Don't throw away pizza boxes, make them into airplanes.

What you need:

1+ pizza box/boxes (with as few grease stains as possible)

1 keychain ring (circuler metal thingy)

Scissors (preferably sharp and big)

Tape (duct, scotch, blue, anything)

Ruler (trust me you'll need one)

String (sorry it wasn't here before)

(I beg you to look at the comments)

Step 1: Body

Cut out a piece of cardboard roughly this shape.

From one side to the other it measures about 14"

This is your body,

next is the wings

(don't pay attention to the slits :] )

Step 2: Wings

Cut out a piece of cardboard that is roughly shaped like this,

it is about 15" side to side and 3" wide,

if your confused with measurments use your head and look at the picture.

Step 3: Back Tail

It's like the wings but smaller.

Make it roughly this shape,

It measures about 7" across and 2" high.

Once again, use your head.

Step 4: Weights

Cut out shapes that look like this or the shape of the nose.

They should be 1 1/2" wide and the height may vary according to your plane's nose.

Step 5: Slitting

Make slits in your plane as wide as your plane wings.

Look at the picture to see the spacing.

For the slits, you can try altering the angle of them, for more lift, which should in theory keep it up longer.
- Credit goes to 11.3 (it's his username) for this tip

Step 6: Shoving In

Shove the wings in.

If you need to use tape to make them stay in thats what it's for.

Step 7: Nose Weight

The weights go on each side of the plane nose.

Attach them by the key chain.

(Sorry it's so blurry look at the intro picture to see it clearer)

Step 8: GETTING IT TO FLY!

It should be ready for flight but if it dosen't work,

try pushing the wings up so the don't sag,

or cut a slit right above the big wings as shown.

Step 9: Step 8 Continued

Now string the thread through the slit and tape the 2 sides of the string to each side of the plane.

Keep experimenting with the angles of the wings until it flies.

If it doesn't work read a book on aerodynamics.

Step 10: How To

Throw them inside or outside on a not so windy day,

Make sure you rate it unless you want to rate it badly in which case don't rate it.

(First Instructable so CONSTRUCTIVE criticism.)

(I ran out of pictures so I put this seal!)

"I think the string must be UNDER the wings, because the wings tends to lift.

Besides, the balance of the frontal counterweight is very simple to achieve: put a finger under the average line of each wing, and the fuselage (aircraft body) should remain horizontal."

-rimar2000 told me this if your not satisfied with your plane try doing it.