https://spacenews.com/engine-shutdow...oster-landing/
Engine shutdown led to failed Falcon 9 booster landing
WASHINGTON — A Falcon 9 first stage failed to land after a launch last month because one of its engines shut down during flight after hot gas breached a worn-out cover.
During a NASA press conference March 1 about the upcoming Crew-2 commercial crew flight, Benji Reed, senior director for human spaceflight programs at SpaceX, said that while the booster used on that Feb. 15 launch was making its sixth flight, some components on it were “life leaders” that had flown more often than any other in the Falcon 9 fleet.
That included “boots,” or covers around parts of the Merlin engines in the first stage. “This was the highest count number of flights that this particular boot design had seen,” he said.
However, one of those boots had a “little bit of a hole” that allowed hot gas to get into parts of the engine during flight, he said. “A little bit of hot gas got to where it’s not supposed to be, and it caused that engine to shut down,” he said.
Reed didn’t mention at what point in the launch the engine shut down, but he suggested it took place during ascent. “A great thing about Falcon 9 is that we have engine-out capability,” he said, meaning that one of the first stage’s nine engines can shut down without jeopardizing the mission. “The vehicle got to orbit and put the satellites exactly where they want to be. The primary mission was accomplished.”
The shutdown of the engine, though, kept the first stage from landing. “When that booster came to return home, because of the problem with that particular engine, we didn’t have enough thrust to get back to where we needed to be, and didn’t land where we wanted to be,” he said......