A detailed preliminary report from the National Transportation Safety Board draws no conclusions on what caused the Cape Air crash which killed pilot Capt. David Willey, a resident of Vineyard Haven, on Sept. 26.

But the full report, according to Luke Schiada, chief investigator of the crash for the NTSB which has involved local, state and federal authorities, may take six to eight months to complete.

“It is important to note we are still in the information gathering stage. There is a lot of data we are still waiting to get,” he said.

Captain Willey was the sole occupant of the 1981 twin engine nine-passenger Cessna 402C plane, which took off from the Martha’s Vineyard Airport at approximately 8:05 p.m. on Friday night on Sept. 26 from runway 33 on a repositioning flight headed for Boston.

The plane crashed shortly after, in the woods near Nip ’N’ Tuck farm in West Tisbury, about three miles northwest of the airport.

The airplane struck the tops of approximately 50-foot-tall trees and crashed in a wooded area between two houses after skimming the rooftop of a nearby house. The aircraft left two impact craters and wreckage strewn along a 305-foot-long debris path.

It was the first fatal crash in Cape Air’s 19-year history.

Information in the report, which was published on the organization’s Web site earlier this week (ntsb.gov) is uncertified and incomplete, Mr. Schiada said.

However the report states that early examination did not reveal evidence of any catastrophic failures.

Based on an initial review of maintenance records, the report states, the aircraft had been inspected on Sept. 17 and had flown approximately 40 hours since that date.

All major portions of the airplane were accounted for at the accident site.

Captain Willey was an extremely experienced pilot. His recent FAA first-class medical certificate was issued on Sept. 16, and according to Cape Air company records, he had accumulated approximately 16,746 hours of total flight experience, including 2,330 hours with the same model Cessna from the crash.

On a rainy night with light wind, the aircraft was cleared for takeoff by the Martha’s Vineyard air traffic control.

And the report states that the pilot of another Cape Air Cessna 402 operated by Cape Air, which departed for Providence approximately one minute after the accident flight, did not report any unusual weather during his initial climb, describing the turbulence below 1,000 feet as light.

The analysis shows radar contact with Captain Willey’s aircraft was lost at an altitude of 700 feet and a ground speed of 160 knots, after initial targets were registered. Working in periodic sweeps, radar registers speed and altitude of aircraft in a series of targets.

“Radar data would have continued for a flight continuing to Boston,” said Mr. Schiada.

The report states: “After takeoff the airplane was instructed to climb to an altitude of 4,000 feet and make a right turn to a heading of 360 degrees. The instructions were acknowledged by the pilot; however, there were no further communications from the airplane.”

Testimony from a witness near the accident site is included in the report. “[The witness] reported hearing the sound of a low flying airplane. He described the engine noise as ‘very loud, like the airplane was at full-throttle.’ He then heard a loud crashing sound,” it states.

The crash investigation team conducts forensic analysis of the crash, from the position of switches on the aircraft to examination cuts in the wreckage and the crash site surroundings. But, said Mr. Schiada, his job is limited to information gathering.

“It’s important not to draw conclusions that may prevent you from looking at the whole picture,” he said, adding: “I don’t issue probable cause.”

Any analysis of the information and conclusions about the crash will come from the NTSB board in Washington, he said.

Mr. Schiada said the purpose of the preliminary report is to provide some information for the public.

The initial examination of wreckage was conducted at the Martha’s Vineyard airport. Mr. Schiada said that investigation at the site is probably completed at this stage.

“We might go back to parts of the wreckage but I don’t see us going back to the actual crash site,” he said.

As part of standard protocol an autopsy is being carried out by a local medical examiner. Also as part of standard procedure, samples were taken for a toxicology examination by the Federal Aviation Administration.

Reports on these examinations will be obtained by NTSB in several weeks, Mr. Schiada said.

Much of the wreckage has been sent to a Maine storage facility, where it will be held by the insurers.

Both engines and propellers from the wreckage have been sent to the relevant manufacturers where the team will carry out further investigation using manufacturer’s tools.

Mr. Schiada said a representative from Cape Air has been on hand throughout the investigation, who provides expertise on factors such as airplane and employment history.