The recorder could yield information on why the Hawker 800 jet crashed while trying to land in this southern Minnesota city on Thursday.
Steven Chealander, a National Transportation Safety Board member, said the agency wouldn't speculate on a cause until the investigation is complete, which could take up to a year.
Investigators will examine the weather, the background of the pilots, the plane's condition, witness accounts and air controller traffic prior to the crash.
"We are in the evidence-gathering stage of this investigation," Chealander said in a briefing to reporters.
The cockpit voice recorder was recovered Thursday and sent to the NTSB lab in Washington for analysis, along with a flight management system, a device that contains data but is less elaborate than the flight data recorders on large jets.
The jet was carrying six casino and construction executives and two pilots when the plane went down, killing all aboard. The executives were coming to Owatonna to meet with representatives of a local glass company called Viracon to discuss a $2 billion hotel-casino complex being built in Atlantic City by Revel Entertainment.
The charter jet went down in a cornfield northwest of Degner Regional Airport. The airport was closed to arriving planes Friday. The only flights allowed were departures, and those aircraft were forbidden to fly over the crash site.
Roy Redman, president of RARE Aircraft Inc., a mechanics company at the airport, said Friday that he was inside and heard the plane land on the runway. Moments later, one of his mechanics who had watched the landing came running around the building, yelling that the jet had gone off the runway and disappeared in some trees in the distance.
Redman, who called 911, said the mechanic told him the jet landed, then went airborne, rolled and hit the ground.
Doug Neville, Department of Public Safety spokesman, said the airport has no control tower, and pilots communicate with controllers in Minneapolis.
An hour before the crash, a 72 mph wind gust was reported in Owatonna, according to the National Weather Service. But witnesses said the crash occurred after the worst of the storm had passed, with the sky clearing and only light rain.
Seven people were found dead at the site. One died later at a hospital.
The victims were identified as:
- Tony Craig, 50, and Chris Daul, 44, both vice presidents of construction development at Revel Entertainment; and Lawrence Merrigan, 62, the company's director of field operations.
- Karen Sandland, 44, a project manager for Tishman Construction Corp. who was working on the Revel project.
- Two executives of APG International, a New Jersey company that specializes in glass facades: Marc Rosenberg, chief operating officer, and Alan Barnett, assistant project manager.
- Two pilots for Allentown, Pa.-based East Coast Jets, Dan D'Ambrosio, 27, and Clark Keefer. The company declined to comment on the pilots' background Friday.
Two other people who were supposed to be on board did not get on the flight, Neville said.