FORT WORTH, Texas — The audio recording from onboard a plane that crashed Sunday morning into Dallas County’s Addison Airport revealed confusion among the pilots in the moments leading up to the crash.

On Tuesday, the National Transportation Safety Board held its last formal press briefing on the crash, in which 10 people were killed when the small plane veered into an airport hangar. The plane, a twin-engine Beechcraft BE-350 King Air, was flying a private party of people to St. Petersburg, Fla.

A cockpit recording captured two hours of audio from the plane leading up to the crash, NTSB Vice Chairman Bruce Landsberg said at Tuesday’s news conference.

Twelve seconds before the plane crashed, “crew comment consistent with confusion” was recorded. Landsberg said he could not elaborate on what specifically was said by the crew.

Crew comment regarding a problem with the left engine was captured about eight seconds before the end of the recording. Three “automated bank angle oral alerts” started about three seconds before the recording ended.

Experts will continue to analyze the recording in Washington, D.C., Landsberg said. The group will release a written transcript when the majority of reports are completed in the investigation.

NTSB will release a preliminary report about the investigation in about two weeks, Landsberg said. A factual report will be released in 12 to 18 months and will be followed by a probable cause of the crash.

The NTSB is analyzing video of the crash, records for the pilot and co-pilot and maintenance of the plane.

A pilot who previously flew with the King Air’s pilot, whose identity has not been released, told NTSB everything was normal during their flight several weeks ago, Landsberg said.

The plane had a maximum capacity of 11 people. Ten people were onboard: eight passengers and the pilot and co-pilot. Nine of the 10 people have been identified through the Dallas County medical examiner’s office and other sources.

Alice and Dylan Maritato were killed in the crash, along with their mother and stepfather, Ornella Ellard and Brian Ellard. Alice, 15, attended John Paul II High School in Plano and Dylan, 13, was a middle school student at All Saints Catholic School.

Steve Thelen, 58, and his wife, Gina, also died in the crash, according to JLL real estate in Dallas, where Thelen was the managing director.

Mary and John Titus, another Dallas couple who died in the crash, and Ornella and Brian Ellard were part of the same Dallas tennis group, of which Mary Titus was the captain, according to records from the United States Tennis Association.

Mathew Palmer, 28, was also listed as one of the people killed in the crash in a press release from the Dallas County medical examiner’s office Monday. Palmer, who lived in Fort Worth, was issued a pilot’s license in 2008, according to FAA records, but details about his involvement in Sunday’s flight have not been released.

According to his wife’s Facebook page, the two just celebrated their one-year wedding anniversary. Palmer’s Facebook page says he is a ranch and arena hand at the Fort Worth Stock Show and Rodeo. Fort Worth Stock Show spokesman Matt Brockman said Palmer was a seasonal employee.