Getting Lined Up on Final
By: Doc Green


An old aviator's saying holds that "a good landing begins with a good approach." And one aspect of the approach is getting lined up with the runway.

While experienced pilots do it naturally without giving it a second thought, new pilots sometimes have difficulty in being able to do it consistently. And if the approach is out of whack, the landing is going to be more complicated than what it otherwise would have been.

This article describes a method for judging where you are in relation to the center line of the runway. And it works, with surprising accuracy.


1. The Many Sides of a Final Approach

Getting lined up on the runway center line is only one part of a good approach. There are other things to be "managed," one of which is the airspeed. You should decide in advance what airspeed you are going to use, and then bring the plane to that airspeed early in the approach. Once the desired airspeed is attained, hold it; keep it "nailed."

And how do you control airspeed? With the stick, of course, as opposed to trying to do it with the throttle. The throttle is used to control the rate of descent. For example, if it appears that you are getting low and undershooting the runway, tweak in a little power to slow the descent. And, it will probably take only a little extra power. Don't overdo it.

Once you have turned on final and are moving in the general direction of the touchdown point, you must be acutely aware of the precise direction of motion of the plane. Yes, it will be approximately in the direction the nose is pointed, but if there is any crosswind at all, the plane will develop a sideways movement along with its forward motion.

In fact if the airspeed is 50 mph, for example, and the crosswind is 10 mph, which is not all that much a few hundred feet up, the crab angle required to correct the crosswind will be over 10 degrees. This is very noticeable and a new pilot may be somewhat unnerved by the fact that the plane doesn't go where it is pointed.

Another aspect of flying the approach is to keep a sharp eye out for obstacles on the runway. Be on the alert for animals and stray airplanes that may wander onto the runway just at the wrong moment. If you are the least bit unfamiliar with the field, it is a good idea to circle at a comfortable altitude and look it over before entering the pattern to land. And especially, look for power lines that may cross the final approach path. Wires are hard to see, so look for the poles on either side of the approach. If you see the poles, chances are good that the wires will be there.

And finally, the three most important rules of flying the approach: (1) Don't stall; (2) Don't stall; and (3) Don't stall. But if you steadfastly hold your airspeed on the desired number - on every approach you fly - the possibility of stalling will not be an issue.


2. See the Parallel Lines

First of all, the "trick" of sighting across a scratch on the windshield or a favorite rivet and using this point to aim the plane at the runway does not work. In fact, doing this will cause you additional trouble because, if a crosswind is blowing in the least, the "sights" will be thrown off. What worked yesterday in yesterday's wind will probably not work in the winds blowing today.

So aiming the plane at the touchdown point does not guarantee good runway alignment. The plane will travel precisely in the direction it is pointed only in zero-wind conditions and with the controls perfectly coordinated. The question now is, How can you tell when you're lined up? Or equally important, How can you tell when you're not properly lined up?

Runways almost always have parallel lines associated with them that run parallel to the center line. On a paved runway, the edges of the pavement provide an obvious set of parallel lines, and if it has a painted stripe down the middle, that's another one. Further, tire marks or seams in the pavement may be present. There may be other less obvious lines parallel to the runway that are off to the side, produced by mowing machines, runway lights, a fence, or lines of trees. These lines are the key to judging your alignment with the runway.

On a grass strip, we don't have the luxury of the edges of the pavement nor a painted stripe, but the lines produced by mowing machines usually are close to being parallel to the center line of the runway. Also, worn grass from frequent landings, fences, lines of trees, and so forth, serve quite well.


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Now, before we get into the details, here is a photo of a beautiful grass strip. See if you can see the parallel lines. There are streaks in the grass, and of course, the line of trees to the left of the approach path provide an obvious reference. In this case, the alignment of the plane with the runway is about as good as it ever gets.

Incidentally, the approach end of this runway slopes downward slightly to the right, and there is a slight uphill grade for a short distance just beyond the threshold.

The next photo is the same but has dashed lines sketched on it to emphasize the parallel lines. These were drawn using the tracks of a mowing machine as a reference. What do you observe about the dashed red line that goes right down the center of the runway? It points straight at you!

The yellow line on the left clearly angles out and away. So does the blue line on the right. This is our clue to where we are: we will be flying in line with the parallel line that points directly at us. The difference in the angles is fairly obvious. The yellow and blue lines are probably not more than 100 feet apart on the ground so we can judge our horizontal position easily to within 50 feet or better, even when we're still a half mile out. This method works!

         
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3. Off Center Line to the Left


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The next photo is of the same strip but we're to the left of the center line. The yellow dots indicate the parallel line that we're lined up with. The red dots show the center line of the runway. We are clearly a bit to the left. Note that the line of trees to our lower left are much closer than before.

Here's a technicality that makes this entire proposition a lot more fun. If we continue the approach without making any corrections, will we end up traveling down the runway on top of the line of yellow dots? Answer: Not necessarily.

From a photo, it is impossible to judge the precise direction of motion of the plane. We can say with reasonable certainty where we are at the instant of the photograph, but we know nothing about the direction we took to get there. For example, if the plane has a pronounced drift to the right, we may indeed pass over the red dot on the runway center line. But, unless a corrective measure is taken, we will continue that drift and probably not end up where we had hoped. It is likely that we will end up awfully close to the trees on the right of the runway.

This is a problem in looking at a photograph, and it's also a problem while actually flying the plane. This is to say once again that it is critically important for the pilot to be aware of the "precise direction" in which the plane is moving. The motion of the plane will seldom be in the exact direction that the nose of the plane is pointing. The ability to sense this comes with practice and experience.

For the purposes of this discussion, we will consider two possible directions for the motion of the plane. One is that in which the plane is moving parallel to the runway. This will likely be the case if we have flown a relatively long final and have established a crab to correct for wind drift.

But there is another possibility. Some new pilots insist on driving incessantly toward the intended touchdown point with little concern for the path they take to get there. They may not be even close to being lined up with the runway center line, but they keep on driving toward that spot where the wheels are supposed to contact the ground. Apparently they do not think about what's going to happen just to the other side of it if they aren't lined up properly. This makes flying more exciting!

Now back to the photograph. If the plane is traveling parallel to the runway, perhaps in a crab, the path of the plane will indeed follow the yellow dots. But if the plane is moving toward the big red touchdown point, it will end up over near the trees on the right hand side unless some fairly strong corrective action is taken.

In the following photos, we indicate these two possibilities by dashed lines of different colors. One color will show the path the plane will take if it is flying parallel to the runway. The other will indicate the path if the plane is flying toward the touchdown point.

But there are an infinite number of other possibilities. In fact, the plane used for taking these photographs was traveling at about a 60-degree angle to the runway. This was done to get little details like windshields and struts out of the picture.


4. Off Center Line to the Right


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Again, this is the same strip. But this time the pilot is far to the right of the center line, so far, in fact, that a low-time pilot should immediately go to full power and set up a climb to go around. There's nothing wrong with declaring a missed approach.

You may note also that the plane is rather low. And further, there are trees looming up into our approach path. All the more reason to go around.

At any rate, assuming were flying parallel to the runway, the green dashed line indicates our impending path. And it will take us either into or over the trees. But if we're driving toward the red touch-down point, we are way out of line, and even if we make it to that point, we are likely to end up near the buildings at the far left corner of the strip. This is not a good approach.

Nevertheless, an experienced and skillful pilot would have no difficulty in making the corrections required for a successful landing. A turn to the left is in order, without delay, and this will have to be followed by another turn to the right to get lined up. And while all this is going on, airspeed, altitude, rate of descent, and the trees must be watched carefully. No problem ... for an experienced pilot, that is.

On the other hand, a pilot with less experience should definitely go around when things are this much awry. There's too much to watch out for. It's too easy to focus on the turns and forget the airspeed, or watch the airspeed and forget the trees, or even misjudge the turns and wind up over in the next county, low to the ground and a bit uncomposed.

And how much experience are we talking about here? Perhaps 40 hours in that particular plane, or 60, or even 100 hours. There's no definite answer; you will know. But definitely not at 20 hours total time, and not 30 either. Give yourself the benefit of the doubt. Enjoy the missed approach, and fly it to the best of your ability.


5. Same Old Song; Different Strip


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Here's the next strip, viewed from short final. It is fairly long and gives the appearance of being narrow. There are trees on both sides of the threshold, but since we're flying an ultralight, our touchdown point will be near midfield almost in front of the house on the right. Can you judge this approach?

This one is easy because the edges of the runway are easily seen. We are obviously to the left of center line, but not by a lot. A gentle correction to the right is all that is required. We have plenty of room for this because of our planned midfield touchdown point.

         
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The next photo shows our take on the situation. The yellow lines indicate our projected path if we make no corrections, assuming we're flying parallel to the runway. The red lines indicate our path if we're driving toward the point of touchdown.


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Here's our next approach. What do you make of it? Clearly we're not lined up; it's not even close, but also, we're high. Is this a missed approach?

The next photo is the approach with the lines drawn to illustrate the probable paths. Again, yellow is the likely path if we're flying parallel to the runway; red is for driving to the point of touchdown.

         
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Whether it's a candidate for a missed approach depends upon several factors, like pilot experience, of course, but also things like airspeed, the power-off glide ratio of the plane, and the direction of motion of the plane. However, because we're high, this one will be far trickier than if we were only not lined up properly. It is likely that a slip will be required to lose the altitude, even while doing the turns to get lined up. Unless you're a pro, better go around.


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Here's the next approach. What do you think?

Note the (almost) parallel lines in the hayfield to the left of the runway. Those in line with the hangar point almost directly at us. Here's the photo with the lines.

         
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Now considering your piloting skills in your plane, would you go around on this one? Here's another good question. Why do we get all the way to short final without doing something about this alignment problem earlier? Getting lined up with the runway is one of our high priority items from the moment we turn on final. Could it be that our final is much too short for our skill level? Maybe we should fly a longer final and start looking at these things early on.


6. The Approach at Johnny's Strip

This next approach is to a strip that is for veteran pilots only. It is short, and there is no possibility for a go around if you get in trouble. Once you're committed to landing, you must land, one way or the other. And it slopes uphill considerably, right toward his kitchen door, in fact.

Further, the fence to the right of the runway is not parallel to the usable part of the strip. Unless you're on your toes, this could be a bit confusing. However, Johnny has placed orange cones on both sides of his strip to help get lined up. (In the photograph, small orange dots have been placed beside these to make them more visible.)

Although it's not the best strip in the world, Johnny is proud of it. He points out that it has a half mile of clear approach over an open field, "and no faster than we fly, it's as good as a mile long!"

         
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The photo shows that our present position is almost exactly in line with the cones to the right of the strip, meaning that we're to the right of center line. However, we're way too high on this approach for this strip. A go around is the only option, short of going someplace else. (If you look closely, you can see a plane that has just landed, up next to the trees.)


7. Veteran Pilot, Right-Seat-Itis

The last approach we'll see in this article is one I find rather amusing. The approach is to my home strip, being flown by a friend who is a veteran pilot. But he almost never flies from the right-hand seat of his non-Challenger. However, on this particular flight, he was indeed flying from the right seat in order to let a visiting pilot friend get a pilot's eye view of the plane. Here's the photo.


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The approach is over trees, then down into a bean field, and then uphill between trees on both sides of the threshold. The opening between the trees at the threshold is 100 feet wide at most. It's a bit tight.

You can see that the veteran pilot fell victim to "right-seat-itis." Objects out the windshield do not appear at the same place relative to the nose of the plane when you're "over there." Consequently, he wound up somewhat to the right of centerline. In fact, he was lined up perfectly just to barely miss the tree on the right and then skirt the edge of the tall grass beside the runway. : )

However, he soon realized the error of his ways and immediately after this picture was taken, pulled the plane abruptly left and then back right, and ended up landing right down, or up, the middle of the runway. But his antics did not go unobserved by those of us watching from the ground, and yes, we had a bit of fun at his expense. Asked him questions like, "When are you ever going to learn to drive that thing?" You know.


8. When to Declare a Missed Approach

We end with a brief note about missed approaches. There is honor in executing a nice, deliberate missed approach procedure. That is, you go to full power as you pull the nose up, letting the nose come up only as the power develops. Watch the airspeed carefully during this transition from a glide or a low-power approach to a full-power climb. This phase of the maneuver is critical. Don't yank the nose up and then, after you get around to it, add the power.

Further, a missed approach, when done properly, should not be a maneuver that is exciting in the least, nor should it produce any pucker factor at all. Make the decision to "go missed" early, before things get really urgent and before you get down to too low an altitude. Then make the transition smoothly without any abrupt control inputs at all.

If you are missing approaches due to adverse circumstances at that particular field, like cross winds for example, consider going to another strip or airport where the winds may be better aligned with the runway, or the approach may be less demanding. There is no dishonor is landing at an "alternate destination."

Finally, once you decide to declare a missed approach and go around for another try, do it. Don't second guess the situation and attempt to land after the initial decision and application of power to go around. This indecision and trying to do too much all at one time is a quick way to get into big trouble.


Doc Green