High Quality Content by WIKIPEDIA articles! On April 4, 1955, a United Airlines Douglas DC-6 named Mainliner Idaho crashed shortly after taking off from Long Island MacArthur Airport, in Ronkonkoma, Islip, New York, United States. The aircraft, registration number N37512, was performing an instrument rating check flight, when, shortly after taking off, it began banking to the right. Seconds after climbing through 150 feet (46 m), the aircraft turned through 90 degrees, causing the nose to drop suddenly, before it impacted with the ground.