Ducted fans can be used to provide either lift or thrust. The answer is 'fans'. Fans are a very important part of a hovercraft whose primary purpose is to inflate the cushion contained within the skirt beneath the craft as well as to provide thrust with which to propel the craft forward. 6.5 Propellers Propellers typically utilise between 2 and 5 blades that are quite a bit longer than those used on ducted fans. Propellers must be replaced if damaged by debris whereas a blade is replaceable ducted fan.
Propellers are generally noisier than ducted fans.
Propellers can be used to provide either lift or thrust. 6.6 Propellers vs. Fans. Less Blade Erosion Large Diameter Small Diameter Must Have Guard Duct is also Guard Replace Whole Prop Replace indiv. Puff ports are apertures through which air is redirected from the lift or thrust system to the front or sides of a hovercraft. When a puff port is opened, the air is allowed to flow out of the craft in whatever direction the operator desires.