 While powered microlights (ultralights) developed from hang gliding in the late 1970s, they were also a return to the type of low-speed aircraft that were common in the earlier years of aviation, but which were superseded as both civil and military aircraft pursued more speed.For a second time in aviation history, during the 1970s, motorization of simple gliders, especially those portable and foot-launched, became the goal of many inventors and gradually, small wing-mounted power packs were adapted.These early experiments went largely unrecorded, even in log books, let alone the press, because the pioneers were uncomfortably aware that the addition of an engine made the craft liable to registration, airworthiness legislation, and the pilot liable to expensive licensing and probably, insurance.