flight planning - checkpoints

woodstock

woodstock

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What do you usually do when you don't have great checkpoints?

Do you make "passing a VOR radial" a checkpoint, etc.

How far apart timewise do you make your checkpoints, too (usually?)

Yesterday (late afternoon) we were flying more or less into the sun (230) and it was just hazy enough to be a pain in the butt. We were flying over some very pretty countryside (note to anyone - the leaves have more or less turned, now. still some color but mostly heading to brown - what a difference one week makes) but mostly a lot of trees, tiny towns, and little roads that were kind of hard to see especially given the sunlight/haze.

It's also possible I made my checkpoints too close together (b/w 5-10 miles, maybe closer to ten in general would have been better).

Coming home was a little better since it was sunset when we took off to come back. We had plenty of lights to look at. Much easier to see roads and towns when they turn the lights on! :yes:
 
ps. I'm at a little over 5 hours of XC now - all dual, but still. I've got TONS of night hours and landings and still need 2 hours under the hood. after the solo XCs I'm more or less done, then.
 
When I was doing my primary XC my checkpoints were about 20 miles apart. I would use intersection of VORs but not just the radial. I would use a radial to aproximate my position though. I would also use VORs, city, lakes, etc. for checkpoints. As I got better at XC my check points have become farther apart but I still use those other things to verify position at any moment in time.
 
ok, so clearly I've got them too close together. 10 miles minimum - plus less writing of times, etc. I'll stretch them out to 10-20 next time.
 
Elizabeth, if you post a proposed route I'm sure that some of us would be willing to look at a sectional and offer up the checkpoints we would use, why, etc. That level of detail might be more helpful to you versus general methods. IOW, for teaching purposes nothing compares to a couple of example points and the logic behind the selection of those points versus other available alternatives.
 
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Last night we went from Leesburg to CHO. I think most of the problem was the sun/haze. The haze helped cut down on the glare from the sun, but then it was hard to see anyway.

thanks Ed.
 
I teach the waypoint spacing to be about 10 minutes apart. Much close and you have overload. Much more apart and you get lost.
 
I learned this from my first dual XC: The checkpoint does not HAVE to be on the course line.

Draw your course line. Now draw or imagine parallel lines 1.5inches (about 10 miles on a sectional) on either side of it. Unless visibility is atrocious, all large features (Lakes, towns, etc) will be visible. You can use any of them as checkpoints.

During your student days, you should probably be able to have one point in sight at all times. Afterwards, how long with a checkpoint behind you before you expect to see the next one is up to your confidence in your ability.
 
Try to think in terms of minutes not miles. At 5 miles apart and 120 Kt you'd only have 2.5 minutes to find a waypoint, log your passing, compute GS change heading etc, and that's just not enough time. Personally I'd want to have at least 5 minutes each or more. Also I recommend that you select your first waypoint very carefully, because missing this one or even finding it late can really get you off to a bad start. You want something that's really easy to locate keeping in mind that depending on the runway your use and other traffic, you could be coming at the first one from several different directions.

Aside from that, I like to consider different kinds of features for "waypoints". Some are good for measuring your progress: major rivers and roadways that you cross more or less perpendicularly. Some are good for bracketing your intended course: terrain features, hiways etc that parallel your course a few miles on either side. In sparsely populated areas, towns and/or the roads coming through them make pretty good checkpoints, but when the towns are close together it's hard to tell one from another. Large bodies of water, especially if they have unique shapes or are otherwise easily identified, like if they have a dam one one end. Sometimes it helps to combine features into groups that make them unique like a town at the intersection of a railroad and a river.

BTW water bodies, especially small ones, pretty much disappear when they are frozen and covered in snow. Powerlines are easy to see if you are flying along one, but not when crossing them. And most airports are hard to spot by themselves (locate them by their proximity to other more easily identified features) but once you spot them they can usually be distinguished from other airports by the configuration and direction of runways.

Choose wisely!:D
 
One thing to remember is that, in flight training, we make our checkpoints closer together than we do in "the real world". One of the reasons being that we want to condense more training "events" into minimum time in order to ensure that you're comfortable with the process. The more times you make your GS/Time/Fuel calculations enroute, the better you'll be at it. 10-minute intervals are probably a good spacing for this purpose. I don't remember what spacing I used for my Private Pilot checkride, but I do remember the examiner prompting me to hurry up and make my time-to-destination calculation ;)

As to the suitability of specific items for checkpoints, that's another reason we make them as frequently as we do in training. First, it allows you to figure out the suitability of different types of waypoints (as well as how they relate to varying flight conditions, like flying towards the Sun on a hazy day). Second, it allows you to have another one nearby in the event that you try to use one that doesn't work.

I can just about guarantee you that some of the things that work for me won't work for you, but here are a couple of general guidelines:

First, the checkpoint should be as perpendicular to your course as possible. Using a highway highway or radial that cuts your course by 30-degree angle will result in a distance/time error if you're even a little off course. Say you're flying a 120-kt airplane, with a 10-minute checkpoint interval (about 20miles). Being 2 miles off course will result in your crossing the checkpoint 1 mile early or late, making for a 5% error in your groundspeed calculations. To be quite honest, two miles is pretty hard for most people if no electronic navigation means are being used. Obviously the farther apart your checkpoints are, the less error this will introduce...1 mile error over 50 miles is only 2%.

Second, the better you can stay on course, the larger the angle you can use to determine your checkpoints, so the type of navigation being used will be a factor as well...If your course follows a straight highway, or you plot the exact course your GPS and autopilot will take you over, you can use most anything visible or electronic as a checkpoint. If you're dead reckoning over the desert or a large body of water with questionable winds-aloft information, you'd better have something long and straight, perpendicular to your course, for a checkpoint, preferably something that will give you a "how far off course" indication as well.

Hope I didn't confuse you too much.

Fly safe!

David
 
Basic rules...

5-10 minutes apart (closer when vis is reduced)
Big and unmistakeable (big towns with roads/rivers running through, major river intersections, interstate highway intersections, etc)
Nothing else similar nearby
 
Ron Levy said:
Basic rules...

5-10 minutes apart (closer when vis is reduced)
...
Click to expand...
Just curious...and most likely I'm using the term "checkpoint" differently than you, Ron, but why would you want them closer together when vis is reduced?

I'm considering checkpoints as preflight-selected (for the purposes of pilot training) distance points for GS/Time/Fuel calculations...they are separate from course guidance, which includes any number of other fixes/waypoints/terrain features that can be used to determine where you are along the course line. It would be these features that I wouldn't want to lose sight of for too long, but the computation checkpoints could be the same distance apart.

Would you mind clarifying that?

Thanks

David
 
MauleSkinner said:
Just curious...and most likely I'm using the term "checkpoint" differently than you, Ron, but why would you want them closer together when vis is reduced?

I'm considering checkpoints as preflight-selected (for the purposes of pilot training) distance points for GS/Time/Fuel calculations...they are separate from course guidance, which includes any number of other fixes/waypoints/terrain features that can be used to determine where you are along the course line. It would be these features that I wouldn't want to lose sight of for too long, but the computation checkpoints could be the same distance apart.

Would you mind clarifying that?

Thanks

David
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That's so you don't lose touch with one, get lost, and have to mag compass heading/time return to the previous waypoint, in the blind. BAD setup. Turn off your GPS. Pilotage is a PTS requirement.
 
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I planned for 10 minutes or so per checkpoint, and always looked for a checkpoint that was a mile or so off to the left or right of the airplane, as finding something right underneath is difficult. I try to choose major things, like reservoirs, crossing a major highway (at least 4 lanes), rivers, or bridges.

Now when I can't find something useful, (think over west texas), then I'll use a VOR radial.
 
I was taught (and still follow) 10-20 miles apart. As stated by others, this distance reduces pilot overload. Another factor I haven't heard mentioned- you fly more VFR. If I have good check points, I just fly to them & just use the electronic instruments as back up. This might also cover the question by MauleSkinner.

This woeks better or worse in different parts of the country. In NJ or other costal states, there are many unique check points to use. Here in Nebraska, I need to learn what constitutes a unique landmark- looking away from the Platte river, it all looks the same for now. I'm sure I'll learn in time.
 
10-20 enroute, a bit closer when I'm closer to the departure/arrival airport (especially in poorer visibility). Maybe a bit farther apart enroute on a long trip. In some parts of Texas and New Mexico you might not have anything closer than 20 miles apart (scrubbrush is not on the chart....)
 
bbchien said:
That's so you don't lose touch with one, get lost, and have to mag compass heading/time return to the previous waypoint, in the blind. BAD setup. Turn off your GPS. Pilotage is a PTS requirement.
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OK...I THINK Ron and I are using terms differently...but I KNOW you and I are, Bruce. ;) GS/Time/Fuel calculations completed every mile or two?

Fly safe!

David
 
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Vary the distance/time to suit your workload and overall requirements. They can be off your wings too, and if you use VORs, crosschecking with another VOR is ideal.
 
Your first couple of checkpoints are absolutely critical. These are what will establish you on your course. Once you are established on your course and take note of that heading everything will just fall in place. You might have to adjust a little bit for changing winds aloft.. Or if you are flying through a front or something. It's better to choose a checkpoint 5 more miles down the course vs. trying to use one that sucks. If you can't find your checkpoint you've got a problem. With a little bit of experience you'll know what checkpoints you might not be able to identify and if you can't thats OK. You'll also know which checkpoints can't possibly be missed..and if you don't see them..well you now know you've got a problem.

On most of my XC flights now. I don't draw a course. Nor do I mark checkpoints on the chart. I know from experience what heading goes where on the sectional. By looking at the chart I'll know what a good checkpoint is and what a bad checkpoint is. There are checkpoints that I'll *try* to find but if I can't I don't worry about it. I have the major checkpoints that I know if I don't see. I've got a major problem.

A lot of my night VFR XC's..My checkpoints may be as far as 30NM or more apart. If I can't see that far I've got no business flying the flight VFR at night. You can't depend on seeing anything but major roads or medium to large cities. I usually turn on airport lights as I go by them to verify that I'm looking at what I think I'm looking at.

I use a sectional like a moving map GPS. I constantly compare the sectional to the world outside the airplane. They should both match each other perfectly. Once you get more experienced a quick glance at the chart followed by a look out the window..and you'll know exactly where you are..Sort of :)

Also..if you are flying with a group of airplanes that have all these fancy GPSs and automagic gizmolators.. They can give you vectors...Right Kent? :)
 
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One other tactic -- don't start your DR route at the departure airport. Instead, choose a starting point you absolutely cannot miss that is within sight of the traffic pattern in the direction you're going. Otherwise, you are always off course to start with just from your takeoff and turnout, especially if you launch off a runway other than the one you expected when you planned. You take off, see the point, fly over the point, and then start your DR nav.
 
I find when it is hard to find a good checkpoint, I'll use stuff like lay of the land. For example - is there a plateau with topographic lines on the sectional? I'll use that. I try to avoid things like Microwave Towers because I almost always miss them.

Also - a checkpoint can be "Between two towers" or something like that too. I use that a lot. Good luck!
 
I was taught to pick them based on the current visibility and to not leave one behind until you can see the next one. So, with 10 miles visibility that means no more than 20 miles apart. Oh, and don't forget that visibilities are reported in statute miles.

I've used the "between two towers" trick that skyhog mentions. For left/right guidance try and get the same relative spacing in reality that you see on the chart. Example: your charted course line shows you passing 1/2 mile to the left of a tower (or lake, or whatever). There is another tower 2 miles to the left. Position the plane so that you between the towers, but 3/4 of the way towards the right tower.

Another trick I use is the intersection of a VOR radial and a road. If the road is perpendicular to the radial, it can serve as a poor man's DME.

Matching what you see on the chart to what you see out the window is an acquired skill. Don't worry if you don't get it at first, it takes practice.
 
Ron Levy said:
One other tactic -- don't start your DR route at the departure airport. Instead, choose a starting point you absolutely cannot miss that is within sight of the traffic pattern in the direction you're going.
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The flip side to this is that your DR route should "end" with a point you abopslutely cannot miss that is just outside the arrival airport vicinity and from which you can turn to a specific course and know that the arrival ariport is right in front of you, whether you can see it immediately or not. It helps to solve the "find the unfamiliar aiport" problem (I teach a similar technique for avoiding heading tot eh wrong pass or valley when doing mountain navigation.)
 
Ron Levy said:
One other tactic -- don't start your DR route at the departure airport. Instead, choose a starting point you absolutely cannot miss that is within sight of the traffic pattern in the direction you're going. Otherwise, you are always off course to start with just from your takeoff and turnout, especially if you launch off a runway other than the one you expected when you planned. You take off, see the point, fly over the point, and then start your DR nav.
Click to expand...


That is great advice, which I had to learn the hard way during my training.
 
When picking checkpoint don't forget to get the roadmap out! When doing XC's in MI going north I always used a major outlet mall as a checkpoint. There was no mistaking it, but it wasn't on a sectional. Roadmaps can be more detailed then the sectionals, I even take the roadmap in the plane as a back up reference sometimes. Plus if you have a road map you can always fly IFR: "I Follow Roads". In fact my trip home to MI is planned IFR for part of the way. I'm going to take off of IPT and fly west pick up I-80 and follow it to Ohio.

If you are forced to pick a less then perfect check point (This little lake here by the railroad tracks) back it up with a couple of VOR radials. In my training I picked a private grass strip as one of my check point (in winter after a snow) but it was the only thing in the area. My instructor did not think it was a very good check point but I had it backed up with cross radials so even if I can't find it visually I will know when I'm there. He was ok with that... and guess what I found the farm strip. The owner had it plowed.

Missa
 
Ron Levy said:
One other tactic -- don't start your DR route at the departure airport. Instead, choose a starting point you absolutely cannot miss that is within sight of the traffic pattern in the direction you're going. Otherwise, you are always off course to start with just from your takeoff and turnout, especially if you launch off a runway other than the one you expected when you planned. You take off, see the point, fly over the point, and then start your DR nav.
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Thanks, Ron - that's a great idea, and it beats overflying the airport or doing a pattern circuit just to get started!
 
If there are few easily identifiable checkpoints on a direct route, I will plan flights that do not go straight to the destination. Instead I will plan the flight to follow a more easily identified course. If the landmarks are easy spot and identify everything else will also seem easier.
 
GaryO said:
If there are few easily identifiable checkpoints on a direct route, I will plan flights that do not go straight to the destination. Instead I will plan the flight to follow a more easily identified course. If the landmarks are easy spot and identify everything else will also seem easier.
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That's a fine tactic -- nothing in the PTS says you have to fly a straight-line course airport-to-airport.
 
Justin's suggestion of combining a road (or other linear landmark such as a river or railroad) with a VOR is clever- I'll have to remember that one.
 
Elizabeth, my rough pass at checkpoints on the route you proposed. Basically on that route you're stuck with highway junctions, or highway-power line junctions, or highways abeam a town. Others might see something I missed, but this is what I would use.
 

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BTW, with GoogleEarth, you can take a sneak preview of your checkpoints before flight -- it doesn't always look as the chart might lead you to believe.
 
Ed Guthrie said:
Elizabeth, my rough pass at checkpoints on the route you proposed. Basically on that route you're stuck with highway junctions, or highway-power line junctions, or highways abeam a town. Others might see something I missed, but this is what I would use.
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Ed, it wasn't clear to me whether you were showing all the possible checkpoints or saying that you'd use all of the ones you've highlighted. I assume the former since unless I got the map scale wrong, some of those are 5 nmi apart.

The only comment I'd add to Ed's excellent checkpoints is that you can back some of the more marginal ones up using other features. For example, if the only checkpoint you had was the "Highway abeam Culpeper" waypoint and hadn't had another one for a while, then you'd want to know where on the highway you were. Since it's pretty straight, you'd be stuck using the Highway alone. However, if you note that you'll be about a third of the way from the West-most lake to the bend in the powerlines, now you have a more precise position to look for instead of just timing your crossing of the Highway.

Chris
 
Ron Levy said:
BTW, with GoogleEarth, you can take a sneak preview of your checkpoints before flight -- it doesn't always look as the chart might lead you to believe.
Click to expand...

Cool idea. Why the heck didn't I think of that?

You could even print out your entire route on a color printer and tape it all together and fly a model airplane over it going "Brrrrrrrrr" with your lips to make the engine sounds (unless you're a glider pilot, then make whooshing sounds) to practise. :)

In all seriousness, that might be an interesting teaching tool to put together (with or without sound effects) to teach checkpoint choices with the chart. Easier to do that on the ground than in the air. You could do it once to a local airport and have it as a standard teaching tool for all students when starting on the cross country training. Then go fly it with them for real (with sound effects, of course).

Chris
 
cwyckham said:
Ed, it wasn't clear to me whether you were showing all the possible checkpoints or saying that you'd use all of the ones you've highlighted. I assume the former since unless I got the map scale wrong, some of those are 5 nmi apart.
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It was a bit of each. IOW, I marked every reasonable checkpoint and I marked every checkpoint I would use if my task is to imitate a student pilot going on an x-country flight. As you note above, the checkpoints I marked are pretty much everything worth using on the direct route. Any other checkpoint that might be selected will have a large ambiguity factor. With that in mind, sometimes I was forced to take a 5 nm distance between two checkpoints, sometimes the distance is a bit more (I think there might have been some ~10 nm, but I worked this totally on a PC so I'm not exactly sure as to the exact distances--with no plotter capability I simply eyeballed using 1 degree longitude = 1 nm).
 
Ed Guthrie said:
Elizabeth, my rough pass at checkpoints on the route you proposed. Basically on that route you're stuck with highway junctions, or highway-power line junctions, or highways abeam a town. Others might see something I missed, but this is what I would use.
Click to expand...


thanks Ed - more or less what I chose.
 
Ron Levy said:
BTW, with GoogleEarth, you can take a sneak preview of your checkpoints before flight -- it doesn't always look as the chart might lead you to believe.
Click to expand...

One caveat - Google Earth can be YEARS out of date, so it you're using man-made artifacts for checkpoints they may or may not be on Google Earth.
 
woodstock said:
thanks Ed - more or less what I chose.
Click to expand...

No problem. My apologies that I took so long to cobble together a map image with a course line drawn on it. I've been traveling too much lately.
 
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