Hang Gliding - FAQ - What's needed?
Free Variometer
Okay, you paid for lessons, bought a decent glider, a parachute with a para-swivel, a comfortable harness, and a helmet. Now, you fly well enough, but somehow thermalling is just not coming together for you. A variometer would really help, but the wallet is kinda tapped out for now. Is there some kind of trick that you can learn to judge altitude well enough to "do without" instruments? Okay, maybe not altitude precisely, but rather "rate of climb"? You may have already discovered that air going up can feel about like still air, or even sink, after the first few seconds. This "rate of climb" is very hard to judge when looking straight down, right? Put your wallet away; this won't cost a cent. This trick is called the "Hill Variometer"; the secret is to use more than one hill.
As a start, you MUST have enough altitude to circle a few times, fall out of the side of the thermal, recover, and then, fly to a safe landing area. You can lose 50 meters (yards) of altitude, and maybe more, when you exit a thermal unexpectedly. When you get too low, it is safer to avoid a thermal. This is very important to your health.
Now, from a safe altitude, you will be flying along and feel the glider start to rise. Maybe the nose will go up first. In that case, pull the nose down enough to fly straight into the thermal. A very strong thermal can overpower you, raise the nose too high, and reverse your flight path. You need to turn back to your original course, add more speed, and hit the thermal again, but harder. This time, keep the nose down until you enter the thermal.
A wingtip may rise up instead of the nose, telling you that there is a thermal under that side of the glider. If you can, pull that high wing down; turn 90 degrees toward the side that lifted, and enter the thermal. If the thermal overpowers you, so that you cannot turn into it directly, the glider will want to try to turn away from the thermal. Let the glider turn away, 90 degrees in the wrong direction, then make a 180-degree turn back to the thermal and fly straight into it, as described above.
You will need enough thermal (lift) to be behind you, to give you room enough to circle. So, when the nose lifts, continue to fly straight across the thermal for several seconds (count to five or more), then begin your circle by making a hard 90 degree turn. Once you have flown across the thermal and made the hard turn, let that hard turn flatten out somewhat, so the hard turn becomes a nice, smooth circle. You want to do all of this slowly in large thermals, and rapidly in small thermals. This smooth circle must fit in between the place where the nose went up, and the place where you made the hard turn. Relax, coordinate the turn, and let the glider circle and climb.
It is very difficult to tell if you are climbing or descending, by looking straight down. This just does not work unless you have a lot of experience, and poorly even then. There is a better way.
If there is a hill near where you are circling, choose any rock, bush, or landmark on the hill, that is exactly at your altitude. Every time you complete one circle, compare the angle that you see your landmark from now. If you find that you are soon looking downward at it, then you have climbed. Looking up for your landmark tells you that you are descending. In either case, immediately disregard your old landmark and choose a new one, exactly at your altitude, and begin again. This works well if there is a hill close by, whether you are thermalling or just flying around in good lift.
Now suppose that you have thermalled high above your little hill, and there are no landmarks to be found at your altitude. Here comes the secret. Picture in your mind a lever and fulcrum system, such as might be used to move rocks. In the case of thermalling, the "lever" is your line of sight, and the "fulcrum" is any hilltop or ridge-top that is visible in the middle distance, as long as some terrain is visible past that hilltop. You are not interested in the fulcrum; it is only a pivot point. You want to look at the terrain above (past) the fulcrum. This fulcrum may be a kilometer (half a mile) away, or even ten kilometers (five miles) away. On each circle you make, you are very interested in the terrain that you can see behind your high point or fulcrum. As you can see more scenery behind your fulcrum, you are climbing. As you can see less scenery behind your fulcrum, you are descending - the fulcrum is now blocking more of your view. As you get even higher, you can disregard your old fulcrum and choose another, even farther away - as long as you can see any scenery beyond it. A fulcrum with only the sky behind it would be useless for our purpose, which is to judge your increase of altitude.
The best fulcrum is always a high point, at a slightly lower altitude than you, located less than halfway between you and the farthest scenery that you can see clearly. This gives you the most noticeable change in scenery as you climb or descend. Now, all you need is a thermal.
Having said all that, a real Variometer still can teach you a lot, in a very short time. Most HG pilots will recommend getting a variometer. Any time you can borrow one (or buy one on the legendary HG pilot-to-pilot credit terms), I would still recommend that you jump on it, if that is in any way practical.
As you advance in skills, if you have an actual variometer instrument, you may become somewhat dependent on those readings, to help you find lift. You can improve your skills, and maybe your enjoyment of flight, if you sometimes silence the thing, and/or turn it away from you, so only your natural senses are used in flight. Do this at high altitudes at first, and as you "wire in" to the skills of flying without a vario, you can try it at lower altitudes. You can always turn the thing back on, if you need to, to re-gain any lost altitude. If you develop the skills to find and stay in lift, without a vario, then your flying day will not be ruined if you (one day) have a battery failure. You might even discover and enjoy the challenges of flying without a variometer.
Free Altimeter
Most people can not judge the height of a tall structure accurately, and they certainly can not judge their altitude above the Earth accurately.
It would help a lot if you could practice this skill, but to do that, you need to start from altitudes that are measured to some fair accuracy. Altimeters can lie, they have a lag time, anyway. So, let's go measure some high vantage points...:-)
Background: due to the magic of isosceles triangles with a 90 degree corner, and a trigonometry function, two sides of that 90 degree/ isosceles triangle will always have the same length.
Process: Take any piece of paper (letter-size is good) with square corners, and fold one edge to meet an adjoining edge, so that a crease forms at one corner of the page, and travels diagonally across the sheet. The crease and one edge of the paper will form a 45 degree angle, very accurately. We will use this 45 degree angle to measure the heights of bridges, lookout towers, and tall buildings (with special emphasis on the ones that can be accessed safely by ordinary people on foot).
Sight along the bottom edge of the paper, in a level line, to the bottom of any tall building. Sight along the 45-degree edge of the paper, to the top platform or window of that building. Move away from the building, until the "level" sight line is at the bottom of the structure, and the "45 degree inclined" sight line points at the high place, where you can stand. When both sight lines are correct, measure the distance from your position on the ground, to the base of the structure. If you know the length of your paces, you can simply "pace off" this measurement. (One pace is the length of a stride, from the place where the right foot touches, to the place where the right foot touches again, when walking normally.)
If you pace 100 yards (meters) to the base of the structure, then the structure is 100 yards (meters) tall. Do not be surprised if your present estimates of structures' heights are not very accurate, now. This process is intended to teach the ability to become more accurate in these estimates.
What Is Important: now you know (with fair accuracy) the heights of local buildings, bridges, et c. Okay then, go (in person) to these high places, and look, really LOOK, down at the world below you. Learn the appearances of people, vegetation, cars, small structures, and the landscape below, from these exact altitudes. It is important in your flying to be able to judge these altitudes fairly accurately BY EXPERIENCE, not by guesswork, so that you can make better decisions, when coming down to land. It will be some time (as measured by logbook time only) before you are quite confident in your instant estimates, as you make them in flight; do NOT be concerned about minor errors. Your estimates of altitude will improve with each exercise you perform (as described above).
When you have "educated" your perceptions of the world to some degree, then you can have a bit of fun with it, by reversing the process as a check of your ability. Go to a high place (such as an unmeasured bridge or building) and write down the altitude as you perceive it from there. Then make the usual correct measurement from the ground level, and compare the results. At first, errors of a dozen yards (meters) may happen; with some serious practice, you will be able to state an altitude with just one look down, within a few yards (meters) of the correct altitude. In flight, you will use this new ability as naturally and easily as you now read the newspapers.
In other words, you would not see the number of letters in the words as you read, but you would make instant sense of the meaning of the writer. In flight, then, you could "see" the number of yards (meters) of altitude that you have, at any certain time, and you would know that you are THIS high above ground, and the landing field is THAT far away, as instant (and accurate) estimates. You will know if/when you will need to fly straight and smoothly, to arrive at the landing field's downwind fence, with at least 100 yards (meters) of altitude to spare. You should always choose to arrive above the landing field with plenty of altitude. Once you are above the landing field, you can "lark around" as much as needed, to use the surplus altitude (and to have some fun), always keeping one eye on the target spot.