The report says dirty water similar to that left behind after dousing a fire was found in part of the engine. Clear water was found elsewhere in the fuel system. The National Transportation Safety Board says it's trying to find where that water came from.
"Attempts to determine the source of that water, whether from fire suppression or the fuel supply system itself, are ongoing," the report states
Water in fuel could make the engine sputter, as reported by witnesses, contributing to the crash.
A final report isn't due for months.
The single-engine Piper PA-32 crashed into a home in west Jackson just after taking off from Hawkins Field. Killed were flight instructor John Edward Tilton Jr. and fellow pilots W.C. Young and David Williams, all flying to an air safety meeting in Raymond, Miss.
The plane struck the home of Loretta Jamison, who jumped out a window to escape what became a towering fire. Jamison suffered second-degree burns on her hands and cuts.
The plane's owner, Roger Latham, had planned to go, but instead went deer hunting.
The preliminary report indicates little else was wrong with plane, although witnesses say the preflight inspection was quick. The trio was late for the meeting's scheduled start when they took off about 5:12 p.m. There was a small puddle of fuel on the runway under the fuel strainer and a tire was low, but the plane took off strongly, a witness said.
Less than two minutes after takeoff, the pilot radioed back to the airport, saying "We got an engine problem, we're turning back toward Hawkins," the report says. After the controller said the plane could come back, the pilot replied "We're headed back, we'll try to make it."
The pilot made no further radio transmissions. Radar showed the plane turning right as it descended, losing contact at 500 feet, the report says.
The plane crashed, ending upside down, less than a mile from the runway.