SWANZEY, N.H. – Fog may have contributed to an aircraft crash in Swanzey that killed a Maine pilot on Thursday.

The plane, flown by Douglas Nelson, 46, of Hampden, Maine, went down about 75 feet from the southern end of the main Dillant-Hopkins Airport runway.

The crash occurred at night, and fog had enveloped the airport as well as another where the pilot had planned to land.

“It was the worst possible time to come in,” said Dillant-Hopkins Airport director Ed Mattern.

Nelson was the only person aboard. He was a commercial pilot for the Air Now cargo service, based in Bennington, Vt.

The plane, a 24-year-old twin-engine turboprop, originally was slated to deliver overnight packages from Bangor, Maine, to Manchester, said Air Now executive vice president Michelle Van Ness. She described Nelson as an experienced commercial pilot.

She told The Boston Globe conditions were “marginal” but “legal” when Nelson took off. She said the weather later forced changes.

“He held over Manchester and talked with air-to-ground communication in Bennington and Boston,” she said, “and it was decided to divert the flight because the fog wasn’t going to lift.”

That was the last the company heard from Nelson until a transmission from Boston reporting the crash, she said.

Nelson’s approach to the airport was not unusual, Mattern said.

The airport does not have a control tower, but an automatic system lets pilots activate runway lights as they near the facility.

“The airport’s systems were working, as far as I can tell,” Mattern said. “There are no issues with our system. But it was extremely foggy. Even if you’re flying on instruments, there is a point where you have to lift your eyes from the cockpit and try to find the ground.”

Federal investigators have not yet released any findings from the accident.