GPSS options with 400A
 

Hi everybody, I'm in the steep learning curve of planning avionics upgrades.

I will most likely change to a GTN 750 and keep one of the older nav/com units.

For the time being, I would like to stay with the 400a.

I'm trying to learn what the options are to integrate modern gps nav with the navomatic.

If I keep all the steam gauges, what are the gpss options that work with the 400a? What are your experiences with DAC, Icarus SAM, others?

What about the gpss in the g500 txi? Will this work with the 400a?

Thanks for advice.

DD

With a moving map...
 

I always set my GPS moving map to project a course line ahead by 50 miles or so.

Then, the few times I have used the autopilot at all, I simply slowly turn the autopilot heading bug and as airplane turns watch until projected course hits the next mark.

Done

Thus, all wind/course corrections already adjusted and accounted for.

Works every time.

This won't automatically follow 20 pre-programmed points, but in my own experience the ATC world never works that way anyway. Things are always fluid, so it is less stressful to be flexible. I just fly bearing altitude vectors (perfectly legal) to some next fix the current controller understands, within 200 miles or so, so it is 'IN' their radar scope and familiarity.

When I have heard pilots grip that their elaborate flightplan got totally changed, I try to explain that that's like filing a flightplan for next tuesday through NYC rush hour. File whatever you want, but once enroute that morning, the controller knows there is a truck overturned 50 miles away and will need to work it out anyway. Semper Gumby

Others' experience may vary.

As far as I can tell, you can interface the 400A directly with your Nav/Com/GPS unit's horz/vert deviation outputs or you can provide the inputs from a EFIS. I know the Aspen display will provide GPSS/NAV/HDG selection directly to the 400A, using their ACU to do this (the EA100 is not needed unless they certify the aspen to provide attitude information...which would be an instant buy for me). I presume the TXI would use a GDL43/e to generate the analog signals but same limitations on the attitude signals. Looks like the Garmin G5 specifically calls out the 400A as supported as well.

In another thread there is a discussion about use of GPS Vertical Guidance (VNAV) outputs and the 400A, which Garmin navigators specifically prohibit unless cleared by Garmin or on their list (the 400 IFCS is on the list BTW). I suggest you call your avionics shop about this as the notes are unclear. Also, this may or may not apply if you source the autopilot from the Aspen/500TXI/etc. Someone mentioned this limitation was removed by the Sandal 3308 so it seems possible that this is the case.

I will be doing this on my restoration this year and will post a note about my installation/use then.

Thanks for the replies.

I thought all skymasters with autopilots had the 400a. I didn't realize there was a 400 IFCS option.

How do I know which I have? Looking at pictures online, it looks like I have the 400 IFCS (it does have flight director buttons on the panel). If so, I think that simplifies the garmin options because it appears to be on their list of supported autopilots whereas the 400a is not?

This is a pic of what I currently have:
Attachment 2353

Cheers,

and

Happy new year everyone!

Yes, congrats Dr. Dan, you have the 400IFCS.

The flight director and autopilot mode buttons are the tell-tale indicators.

Rick

Yes, the 400IFCS is the key to keeping it with glass. Without it, the basic 400A, there aren't any options because of the analog attitude and navigation reference. At least, that was a year ago when I paid a shop to sit down and try to figure it out at their hourly rate. Specifically, I wanted to go to the two G5s with my dual 430W as a lead into something greater once I made some primary improvements to my airplane; gear door removal, cargo pack, and air conditioner.

They went beyond the G5s, looking for any approvals for the airplane, but it failed when you got to the autopilot supplements. Things change, and this was a year ago; I doubt it given what goes into an STC and the remaining number of airframes and their age, but maybe there is hope. The best-case scenario for my airplane they could find was to keep the Sandel 3308, purchase the WAAS software ($,$$$), and buy spares. This far outweighed the only replacement autopilot option; the STEC 55.

I'm not a fan of the 55; I've flown too many airplanes with it, and there is something, at least one feature, that is always out. My avionics guy is not a fan of it (said he would not install one), and the guys at APC will tell you that to keep it right, it takes more maintenance than a 400A (of course, there are more flight profile features). There is also a good Cessna Owners Association article about keeping the 400A as the replacement options are less desirable. Of course, many 400s are in bad shape because no one seems to want to spend money on autopilot maintenance or keep them tuned up (the problem with the 55s I've flow and the manufacture is an hour flight away). Any autopilot needs regular maintenance.

Personally, I'm okay with steam gauges, especially with an iPad with ForeFlight. Of my 22K flight hours, only about 25% of them are behind glass. I flew the B737-200, 300, 500, 700, and 800 and never had a problem jumping from one to the other. I even had a single day where I flew four different models, steam to glass and back. For the money, I'd rather have a weather radar in my Skymaster than spend the money on the typical glass installation. Also, Garmin's planned obsolescence (which the others follow) bugs me for the money that goes into the glass. I once was the Aviation Director of a large corporate flight department. I cannot picture going before the board of directors to ask for money for the airframe on the cycle that Garmin runs; the equipment and installation cost vs. airframe value; I would have been replaced. My CFO (wife) is very lenient, but she would croak if I truly explained that last statement.

Just to add to this it is the only option that will allow you to entirely remove all the analog gauges and your vac system. Lots of folks use the lateral/ (and ILS vertical) guidance outputs from newer systems, including G500/E5/EFD1000/G5 etc.

Thanks guys. I'm happy to hear there's options with the IFCS.

I guess I'll have to think about whether it's worth the extra money for the g500 txi vs a pair of g5's. And also whether it's worth removing the analog gauges and vacuum system.

Cheers
DD

That is the question, Dan. I'm not sure how I would have gone if mine had the ICFS. It's a lot of money into an old airframe with part availability issues and prices for those parts what they are.

I have a P337 with IFCS 400. I went with a G500txi PFD and G5 as backup. Have a GAD43e and GMU out in the wing. I keep the Vacuum System only because it runs the boots for de-ice. The system is fully couple to the A/P will fly with GPSS and will fly approach through GS capture.

I had Carpenter Avionics do an overhaul on the AP last summer. It works great!. If you need I have the manual for the adjustments on the IFSC 400, full service Manual. There are quite a few things you can manage on your own with intercept angles, scalloping on altitude and turn rates. All meant to be done in the air. I looked at a new AP, but 25K to give me the same functions I have already, albeit more accurate, but seems a bit out of line.

That's good to know, thanks.
Did you have to keep your old attitude gyro for the AP? My understanding is that the g500 or g5 can control the AP, but the original gyro attitude indicator must still be connected for it to work properly.

for the benefit of the group, anyone who needs the IFSC Manual I have put it on my google drive, and the link is below.

https://drive.google.com/file/d/1Y68...ew?usp=sharing

With the Gad43e installed you can remove ALL mechanical gyros. So that is the system I have. This does require both the 500txi and the G5 as you need a backup to the 500 as PFD. I can tell you the system works great.

https://drive.google.com/file/d/1M9V...ew?usp=sharing

https://drive.google.com/file/d/1s5B...ew?usp=sharing

Thanks!

DD

Very nice!