December 18, 1922,   The first helicopter actually to fly, designated the Engineering Division H-1, was designed by Dr. George de Bothezat and Mr. Ivan (Eremeeff) Jerome and built at McCook Field under their personal supervision. Construction began in July 1921 and the H-1 made its first public flight on December 18, 1922 (piloted by Major Thurman H. Bane), at which time it rose to an altitude of 6 feet and remained in the air for 1 minute 42 seconds. The H-1 was originally powered by a 170-hp Le Rhone rotary engine; a more powerful rotary, a Bentley BR-2 of 230 hp, was subsequently installed.