Figure 8 Landing Approaches Copy

Figure 8 Landing Approach

Introduction

The Figure 8 pattern is used in a landing approach to stay downwind of the landing area. This pattern allows the pilot to pause the approach and remain in a zone downwind of the landing target regardless of how strongly the wind is blowing.

The Figure 8 pattern can be used in any wind condition and can be held until a good height is reached for the final approach.

The Figure 8 is defined by the glider’s path over the ground—not simply by the heading of the glider. The number of turns and how far the glider needs to turn are directly related to wind speed. As wind speed increases, the crabbing effect increases and the amount of heading change necessary to maintain the Figure 8 ground track decreases.

There is also great flexibility with this pattern. If lift comes along while holding the Figure 8, the pilot can continue the pattern and remain downwind of the landing target. If sink is encountered, the pilot can quickly exit the Figure 8s and begin the final approach.

Staying downwind of the landing area means that during each pass between the turns, the ground path needs to angle slightly downwind from perpendicular to the spot. If the pilot does not maintain this slight downwind angle, the pattern becomes a series of wide S-turns and the pilot begins creeping closer to the target. This is what I refer to as “crowding the approach.”

In light or no-wind conditions, the looping turns at the ends of the Figure 8 may need to be at least 180 degrees in heading. In stronger winds, because of crabbing, the turns may be as little as 90 degrees.

For example, in a 10–12 MPH wind, the glider may be pointed more than 45 degrees into the wind during the crosswind legs while its actual path over the ground remains nearly perpendicular to the target. The turns required to reverse the ground track can therefore be only a little more than 90 degrees.

Instead of concentrating on exact angles, adjust the pattern so there is enough movement downwind over the ground to comfortably make the next reversing turn. Remember: the Figure 8 is your path over the ground.

The pattern can also be adjusted for size, location, and distance downwind from the target.

• Light winds: Use a slightly wider Figure 8 farther back from the target.
• Stronger winds: Increased crabbing allows narrower loops and lets the Figure 8 be flown closer to the target.

Avoid Crowding an Approach

A common problem for pilots learning a Figure 8 approach is creeping forward toward the target because they are actually doing S-turns instead of complete Figure 8s.

It is important to remain behind the planned distance downwind of the spot. When performed correctly, the Figure 8 keeps the pilot from moving progressively upwind while holding the pattern.

Imagine a rectangular box drawn on the ground downwind of the target. A properly flown Figure 8 could be held within that area until the pilot reaches the desired height for the final approach.

When the Figure 8s are done correctly, hold the pattern until the desired height is reached and then begin heading toward the landing target.

The desired height should include a small amount of extra altitude for the glide to the spot. Soft S-turns or speed-to-fly adjustments can be used during final to remove this extra altitude.

The important concept is simple: you can adjust out extra altitude, but you cannot extend a glide without help from lift.

Light-Wind Variation: Wide S-Turn Approach

When the wind is very light—less than about 5 MPH—an alternative is to begin farther back and use wide S-turns.

At sites that do not have enough room for these wide turns, stay with the Figure 8 pattern. At sites with sufficient room, the wide S-turn method can be easier for newer pilots.

In the illustration below, the S-turns can become a full Figure 8 if lift is encountered. If sink occurs, the pilot can reduce the amount of turning.

The goal remains the same: cross the Outer Circle at a height that would carry the pilot slightly beyond the landing spot. Once inside the Outer Circle, soft S-turns can be used to remove the small amount of extra altitude and fine-tune the landing.

Sampling Your Glide on the Way In

As you break out of the Figure 8 or wide S-turn pattern and head toward the spot, begin to sample your glide.

By “sample,” I mean trying to determine where your current flight path will take you.

As you cross the Outer Circle, fly straight toward the spot briefly and look for a point on the ground that appears to be neither moving upward nor downward relative to your glide.

The terrain below that point appears to move downward in your peripheral vision, while terrain beyond it appears to move upward. The point toward which you appear to be gliding is the point of “Zero Motion.”

It is not always easy to see at first, but practicing this sampling technique helps develop a feel for where the glider is actually going.

Remember that you normally want a little extra altitude for the final glide. If you do not have extra altitude, fly near trim speed directly toward the spot. If you do have extra altitude, you can begin adjusting it out with turns or speed.

Adjustments

If You Are a Little Too High

If you are slightly high as you cross the Outer Circle, use gentle S-turns on the way in or, when conditions allow, use speed to reduce the glide.

If You Are Way Too High

If sampling shows that you are much too high, make an immediate turn of at least 90 degrees in ground path—but do not turn directly downwind near the ground.

You can angle slightly downwind of the Outer Circle and make a Figure 8-style loop that brings you back toward the Outer Circle at a better height.

In very light or zero wind, you can move around the Outer Circle until the correct height is reached and then sample again.

If You Hit a Pop or Thermal

If you encounter a pop or thermal while crossing the Outer Circle, respond much as you would if you were suddenly too high. Wait until the glider is back overhead and then turn to keep yourself back, returning to a Figure 8-type loop.

If you are above about 50 feet, you can even turn slightly more downwind for a short time to help keep yourself back.

If You Hit Sink

If you are already a little low or encounter sink while sampling, the answer is simple: continue flying directly toward the spot near trim speed.

In smooth air, trim speed is fine. If the air has some texture or is bumpy, maintain a little brake while flying toward the spot.

The Inner and Outer Circle

So what is the target height, and at what distance should you reach it?

I like to use a distance of a little more than 300 feet, or approximately 100 yards, for the location of the Figure 8s downwind of the landing target. I call this imaginary distance the Outer Circle.

Picture a roughly 100-yard circle around the desired landing point. The Figure 8s are performed just downwind of this circle, with the goal of crossing the Outer Circle at approximately the correct height for the final approach.

That height will generally be somewhere between:

• About 40 feet in very light or no wind
• About 50–55 feet in approximately 5 MPH wind
• About 80 feet in approximately 10 MPH wind

At Ed Levin Park, the approximately 110-yard circle shown below intersects the shallow ditch. Most approaches cross the ditch near the point of overlap.

I also use the approximately 60-foot tree at the corner of the Eucalyptus trees near the beginning of the ditch as a visual height reference.

Wind Speed and Starting Approach Height from About 100 Yards

The following numbers help explain why these approximate heights work for entry-level to intermediate gliders with roughly an 8:1 best glide at 20 MPH trim speed.

Don’t get too caught up in the math. The practical lesson is much simpler:

With practice, you will learn the appropriate height visually and adjust for the wind speed. At Ed Levin, the approximately 60-foot trees provide a useful visual reference.

Higher-Wind Example

In moderate to stronger winds—approximately 5–12 MPH—the Figure 8 can actually become easier because the reversing turns may be less than 180 degrees.

Picture flying at approximately a 45-degree angle in a 12+ MPH wind. To reverse direction at the end of the Figure 8 loop, you may need only about a 90-degree heading change.

During that turn, ground speed is also quite low, so the loop does not carry you very far upwind. This is why Figure 8s can generally be flown closer to the target in moderate to stronger winds.

Light-Wind Example

Now picture flying in no wind. Between the loops at the ends of the Figure 8, you need to travel slightly downwind and roughly perpendicular to the landing target.

This requires turns of a little more than 180 degrees. The loops are also larger because your ground speed is higher.

The solution is to fly a larger Figure 8 slightly farther from the target. This gives you room for the larger turns and prevents the approach from becoming crowded.

For an approach in approximately 5 MPH wind at Ed Levin Park, the pilot should be around tree-top level when leaving the Figure 8 pattern and entering the Outer Circle/final approach area.

In very light or zero wind, the pilot would generally be just below tree-top level. In winds approaching 10 MPH, being approximately 10–20 feet above the top of the corner tree may be more appropriate when crossing the Outer Circle.

The Figure 8s should be flown directly downwind of the target landing spot. Imagine a pie-shaped zone extending directly downwind from the target and keep the Figure 8s within that area.

Always leave enough room to complete the turns without getting closer than approximately 40 feet from the trees.

A Sample Figure 8 Approach

Keep the Figure 8s in the Zone Downwind of the Spot

At Ed Levin, you need a little imagination to de-reference the corner tree and use it as a height reference rather than flying directly toward it.

Make the Important Adjustments Early

The most important part of the approach is making your adjustments before turning onto final as you cross the Outer Circle.

Anticipate some altitude loss during the final turn and glide toward the Outer Circle.

Learn to cross the Outer Circle with a little extra height. You can use speed and/or turns to fine-tune the height during the approach.

If you are too low, there is no reliable way to regain the altitude needed to reach the spot. You can use the best speed to fly and hope for lift, but lift may not be there.

Once you break out of the Figure 8 pattern, continuously monitor your glide. If you turn toward the Outer Circle and realize you are going to be higher than desired, make an additional turn or two while you still have altitude.

After crossing the Outer Circle, make only the final fine adjustments.

Using Speed to Adjust the Final Glide

In moderate to stronger winds—approximately 5 MPH or more—and while still above roughly 25 feet, speed can help reduce excess glide.

For example, if it appears you will fly approximately 30 feet beyond the spot, flying more slowly into the headwind can substantially reduce the distance traveled over the ground.

Once you reach approximately 25 feet, do not fly slower than approximately hands just above the shoulders. A landing requires energy in the glider, and approaching too slowly can be dangerous.

Also avoid sharp turns at this height. Flying slightly beyond the target and landing safely is far better than making an aggressive low turn in an attempt to hit the spot.

Very Light Wind

In very light wind, speed adjustments do not reduce the glide nearly as much. Instead, you may need to add some S-turns shortly after crossing the Outer Circle.

At approximately 40 feet above the ground, somewhat stronger carving turns can still be used within reason. As you approach approximately 25 feet, transition to only soft turns.

Eyes on the Horizon for Better Flare Timing

During the final approach, your eyes should primarily be looking forward toward the horizon.

You might ask, “Shouldn’t I be looking at the ground?” The answer is: mostly no.

Looking toward the horizon helps reduce some misleading visual perceptions and can improve flare timing.

On final approach, maintain a steady speed and definitely no slower than approximately hands just above the shoulders.

When you stare down at the ground, your eyes perceive an exaggerated sense of ground speed—sometimes referred to as “ground rush.”

You still need to be aware of hazards such as rocks, burrowing-animal holes, or vegetation that could catch your feet. Quick visual scans can address those concerns, but your primary visual focus should remain ahead toward the horizon.

I don’t think there is one exact distance to look ahead—perhaps around 50 yards. It is something that tends to click once you develop the habit of looking forward.

Video Examples of Landing Approaches

The following video shows five landing approaches. One is a Figure 8 approach, while a couple of the Downwind–Base–Final approaches use a Figure 8 near the end to remove some excess altitude.

Figure 8 Approach in Higher Wind

This video shows a Figure 8 approach in approximately 12–15 MPH wind. Notice how the stronger wind and crabbing reduce the amount of heading change required during the reversing turns.