it never received a USAF serial. The first flight took place at Groom Lake on 1 August 1955, during what was intended to be only a high-speed taxi test. The sailplane-like wings were so efficient that the aircraft jumped into the air at , amazing LeVier who, as he later said, "had no intentions whatsoever of flying". The lake bed had no markings, making it difficult for LeVier to judge the distance to the ground, and the brakes proved too weak; he bounced the U-2 once before it stopped rolling, but the aircraft suffered only minor damage. LeVier again found landing the U-2 difficult during the first intentional test flight three days later. On his sixth try, he found that landing the aircraft by touching down on the rear wheel first was better than making the initial touchdown with the front wheel. Pilots continued to have difficulty during landing because the ground effect held the aircraft off the runway for long distances. On a test flight on 8 August, the U-2 reached , proving that Johnson had met his promised specifications and deadline. By 16 August, the prototype flew at , an altitude never before reached in sustained flight; by 8 September, it reached . By January 1956, the U-2 had so impressed the USAF that it decided to obtain its own aircraft. The USAF purchased a total of 31 U-2s through the CIA; the transaction's code name, Project DRAGON LADY, was the origin of the aircraft's nickname. Meanwhile, U-2s conducted eight overflights of the U.S. in April 1956, convincing project overseers that the aircraft was ready for deployment. As often happens with new aircraft designs, there were several operational accidents. One occurred during these test flights when a U-2 suffered a flameout over Tennessee; the pilot calculated that he could reach New Mexico. Every air base in the continental U.S. had sealed orders to carry out if a U-2 landed. The commander of Kirtland Air Force Base near Albuquerque, New Mexico, was told to open his orders, prepare for the arrival of an unusual aircraft making a deadstick landing, and get it inside a hangar as soon as possible. The U-2 successfully landed after gliding for more than , and its strange, glider-like appearance and the space-suited pilot startled the base commander and other witnesses. Not all U-2 incidents were so benign, with three fatal accidents in 1956 alone.