Garmin DIRECT TO gotcha

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bnunn

Filing Flight Plan
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May 23, 2008
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19
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Sherman, Texas
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Display name:
Bob
Yesterday, I filed IFR and was cleared as filed, direct from KDRI to KSWI. I entered this into my 530W and got an DTK of 314 degrees. After taking off, we coupled up to the Stec-55x, captured the route and begin the flight.

I was flying right seat, with a friend of mine, in training, in the left seat. As we were handed off from Departure to ATC, My "IFR pilot in training", thinking he was keying the microphone yoke button, inadventenly disengaged the autopilot. As we were discussing various issues, I failed to realize the autopilot was off. When I did, instead of correcting and getting back on course, I reached up to Mr. Garmin and pushed <DIRECT><ENTER><ENTER>. It makes that pretty magenta line set a new course from my current position directly to my destination. Not much of a problem in the VFR world and probably used quite frequently. It wasn't long until ATC was calling advising that we were off course by a mile and a half. I looked up at my 530 display and we were "centerline". What was he talking about? How could I be off course? Instead of trying to figure out how to get back on the course he was talking about (which was the 314 DTK from KDRI to KSWI, and I now had no idea of where it was), I asked to go direct to the IAF for the VOR/DME approach to my destination. He approved the new route, I selected it from the PROC page in the Garmin and problem solved.

Let me say, the entire flight was VMC. But I file IFR for all of my cross country flights. The mistakes in the previous paragraph were small, but noteworthy. Noteably, and the main reason for the post is to point out how using "give me direct" from my current position, in certain conditions, could cause bigger problems.

Here's the question. After creating a new course, as I did when I hit <DIRECT><ENTER><ENTER>, how do I get back to the course that was filed with ATC? Probably easy enough had the course been a Vector Airway or a radial from a VOR or to a VOR, but this was a course directly from one airport to another. I have an idea and it involves creating a temporary waypoint, but I'm still a relative newbie with the 430/530 equipment. What do you think?

I've already learned several lessons here, and I know I'll be more prudent in the future about using the <DIRECT><ENTER> button.
 
You should be able to go to the flight plan (FPL) page and enter a flight plan from the original departure airport to the original destination airport, then activate the leg. That's just what you did the first time; if you do it again, the 430/530 will do the same thing it did the previous time.
 
I don't have guides in front of me, but I believe what you could have done is:

Put the GPS in OBS mode, and set the OBS to the desired track. Then treat it like a VOR and intercept the needle. Of course, you need to know the desired track.
I often recommend that folks should get very comfortable with using the GPS in OBS mode, as it turns any waypoint into a VOR, pretty much, and most of us are comfortable with manuevering that way.



If you're ever given a vector and told to intercept your flight planned route, you can bring up the leg in the flight plan, hit the MENU button, and activate the leg. That will show the pre-calculated course (which should match the airway/route) and you can intercept that.
 
bnunn said:
Yesterday, I filed IFR and was cleared as filed, direct from KDRI to KSWI. I entered this into my 530W and got an DTK of 314 degrees. After taking off, we coupled up to the Stec-55x, captured the route and begin the flight.

I was flying right seat, with a friend of mine, in training, in the left seat. As we were handed off from Departure to ATC, My "IFR pilot in training", thinking he was keying the microphone yoke button, inadventenly disengaged the autopilot. As we were discussing various issues, I failed to realize the autopilot was off. When I did, instead of correcting and getting back on course, I reached up to Mr. Garmin and pushed <DIRECT><ENTER><ENTER>. It makes that pretty magenta line set a new course from my current position directly to my destination. Not much of a problem in the VFR world and probably used quite frequently. It wasn't long until ATC was calling advising that we were off course by a mile and a half. I looked up at my 530 display and we were "centerline". What was he talking about? How could I be off course? Instead of trying to figure out how to get back on the course he was talking about (which was the 314 DTK from KDRI to KSWI, and I now had no idea of where it was), I asked to go direct to the IAF for the VOR/DME approach to my destination. He approved the new route, I selected it from the PROC page in the Garmin and problem solved.

Let me say, the entire flight was VMC. But I file IFR for all of my cross country flights. The mistakes in the previous paragraph were small, but noteworthy. Noteably, and the main reason for the post is to point out how using "give me direct" from my current position, in certain conditions, could cause bigger problems.

Here's the question. After creating a new course, as I did when I hit <DIRECT><ENTER><ENTER>, how do I get back to the course that was filed with ATC? Probably easy enough had the course been a Vector Airway or a radial from a VOR or to a VOR, but this was a course directly from one airport to another. I have an idea and it involves creating a temporary waypoint, but I'm still a relative newbie with the 430/530 equipment. What do you think?

I've already learned several lessons here, and I know I'll be more prudent in the future about using the <DIRECT><ENTER> button.
Click to expand...

I'd advise you download the Garmin simulator from:
http://www8.garmin.com/include/SimulatorPopup.html

You really want to know the GPS well before flying IFR. The problem you had can easily be fixed just by understanding the flight plan mode. Know the flight plan mode *WELL* before flying IFR.
 
Both of those are great ideas. Jay, yours is probably more intuitive than Tim's. I was thinking there was a solution by using the flight plan method. Although I didn't use the flight plan page to start out with. I just used the DIRECT to method, which loaded it into the Active "00" slot and was wiped out when replaced with my new DIRECT TO plan. I practiced this with Garmin's 430w/530w simulator and it works just fine. I went to the Flight Plan page and created the flight, then selected it.

Tim, I also like your OBS method and agree that I need to get much more familar with using that feature.

Thanks for your responses.
 
It's always a good idea to put your flight route into a flight plan page, so you can take advantage of the full utility of the GPS unit. I still (sadly) know a lot of pilots who fly using only the DIRECT button.
 
One of my CFII's over the years once told me I should always tell the GPS where I was flying FROM.
 
TMetzinger said:
It's always a good idea to put your flight route into a flight plan page, so you can take advantage of the full utility of the GPS unit. I still (sadly) know a lot of pilots who fly using only the DIRECT button.
Click to expand...

Another thing to do is add waypoints every 25-50 nm between departure and destination waypoints in the flightplan route. You can then fly direct to the nearest waypoint to put you back on track.
 
Skypilotcfii said:
Autopilot? Does it not give a warning tone if you disconnect it using the yoke switch?
Click to expand...

Aha! I was waiting for that question. :D Yes, the autopilot did give a warning tone. But it didn't take long for ATC to respond. Remember that it happened during a handoff from Departure to Center. Pilot squeezes autopilot button and responds to the handoff, tunes the new frequency, flips the radios, listens to ATC, keys the autopilot button again and calls up Center. Right seat guy (me), is a bit confused why I'm hearing a tone everytime training pilot keys his mic. At first I think something is wrong with my headset. I'm not used to being plugged in over here on the right side. I get concerned that Center hasn't responded. I key from my side and report in. By now, I guess we've drifted the 1-1/2 off course and got the call. Realization sets in of the chain of errors. Is my face red enough yet? :redface: And, yes, I did go back to departure and confirm the handoff.
 
Steve said:
One of my CFII's over the years once told me I should always tell the GPS where I was flying FROM.
Click to expand...

During my PPL checkride, I was setting up for the XC portion. The plane I was using had a 430, so I put Direct To (Tulsa, I think). I always just used the Direct To.

The DPE saw a 'training moment' and pounded it into my head to always put where you are going FROM and where you are going TO, use the flightplan function.

I've tried to follow that advice.

One time when I didn't, I learned a bit of a lesson. A previous renter had left an active flight plan in the GPS. I was working on touch-and-gos at an airport about 30NM away and coming home. I put in the direct-to back home, and headed back - not that I really needed it, I could have just followed the highway. About half-way, the GPS switched to a different destination. I thought I did something wrong and did it again. Same result, the GPS swithced to a different destination.

After I landed, I figured it out. The Direct-To is only a temporary override of the active flight plan. When I got near my destination, which happened to be the start of the flight plan, the GPS automatically switched to the next waypoint in the flight plan leg. Since then, I've made sure there is no flight plan loaded.
 
jmaynard said:
You should be able to go to the flight plan (FPL) page and enter a flight plan from the original departure airport to the original destination airport, then activate the leg. That's just what you did the first time; if you do it again, the 430/530 will do the same thing it did the previous time.
Click to expand...

Jay has the easiest answer.
 
john smith said:
Another thing to do is add waypoints every 25-50 nm between departure and destination waypoints in the flightplan route. You can then fly direct to the nearest waypoint to put you back on track.
Click to expand...


Why in the world would you ever want to do that? Seems like a lot of effort for nothing. How would you determine the location of the added waypoints without a computer?

-lance
 
Henning said:
Jay has the easiest answer.
Click to expand...
Nah - mine was easier:

1. Press OBS
2. Turn the OBS knob to 314 degrees (on the CDI)
Go intercept and track.

One press, one spin, and you're done!

Granted, he KNEW already that 314 was the track required. If he didn't than Jay's method would be the only way to do it.
 
lancefisher said:
Why in the world would you ever want to do that? Seems like a lot of effort for nothing. How would you determine the location of the added waypoints without a computer?
Click to expand...


You start our direct Point A to Point B.
The GPS draws the line.
At even intervals along the line you move the cursor and mark the spot as a waypoint (M1, M2, etc).
The new waypoints are entered in the flight plan.
You can pick airports along your route if you like.
It really isn't rocket science.
 
OBS seems pretty simple. I did know the DTK before takeoff, because we wrote it down and turned the heading bug as a reminder. This was a departure from an uncontrolled field, Polk Approach was contacted after we were airborne with the IFR request. Had it been a controlled field, the heading bug may have been used for different assignments.

Anyway, I find these posts helpful. It seems to always educate me and I appreciate your input. Thanks Matthew for adding that bit of insight on another quirk that could jump up and bite you. From now on, I will enter a flight plan and make it active.
 
TMetzinger said:
Nah - mine was easier:

1. Press OBS
2. Turn the OBS knob to 314 degrees (on the CDI)
Go intercept and track.

One press, one spin, and you're done!

Granted, he KNEW already that 314 was the track required. If he didn't than Jay's method would be the only way to do it.
Click to expand...
Actually, I always make a point to set the heading bug when flying, and since they were using the autopilot it was probably already set anyway. So your way is really 1 step: Press OBS, then go intercept and track.
 
If you entered both airports into a flight plan, then resuming navigation from a direct-to as you described is a simple matter. Press direct-to, direct-to, enter. This activates the current leg for navigation.

If you didn't enter a flight plan in the first instance, you could enter the flight plan and activate it.

If you have a flight plan and wish to join a particular leg, then press the FPL button and move the cursor to the waypoint that ends the leg, press direct-to twice and then enter. Pressing direct-to two or more times toggles between activating the leg ending at the waypoint and going current position direct to the waypoint.
 
How many minutes had elapsed between the inadvertent shut off and your being alerted? It sounds like the controller was pretty much on top of your being off course. They sometimes give more latitude than that if they know it's a training flight.

Also, was there a regular scan that periodically included the radio stack and it's various settings?
 
Jay had it right. Messing with the OBS button is just as bad as using the direct button instead of setting up a flight. OBS suspends automatic sequencing, can lead to confusion, and adds extra workload should your route be amended.

Put the cursor over the appropriate item, hit menu, and select activate leg. You'll once again have a proper flight plan set up that you can then further manipulate.

Felix
 
Again, Felix, that would NOT have worked in this situation. The flight plan was from Present Position direct to destination, NOT departure-destination. There WAS no flight plan originally entered.

So, you either have to enter the departure airport (lots of knob twisting) or you have to use the OBS function (less)

I agree that if you had a flight plan entered (which is why you'd worry about waypoint sequencing) that activating the leg would be the way to go. But when you want only to go to one waypoint via a specific track, OBS is the way to go.
 
That happened to me a few times as a renter when GPS was just starting to become prevalent.

I thought "what a stupid GPS"....:)

Matthew said:
One time when I didn't, I learned a bit of a lesson. A previous renter had left an active flight plan in the GPS. I was working on touch-and-gos at an airport about 30NM away and coming home. I put in the direct-to back home, and headed back - not that I really needed it, I could have just followed the highway. About half-way, the GPS switched to a different destination. I thought I did something wrong and did it again. Same result, the GPS swithced to a different destination.
Click to expand...
 
TMetzinger said:
Again, Felix, that would NOT have worked in this situation. The flight plan was from Present Position direct to destination, NOT departure-destination. There WAS no flight plan originally entered.
...
Click to expand...

So tell me how the controller sees that flight path on the scope and knows you're a mile off of the course. Can he enter "Present position of that target DIRECT to airport?" :dunno:
 
mikea said:
So tell me how the controller sees that flight path on the scope and knows you're a mile off of the course. Can he enter "Present position of that target DIRECT to airport?" :dunno:
Click to expand...


He's looking at your orginal cleared path - direct from the departure airport to the destination. In this case, the airplane wandered off course when the autopilot was disconnected. Then the pilot tried to go direct from where he was, rather than navigate back to the course.

Just as if you'd gotten off course tracking a VOR radial, then instead of correcting to intercept the course, you turned the CDI knob to center the needle and then started tracking that new course.
 
sba55 said:
Jay had it right. Messing with the OBS button is just as bad as using the direct button instead of setting up a flight. OBS suspends automatic sequencing, can lead to confusion, and adds extra workload should your route be amended.

Put the cursor over the appropriate item, hit menu, and select activate leg. You'll once again have a proper flight plan set up that you can then further manipulate.

Felix
Click to expand...

Felix,

If you have a flight plan loaded and wish to navigate on a specific course to the active waypoint in the flight plan, as might be required after a departure vector where you are asked to intercept a radial and track it inbound, the following procedure maintains the auto sequencing:

1) Set the desired OBS course on your HSI (or CDI)
2) Press the OBS button on the 430 twice

The first press of the OBS button puts the 430 into OBS mode and selects the course set on the HSI. The second press of the OBS button, turns off OBS mode, so auto sequencing will take place and it preserves the selected course to the next fix. You can use this approach on any waypoint in the flight plan, by first making the desired waypoint active.

I owned a 430 and a 530 for mucho years before I finally read the manual and found several neat features that were staring me in the face. One that I have found to be particularly useful is the direct-to dialog. Normally, when you press the direct-to button, the active waypoint is automatically nominated in the waypoint field. So to center the CDI to navigate to the fix, you just press enter twice.

What I found in the manual that was hidden in plain sight was that there are other choices in the dialog. Instead of pressing the enter twice, you can scroll the cursor to one of three fields below: FPL, NRST, or CRS.
The FPL field allows you to select any waypoint in the flight plan. The NRST field allows selection of one of the 25 nearest airports. The CRS allows you to select a specific course to the active waypoint without using OBS mode. After one of the three selection choices are made, you press enter twice to activate it.

You can even chose a waypoint from either the FPL or NRST field and press enter once to accept it and then move the cursor to the CRS field and choose a course and then press enter twice. What you will get is the selected course to the waypoint and if it is in your flight plan, the rest of the course will auto sequence.
 
John Collins said:
If you entered both airports into a flight plan, then resuming navigation from a direct-to as you described is a simple matter. Press direct-to, direct-to, enter. This activates the current leg for navigation.

If you didn't enter a flight plan in the first instance, you could enter the flight plan and activate it.
Click to expand...
It's been a while since I flew with a Garmin but that's how I remember it too... press direct-to twice. It's also useful when getting vectors to intercept a departure or an airway.
 
TMetzinger said:
He's looking at your orginal cleared path - direct from the departure airport to the destination. In this case, the airplane wandered off course when the autopilot was disconnected. Then the pilot tried to go direct from where he was, rather than navigate back to the course.

Just as if you'd gotten off course tracking a VOR radial, then instead of correcting to intercept the course, you turned the CDI knob to center the needle and then started tracking that new course.
Click to expand...

I get the part about how the planned path and new path diverge.

How does the controller see your planned path on the scope, enough to see you're off of it by a mile? Can he just envision it mentally?

What I'm thinking. I know the scope would have airways on it. Does it also display the flight plan for a target?
 
No, it doesn't. I believe the controller could just see the departure and destination airports and see the airplane was not on a line between them.
 
John Collins said:
What I found in the manual that was hidden in plain sight was that there are other choices in the dialog. Instead of pressing the enter twice, you can scroll the cursor to one of three fields below: FPL, NRST, or CRS.
The FPL field allows you to select any waypoint in the flight plan. The NRST field allows selection of one of the 25 nearest airports. The CRS allows you to select a specific course to the active waypoint without using OBS mode. After one of the three selection choices are made, you press enter twice to activate it.
Click to expand...

Wow, all this time behind a 430 and two trips through the manual, and I didn't even know you could do that. Thanks! Gonna have something to play with next time Pete's flying me around. :rofl:
 
Yeah...need to play with that the next time I'm flying...that is, if I can quit shivering long enough to twist the knob. (It's projected to stay in the single digits this coming week.)
 
I think it was the fact that this all happened during a handoff from Departure to Center. When Center picked us up, he must have noticed that we were not on the course he expected. Tim, I believe you're right on.

John, great post on using the 430/530. I'm going to fire up the simulator and step myself through your notes.
 
This is much easier than most of these answers would lead you to believe. If you were on a flight plan when this happened...

Instead of <DIRECT><ENTER><ENTER>

use <DIRECT><DIRECT><ENTER>

Same can be used when you review the FPL and highlight a destination. direct, enter, enter will take you direct to that destination. Direct, direct, enter will instead activate the leg to that destination.

A GPSS autopilot would intercept the course and life would be good.
 
An interesting twist on the story, I had the opposite happen. I had a flight plan entered in the GPS for an IFR flight GPS direct. Took off and flew runway heading for a bit before being given a proceed on course, and the controller got confused when I tried to get to my originally planned line. Problem solved by hitting D -> and getting a new course.
 
scit106 said:
An interesting twist on the story, I had the opposite happen. I had a flight plan entered in the GPS for an IFR flight GPS direct. Took off and flew runway heading for a bit before being given a proceed on course, and the controller got confused when I tried to get to my originally planned line. Problem solved by hitting D -> and getting a new course.
Click to expand...

Yeah, I generally just do that when I get vectors on takeoff, unless I've filed an airway. Most of the waypoints on my flight plans are far enough away that the next controller would never know the difference.

Now, if I heard "turn (right/left) heading xxx, intercept course, and resume own navigation" I might go back to the original course. But, I've never heard that except in reference to an airway that I filed.
 
flyingcheesehead said:
Yeah, I generally just do that when I get vectors on takeoff, unless I've filed an airway. Most of the waypoints on my flight plans are far enough away that the next controller would never know the difference.

Now, if I heard "turn (right/left) heading xxx, intercept course, and resume own navigation" I might go back to the original course. But, I've never heard that except in reference to an airway that I filed.
Click to expand...
Do you vary that if you are cleared to deviate for weather?
 
gprellwitz said:
Do you vary that if you are cleared to deviate for weather?
Click to expand...

Huh? Vary what?

If I'm cleared to deviate for weather, well, the autopilot either gets shut off or put in HDG mode and I don't change anything on the GPS unless my deviation clearance included "direct XXX when able."
 
flyingcheesehead said:
Huh? Vary what?

If I'm cleared to deviate for weather, well, the autopilot either gets shut off or put in HDG mode and I don't change anything on the GPS unless my deviation clearance included "direct XXX when able."
Click to expand...

I have a GNS530W and a GDL69A that feeds NEXRAD to it. My autopilot has a GPSS adapter for roll steering.

When deviating around large areas of weather, I have found using the +Map feature very useful. I make sure the autopilot is in heading mode and the GPSS is also in heading mode. On the Map page, I turn on the cursor and move it to a point that will avoid the weather, and press direct-to, enter, enter. This generates a waypoint at that location named +Map. I then press the FPL key and add +Map to my flight plan. I then turn the GPSS back to GPS and the autopilot flys my deviation and resumes my flightplan at the end of the deviation. If I need to adjust the deviation as the situation unfolds, I can use the same procedure and since +Map is in the flightplan, it works like rubberbanding the route to the adjusted deviation.
 
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