The M-497 (nicknamed Black Beetle by the press) was an experimental jet-powered railcar test bed of the New York Central Railroad, developed and tested in 1966 in the United States. Two second-hand General Electric J47-19 jet engines, originally used as boosters for the Convair B-36 Peacemaker intercontinental bomber, were mounted atop an existing Budd Rail Diesel Car, an RDC-3 of coach and baggage-mail configuration which had received a streamlined front cowling. The construct was then successfully sent on test runs over the existing tracks between Butler, Indiana, and Stryker, Ohio. The line had been chosen for its arrow-straight layout and good condition, but otherwise unmodified track. On July 23, 1966, the car reached a speed of 183.68 mph (295.6 km/h), an American rail speed record that still stands today.