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
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
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
Make it roughly this shape,
It measures about 7" across and 2" high.
Once again, use your head.
Step 4: Weights
They should be 1 1/2" wide and the height may vary according to your plane's nose.
Step 5: Slitting
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
If you need to use tape to make them stay in thats what it's for.
Step 7: Nose weight
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!
try pushing the wings up so the don't sag,
or cut a slit right above the big wings as shown.