Benhoff's husband, Daniel, said she had worked for Katz for 16 years, traveling regularly to places such as Florida and New York.
"She was his main flight attendant," he said. "She went everywhere with him."
Benhoff got to know Katz's children and late wife over the years, he said, and had known his grandchildren since they were born. She spent much of the last 16 years on call for Katz, who sometimes made last-minute decisions to fly.
But she loved her job, he said, and was looking forward to a few more years before she planned to retire. She and her husband divided their time between Easton and their second home, in Ocean City, Md.
"We loved our time together," Daniel Benhoff said. "She loved the beach - we'd just sit on the beach for hours and talk."
Married since 2007, Daniel Benhoff said he had known his wife for years through family friends.
"I fell in love with her from day one, and I couldn't go back," he said. "It was easy to fall in love with her. . . . It's unthinkable what happened."
McDowell was a registered pilot and also certified as a flight instructor, ground instructor and mechanic, according to his FAA licenses.
His current pilot's license was issued in 2008. He received his most recent medical certificate, indicating that he was physically fit to fly, in February, which noted only that he needed to wear glasses for nearsightedness.
A man who said he was McDowell's nephew declined to comment on Facebook and asked for privacy for his family during "this difficult time."
Shelly de Vries said her husband of 12 years came to the United States from Holland in 1990 for piloting school in Virginia.
In 1992, he was a passenger on a training flight out of South Jersey Regional Airport that crashed, killing one person on board, his wife said. He was not deterred.
Flying was "his love, his dream," she said.
Mike de Vries' parents had come from Europe to visit him at the time of the crash.
"He was a great son, a good man, a very good man," said his father, Harry.
Her husband, Shelly de Vries said, spoke warmly of Katz and called him a "wonderful man."
If they flew to Europe and Katz expected to stay several days, he would insist that de Vries fly the plane to Holland to visit his parents, she said.
"He loved Mr. Katz," she said.
He worked on-call for Katz, sometimes traveling for up to 20 days, and often joked that he was "a limo driver in the sky."
De Vries' and his 18-year-old daughter, Morgan, shared a passion for sports cars. On Sunday, when Morgan saw a white Rolls-Royce and took a picture, her first thought was to send it to him, she said.
"It's still my daddy, my daddy can't go away," she said in tears on Monday. "It's so hard to think of that."
Inquirer staff writers David O'Reilly, Tricia L. Nadolny and Robert Moran contributed to this article.