ultralight aircraft defined in Federal Aviation Regulations. Aircraft falling within the US ultralight specifications are extremely lightweight (less than 254 pounds if powered, or 155 pounds if unpowered), are intended for operation by a single occupant, have a fuel capacity of five US gallons (about 19 litres) or less, a maximum calibrated airspeed of not more than , and a maximum stall speed of not more than . Ultralight aircraft in the US do not require pilot licensing, medical certification, or aircraft registration. Aircraft certified as light-sport aircraft exceed the limitations defined for ultralight aircraft and require that the pilot possess, at a minimum, a sport pilot certificate. Among these aircraft were found those that were specifically designed to meet the LSA requirements, as well as overweight ultralights (commonly known as "fat ultralights") that previously were operated in technical violation of 14 CFR 103. In addition to aircraft specifically designed to meet the LSA requirements, certain certificated aircraft, such as the original Piper Cub, happen to fall within the definition of a light-sport aircraft and can be operated by individuals holding FAA sport pilot certificates. The aircraft can not be re-certificated as LSA, however: although sport pilots may operate conventionally certificated aircraft that fall within the definition of an LSA, the aircraft themselves continue to be certificated in their original categories. Several designers and manufacturers of experimental aircraft kits have developed models that are compliant with the light-sport aircraft rules. In June 2012 the FAA indicated that they would re-visit the LSA program after their own studies indicated that "the majority" of LSA manufacturers they had inspected failed to show that they were in compliance with the standards. The FAA announcement said that as a result the "original policy of reliance on manufacturers' Statements of Compliance" ... "should be reconsidered." AOPA points out that this is a normal development of a maturing standard and does not expect any significant changes in the rules, only more scrutiny by FAA to assure compliance. FAA certified models Aircraft that met light-sport requirements when the rules were announced appear in FAA's list Some additional models of S-LSA, E-LSA and E-AB aircraft that meet light-sport requirements are listed here. Europe In June 2011, the European Aviation Safety Agency published CS-LSA "Certification Specifications for Light Sport Aeroplanes". This introduced a new category of manufactured sport aeroplanes similar to the light-sport category found in the USA and