the wet ground in the pioneering days of Aviation refer to dirt or grass covered runways. Are you reading about Lindburgh's flight?

Soft spots here are referring to literal places on the ground that are not hard because they are wet. I'm assuming the runway must not have been made of concrete or asphalt because otherwise it wouldn't become soft when wet. Soft spot has another figurative meaning as well: something or someone that a person is sensitive toward or doesn't like to reject. For example, "I have a soft spot for dogs, so I adopt every stray puppy I find."

"he entered the cockpit. At 7:52 a.m. he was roaring down the runway, his plane lurching on the soft spots of of the wet land" this passage talks about the pioneering transatlantic flight. <3

"he entered the cockpit. At 7:52 a.m. he was roaring down the runway, his plane lurching on the soft spots of of the wet land" this passage talks about the pioneering transatlantic flight~

Is it "lurching ON"? If not, could you give more context?