The CEO of an Edmonton engineering firm and the founder of a Calgary oil services company are among the victims of two weekend plane crashes in B.C.

On Sunday afternoon, a Cessna 172 flown by businessman Allen Williams was en route from Golden to Edmonton when it went down minutes after takeoff.

His three-year-old granddaughter, Kate, is the only survivor of the crash that killed Williams and his colleague, Steven T. Sutton.

"Both men are treasured husbands, fathers, grandfathers, and mentors who will be greatly missed," said a statement released by A.D. Williams Engineering on Monday.

Williams started the engineering firm in 1978 and handed it over to his son Reagan in 2005. It now has five offices across Western Canada. Sutton was the company's chief financial officer.

An experienced pilot, Williams recently celebrated his firm's 30th anniversary and his own 65th birthday.

Search and rescue officials say bad weather and the rugged terrain at the crash site made it difficult for them to reach the plane Sunday. A rescuer was eventually lowered from a helicopter and pulled the little girl to safety.

Officials say Kate Williams survived because she was strapped into a child's car seat on the plane. She suffered head injuries but is in stable condition.

Plane's engine failed, killing 3 men

On Friday, three Calgary men died when their plane crashed near Invermere, B.C. They were on their way from Salem, Ore., to Springbank, Alta., when the engine of their Piper Malibu failed.

The plane was piloted by Ronald Bullen, 69, founder of oil services company Canadian Fracmaster. In the 1980s, Bullen's business was one of the first western companies to work with the Soviet Union to help develop oil reserves in Siberia.

Police said Bullen was flying his friend William Wood, 63, and Wood's son David, 37, who had just finished his final architecture exam at the University of Oregon, home to Calgary for a celebration party Friday night.

Meanwhile, two people escaped serious injuries Sunday afternoon when their homemade RV-6A aircraft made a hard landing at the Springbank airport, skidding onto its nose, said the airport's manager.

With files from the Canadian Press