On Monday, June 8, 2020 at 12:49:00 PM UTC-7, wrote:
William C Holbrook passed away peacefully last night at the age of 98. He was a long time family friend, professional pilot and holder of many soaring records. Also a member of the SSA hall of fame.
He and my father, Ed Byars, had a long friendship and contributed much to the art of soaring with their Soaring Symposiums.

Condolences to the entire Holbrook family - He did a lot to advance the sport of soaring