Glider flying tips

by goeland86 | April 3, 2015 | (5) Posted in Tips

Ok, so, I just finished watching the HoTT Fan episode.

Josh keeps saying he's bad a flying gliders. I've started with gliders, and I'm competing with hand launch gliders, and I love teaching others how to fly a glider. Here's my tips for gliding.

  1. KEEP THE NOSE BELOW HORIZONTAL! A glider flies better with more speed than just barely above stalling speed. There's thousands of people who can explain the equations of why that's true. The simple way to understand this is: airfoils generate more lift with more air speed. With a glider you need to balance this nose-down attitude to keep speed with how much altitude you're losing. Ideally you find a thermal which keeps your altitude steady or climbing, but where the nose of the glider stays pointed downwards. That way when you're in a mass of climbing air, you can minimize your descent to be equal or less than the ascent of the air. Here's an image explaining how this works. Gravity (weight) in red. Wing lift in green. Ascending air speed in blue. Notice the lift is tilted, because you're moving forward. The green arrow doesn't counteract all of the vertical forces of the red - but added to the blue, the difference is 0 or positive. (Blue + Green - Red).



  2. When turning, let the glider bank into the turn! Banking will let your glider generate less drag - the tails will have to move less overall, because you'll need less input on the rudder, and less input to counteract the banking on the ailerons. The tails' drag is usually not noticeable until you get to a certain skill level. But the aileron drag you should be able to notice very quickly how you're slowing down. When I'm circling a thermal - I almost only ever use rudder and elevator, and leave the ailerons alone! This is even more true when your plane has dihedral, and almost all gliders have a few degrees built in. Check out a hand-launch glider circling in this video: (DLGs fly lower and are easier to see, but bigger gliders should do the same!)


    (full video credits to the youtuber, this is not my video!)

  3. Don't move the sticks unless you have to. The way to find a thermal is by finding a gentle line and let the plane follow it - when you see the plane getting bumped around (banking a wing, plane nosing down and accelerating, or simply climbing without nosing up), you're finding air currents. You need to read those. You can't read the air if you're the one bouncing the plane around - let the glider speak to you. It's like trying to hear a cat walking while talking - it won't work, unless the cat is walking on your piano. I'm not saying there aren't piano-like thermals, but they're very rare.

  4. Trim the plane when the air is dead calm. You want the default trim on your glider to be completely neutral when just slightly nose down. It needs just enough nose down to maintain speed. The ideal nose-down is beyond the stalling angle. When you're trimming, find out the trim click when you're on the edge of stalling, and give it a couple or three clicks more. This strongly depends on the plane, but this really helps you. Gliders are pretty good about maintaining energy in flight, that means they don't normally slow down in turns, unless you're being very aggressive on the sticks. Be gentle, think of flying a glider as petting a kitten or puppy!

  5. Keep the wing tips light. The lighter your wingtips, the easier it'll be for your glider to oscillate with turbulence because the tips will have very little momentum fighting against it. This will help you read the air currents. And keeping the glider tips and tail light means you lower the overall weight of the craft, because you'll need less weight in the shorter end of the momentum to balance it out. Josh Bixler explains this pretty well in one of the build videos (I think the FT Spitfire video, but probably in others, too). It's even more true for gliders, where having a lighter plane means you have a longer flight for a given height. Less weight means you can fly slower, which means you don't nose down as steep.

 

So these are just the first 5 tips to keep in mind when heading to the field with a glider. I'll post another article about reading the air to help you find and center the flight path in the thermal - it's a much longer explanation. These are just quick tips. Good thermal hunting, Josh!

COMMENTS

1959cutter on April 4, 2015
in 1970,
my dad was taking glider lessons in the desert in arizona,the instructor said flying a glider in lift , is like dropping a feather in an elevator that is going up.
gravity pulls the feather down as the evevator has passed two floors faster going up.
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goeland86 on April 5, 2015
That's a good analogy. Except you want to mention that in this case, the elevator is for purposes of explanation, infinitely tall. There's no elevator floor you can hit. Now outside the elevator, that's a different story of course ;)
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kwak on April 5, 2015
(from more than 30 years of flying R/C sailplanes...)

Keeping the nose down -- there is a lack of understanding in this paragraph of how a sailplane flies. Sailplanes are never simply flown at one airspeed -- nose down. A slower airspeed gives the minimum sink rate. A higher airspeed gives the maximum distance covered (best glide ratio). When you are in lift slow down to take advantage of the minimum sink rate and spend more time in the rising air. When you are in sink lower the nose to pick up speed to cover more ground and get away from the sink faster.

Visual indicators -- the fuselage (nose to tail) is often kept level. In lift the tail rises above the nose. In really good lift you can even lift the nose above the tail without stalling. Weird, huh! In sink the tail is pushed below the nose.

CG -- something from the Hott Fan video about Josh moving the CG forward. With the CG too far back the sailplane gets squirrely and is difficult to fly. With the CG ahead of that the sailplane will be able to turn tightly in light lift, but to cover a lot of ground you need a click or two of down trim. With the CG forward the sailplane is in nose down mode and wants to cover a lot of ground. This is good in windy conditions. But it does not help if you want to turn tightly in light lift. But it is good if you are trying to fly the sailplane like an airplane.
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goeland86 on April 6, 2015
kwak, of course. The main point is that when I see beginners learning, they try to fly with the attitude flat and slow it down to a stall when trying to cover ground. What I've found is that the first thing to do is to get new pilots to understand that stalling the plane is worse than losing a little bit of altitude. From a DLG background, you see things a lot better when you fly closer to you.

I've already written a follow-up with a few tips about beginning to read the air for thermals, it's just waiting for publication at the moment. I'll link it from this article when it's up.

The main reason I wrote these few tips was as a general pointer for people coming from the powered background wanting to learn soaring - I thought these were the most essential criteria to remember, and of course there's a lot more to it than just these few. I'd be honored if you would write a "advanced glider tips" since you probably know a lot more than I do about flying in lift and so on. I searched and noticed almost nothing on flitetest about how to fly gliders. There are a lot of tips for flying powered planes though, and I wanted to fill in that void, since it sounds like they're going to be reviewing more gliders.
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Njfoam on April 11, 2015
Captain sully landed in the Hudson ! But indeed made a very nice landing... Great tips , can't wait to get my gliders out!
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1959cutter on April 6, 2015
in the aviation industry,hours on a glider count toward your power pilot license,but power time counts "0" toward a glider solo/license.
It's the reason Captain Sully Sullenberg made a picture perfect landing in the patomic,as he is a glider geek!
i land all my planes deadstick,and i used to pee off my flight instructors as i would land the aircraft the same way flying full scale(ultralight).
if it wont glide,it wont fly well
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1959cutter on April 6, 2015
i forgot to mention that flying gliders is way cheaper than power,so all you kids that want to be a full scale pilot,take soaring lessons to get started.
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Glider flying tips