Flying geese are a widely used subunit in patchwork quilts. Each flying goose consists of a goose triangle (across the width of the block) and two sky triangles (at each side of the block). This instructable shows 3 methods of how to make flying goose blocks.
I don't know where the name comes from but I would think it is the way a skein of geese lines up as they fly across the sky http://www.aerospaceweb.org/question/nature/formation/snow-geese.jpg .
Step 1: Materials and tools
2 or more contrasting fabrics, quilters usually use 100% cotton
a rotary cutter and plastic ruler - or marking pen and scissors
iron & ironing board
washable or air-erasing marking pen
Step 2: 3 easy methods
1) Using a rectangle and two squares to make a single goose
2) Traditional piecing where each triangle is cut before being sewn together
3) Speed piecing where the cutting is done after the sewing
Method 1 has left over (or waste) fabric, but you can make individual flying goose units
Methods 2 & 3 leave no left over fabric, but make up to 4 flying geese
Method 2 will yield 4 flying geese where the goose fabric is the same, but you could use different sky fabric for each unit
Method 3 yields 4 identical flying goose units - good if you want to make lots the same.