Speculation that sabotage caused the crash on 19 December that killed Michael Connell, a top-level information technology consultant for the Bush administration and the Republican Party, has been dampened. Results of the US National Transportation Safety Board's preliminary investigation suggest a loss of control of the aircraft.

Preliminary information provided by the NTSB indicates that Connell, a private pilot with an instrument rating and a total of 510h, lost control of his Piper PA-32R Saratoga on an instrument approach to Akron-Canton Regional airport in instrument conditions that night.

The aircraft left a 90m (290ft) trail of debris in the front yard of a vacant house 3km (1.7nm) from the airport before catching fire.

The aircraft had been "well left" of the localiser 4km from the airport when air traffic controllers interrupted the approach, asking Connell to climb and maintain 3,000ft. After initiating the climb, Connell declared an emergency. A witness reported hearing a "loud" engine sound before the crash.

Connell and other high-ranking Republicans, including Karl Rove, are key figures in an investigation linked to the 2004 presidential elections in Ohio. An ongoing lawsuit against then Ohio secretary of state Kenneth Blackwell, who hired one of Connell's companies to set up an official election website for the state, alleges ballot rigging and other illegal activities that Connell was thought to have information about or to have participated in, dealings that have fuelled conspiracy theories on the crash.

The NTSB says the temperature was 1deg C at the surface, with cloud layers down to 500ft or lower at the time of the accident. Investigators found no anomalies with the flight-control system "that would have precluded normal operation".

Lee Schiek, manager at College Park airport in Maryland, Connell's departure airport and the nearest general aviation airport to downtown Washington DC, says Connell had been flying to the airport once or twice a month for the past year, generally staying one night and leaving the next day.

Police security at the airport is tight, as College Park is one of three airports in a special zone where pilots must obtain background checks and receive approval from federal authorities for each take-off and landing. Schiek says a review of a security camera of the airport's only pedestrian entry during Connell's most recent visit on 18 and 19 December showed no intruders.

Connell had planned to leave the airport at noon that Friday, says Schiek, but waited until after 15:00 to decide to take off because of frontal and icing conditions along the route.

He was offered fuel, but declined, earlier telling airport employees that the flight in from Akron took only 70min.

"Nothing here raised any eyebrows," says Schiek, adding that Connell performed a "thorough" pre-flight check before departure. During a previous trip in the summer, however, Schiek says that a handful of people came to the airport to await Connell's arrival. Employees of the airport drove him to a nearby train station to avoid a confrontation. Representatives of the group say they came to the airport that day to issue a subpeona to Connell and that the meeting was peaceful.

Source: Flight International