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Add GPSS / Roll Steering Converter???


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Hello all,

I have an '82 M20K, with a G530W and a King KAP 150. Works great, still learning how to fully use it as I get my IFR training.  I have been looking at possibly adding a DAC GDC31 roll steering converter to add GPSS capability. When I talked to some of the local pilots, they mention that they usually only fly heading mode anyway, so didn't know if it would be worth it in the long run. Thoughts/Ideas/Suggestions? I found a used one for under 1 AMU, but wasn't  sure how bad the install would be. 

1. What benefit will it add other than following the magenta line?

2. Guesstimate on install time/cost?

Thanks in advance for the comments!

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GPSS is really nice especially with a waas navigator. Heading bug only sounds like a waste to me but I see the appeal. Very similar to only using the direct to button on the gps. 

I’d spend the funds to get it installed.  However, the G5/E5 would be calling my name. 

- the advantage is the AP will fly most of your flight plan without hand holding it at every turn. For an RNAV approach it lowers the workload at a busy time. 

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Before upgrading my avionics and working on my IR, I asked the same question about whether getting GPSS was worth it.  The answer I got from a friend was HECK YES.  After finishing IR, I could not agree more with his advice.  

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I was in the same predicament a year ago. I was looking at the DAC GDC31 which was gonna cost around $1800+- as I recall not including install.  Since I was already installing other items in the plane I was talked into the G5 HSI that has built in GPSS.  I’m really glad to have made this choice.  

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I did my ifr in my J without GPSS. The heading bug worked just fine.  I’ve never had GPSS so I didn’t know anything different. 

Personally I wouldn’t look at a used converter at this point. The G5 hsi will provide GPSS. The price point is higher but at least you get rid of the future overhall cost of a king HSI.

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It is the best bang-for-the-buck upgrade out there if you pair it with a WAAS navigator and fly IFR. I don't believe DAC is around any more, though, so factor that in. If you get it cheap and get a deal on installation then go for it.

However, as noted, a G5 HSI installation (or an Aspen, G500) will also add the GPSS plus a lot more. If you don't have an HSI, I wouldn't spend more than 1000-1500 on a plain GPSS module since a G5 HSI kit will be 3000 plus installation. There is a value equation to be worked with your future panel plans.

FWIW I have a plain DG, STEC-30 & GPSS but wish I had an HSI. My plane came that way except I did the WAAS upgrades, and still haven't chosen my HSI/PFD upgrade path yet. But the plane flies the lateral courses perfectly with GPSS.

Sent from my LG-US996 using Tapatalk

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We had the Icarus SAM GPSS module installed when we did the GTN and never looked back. In addition to the GPS Steering, the SAM display has two dozen user configurable options in addition to aural annunciations such as pre-selected altitude alerts, GUMPS check when 1300 feet above the destination airport as well as Decision Altitude. Unfortunately, Icarus ceased production of the unit but still supports it.

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GPSS is nice to have anytime the autopilot is on. But wait till you let it couple an approach for you or fly a hold. You'll wonder why you waited so long.

But as others have said, GPSS without an HSI is only half of the IFR equation. Pair GPSS with an HSI and you've moved into a whole other level of easy when shooting approaches.

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@CharlesHuddleston

Wait a sec...

I think you may have misunderstood what somebody was telling you...

The GPSS runs in heading mode... because that is how they operate.

In heading mode, it allows your GPS to sequence all the way through your flight plan without dialing in new headings at each waypoint...

At least that’s what I think you may have missed...

In IFR flight there are two solid memory / distraction challenges...

- Turning at the waypoint on time...

- Leveling off at the newly signed altitude...

It is incredibly easy to be busy with one important thing and forget to level off in a timely fashion...

For a few amus... get the boxes that can help with this memory challenge...

Probably not very helpful for training.  Most training assumes all the fancy boxes have gone TU for your protection...

Your plane is going to Rock when completed!

Get on the training to stay ahead of the monster.

Best regards,

-a-

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Thanks for everyone's input. The plane had a King HSI installed when I got it, so adding the GPSS to the KAP 150/G530W combo was the easiest solution. When I searched on MS, I actually found the information about the GAC module. From there, have found a used one at a decent price, which was removed during an upgrade. From the DAC paperwork that I've read, the unit has a MTBF of 50,000 hrs, so I not at all worried about it being used!

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The GDC31 GPSS is a good unit.  It is actually set up to be a submode of heading. So when the DAC GPSS switch is set to HDG, it simply passes the heading through to the autopilot.  When set to GPS, it modifies the heading signal to fly curved lines.  Its a very important distinction and adds to the workload of checking out in a technically advanced aircraft.  When you hit AP-ON, in the soup,  you shouldnt be surprised when it suddenly takes a hard right, you expected HDG and got a hard right to intercept a full scale course deviation.

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I have to take the contarian view on GPSS. I personally wouldn't pay anything extra for it. But it's nice when it comes with your avioincs as it did on my G500. But from where I sit, it's just one of the fastest gadgets to losing instrument proficiency. If a pilot needs it to keep up they really shouldn't be relying on it to fly in the system let alone fly IMC. It shouldn't be a crutch to allow getting behind the aircraft and delegate your PIC responsibilities to the GPS and GPSS. Consider what's going to happen to the pilot that habitually engages the AP on departure to use it throughout the flight till the day comes when a failure of some sort takes out the AP. How is a pilot that hasn't been maintaining their proficiency going cope now? Although that may not be popular,it has been my personal philosophy for maintaining my own proficiency.

 

Don't get me wrong. Using all your available resources is smart flying, but becoming dependent on technology to the point you have no proficiency without it is a huge mistake IMO.

 

 

 

Sent from my iPhone using Tapatalk

 

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I have to take the contarian view on GPSS. I personally wouldn't pay anything extra for it. But it's nice when it comes with your avioincs as it did on my G500. But from where I sit, it's just one of the fastest gadgets to losing instrument proficiency. If a pilot needs it to keep up they really shouldn't be relying on it to fly in the system let alone fly IMC. It shouldn't be a crutch to allow getting behind the aircraft and delegate your PIC responsibilities to the GPS and GPSS. Consider what's going to happen to the pilot that habitually engages the AP on departure to use it throughout the flight till the day comes when a failure of some sort takes out the AP. How is a pilot that hasn't been maintaining their proficiency going cope now? Although that may not be popular,it has been my personal philosophy for maintaining my own proficiency.
 
Don't get me wrong. Using all your available resources is smart flying, but becoming dependent on technology to the point you have no proficiency without it is a huge mistake IMO.
 
 
 
Sent from my iPhone using Tapatalk
 


I don’t think anyone is suggesting you buy one of these so you can become a child of the magenta line and a king at AP button pushing.

I hand flew for 10 years, 7 of those in my Mooney with a freshly stamped IFR ticket in my pocket. I still remember the anxious feeling I would get when I would hear those words “I’ve got a lengthy re-route for you, advise when ready to copy”. Sure I did it manually, but it didn’t mean I liked it. Not to mention after a long hand flown flight in the soup how poorly I performed due to the fatigue.

An autopilot like you suggest is just another tool to be incorporated into your flying. Ironically on the 6 month IPCs I do, the instructor I use won’t even let me fly a coupled approach. When I practice with a safety pilot, I will mix in coupled approaches or just fly them by myself visually with the AP coupled just so I do stay current on flying them coupled. Like I did in the video I posted.

It doesn’t mean the world works this way. I have flown with pilots who are addicted to their autopilots. So much in fact, I have asked why are they asking me to be their safety pilot when it’s clear they’re letting George do all the work. Those are the ones who I worry for.


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Training should focus on risk reduction.  So, which is more likely:

a). The autopilot fails in IMC and you’re unable to hand fly?  If so, practice hand flying skills  

b)  while engaged hand flying in IMC you lose situational awareness, deviate from the approach & become a CFIT statistic?  Then practice autopilot-assisted IFR procedures.   

My hunch is that with 3 or four non-tumbling attitude indicators in my view scenario a) is less likely for me than b).  So my CFII & I train mostly with the  autopilot on.  

But it’s an old debate....I just finished reading “Digital Apollo” which might be summarized as “the right stuff” versus full automation.   Apollo was one of the first fly by wire vehicles. Its computer was simple but essential. Without it the lander couldn’t be flown. Capable of fully automated landing, each of the six landings in fact were “hand flown” in the final moments.  Except that the computer stabilization was running full time...

86D80F91-698B-4B87-84FF-275491B44A1C.jpeg.95deadd37b68a22a4268924944c6bd7a.jpeg

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5 hours ago, kortopates said:

I have to take the contarian view on GPSS. I personally wouldn't pay anything extra for it. But it's nice when it comes with your avioincs as it did on my G500. But from where I sit, it's just one of the fastest gadgets to losing instrument proficiency. If a pilot needs it to keep up they really shouldn't be relying on it to fly in the system let alone fly IMC. It shouldn't be a crutch to allow getting behind the aircraft and delegate your PIC responsibilities to the GPS and GPSS. Consider what's going to happen to the pilot that habitually engages the AP on departure to use it throughout the flight till the day comes when a failure of some sort takes out the AP. How is a pilot that hasn't been maintaining their proficiency going cope now? Although that may not be popular,it has been my personal philosophy for maintaining my own proficiency.

 

 

While I have GPSS, I don't use it as a crutch but as a fatigue saver. When encountering hard IFR I typically disengage the A/P and fly by hand for half hour stretches, just to keep my skills up. And the few times that I made approaches in actual conditions, I flew them by hand. Having lived through several failures of the KAP 150, I've grown accustomed to not count on it when I may need it the most.

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On 10/17/2018 at 12:48 AM, KSMooniac said:

It is the best bang-for-the-buck upgrade out there if you pair it with a WAAS navigator and fly IFR. I don't believe DAC is around any more, though, so factor that in. If you get it cheap and get a deal on installation then go for it.

However, as noted, a G5 HSI installation (or an Aspen, G500) will also add the GPSS plus a lot more. If you don't have an HSI, I wouldn't spend more than 1000-1500 on a plain GPSS module since a G5 HSI kit will be 3000 plus installation. There is a value equation to be worked with your future panel plans.

FWIW I have a plain DG, STEC-30 & GPSS but wish I had an HSI. My plane came that way except I did the WAAS upgrades, and still haven't chosen my HSI/PFD upgrade path yet. But the plane flies the lateral courses perfectly with GPSS.

Sent from my LG-US996 using Tapatalk
 

Totally agree with this approach.  The G5 gets you 8 pounds lighter, GPSS, auto slewing, and a backup AH. 

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  • 11 months later...

I have a DAC GDC-31 Roll Steering Adapter for sale, which was removed after a panel upgrade completed last February (installed Aspen PFD that now communicates with the autopilot).  The unit worked very well in my 85 231k between a Garmin GNS 430 and KFC-150. The GPSS button is lit and you simply toggle between HDG and GPSS.  The KFC-150 will then couple with the GPS to fly departure, en-route and approach legs.  It is pretty amazing if you've been hand-flying, those, and switch to letting the autopilot fly the routing instead.  Reduces workload and makes flying  much easier.  I"m putting this on e-bay for $1,350, but I'd sell it to someone on Mooneyspace for $1,200. 

L1060049.JPG

Edited by byrdflyr
typo
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