Excess weight of those onboard is the reason why a British Columbia plane crashed on Aug. 17, killing four men, the Transportation Safety Board says.
"The aircraft has four seats and they were four reasonably big guys onboard," TSB member Bill Yearwood said in an interview.
The single-engine Piper PA-24 Comanche crashed just 30 kilometres after taking off from its base in Penticton. According to Mr. Yearwood, the plane was destined for Victoria on a leisurely trip to drop off one of the passengers.
"There was very little baggage on board," he said.
According to an online specification, the single-engine PA24 has a maximum payload of 1,240 pounds.
Following seven days of intensive search and rescue, involving 20 military and civilian aircraft, the plane was found near Apex Mountain, in a high-collision terrain. According to TSB's investigation, the plane collided with trees.
"They took the aircraft into relatively high terrain on a relatively warm day and all those things combined led to reduced performance," Mr. Yearwood said. "Any time an aircraft is heavily loaded, that affects its performance."
The aircraft had to clear more than 7,000 feet to go above Apex mountain, which is described by a local flight school as an optical illusion.
"We use that particular terrain in one of our mountain courses to show our students the optical illusion. There is an appearance that the terrain climb is shallow but it's quite steep," said Mark Holmes, owner of Southern Aviation Skies in the Okanagan.
He said several accidents have occurred in the area.
"Airplanes, when they are climbing are using all their power to climb. You can climb or you can turn and you can't do both very well," said Mr. Holmes, describing the challenge of clearing the Apex summit.
Following the TSB's fact-finding mission, it was discovered that the engine was running at the time of impact, which rules out speculation that fuel shortage may have been a cause, Mr. Yearwood said.
The men onboard were identified as pilot and owner Rama Jesus Tello, 36; his brother Maya Paulo Nicholas Tello-Wrigley, 21; Salem Dedovic, 30 and Jason Kevin Christopher Patrick Minor, 35.