
Various immovable blocks (notably obsidian and tile entities such as furnaces ) provide limits and frameworks. These can simply be arranged in a line in front of the piston, but slime and honey blocks allow carrying along blocks placed to all sides of that line. Pistons are capable of pushing or (sticky pistons) pulling up to 12 blocks.
The key blocks for flying machines, more or less in order of appearance: 2.3.6 Driveable flying machine E, 4-way, compact.2.3.5 Driveable flying machine D, 4-way.2.3.4 Driveable flying machine C, 2/4-way.
2.3.3 Driveable flying machine B, 2-way.2.3.2 Driveable flying machine A, 2-way.