Despite Lilienthal's fate, the brothers favored his strategy: to practice gliding in order to master the art of control before attempting motor-driven flight. The death of British aeronaut Percy Pilcher in another hang gliding crash in October 1899 only reinforced their opinion that a reliable method of pilot control was the key to successful—and safe—flight. At the outset of their experiments they regarded control as the unsolved third part of "the flying problem". They believed sufficiently promising knowledge of the other two issues—wings and engines—already existed. The Wright brothers thus differed sharply from more experienced practitioners of the day, notably Clément Ader, Maxim and Langley who built powerful engines, attached them to airframes equipped with unproven control devices, and expected to take to the air with no previous flying experience. Although agreeing with Lilienthal's idea of practice, the Wrights saw that his method of balance and control by shifting his body weight was inadequate. They were determined to find something better.