Crash Probe Focuses on Safety Belts : Sky diving: The 16 victims were sitting on the floor of a plane that had no seats. Many parachutists disdain the harnesses.

The investigation of the deadly crash of a twin-engine plane carrying two teams of international sky divers focused Thursday on whether the jumpers wore safety belts during takeoff.

Wednesday’s crash at the Perris Valley Airport in rural Riverside County killed 16 people, including veteran sky-diving instructors and a trio of sky-diving camera operators, one of whom may have inadvertently had his video camera running as he died. Six other people on board were seriously hurt.

The disdain that many sky divers hold for seat belts, combined with the fact that many of the bodies in Wednesday’s disaster were hurled to the front of the De Havilland DHC-6 Twin Otter, has fueled speculation that the passengers wore no restraints.

“We have a rather flexible policy on (the use of seat belts),” Jim Wallace, chief instructor of the Perris Valley Sky Diving School, which sponsored the doomed excursion, said Thursday. “We don’t have a stringent policy that says everybody must have that seat belt on.”

Wallace’s comments seemed to contradict statements he had made the day before, when he insisted that the jumpers used restraints. Federal law requires safety belts, and in some cases shoulder harnesses, to be used during departures and landings of most civilian aircraft.

But many sky-diving enthusiasts, who often speak with a certain bravado, say they do not like to use restraints because they can dangerously restrict movement within an aircraft. Or, they say, the buckles can be mistaken for the handles of a parachute and lead a jumper to accidentally deploy a chute in flight.

Federal investigators would not say whether the use of restraints would have saved lives in this accident, which claimed an unusually high number of victims for crash in which there was no fire.

“We will be looking at survival factors, particularly in this accident,” said Susan Coughlin, acting chairman of the National Transportation Safety Board, who is heading the investigation.

“There are restraint systems on board,” she added. “At this point, we are trying to document whether or not they were in use. . . . We have not convinced ourselves that they were used.”

Coughlin said the sky-diving camera operators on the plane had helmet-mounted cameras. One of the cameras apparently was activated during takeoff and investigators are trying to enhance the tape to see if it provides any clues.

Coughlin spoke to reporters about 50 yards from where the crumpled plane lay in a remote, grassy field. All around, investigators pored through the rubble, took measurements of pieces of equipment, shot pictures and interviewed witnesses. Ultra-lights were taking off from a nearby dirt road.

According to witnesses, the Twin Otter took off about 11:15 a.m. Wednesday on its second run of the day. As it climbed, it suddenly yawed to the right, rolled almost to a 90-degree bank and slammed nose-first into the ground. The wreckage finally came to a stop about 150 feet from the initial point of impact, Coughlin said.

The jumpers were sitting on the floor of the seatless plane, suited up with bulky parachutes and jumping uniforms. The passengers included two teams practicing for national sky-diving championships, including a four-member team from Holland, a New Zealander and a Frenchman, as well as several well-known local jumpers.

The accident tore at the heart of the close-knit sky-diving community based in Perris Valley, said to be the nation’s busiest and most popular area for jumping.

Friends and colleagues, some of whom witnessed the crash, spoke Thursday of their love for the sport, their dismay at what had taken place and their sadness over the loss. Many expressed concern that Perris Valley Sky Diving School might be grounded.

And several reiterated their firm conviction that seat belts may actually hinder jumpers.

Eric Stephenson, 31, was among several veteran sky divers who said he doubted that restraints would have saved lives in this case. He argued that belts are in fact hazardous to jumpers. A parachutist, he said, especially a beginner, can easily confuse a safety belt buckle with the clips or handles used in deploying a chute.

Another jumper, who did not want his name published, agreed: “I don’t think you’ll ever see a sky diver who will wear a restraint.”

Mike Hunter, a 17-year veteran of jumping who recently moved to Southern California from Canada, also insisted it is safer to not wear a safety belt.

“I wear them when I have to, but I prefer not to, “ he said, defining the “have-to” moments as during bumpy flights.

Several jumpers praised pilot Rowland Guilford, who died in the crash, as a conscientious, safety-minded veteran. Federal investigators said he was properly certificated.

“He flew just the way I want to,” said Hunter, who had flown with Guilford in the same Twin Otter two days before the crash. “It was a perfect flight.”

Officials from the National Transportation Safety Board and the Federal Aviation Administration, joined by investigators from the Canadian Safety Board, said they also were checking reports that the plane’s engine made unusual sounds before crashing. In addition, they will look at the airworthiness of the aircraft, how its two turboprop engines performed, the operation of the Perris Valley school, maintenance of the aircraft and the plane’s service history.

Coughlin said the Twin Otter had just taken on fuel before the flight. The plane, which was built in Canada, is configured to hold 20 passengers plus two crew members. Weight may be a factor, the NTSB official said; the plane is not supposed to carry more than 12,000 pounds.

Times staff writer Tracy Wilkinson in Los Angeles contributed to this story.