Dynon Auto Pilot

The latest avionics article in Kitplanes by Stein Bruch about auto pilots leaves me with a question or two so please advise.

In order to have the most functionality (and ease of operation) with my Dynon AP set up, it seems that I would like to have the Dynon AP-74 module plus the SL30 (nav/com) in place of the SL40 (com). And it would be best to install it with Van's blessings prior to sign off. Suppose that I could add these after sign off? Right/wrong?

I realize that Van's needs to decide to offer these as an option so maybe it isn't in the cards. Our RV-12 will be use a lot as a pleasure cross country machine. Maybe some of you have already approached Van's with this idea. I would like to hear your suggestions.

Auto pilot

Here is my commuication with Dynon re the auto pilot..I don't see anything about a different com unit.

FROM DYNON...

All you need to have a fully functional AP is the D180 and the two servos. You can operate the AP from the D180 menu but for $450 the AP74 module is worth the money. Here are some features that it offers.

Enhance the usability of your Dynon EFIS?s built-in autopilot by adding dedicated
controls for selecting magnetic heading, GPS track, NAV, and altitude hold modes.
The AP74 also adds the ability to preselect whether HDG, TRK, or NAV mode will
be flown upon autopilot engagement.

Other features: a knob for adjusting autopilot and other EFIS values such as the
altimeter setting; light sensor for automatic screen dimming; voice alerts; autopilot
mode status via LED button lights.

The GPS TX will be wired directly into one of two serial inputs on the D180.

Hope this helps,

Mike H

Dynon General Support
[email protected]



-----Original Message-----
From: "John<[email protected]>
Reply-To: "John " <[email protected]>
Date: Sun, 11 Jan 2009 15:17:51 -0700
To: <[email protected]>
Subject: A Question

>I have just started a Van's RV-12 ELSA. If the planned installation includes the Dynon DEK-D180, which seems very likely, what "parts" or units do I need to get two axis auto pilot? I am somewhat confused after looking at your web site as to what would be required.
>
>I would appreciate knowing what I need to plan for since I would like to incorporate the autopilot as I build rather than as an after thought. Also, how is my GPS (I have several, including one that connects via Blue Tooth) tied into your system?
>
>Thanks for the information. I look forward to your units because several other RV builders in my area use a Dynon product and seem to be universally pleased.
>
>Thank you.
>
>

You only need the SL30 if you want the AP to track a real VOR or Localizer. These days most VFR pilots have little use for this since you can have a virtual VOR with most handheld GPS's anywhere you might want one.

The AP74 is optional in all cases but sure makes for some nice additional features. So nice, it is manditory in my book. Big bang for little buck to add this box to the system.

E. D. Eliot said:

In order to have the most functionality (and ease of operation) with my Dynon AP set up, it seems that I would like to have the Dynon AP-74 module plus the SL30 (nav/com) in place of the SL40 (com). And it would be best to install it with Van's blessings prior to sign off. Suppose that I could add these after sign off? Right/wrong?

Click to expand...

FYI - if you want the Dynon AP to be driven by both the SL30 and the GPS, you are going to want/need the HS34 and the AP74.

I have a 496 in my RV-9 driving the AP74 along with a D100 for the EFIS and for long VFR cross country trips I see no need for the VOR. The 496 does it all, including approaches, if you get stuck on top.

If you want to change your -12, buy the parts from Van's and don't install them. Just sell them as new and put in the SL30.

N941WR said:

FYI - if you want the Dynon AP to be driven by both the SL30 and the GPS, you are going to want/need the HS34 and the AP74.

Click to expand...

That's not quite right. The FlightDEK-D180 has two serial inputs. The SL30 outputs all the VOR/LOC/ILS data through serial, as does your GPS. You don't need the HS34 for that.

I'll agree with the others that the AP74 should be almost mandatory. Yes, the system functions just as well without it, but it doesn't WORK nearly as nicely when you have to dig around in the menu system via the pushbuttons. That Value knob is a real pleasure to use.

For a VFR airplane, forget the SL30. The only advantage would be the ability to fly true VOR and ILS/LOC approaches, which, presumably, you won't be doing in a VFR airplane.

AP 74

The red RV pictures from Sun N Fun show a AP-74 installed. It is just to the right of the Dynon EFIS. My guess is it is a part of the autopilot option kit which has not been released yet. Van's has previously said that they won't bring out any of the options until all of the main kits are developed and in production. Don't know if that is still true.

From what I have heard the AP-74 "makes" the whole autopilot function. Having a knob with selectable functions would be great. I plan on getting it when available.

Rich

Yep technically with the D180, you don't need the HS34 but.....The HS34 does for dual navigation sources similar to what the AP74 does for the AP, makes it much more usable.

The HS34 with dual navigation sources makes switching between those sources effortless. It also allows you to have multiple sources on the HSI at the same time. You can't do that without the HS34. Without it you must either select the GPS overlay or the NAV overlay. With it you can mix and match up to one main CDI and two RMI pointers.

N941WR said:

FYI - if you want the Dynon AP to be driven by both the SL30 and the GPS, you are going to want/need the HS34 and the AP74.

Click to expand...

KPmarc said:

That's not quite right. The FlightDEK-D180 has two serial inputs. The SL30 outputs all the VOR/LOC/ILS data through serial, as does your GPS. You don't need the HS34 for that.

Click to expand...

Dynon Auto Pilot questions

Thanks everyone for the quick and explicit answers. It is good to see that the Red One has the AP-74 installed into the panel - that will be really nice. Thanks again, E. D. Eliot

Which autopilot

I will be ordering the avionics kit soon and am debating about the autopilot. I have already installed the autopilot brackets. Thanks to Dave G for sending them to me.
Should I buy the autopilot option from Van's or buy a TruTrak unit? I know that buying the Dynon will be less money, but I was thinking that it might be better to have a stand alone unit in case the EFIS fails.
Are the TruTrak autopilots better?
Will the TruTrak servos mount on the RV-12 autopilot brackets? Even if the servos fit, there is the still the problem of connecting the linkage between the servo and the RV-12 control system.
Maybe I should just go with the Dynon from Van's. Thanks for helping me decide.
Joe

Joe,

Are we talking about an RV-12?

If that is the case, go with the Dynon servos. They are the only ones that will work with your Dynon EFIS.

As for worrying about needing an autopilot if the EFIS fails, you are flying an LSA in clear weather are you not?

Remember, the autopilot is really a back up for the pilot, not the other way around.

Yes, the TT will bolt up on the Dynon mounts but as I said, the Dynon EFIS will not control them so you would have to install a TT AP head.

My suggestion is to go with the Dynon units, then if you don't like them after you are flying, replace them with a full TT setup.

Go for the AP74. You won't regret it.

My 9A has the AP74, SL-30, D100, D180 and Lowrance GPS. I fly VFR so the SL30 turned out to be overkill for me versus the SL-40.

But to drive the A/P from SL30 or GPS all you have to do is change NAVSRC. Two button pushes.

99% of the time I let the GPS & NAV drive the A/P but I find I use the AP74 very often to set & reset alt, and use TRK instead of NAV. As I approach my destination, I reset alt allowing me to focus 100% on traffic and flying.

The AP74 and the A/P is a real workload reduction tool in these hot rod airplanes.

What is the difference between TRK & NAV with the AP74 using the Garmin 496 and no SL-30?
Larry

TRK is just GPS ground track

NAV can be GPS Nav (following a GPS flightplan) or NAV as in VOR/LOC navigation...

On the Dynon they differentiate between the two by making GPS navigation Magenta and VOR/LOC/ILS navigation Green.

More information on TRK versus NAV

Brian is correct.

Using my Tucson to Long Beach run as an example, I have approx 7 waypoints programmed into the GPS for the 380nm route. The A/P follows my Lowrance GPS nicely but let's assume there's a cloud ahead. By punching TRK on the AP74 and changing the GPS track, I can go around the cloud w/o disengaging A/P. Once past the cloud, I punch NAV on the AP74 and the A/P returns to it's pre-programmed path.

Yes, you can do the same thing w/o the AP74 by punching various buttons on the D100 but that's like having a tv with no remote.

So I take that using the NAV button with multiple way points programmed in the GPS (flight plan?) the autopilot will fly to each point in the order programmed and make whatever turn is necessary to fly to the next? In your example above, I don't quite understand where the TRACK comes from on the GPS. I can't remember seeing that in my Garmin 496 instructions.
Obviously, GPS in the air is new to me.
Thanks,
Larry

Nav will take you to a waypoint...Trk takes you to whatever heading your waypoint is at that time. The earth is round, so that heading will change and you will have to keep resetting. If you use Nav, all is taken care of for you.

Thanks, that explains it succinctly!
Larry

More info on the AP74

LIMA HOTEL said:

So I take that using the NAV button with multiple way points programmed in the GPS (flight plan?) the autopilot will fly to each point in the order programmed and make whatever turn is necessary to fly to the next? In your example above, I don't quite understand where the TRACK comes from on the GPS. I can't remember seeing that in my Garmin 496 instructions.
Obviously, GPS in the air is new to me. Thanks,
Larry

Click to expand...

No problem. It makes sense to ask questions before you embark.

Yes, my Lowrance gps allows me to create a route. I use airports or any waypoint I choose when I compose my routes. With the Lowrance, I can mark a location, such as a road or a large parking lot, and save it as a waypoint. I give my waypoints meaningful names so that they make sense when I create routes.

Once you have established your waypoints, you then create a route which is an assemblage of waypoints. I also give my routes meaningful names.

Returning from SOCAL, I simply tell the Lowrance to reverse course and load that in.

The Dynon AP is slaved to the Lowrance via a serial cable. Data travels from the Lowrance to the D100. The D100 commands the two Dynon servos to maintain ALT and direction of flight. Direction can be established via ground TRK (like Brian said), heading, or NAV which is my pre-established route.

The AP74 gives the pilot another tool to engage AP and make changes. I am unfamiliar with the 496 so please confirm that it has the same capabilities and connects via serial. I would be shocked if the Garmin product does not have the same features.

One caveat. The Dynon A/P does not get altitude settings from the gps. I set altitude directly thru the AP74 into the D100 and it follows whatever alt I request.

RATE OF CLIMB: I set the parameters in the D100 for a 500 foot per minute climb / descent rate. When I leave LGB at sea level, I set the AP for 9500 and it climbs at a leisurely 500 fpm. It also descends at the rate when I approach the destination and set the ALT for pattern ALT.

I know there are other A/Ps that will do more.

Hope this helps. Feel free to call or email if you want additional explanations. This stuff was WAYYYY over my pay grade when I started 3 years ago. Fortunately, I had access to three experts who assured me it would work. It did. We like it so much we're duplicating the setup for the 6A we're building now.

Couple comments and a question or two from an RV-6/D100/D10A/AP-74/SV-32/G396/SL-40 user.

I concur with the thoughts on the AP-74. It makes setting the heading bug, the altitude bug and the altimeter very quick and easy. You can do it with the EFIS, but once you have the AP-74, you'll really like it for those selections. Selecting, preselecting, or changing AP modes is also very nice with the AP-74. It provides so much functionality in such a small package, its hard to beat (till the AP-76 comes along, eh Brian! )

The TRK mode simply holds the airplane on the current GPS track...in other words the track across the ground as calculated by the GPS. It will change heading to correct for wind to maintain that track (and that track is typically displayed at the top of the GPS azimuth arc...looks like a heading, but its the GPS track). In TRK, that track is independent and irrespective of any GPS waypoints or flight plan you have in the GPS...i.e., it does this with or without a magenta line on the GPS, and it doesn't follow the magenta line...it keeps the track across the ground the same. (I proably beat that up a bit. )

Quick question Barry, why do you use TRK to go around the cloud, versus HDG? Not a hit, just wondering...new techniques are always good to learn!

The NAV mode tracks the magenta line (GPS NAV flight plan from waypoint to waypoint). It makes heading changes to stay on the line. And the X96 does work just the way Barry described it with his Lowrance, and via serial.

I have found my Dynon AP to overshoot initially when capturing a Go To waypoint, but it settles down after a little bracketing. When following a flight plan, it flies over each waypoint, overshoots a bit when getting on the next leg, but also settles in after a little bracketing. Its not too bad, but not quite full-on GPSS, which leads the turns, rather than fly over each waypoint (I thought that was in a recent firmware update, but not sure...thoughts Brian...is that an AP-76 thing too?) But overall, it works fine for basic X-C nav.

I have an SL-40 versus an SL-30, but am considering the upgrade, so I can file /A and shoot the occasional ILS/VOR/LOC approach if needed to bust out of or into a docile marine layer (my personal need/limitation). I won't fly approaches with the 396, due to the legalities (of course), but also because it drops the NAV data about 500-600 feet above the last waypoint, when it pops up the message "Approaching VNAV Waypoint". Don't want my Nav Source going stupid as I approach mins, so I just don't want to go there. Hopefully my conservative flight planning and go/no-go criterion will keep me out of a position where I need to drop through clouds using a VFR GPS...very much an emergency situation in my book.

What Brian said about the HS-34 and being able to display both GPS (magenta) and VOR/ILS (green) data on the HSI is true...and tempting if I do the upgrade! But I was under the impression that if you want to switch between GPS and VOR/ILS (without the HS-34), you just need a toggle to switch the serial feed to the EFIS between the two sources. Is there also a need to go to the menus and switch the NAV Source, or is that an alternate method to do the same thing? Thanks!

Its a great package from Dynon though...great stuff!

Cheers,
Bob

Answers for Bob (hopefully)

rvmills said:

I have found my Dynon AP to overshoot initially when capturing a Go To waypoint

Click to expand...

My Lowrance does not overshoot so my guess is (and it's only a guess Bob) that the data from the gps is causing the overshoot. My low $$ Lowrance smooths the turns and works great.

rvmills said:

...you just need a toggle to switch the serial feed to the EFIS between the two sources. Is there also a need to go to the menus and switch the NAV Source, or is that an alternate method to do the same thing?

Click to expand...

All I have to do to switch between my SL30 and GPS is tap NAVSRC. No serial toggle switch is reqd. However, my configuration is AP74, D100, D180 and the SL30 serial is connected to the D180. Therefore, NAVSRC is selecting D100 serial, then D180 serial.

HDG versus TRK: There may be a better answer to this question than mine but I use TRK so that I can parallel the GPS route on the Lowrance moving map screen. IE, looking out the window I notice something I choose to avoid such as a cloud. I switch into TRK, bend the airplane left as required, then mimic the GPS route by modifying TRK back to the original. When the issue is passed, I modify TRK again so that it gradually intercepts the NAV route. Once the lines converge, I tape NAV to once again follow the GPS pre-programmed route.

Do I love it? You betcha. Is it a workload reduction I appreciate every time I fly into SOCAL where ATC speaks faster and more often than anything I ever heard before? You betcha again.

Thanks Barry. The NAVSOURCE thing sounds like a D180/D100 thing...another option I'm considering...ah time and money, where art thou!

Interested in how you are bending or adjusting your track. Are you "rubber-banding" away from the GPS course line and then back (on the GPS), or are you control wheel steering away from and then back to the course line, or are you deselecting the roll mode, then turning, and then engaging track to go around the cloud (or whatever you are deviating around). Just interested as a gadget guy...filling in the bag o' tricks, so to speak!

Roger the ZLA and SOCAL busy-ness. Wait till you fly into NYC or DC...there's another "youbetcha!"

Cheers,
Bob

rvmills said:

(I thought that was in a recent firmware update, but not sure...thoughts Brian...is that an AP-76 thing too?)

But I was under the impression that if you want to switch between GPS and VOR/ILS (without the HS-34), you just need a toggle to switch the serial feed to the EFIS between the two sources. Is there also a need to go to the menus and switch the NAV Source, or is that an alternate method to do the same thing? Thanks!

Click to expand...

Yep, the Dynon can support GPSS but not GPSV. Bottom line with Dynon is that if it can drive the HSI, their AP can fly it with the exception of the vertical axis.

You can have softkey selection of two different nav sources without the HS34 if you have a D180 or a multi screen D100/120 combo. The D100 only has one serial port and if you only have a D100, you need a toggle switch to pick what source you want to use. With the D180 or two screen combo's you have more ports and can use the screen menu's and buttons to select the source.

You cannot however show more than once source at a time on the HSI without the HS34. You can with it.

Answers for Bob (hopefully)

rvmills said:

Thanks Barry. Interested in how you are bending or adjusting your track.

Click to expand...

Nothing hi tech Bob. Given my settings, TRK follows the present course established by NAV. If NAV (based on the GPS) gives me a heading of 270 deg towards Blythe (I.E.), and a reason to change course appears (such as a cloud), I press TRK, bump the AP74 knob, & change the heading to avoid the cloud.

Once I pass the cloud, I bump the AP74 knob again and change the heading towards the GPS course that still appears on the Lowrance moving map. When it intersects (or gets close), I switch the AP74 into NAV mode.

I find that if I switch into NAV right after the intermediary course change (IE, cloud), the airplane will make a turn towards the GPS course and then another turn when it arrives. That's wasteful in fuel and time so I gradually approach & intersect the GPS course in this manner.

The workload reduction offered by the A/P is so profound that I can keep on top of many details that might otherwise get less attention. When people look at these RV airplanes and observe the level of technology we're able to employ, they are simply amazed. Given that I am a retiree from the software and computer hardware industry, I wouldn't have it any other way.

I realize that this stuff takes time to get used to but there's nothing like a hot cup of coffee while sitting in a parked airplane studying.

LIMA HOTEL said:

Thanks, that explains it succinctly!
Larry

Click to expand...

As a sidenote, if you are using a 496 you have to have the correct interface settings to make NAV work with a 180. The aviation to NMEA settings have to be set to "normal", not "fast".

Brantel said:

Yep, the Dynon can support GPSS but not GPSV. Bottom line with Dynon is that if it can drive the HSI, their AP can fly it with the exception of the vertical axis.

Click to expand...

Brian, roger on GPSV...I use the VSI setting in the Dynon to match the VNAV setting in the 396 to follow a VNAV descent on the ADI and HSI...poor man's coupled descent!

I know you've been watching the development of the Dynon AP feature set closely, with the future full-up IFR panel as a downstream goal. Since my panel is VFR now, I've been living with the non-GPSS tracking in the GPS mode...not a big deal...just a little bracketing after turns. However, getting GPSS in the FW update was a bonus in my mind, so that the AP stopped treating all waypoints as flyover waypoints, and then correcting back to course after a turn. On this last X-C, it seemed to me that it was still flying over waypoints...though I have to admit that course changes were small, so I may just not be seeing the GPSS at work. Next time out, I'll plug in a route with some big turns in it, and see if it leads the turns. Just to be sure, is there anything I need to do to "turn on" or enable GPSS, or does having 5.3 just make it happen?

Brantel said:

You can have softkey selection of two different nav sources without the HS34 if you have a D180 or a multi screen D100/120 combo. The D100 only has one serial port and if you only have a D100, you need a toggle switch to pick what source you want to use. With the D180 or two screen combo's you have more ports and can use the screen menu's and buttons to select the source.

You cannot however show more than once source at a time on the HSI without the HS34. You can with it.

Click to expand...

Got it...two screens (thus two serial ports) means no need for toggle, but you must switch via menus/softkeys. Without an HS-34, the toggle seems easier...me thinks the only downside to a toggle would be if you later add the HS-34, you'd need to rewire the NAV sources to separate EFIS units so you could display all sources at once, which I'd see as a great SA builder (on a GPS course, but a quick look at a nearby VOR for position crosscheck, etc). Lots of data, but good info if you need/want it. Thanks!!

MrNomad said:

Nothing hi tech Bob. Given my settings, TRK follows the present course established by NAV. If NAV (based on the GPS) gives me a heading of 270 deg towards Blythe (I.E.), and a reason to change course appears (such as a cloud), I press TRK, bump the AP74 knob, & change the heading to avoid the cloud.

Once I pass the cloud, I bump the AP74 knob again and change the heading towards the GPS course that still appears on the Lowrance moving map. When it intersects (or gets close), I switch the AP74 into NAV mode.

Click to expand...

Barry, what do you bump the AP-74 knob to? Mine is set to change the heading bug without a push, to change the altitude bug with one push, and to change the altimeter with two pushes (just how I like to use the knob). I wasn't aware that the knob can set or change the GPS track (I actually don't think it can...but if so, would love to know!). Honestly not trying to pick nits with you, but it sounds like you are changing the heading bug...but if you are in TRK, the airplane won't follow the HDG bug, as far as I know. If there is a feature I don't know about or understand, just trying to add it to the quiver!!

I'm kind of a cheater, I guess, as I will use HDG to deviate as needed, then I'll just hit "Direct To" on the GPS when I know I'm clear, and go straight to the next waypoint, rather than fly back to the original course. Might not be able to do that on an IFR flight plan, or if airspace is a constraint, so your method is good to have in the pocket too!

MrNomad said:

I find that if I switch into NAV right after the intermediary course change (IE, cloud), the airplane will make a turn towards the GPS course and then another turn when it arrives. That's wasteful in fuel and time so I gradually approach & intersect the GPS course in this manner.

Click to expand...

Agreed...a very good technique. The AP will make a pretty aggressive turn to get back on course, and your method saves a lot of turning/bracketing. Also why I cheat and go direct if there are no constraints...but if there are, I would do it just as you do...good description!

MrNomad said:

The workload reduction offered by the A/P is so profound that I can keep on top of many details that might otherwise get less attention. When people look at these RV airplanes and observe the level of technology we're able to employ, they are simply amazed. Given that I am a retiree from the software and computer hardware industry, I wouldn't have it any other way.

I realize that this stuff takes time to get used to but there's nothing like a hot cup of coffee while sitting in a parked airplane studying.

Click to expand...

Couldn't agree more...on all counts. I'm a believer in sitting in the cockpit and playing with the avionics a lot. I'm comfortable with the Dynon gear (it's easy gear to get up to speed on!), and thanks for letting me pick your brain (and Brian's). Gives me some things to play with when the radio is quiet and the XM is making the time go by!

Cheers,
Bob

rvmills said:

However, getting GPSS in the FW update was a bonus in my mind, so that the AP stopped treating all waypoints as flyover waypoints, and then correcting back to course after a turn. On this last X-C, it seemed to me that it was still flying over waypoints...though I have to admit that course changes were small, so I may just not be seeing the GPSS at work. Next time out, I'll plug in a route with some big turns in it, and see if it leads the turns. Just to be sure, is there anything I need to do to "turn on" or enable GPSS, or does having 5.3 just make it happen?
Bob

Click to expand...

I think there is some misunderstanding...while the Dynon AP supports following GPSS with the HS34, you need a GPS that outputs the GPSS signals. No handheld units will do this. You need a panel mount that has ARINC interfaces and you need the HS34 to get these signals into the Dynon.

GPSS is a function of the GPS not the AP.

TRK mode makes the airplane turn to a gps ground track that matches the current heading bug setting. It does not directly change the gps ground trak, it turns the airplane to change it.

Move the heading bug while in trk mode and the airplane will follow it. In this mode it is not a heading bug but instead a track bug. I think when the AP is in TRK mode, the heading/track bug turns Magenta instead of the normal Yellow.

rvmills said:

Barry, what do you bump the AP-74 knob to? Mine is set to change the heading bug without a push, to change the altitude bug with one push, and to change the altimeter with two pushes (just how I like to use the knob). I wasn't aware that the knob can set or change the GPS track (I actually don't think it can...but if so, would love to know!). Honestly not trying to pick nits with you, but it sounds like you are changing the heading bug...but if you are in TRK, the airplane won't follow the HDG bug, as far as I know. If there is a feature I don't know about or understand, just trying to add it to the quiver!!

Bob

Click to expand...

Thanks Brian, the info on GPSS and TRK makes sense. I knew GPSS is output by the GPS, but hadn't considered whether it would be put out by my GPS...dooohhhh!

On the TRK, I knew that it holds a basic GPS track, just haven't played with it enough to see how it works...and didn't know the track was adjustable with the heading (er, track) bug. Totally 'splains how Barry is using it. Will check and see if the bug is magenta in TRK...I'll bet you're right (wouldn't bet against ya!)

So a new mode to play with! And to bring it back to OT, it'll be easy to use with the AP-74.

Cheers,
Bob