Bach suffered a head injury and broken shoulder after his single-engine amphibian aircraft clipped power lines Friday afternoon about three miles west of Friday Harbor Airport in Washington state.
He was taken to Harborview Medical Center in Seattle, where a nursing supervisor on Sunday said Bach remained in serious condition.
Bach's son, James Bach, said Sunday morning that his 76-year-old father hasn't been able to say anything because he has a tube down his throat, but he is responding to doctors and people around him, and he has good cognitive function.
"He clearly is lucid and that's the most important thing with the head injury, that he's got his mind," James Bach told The Associated Press. "We think it's a big improvement from yesterday and we're hoping that this recovery will continue to be swift. We're happy there are no complications."
He said he didn't know how long his father would remain in the hospital.
The elder Bach, an avid pilot, was flying alone on his way to visit a friend on San Juan Island when the plane went down Friday.
Richard Bach's best known work is "Jonathan Livingston Seagull," a short fable published in 1970 about seagull seeking to rise above the dreariness of his flock. The simply crafted book rose to No. 1 for several weeks on the New York Times bestseller list.
Bach, who has flown airplanes his entire adult life, often touched on his experience in the cockpit of his beloved plane in his writings, many of which are inspirational in nature and delve into themes of self-discovery and creativity. Besides "Seagull," his other popular works include "Illusions: The Adventures of a Reluctant Messiah," a mystical story of a Midwestern barnstorming pilot's quest for self-discovery.
He moved to Washington state's remote San Juan Islands more than 20 years ago, living on Orcas Island.
(Copyright 2012 by The Associated Press. All Rights Reserved.)