The concept of a supersonic civil airliner became very popular in the 1960s, giving birth to the Concorde supersonic airliner jointly developed by Britain and France in small batch production and commercial operation for many years, as well as the Soviet TU-144 passenger aircraft with less production. Even Boeing's 2707 plan fell short, reaching the full-scale model stage.
However, neither concorde nor the TU-144 was the first civil airliner to perform supersonic flights. Concorde broke through the sound barrier in October 1969, and the TU-144 in June 1969. The first time a mass-produced civil airliner broke through the sound barrier was an inconspicuous model that was completed on August 21, 1961.
The Douglas DC-8 is a model that Chinese aviation fans are not familiar with, but in fact, its appearance is basically the same as that of competitors and the well-known Boeing 707. Wing suspension type 4 rounds, lower single wing layout, the fuselage is slender, the appearance appears more slender than the Boeing 707, the nose protrudes more. The DC-8 first flew in 1958, after the Boeing 707 in 1954. The overall performance of the two is comparable, and the passenger capacity DC-8 is slightly larger.
DC-8 in the Chinese Aviation Museum
Because the Boeing 707 was introduced to China, and its military version of the KC-135 series is still in service with the U.S. Air Force, the DC-8 is far less well-known in China than the Boeing 707. The fate of Douglas was also quite bumpy, due to operational problems, in 1969 and Macdonald merged to form Macdonald. Douglas Corporation, eventually annexed by Boeing in 1997.
But the first supersonic flight of a civil airliner was completed by the DC-8.
DC-8 number N9604Z, picture from extranet
For performance demonstration, douglas planned the supersonic flight just 3 years after entering the commercial flight. This is not to prove that the DC-8 has supersonic cruise capability, but only to "be the first", with the intention of confirming whether the aircraft can "achieve this performance and will not fall apart", thus surpassing its competitor Boeing 707.
On August 21, 1961, the DC-8, numbered N9604Z, was replaced by test pilot William H. Thompson. Maglud took off from Edwards Air Force Base under his pilot, putting the pusher into a half-G dive after reaching an altitude of 52,000 feet. The DC-8 is designed to fly without supersonic speed, so it can only break through the sound barrier in dive. Not long after at an altitude of 45,000 feet, mach 1.01 was reached, or 1.01 times the speed of sound, and lasted for 16 seconds.
At this point, the DC-8 also set a record for the flight altitude of a commercial civil airliner of this class at that time, and a record flight speed of Mach 1.01.
The test pilot did not adjust the trim to put the plane into dive, which allowed the plane to pull up autonomously. However, in the process of completing the supersonic flight pull-up, the test pilots found that the stabilizer (which can be understood as the elevator of the horizontal tail) was overloaded with action motors, and the aircraft entered a stall state. To know that such a large aircraft stall is very dangerous, if you enter the spiral can be said to be nine dead for a lifetime. But the test pilot handled it very accurately, and he continued to push the rod, reducing the load on the stabilizer motor, and gradually changed out of the stall, eventually resuming operation at 35,000 feet. Thus safely completing this play (zuo) life (si) test.
The DC-8 was later delivered to Canadian Pacific Airways for commercial operation, and 20 years later the aircraft was decommissioned and scrapped.
The DC-8 and the accompanying F-104 were tested in supersonic flight this time, and the picture is from the extranet
It is worth mentioning that in 1947 Chuck, who carried out the world's first supersonic flight. Jaeger flew another F-104 to accompany the DC-8's supersonic test flight.