Maintaining tension in the hourglass.

When you turn the first corner to go up, follow it up with your hand and fly it over your right shoulder. Make a sharp turn (this one isn't too hard) and follow it to your left shoulder which is where you need to make your next turn. (Got that? First turn over your right shoulder, second turn over your left shoulder.)

Now is where, if you are going to lose tension, this is where it is going to happen. What do you do when you lose tension when flying level? You back up, right. Do the same thing here. Just remember, "backing up" while overhead means moving down. Now the flyer doesn't have to move down, just the hand.

Always follow the airplane with your hand no matter what maneuver you are flying. So, with the hourglass, we follow the plane up over our right shoulder, turn the corner and follow it to the left shoulder, and here is where we deviate. If you have tension problems--or "just to be sure", you can bring your hand down with a smooth but quick motion in the direction that you are planning to turn just as you apply that input to the plane while on top.

If done at the proper time and *Smoothly*, you will be adding tension just when you need it, at that upper left corner.

Now, one more thing. You know how we can "whip" a plane simply by backing up after the engine quits? Just back up while it is gliding and you can add enough speed to keep it in the air forever (or until you get tired or stumble over your feet or hit a tree or...) In the opposite fashion, if you move forward during the glide, the plane will settle rapidly. A "little" of this can help in the landing to get the plane to the spot you want it in windy conditions. But the same thing applies to the hourglass.

When you bring your hand down, you are not only adding tension, you are "whipping" the plane through that top corner. But now, on the way down, if you "let out", move your hand forward just a little as your reach the bottom (I know, we don't feel like we want to do that since we are trying to turn that next corner) the plane will slow down as it is heading down hill and make that bottom corner much easier to turn.

OK, so now I have told you "all there is to know about the hourglass" (the line forms below for additional comments.) And, no, we didn't "invent" any of these techniques. They were all "stolen" from someone else. You learn a lot by watching other flyers. See what they do, and then ask why they do it. Just be careful. Sometimes we do things that we shouldn't be doing. Copy it only if you are having a problem in that area and if they have a reason why they are doing it.

Matt had a problem with the overhead eight that was solved by...but we will save that for another thread.

Maybe I can include it more often after I see what a soft, soft, hard, soft quartet of "120 degree" corners produces! (And, yes, the triangles are another maneuver of mine that always looked bad to me!)

Thanks, Leonard! (Professor of Stunt? What's next on the lecture schedule?)

Kiwi

>>is a horse power stunt and if you lack power you'll need to set up by wipping, flying out and make it bigger.<<

Well, it is a horsepower manouver in a sense. Depends on the power to weight. This is a manouver that will tell you if your plane is overweight. Easiest, I think is just to stand it up. A common mistake is to make it too wide. The wider it is, the sharper the corners and the more impossible is becomes.

Excellent disection of flying the hourglass - it's exactly how I do the hourglass myself. Incredible maneuver when it all comes together right! Now on to the overheads!

Interesting stuff in this thread. One comment in exception to Scott's latest, however.

When he says "bend you back" I think he is making a mistake. One of the commonest errors in the hourglass is making it oversize, both too wide and usually too tall, thus making it go past vertical and behind the pilot's head.

I would make the following suggestions instead:

To make the height correct tilt only your head backward and keep the ship in sight throughout. If you've got to bend you back signicantly it'll almost certainly result in a too tall manevuer.

Too control the tendency to fly it too wide do the maneuver directly in front of you and purposely place the corners so that the first is over your left foot, the second over your right shoulder, the third your left shoulder and the last over your right foot. AVOID TURNING YOU BODY TO PREVENT SPREADING THE MANEUVER OUT.

The vast majority of over wide hourglasses are the direct result of flying the TRIANGLES incorrectly and then translating those error, to the hourglass. All corners of both maneuvers should be equilateral...equal...and, thus 120 degree changes of direction. The vast majority of flyers overturn the first corner of the triangles and underturn the top corner. This results in a manevuer which is too wide and has more acute included angles at the left and right than at the top.

The natural inclination (correct, but only if one flies the triangles properly) is to enter the hourglass exactly as one does the triangles. If, however, you're guilty of overturning the triangle entry, duplicating that entry in the hourglass will unfailingly result in a maneuver which is much too wide. Almost all the strange looking hourglasses you see in which the airplane goes inverted for a goodly amount of time to try and achieve an intersection are the result of such entry errors.

I like to use (and think) the phrase..."stand it up"...when training hourglasses. If the pilot thinks in terms of going "just past vertical" in the entry he will be amazed at how much easier the maneuver becomes and how much more like the picture in the rulebook it looks!

I am presently flying two stunters, a modern and a classic (Fox 35, 38 oz). The modern has to be flown exactly as Scott says, otherwise it will surely slack off. The classic model accelerates during climb and seems to be at MAX speed when I hit the second corner (can be hit very hard although this is not necessary), then it slows down slightly but never loses tension. After the third corner the engine goes back to 4-stroke and the model comes down slowly, so the fourth corner is a real delight, easier than the last corner of the square loop or the reverse wing-over. It seems that there are differences on the flying techniques regarding these two very different engine/planes.

jmh