Figure 1-12. Examples of LSA, from top to bottom: gyroplane,  airplane, powered parachute, and weight-shift control aircraft. Figure 1-11.  An ultralight vehicle trike: a Rogallo wing on a  modified undercarriage. by a single occupant, have a fuel capacity of fi ve gallons  or less, a maximum calibrated airspeed of not more than 55  knots, and a maximum stall speed of not more than 24 knots.  Ultralight vehicles do not require pilot licensing, medical  certification, or aircraft registration. Ultralight vehicles are  defined in more detail with their operating limitations in 14  CFR part 103.  Because training was so important for the single-place  ultralight vehicle pilots, the FAA granted an exemption that  allowed the use of two-seat ultralight vehicles for training,  and the sport of two-seat ultralight training vehicles grew.  Throughout the 1990s, worldwide sales of both single- seat and two-seat ultralight vehicles soared, but it was the  proliferation of two-seat trainers that took the industry and the  regulators by surprise. Worldwide sales of two-seat ultralight  vehicle trainers vastly outnumbered the sales of single-seat  ultralight vehicles; and it became clear that the two-seat  trainers, which were intended to be operated as trainers only,  were being used for sport and recreational purposes. This  created a demand for increased comfort and reliability, which  resulted in heavier, more sophisticated machines.  To address the evolution of the ultralight vehicle and its  community of sport users, the FAA issued new rules on  September 1, 2004. These rules created a new category of  LSA and a new classification of FAA pilot certification to fl y  LSA, called Sport Pilot. Additional guidelines established by  the FAA can be found in 14 CFR part 61.  [Figure 1-12]  This  handbook focuses on the WSC aircraft.  Aircraft certificated as LSA exceed the limitations defi ned  for ultralight vehicles and require that the pilot possess, at a  minimum, a Sport Pilot certificate. The sport pilot rule defi nes  the limitations and privileges for both the sport pilot and the   Light Sport Aircraft (LSA) 1-6