ALLAGASH, Maine — Snowy conditions might have caused an airplane crash that killed a Maine Department of Inland Fisheries and Wildlife warden pilot a year ago, according to a preliminary report released this week.

Daryl Gordon, 60, of Eagle Lake, a 25-year veteran of the Maine Warden Service and a certified commercial pilot, was killed when the state-owned Cessna he was piloting crashed onto frozen Clear Lake about 30 nautical miles southwest of Ashland during a snowstorm on March 24, 2011.

A search was initiated for Gordon after his wife, Rita, reported that he had not returned to their Eagle Lake home after the end of his patrol. Searchers began looking for Gordon and his plane that night and found them the next day.

The National Transportation Safety Board report, released Monday, does not state why Gordon’s plane crashed, but it refers to “whiteout” and “flat light” conditions created in areas below an overcast sky or on reflective surfaces such as blowing snow or sand.

In flat light or whiteout conditions, “neither shadows, horizon, nor clouds are discernible; sense of depth and orientation is lost; only very dark, nearby objects” are visible, the report states.

DIF&W officials told federal investigators that almost immediately after Gordon’s ski plane left on its final takeoff, visibility was reduced to less than a half-mile because of snow.

According to the warden service, Gordon had dropped off the airplane he customarily flew at the department’s seaplane base in Greenville for routine maintenance earlier in the day.

He left the Greenville area in another ski-equipped airplane to continue his patrol of remote northern Maine, providing information for law enforcement and wardens working on the ground and surveying the area for deer.

While on patrol, Gordon learned that another game warden had mired his snowmobile in deep slush on Eagle Lake, so Gordon stopped to help, according to the warden service.

Gordon flew the warden to another location to retrieve a come-along that the pair used to free the snowmobile, and Gordon left about an hour later.

The report indicates that “scattered snow showers or snow squalls” were likely occurring near Gordon during his flight. NTSB investigators found no mechanical difficulties with the plane that could have contributed to the crash.

Final NTSB reports usually take about a year to complete. NTSB spokesman Terry Williams cautioned against drawing conclusions from the report.

“These are the facts as we know them right now,” Williams said Tuesday. “We release information as we gather it to keep people informed.”

An earlier NTSB report noted that plane wreckage had been scattered across about 350 feet.

Gordon’s death hit the warden service hard. Gov. Paul LePage ordered flags flown at half-staff on March 30, 2011, the day of the warden’s funeral. Gordon’s colleagues recalled him as a soft-spoken, hard-working man who enjoyed his job.

“He held a low profile,’’ retired Game Warden Gary Pelletier said. “He wasn’t disliked by anybody; he was low-key and easy to get along with.”