It turns out that in April 2019, in addition to the explosion during ground testing of the Crew Dragon emergency rescue system, there was at least one other emergency situation that occurred during testing of landing parachutes.
Head of NASA's manned programs, Bill Gerstenmeyer, declared that
The April tests of the Crew Dragon manned parachute system were not completely correct.
In normal mode, the Crew Dragon ship must land on the water surface using four parachutes.
The first launch of Crew Dragon into space took place on March 2, 2019, as part of the DM-1 mission, he successfully completed his flight to the ISS without a crew, made docking in a fully automatic mode, and returned to Earth.
However, on April 20, the same capsule exploded during fire tests of engines of the emergency rescue system. The causes of the accident have not yet been named, nothing is known about how this will affect the timing of the first manned flight, which was previously planned for the period after July 25, 2019.
Publication about an explosion during a ground test of the Crew Dragon ship rescue system
Now it became known about another accident when testing the Crew Dragon spacecraft systems.
The head of NASA's manned programs, Bill Gerstenmayer, said that the parachute system failed to test, speaking at the hearings of the US parliamentary space subcommittee
Witness: Mr. William H. Gerstenmaier, Associate Administrator, National Aeronautics and Space Administration.
1:34:00 is the time when there was a story about testing and rejection:
According to Gerstemeyer, tests of the Crew Dragon parachute system were carried out on the dry Delamar Lake in Nevada.
The capsule was dropped from a great height, after which the landing parachute system was activated.
Previously, several dozen tests of this system were performed, all of them, basically, ended normally.
In the course of one of the tests, the ability of the Crew Dragon parachute system to ensure a safe landing in the event of one of the four parachutes failure was tested.
Checked the performance of the landing system in an emergency situation on board.
One of the four parachutes of the Crew Dragon landing system was deliberately incapacitated before the test, the other three were to ensure a safe landing, and the test capsule should not have been damaged.
Unfortunately, an accident occurred while performing this test, the three remaining parachutes did not work as they should, and the test capsule was damaged when it hit the ground.
According to Gerstenmayer, it is not yet clear why this accident occurred, whether there was a violation of the capsule separation procedure itself when dropping from a height, problems with the construction of parachutes, or if the system failed abnormally for other reasons.
Now NASA and SpaceX experts are investigating the causes of this accident.
How the Crew Dragon parachute system works is shown below in the photo and video:
Video test of the parachute system of the manned spacecraft Crew Dragon in 2018: