The two-seat Model 47B was the first commercial evolution of Bell's pioneering Model 30 and this example, the 36th built, is on display at the NASM Udvar-Hazy Center. This rather unassuming helicopter has actually a rather impressive pedigree: it set the World's hovering record of fifty hours, fifty seconds and its last flight occurred in Dec. 2004, more than 57 years after its first flight to make it the longest-flying helicopter in history.