What was the first supersonic airliner?
The McDonald Douglass DC-8
Here is an amazing video of how the DC-8 went faster than the speed of sound. This was eight years before The Russian TU-144 and The Concorde
See how the battle between the Comet, Boeing, and Douglas Airlines led to the world record flight that even most aviators have never heard of before.
In August 21, 1961, test pilot captain William Magruder, copilot Paul Patten, flight engineer Joseph Tomich, and flight test engineer Richard H. Edwards flew Douglas DC-8-43 no. With the registration N9604Z took off for a test flight at Edwards Air Force Base in California. The airliner type aircraft exceeded Mach 1—the only intentional supersonic flight by an airliner other than the Concorde and the Tu-144. Bill Wasserzieher interviewed Richard Edwards in May 2007.
In order to reach the speed of sound the pilots put the large airliner into a steep dive. After reaching the sound barrier the pilots were not able to pull the aircraft out of the dive due to shock wave passing over the elevators of the aircraft. After failing to pull up the pilots decided to use the aircraft’s stabilizer manually to pull out of the dive however, that did not work either. After passing through 35,000 feet the only option was to further steepen the dive in order to take the aerodynamic load of control surfaces which ultimately worked and they were able to level off the aircraft.
Check out this amazing video.