"He was very comfortable behind the wheel," she said. "He knew motors, engines, air and oil."
She was "extremely comfortable" flying with him, she added.
Tesla Motors of Palo Alto confirmed Wednesday that three of its employees were killed in a small-plane crash in East Palo Alto.
"Tesla is a small, tightly knit company, and this is a tragic day for us," said Elon Musk, CEO of the electric-vehicle manufacturer.
He declined to name the employees, saying that the company was working with authorities to notify the families.
"Our thoughts and prayers are with them," Musk said.
Sources close to the company identified the three men as Bourn, a senior electrical engineer and Santa Clara resident; Andrew Ingram of Palo Alto, an engineer; and Brian Finn of East Palo Alto, a senior manager.
Houck considered Bourn a good friend, calling him "an outdoor adventureman with a zest for life. ... He was a real life enthusiast."
Bourn also was beloved by members of the robotics team at Castilleja School, where he had volunteered as a mentor for the past six years.
"My daughter is studying what she's studying in college because of the commitment of people like Doug," Castilleja parent Beth O'Malley said Thursday.
O'Malley said Bourn had offered to take her and her husband flying several times, although they never went.
"I always felt like if there was anybody I would trust (flying) it would be Doug," she said.
Bourn even traveled with the Castilleja team to robotics competitions.
"He really forced the girls to take the time to understand the physics of the problem, and he gave the girls a lot of room to fail — to learn and to fail," O'Malley said.
"He didn't stand there and tell them how to do it. He'd make suggestions, but ultimately it was their decision how to build the robot and how they would enter the competition."
Bourn enjoyed motorcycles and was a member of a beer club. He would often go to Devil's Canyon Brewery in Belmont on the last Friday of each month with co-workers, Houck said.
"It's really sad for Tesla. He was instrumental in getting the Roadster out the door" and was developing the Model S, she said.
A highly detail-oriented engineer, he worked on batteries and electrical systems for the company.
Vicky Tuite, a friend and former colleague at Tesla, said Bourn had come to her birthday party last month.
"He was a great guy," Tuite said, adding that he worked on the first powertrain for the Tesla Roadster.
"He was one of the original handful of people to work for Tesla," she said.
Tuite, whose husband is an amateur pilot, said she would not have hesitated to fly with Bourn.
Bourn held commercial pilot, instrument, multi-engine, ground instructor and single/multi-engine flight instructor ratings, according to a biography posted on the American Society of Mechanical Engineers website before a talk he gave in 2007. The bio noted he enjoyed "motorcycling, skydiving, flying, and teaching others how to fly."
Bourn graduated from Stanford University with a bachelor's degree in electrical engineering. He worked for IDEO of Palo Alto as a senior engineer from 1995 to 2005, his former employer confirmed.
Finn had worked for Tesla for a year and eight months, according to his profile on LinkedIn.com. He received his bachelor's and master's degrees from Northern Illinois University in 1990 and 1992, respectively. He previously worked for Volkswagen Electronics and Volkswagen of America.
He enjoyed gardening, cycling, skiing and playing the guitar, his profile stated.
Ingram, a 2001 Harvey Mudd College graduate, previously worked for Dolby Laboratories and Christie, Parker and Hale.