Substance Found in Fuel Tank of Plane : Crash: Investigators analyze contaminant found after accident that killed 16 sky divers. Airport was using new company to gas aircraft.

Five gallons of an unknown contaminant have been found in the forward fuel tank of an airplane loaded with sky divers that crashed during takeoff Wednesday at Perris Valley Airport, killing 16 people and injuring six others, federal authorities said Saturday.

Remnants of the contaminant also were found in the right wing engine that failed and a fuel truck at the airport, said Don Llorente, a spokesman for the National Transportation Safety Board. Tests were being conducted to determine the nature of the emulsified substance, he said.

Rafael Chodos, an attorney for airport owners Ben and Diane Conatser, said an outside fuel company had just provided fuel and pumping services to the airport the day of the accident.

The airplane had been refueled shortly before takeoff, Llorente said. Although the contaminated fuel was found in the forward tank that feeds fuel to the right engine, none was found in the rear tank even though both were refueled at the same time.

The disparity prompted speculation that the substance moved as a blob through refueling hoses that are capable of holding 14 gallons of liquid.

Llorente, who said it was premature to draw conclusions, did not address how the contamination occurred, or whether it reflected deliberate or unintended actions.

Chodos also dismissed reports that pilot Rowland Guilford, who was killed in the crash, was unqualified to fly the DeHavilland Twin Otter. Guilford, although relatively new to the Otter, was a certified multiple-engine instructor who had more than 1,000 hours flying sky divers, he said.

“Everybody wants to jump to some conclusion around here,” Chodos said. “But this place maintains as high standards as possible in this business.”

Guilford, married for 21 years and the father of four girls and a boy, made his living as an air-conditioning and roofing salesman but earned extra money on piloting jobs. He flew often at the California City Skydive Center near Mojave, said operator Judy Celaya. She described Guilford as “a dear, dear friend of a lot of us.”

He was “a meticulous, safe pilot,” his brother, LeRoy Guilford, said. “When you went flying with him, you got bored he took so much time going through the safety checks.”

One witness said the plane was about 50 feet in the air before it abruptly veered to the ground on Wednesday morning. The six survivors, including members of a competitive U.S. sky-diving team, sat in the rear of the plane and were cushioned by the bodies in front.

The NTSB’s Susan Coughlin said an examination of the wreckage showed that the pilot and a passenger sitting in the co-pilot’s seat were the only people aboard wearing waist safety belts, and neither was wearing a shoulder harness. One of the shoulder harnesses was inoperable. Even had they worn the shoulder harnesses, neither could have survived the impact, she said.

Few sky divers at Perris faulted the apparently lax attitudes concerning safety belts. Several argued that the regulation does more harm than good because a neophyte fumbling for a seat belt could accidentally deploy a reserve parachute inside a plane--an incident that could create another life-threatening emergency.

A trust fund is being established for Guilford’s family at Riverside National Bank. Another fund has been established to pay for the sky divers’ medical and funeral expenses.