removed.
Click to expand...
The STEC GPSS is just a toggle switch. You can toggle it to heading and it uses the heading bug on your CDI. You can toggle it to GPSS and it flies the programmed route or approach when the GPS is in GPS mode. The STEC GPSS is only active when the S-30 is in the HDG mode.
 
kshaw said:
The STEC GPSS is just a toggle switch. You can toggle it to heading and it uses the heading bug on your CDI. You can toggle it to GPSS and it flies the programmed route or approach when the GPS is in GPS mode. The STEC GPSS is only active when the S-30 is in the HDG mode.
Click to expand...

It uses the heading bug on the DG/HSI, not the CDI.
 
To track a VOR radial or LOC the S-Tec 30 must be in the track "high" sensitivity mode, not HDG.
From the S-Tec system 30 manual..."13. The HI-TRK Mode is designed for Localizer approaches, GPS/LORAN tracking, and a more aggressive NAV tracking such as VOR approaches." GPSS without the G5 HSI is accomplished by the ST-901 which, as the other post said, is a toggle GPSS on or off in HDG mode. In my installation the ST 901 was removed when the G5 HSI was installed because that device provides the roll steering. So I fly in System 30 HDG mode for GPSS tracking, LPV/LNAV approaches (auto trim flies the vertical path) but during VOR/LOC tracking the System 30 is in HI track and, or course, the GNS 530W is in CDI mode.
 
You must log in or register to reply here.
Back
Top