G1000 approach question with GFC700 AP

[Knuckledragger00]

New to the G1000 and have watching the King videos.  They say to “load” approach and when cleared you can just hit “Approach” on the AP (GFC700) to activate it.  When I watched the Garmin tutorial they say to hit “Activate” and then hit “Approach”.  My question is will hitting “Approach” on AP activate it or do you need to hit Activate first and then Approach?  Thanks in advance.

[donkaye, MCFI]

50 minutes ago, Knuckledragger00 said:

New to the G1000 and have watching the King videos.  They say to “load” approach and when cleared you can just hit “Approach” on the AP (GFC700) to activate it.  When I watched the Garmin tutorial they say to hit “Activate” and then hit “Approach”.  My question is will hitting “Approach” on AP activate it or do you need to hit Activate first and then Approach?  Thanks in advance.

If you want to run an approach, you need it to be activated, which can be done by either going direct to the first waypoint on the approach or by activating the approach.  The AP will follow the flight plan, it doesn't active it.

[Knuckledragger00]

Don,

That makes sense but i am confused regarding the GFC700.  They have a third option which is a button on the autopilot that says ‘APR’.  According to Martha (King) she says if you hit that it will activate the approach.  When I watched the Garmin video on the GFC700 they say you need to still hit ‘Activate’, then hit  ‘APR’ .  Honestly this G1000 seems incredibly complex and I have at least 40 hours study time on it so far!

 

[carusoam]

KD,

While waiting for Don...

Expect some of your questions to come from the basic AP ops manual...

The various methods of operation include the accuracy and choppiness the AP will use to follow a course...

When in approach mode accuracy is everything...  some choppiness will come with that...

When to be in approach mode before the FAF should be detailed in the manual as well...

APs have the thickest manuals with so many examples... or in the event of e-manuals... they have 150+ pages of pure drudgery...  

Stand by for Don to get back...

Enjoy the reading!

Best regards,

-a-

[Ragsf15e]

36 minutes ago, Knuckledragger00 said:

Don,

That makes sense but i am confused regarding the GFC700.  They have a third option which is a button on the autopilot that says ‘APR’.  According to Martha (King) she says if you hit that it will activate the approach.  When I watched the Garmin video on the GFC700 they say you need to still hit ‘Activate’, then hit  ‘APR’ .  Honestly this G1000 seems incredibly complex and I have at least 40 hours study time on it so far!

 

So the Meridian I fly has the same setup.  

Activating the approach on the gps does certain things (ILS frequencies, nav modes, steer points, etc).  However, it doesn’t set autopilot modes.  The APP button sets modes like Loc, glidepath, glideslope, etc.

Activate the approach on the GPS as Don said via the proc button.  Activate the appropriate approach modes on the autopilot with the App button on the autopilot when cleared the approach.  The approach button on the AP will give you Loc, GS, GP, etc that you wouldn’t be able to activate without pushing approach.  Example... getting vectors for an ILS.  Autopilot in heading mode, load/activate the approach on the gps through the g1000.  When cleared the approach, hit App on AP and you’ll see LOC and GS (loc and glide slope) pop up in the autopilot mode window.  They will be white until the airplane intercepts the loc and glideslope, then they will become green as the active mode.  The autopilot will then intercept the loc. On a Gps approach, GP will pop up when you hit approach (glidepath).  Generally, only hit approach on the autopilot when your cleared for the approach.  There’s more to it than this, but I can’t type anymore on the phone, good place for an instructor in person...

Edited September 11, 2019 by Ragsf15e

[donkaye, MCFI]

38 minutes ago, Knuckledragger00 said:

Don,

That makes sense but i am confused regarding the GFC700.  They have a third option which is a button on the autopilot that says ‘APR’.  According to Martha (King) she says if you hit that it will activate the approach.  When I watched the Garmin video on the GFC700 they say you need to still hit ‘Activate’, then hit  ‘APR’ .  Honestly this G1000 seems incredibly complex and I have at least 40 hours study time on it so far!

 

The Garmin video is excellent.  I would believe him.  I don't have a GFC 700 to go out and test the Kings statement, but you can try a test.  Program a flight from airport A to airport B.  Load an approach to airport B.  With the plane on autopilot going to airport B in NAV mode, push the APPR button.  Does the plane show a "direct to" the first waypoint on the approach?  If not, and I expect that to be the case, the Kings need to change their manual.  It just doesn't make sense that the AP would control the flight plan.  It is supposed to fly the flight plan.

[Ragsf15e]

1 minute ago, donkaye said:

The Garmin video is excellent.  I would believe him.  I don't have a GFC 700 to go out and test the Kings statement, but you can try a test.  Program a flight from airport A to airport B.  Load an approach to airport B.  With the plane on autopilot going to airport B in NAV mode, push the APPR button.  Does the plane show a "direct to" the first waypoint on the approach?  If not, and I expect that to be the case, the Kings need to change their manual.  It just doesn't make sense that the AP would control the flight plan.  It is supposed to fly the flight plane.

Don, on your setup, what do you push to get the LOC and GS modes to activate on your autopilot?

Thats what the APP button does on the GFC700.

[donkaye, MCFI]

19 hours ago, Ragsf15e said:

Don, on your setup, what do you push to get the LOC and GS modes to activate on your autopilot?

Thats what the APP button does on the GFC700.

Before GPSS you flew in NAV mode enroute and APR mode when inbound and cleared for an approach.  In addition to enabling vertical guidance on an ILS approach, the gain on the autopilot was increased in approach mode so you maintained a tighter lateral tolerance in Approach mode.  Technically, you could fly an approach without vertical guidance in NAV mode, but your lateral deviation could be greater than in APR mode.  Both enroute navigation and approaches were flown on the autopilot by corrections to course deviation.  Then along comes GPSS which bypasses the HSI and feeds inputs directly to the autopilot, usually through an adaptor (a digital to analog converter).  GPSS, however, only provides lateral navigation, although much more accurate than the previous error correction method.  When flying an approach, though, the AP needed to go back to the old method because it provided vertical navigation for a glide slope.

On the GFC 500, LOC only and VOR approaches are flown in NAV mode (per the AFMS Supplement) and CDI selection is done on the G500 TXi.  Any approach with vertical navigation including LP+V approaches are flown in APR mode.

Edit:  See corrections below.

[Ragsf15e]

9 hours ago, donkaye said:

Before GPSS you flew in NAV mode enroute and APR mode when inbound and cleared for an approach.  In addition to enabling vertical guidance on an ILS approach, the gain on the autopilot was increased in approach mode so you maintained a tighter lateral tolerance in Approach mode.  Technically, you could fly an approach without vertical guidance in NAV mode, but your lateral deviation could be greater than in APR mode.  Both enroute navigation and approaches were flown on the autopilot by corrections to course deviation.  Then along comes GPSS which bypasses the HSI and feeds inputs directly to the autopilot, usually through an adaptor (a digital to analog converter).  GPSS, however, only provides lateral navigation, although much more accurate than the previous error correction method.  When flying an approach, though, the AP needed to go back to the old method because it provided vertical navigation for a glide slope.

NAV mode on the GFC 700 is GPSS and all approaches without vertical navigation are flown in NAV mode.  Approaches with vertical navigation are flown in APR mode.  I don't know if APR mode uses GPSS in some manner.  I suspect not.  Based on this it is pretty obvious that APR mode doesn't activate an approach, but flys it.

Now to my setup.  On the GFC 500, LOC only and VOR approaches are flown in NAV mode and CDI selection is done on the G500 TXi.  Any approach with vertical navigation including LP+V approaches are flown in APR mode.

I don’t fully agree.  “All approaches without vertical guidance are flown in Nav mode” is not what’s indicated or it’s misleading.  Yes, you can push the nav button instead of the approach button  but it will say “Loc” or “gps” or “vor” for the lateral guidance.  

Pushing the approach button automatically selects the appropriate lateral and vertical guidance modes for the approach you’ve loaded and sets them in the white autopilot standby area until they automatically switch over to the green primary guidance mode.

Some of those guidance modes like loc, gps and vor could be selected with the nav button but the vertical modes cannot.

If you’re in heading mode getting vectored  for an ils and get “intercept the localizer inbound, maintain 4,000’”, then you’ll push nav to get just the “loc” mode instead of “app” button which will give you both loc and gs.  Both will intercept the localizer but if gs is showing on the vertical side of the autopilot modes, you’ll also start down at glideslope intercept.

Generally, just use approach button when cleared the approach.

[Ragsf15e]

NAV mode on the GFC 700 is GPSS and all approaches without vertical navigation are flown in NAV mode.  Approaches with vertical navigation are flown in APR mode.  I don't know if APR mode uses GPSS in some manner.  I suspect not.  Based on this it is pretty obvious that APR mode doesn't activate an approach, but flys it.

 

Don, this is the part that’s not how I see it... there’s no “nav” mode.  There is a “nav” button.  If you push the nav button, the mode you get is dependent on your current navigation data selection on the HSI and vor/loc frequency.  The autopilot mode will indicate gps, vor, or loc.  If GPS, yes it’s GPSS.  If vor or loc, you get the raw data from the ground station.

you could definitely fly non precision approaches by pushing the nav button.  You’re getting the same thing.  Generally I teach the habit pattern of pressing App as it doesn’t matter what type of approach you are doing.  Of course, always check what standby mode(s) pop up after pushing either button to make sure you get what you want.

[Knuckledragger00]

2 hours ago, Ragsf15e said:

I don’t fully agree.  “All approaches without vertical guidance are flown in Nav mode” is not what’s indicated or it’s misleading.  Yes, you can push the nav button instead of the approach button  but it will say “Loc” or “gps” or “vor” for the lateral guidance.  

Pushing the approach button automatically selects the appropriate lateral and vertical guidance modes for the approach you’ve loaded and sets them in the white autopilot standby area until they automatically switch over to the green primary guidance mode.

Some of those guidance modes like loc, gps and vor could be selected with the nav button but the vertical modes cannot.

If you’re in heading mode getting vectored  for an ils and get “intercept the localizer inbound, maintain 4,000’”, then you’ll push nav to get just the “loc” mode instead of “app” button which will give you both loc and gs.  Both will intercept the localizer but if gs is showing on the vertical side of the autopilot modes, you’ll also start down at glideslope intercept.

Generally, just use approach button when cleared the approach.

Rag,

So go from “Load” to then hitting “APR” without hitting “activate” on anything with a Glide Slope (when cleared)?  Everything without vertical guidance needs “Activate” then “APR” or even just “Nav”?

Greatly appreciate all the help here too BTW!

Edited September 11, 2019 by Knuckledragger00

[Ragsf15e]

48 minutes ago, Knuckledragger00 said:

Rag,

So go from “Load” to then hitting “APR” without hitting “activate” on anything with a Glide Slope (when cleared)?  Everything without vertical guidance needs “Activate” then “APR” or even just “Nav”?

Greatly appreciate all the help here too BTW!

Nope, you need to hit activate first.

Activate sets up the appropriate navigation for the approach within the G1000.  You need to do that even if you hand fly the approach.

APR after activating will give you the correct autopilot modes.

Two separate things - navigation settings and autopilot pilot modes.

Yes they work together and interact, but you need to do both and work to understand what functions each does (which clearly you’re working hard on).

Edited September 11, 2019 by Ragsf15e

[Ragsf15e]

And to be completely honest, you don’t NEED to hit activate or APR.  They just take care of lots of little tasks that we use to do manually and set the autopilot modes.

Example, don’t activate the approach... you can dial in the ils freq, set the hsi to vloc (green needles), set the gps steerpoint to the FAF, use OBS to set the inbound course to the faf, then deselect obs.  Or you could just press “activate”.  Either way, you could hand fly the approach.

There is a regulatory requirement to load the approach from the gps database if you’re using the gps waypoints for navigation or dme.  But hitting activate just takes care of lots of little tasks we use to do manually.  “Appr” isn’t required if you’re going to handfly.  It is required if you want the autopilot to enter glidepath or glideslope (GP or GS) mode.

Edited September 11, 2019 by Ragsf15e

[midlifeflyer]

Let's make sure we are not confusing "activating an approach" from a GPS navigator standpoint with switching to "APR mode" on an autopilot. @Knuckledragger00, if you want to fly the approach, the approach needs to be activated. If you want the autopilot to fly an approach with vertical guidance, you need to activate the approach and put the autopilot into APR mode. That is going to be true of every combination on navigator and autopilot I know of.

Activating an approach works the same on the Garmin navigators, whither GTN, GNS, or G1000. You can activate the approach in a number of ways. Selecting "activate" is one. Punching Direct to a waypoint on the approach is another. Activating a leg on the approach is a third. If the Nav unit provides vertical guidance, it will give it to you. So, in the G1000, once the approach is activated, the glidepath G indicator and the associated diamond will come in as you approach the FAF. On a traditional HSI, the GS needle will activate.

But unless the autopilot is switched to APR mode, the autopilot will not capture the glidepath the navigator displays. 

Here's a screenshot. It is the GPS 3 to my home base, TTA. 2100 is the altitude from before IKTOW until intercepting the glidepath at HEDYY.  If you are following along, the autopilot has been actively flying the airplane in NAV and ALT mode since before IKTOW.

But I did not press the GFC700's APR key to tell the autopilot I wanted it to capture the glidepath at HEDYY. You can see the result. Well past the FAF, only a half mile from the runway, and still at 2100. If I had changed to APR Mode on the GFC700 well before HEDYY, we would see a white GS on the nav line (second text line of the display) which will flash and turn magenta as the glidelpath is intercepted and captured by the autopilot.

 

Edited September 12, 2019 by midlifeflyer

[donkaye, MCFI]

7 hours ago, Ragsf15e said:

Generally, just use approach button when cleared the approach.

You are absolutely correct. For all practical purposes APR can be used for all approaches on the G1000 except a BC approach, of which there are few left.  Garmin improved upon their documentation with the GFC 500, but its operation from the AFMS conflicts with what's published for both the GFC 500 and GFC 700.  According to the documentation both units can run approaches without vertical navigation in the NAV mode, but because of increased gain can fly them better in APR mode.  BC on the G1000 needs to be flown in NAV mode. I've attached the relevant documentation for approaches run with the GFC 700 and the GFC 500.  The first one is the GFC 700 and the second and third ones are for the GFC 500.

If sorry for confusing the issue by my first post.

[Knuckledragger00]

Don, Mid, Rag and Car, thank you all so much for this help!  The fog is clearing and I am fairly certain I wont be flying a GPS approach and wondering why I haven’t captured the GS (which has sadly happened).  This has really helped!!

[Ragsf15e]

2 hours ago, Knuckledragger00 said:

Don, Mid, Rag and Car, thank you all so much for this help!  The fog is clearing and I am fairly certain I wont be flying a GPS approach and wondering why I haven’t captured the GS (which has sadly happened).  This has really helped!!

No problem.  One last thing... when flying G1000, the stuff up here (see picture) must be in your scan and definitely needs double checking every time you press an autopilot button or change a gps steerpoint.

The green part is the autopilot lateral and vertical modes (green is active, white modes are in standby).  The center of that part, “AP” in the picture, tells you if the autopilot or flight director is engaged.  Easy to set up autopilot modes, let go of controls, never engage autopilot, airplane flying itself aimlessly for a while.  Ask me how I know.  It will be blank or just say FD if autopilot is not flying.  AP means autopilot is on and you get the green modes.

Just above that is the magenta line with your current gps steer point and dme.

Put those lines in your cross check.

 

[donkaye, MCFI]

1 hour ago, Ragsf15e said:

No problem.  One last thing... when flying G1000, the stuff up here (see picture) must be in your scan and definitely needs double checking every time you press an autopilot button or change a gps steerpoint.

The green part is the autopilot lateral and vertical modes (green is active, white modes are in standby (Armed)).  The center of that part, “AP” in the picture, tells you if the autopilot or flight director is engaged.  Easy to set up autopilot modes, let go of controls, never engage autopilot, airplane flying itself aimlessly for a while.  Ask me how I know.  It will be blank or just say FD if autopilot is not flying.  AP means autopilot is on and you get the green modes.

Just above that is the magenta line with your current gps steer point and dme.

Put those lines in your cross check.

 

One nice thing about the GFC 500 is that, if the AP is not engaged. but the flight director is on, the magenta flight director is hollow, so there should never be an issue about whether the AP is engaged or not.  I don't remember if the G1000 NXi has that feature.