The air traffic control tower at Lawrence Municipal Airport cleared Alan Lavender to land his small plane after a short flight on Feb. 28, but the former Newburyport mayor never responded. Moments later, the amateur-built craft swerved to the left, then to the right, and took a nose dive.

The National Transportation Safety Board released the details on Tuesday as the investigation continues into the crash, which killed the 73-year-old pilot after his Sonex aircraft plunged about 500 feet into the roof of a building at the Pride’s Crossing condominium complex in Methuen.

The preliminary NTSB report provides a summary of the details that investigators have collected so far as they look for the cause of the crash.

The document summarizes the reports of several witnesses who said they saw flames aboard the plane before it crashed. Investigators also found fire damage on the engine of the plane, which was thrown from the body of the aircraft by the impact.

“Witnesses reported that they saw the belly of the airplane ‘engulfed in flames’ and described the flames as ‘very bright red’, ’’ the report said. “In addition, one witness reported that fire was coming out near the propeller as the airplane descended.’’

The report said Lavender bought 12 gallons of fuel around 12:45 p.m. on the day of the crash, and he took off about 10 minutes later. He crashed shortly after 1 p.m., and investigators said there were about 7 gallons of fuel left in the 17-gallon tank when authorities got to the plane.

The tank was intact, but the fuel lines had been severed and were leaking when rescuers arrived at the scene. Authorities have previously said a small fire broke out after the crash, and that sprinklers in the building helped contain the flames.

Lavender, who served as mayor in Newburyport from 2002 to 2003 and was well-known in the community, died. Nobody in the building, which is across the Merrimack River from the airport, was hurt.

Citing pilot logbook records, the NTSB wrote that Lavender had gotten his sport pilot certificate May 21, 2014. The plane was certified as airworthy May 4, 2016.

He had logged 28.4 hours by last October, and he had been maintaining the plane, according to the report.

“In an e-mail two days prior to the accident, the pilot reported that he completed maintenance and started the airplane with no issues, but elected not to fly because of the winds,’’ the report said.

Andy Rosen can be reached at andrew.rosen@globe.com. Follow him on Twitter at @andyrosen.