Harrier Jump Jet II Plus configuration) was delivered in December 2003, ending the Harrier production line. The Harrier Jump Jet, capable of taking off vertically, can only do so at less than its maximum loaded weight. In most cases, a short take off is performed, using forward speed to achieve aerodynamic lift, which uses fuel more economically than a vertical take off. On aircraft carriers, a ski-jump ramp is employed at the bow of the carrier to assist the aircraft in becoming airborne. Landings are typically performed very differently. Although a conventional landing is possible, the range of speeds at which this can
Claims to the first powered flight that have received significant attention include: In judging these claims, the generally accepted requirements are for sustained powered and controlled flight. In 1890 Ader had made a brief uncontrolled and unsustained "hop" in his Éole, but such a hop is not regarded as true flight. The ability to take off unaided is also sometimes regarded as necessary. The air historian Charles Gibbs-Smith has said that, "The criteria of powered flight must remain to some extent a matter of opinion." Some notable powered hops were made before the problem of powered flight was finally solved. In 1874 Félix du Temple built