A wingpack consists of a backpack with one or two pairs of wings on either side of it. These wings are flapped by a mechanism housed inside the backpack itself. The wingpack is controlled by various devices worn on other parts of the body; the wingpack itself senses changes in the position of these devices, and uses this information to adjust the attitude of its wings. This allows the wearer to control the pack using their legs or with other posture changes, thus leaving the hands free to wield weapons.
Wingpacks are powered by force crystals. This is because no other power source can provide both the power density and energy density needed to propel an aerial vehicle powerful enough to lift a human yet light enough to be worn on that human's back. Unfortunately, force crystals are also expensive to produce and can only be used once. As a result, wingpacks are not an economical form of transportation.
In addition to flapping wings, a wingpack also contains absolute levitation devices. These support most of the wearer's weight, and are essential during takeoff as they allow the wingpack to hover when it does not yet have sufficient speed to generate lift through its wings. Since the levitation devices on a wingpack are alone sufficient to achieve flight, the main purpose of the wings is not for lift but for thrust. The fact that the wings have considerable surface area is still essential because it allows the wingpack to make tighter turns than would be possible using only levitation devices and a propeller. Also, having wings allows the levitation devices to be temporarily disengaged. The resulting powerdive is a quick way to pick up speed, and plays an important role in wingknight tactics.
Wingpacks also contain bubble field generators in order to reduce drag. Since normal humans are not very streamlined, the speed of a wingpack would otherwise be limited by drag. This drag reduction is thus essential to allow wingpacks to outrun fast hoverships such as windchariots.
Wingpacks are designed to carry a single person because any extra weight would require additional lift and thrust, which are expensive to provide with a device powered by force crystals. However, a vehicle large enough to carry an alternative form of motor renders this restriction unnecessary. Thus, large airships can be built and are generally much more economical to operate than wingpacks. However, wingpacks retain an important tactical niche because they are vastly more maneuverable than airships; often, the best defense against an airship is to send wingknights to storm it.