(CNN) -- The flight data and cockpit voice recorders from JetBlue Flight 191, which made an emergency landing this week, have been retrieved and will be analyzed, officials said Thursday.
The National Transportation Safety Board will download the data Friday, said spokeswoman Kelly Nantel. Information gleaned from them will be given to the FBI, she said.
Investigators are looking into the apparent midair meltdown of the captain, Clayton Osbon, whose remarks and erratic behavior Tuesday led the co-pilot to lock him out of the cockpit.
Crew and passengers subdued Osbon as he screamed and banged on the door so hard the first officer thought Osbon would come through, according to a federal criminal complaint filed Wednesday against Osbon.
The complaint says Osbon began making remarks during the flight that concerned the first officer, who is his co-pilot.
"Osbon yelled over the radio to air traffic control and instructed them to be quiet. Osbon turned off the radios in the aircraft, dimmed his monitors and sternly admonished the FO (first officer) for trying to talk on the radio," the U.S. attorney's office in the Northern District of Texas said in a written statement. "When Osbon said 'we need to take a leap of faith,' the FO stated that he became very worried. Osbon told the FO that 'we're not going to Vegas,' and began giving what the FO described as a sermon."
It was not immediately known whether the alleged remarks are audible on the voice recorder. But federal regulations state that planes manufactured since 1991 must record cockpit chatter on microphones. The JetBlue plane was new and would be subject to the rule.
The cockpit voice recorder captures two hours of data and the flight data recorder, which measures the plane's speed and altitude, contains 25 hours.
About 3½ hours into the planned five-hour flight from New York's Kennedy International Airport to Las Vegas, the pilot left the cockpit to use the lavatory, but he failed to follow security protocol, alarming the crew, according to an affidavit filed in support of an arrest warrant. He then banged on the lavatory door and told the female passenger inside that he needed to go to the bathroom.
By that time, the first officer had summoned another JetBlue pilot who had been traveling as a passenger to enter the cockpit and the two locked themselves inside, the affidavit states.
From the cabin, Osbon tried to enter his security code to gain access to the cockpit "and he banged on the door hard enough that the FO thought he was coming through the door," according to the affidavit. But the door held and, over the PA, the first officer ordered passengers to restrain Osbon. Several did just that, subduing the pilot in the forward galley.
Osbon, who was been charged with interfering with a flight crew, has not made a public statement. He has been suspended pending an investigation and is receiving medical treatment, the airline said Wednesday. A court official said Osbon was still under care Thursday.
JetBlue has repeatedly praised the first officer, along with an off-duty captain who stepped in to assist and other crew members.
Some passengers have referred to the first officer as a hero. But his mother said on Thursday that he would reject the label.
"Knowing my son, he would think that he's not a hero. He just did what he was paid to do," Jean Beatrice Dowd said of Jason Dowd.
"That's just his job, and he loves his job. He's just a quiet man."
He called his parents the night of the incident, his mother said. "He was pretty shaken up, and he couldn't say much."
The incident took place on a significant date for the family -- the 10th anniversary of the death of Jason Dowd's older sister, who died of cancer, Jean Dowd said.
"I know he was thinking of her, too, at the time this was all going on," Dowd said.
The incident "has been earthshaking for us, too," she said. "To lose him would have been terrible for us."
Jason Dowd, 41, who is married and has two young children, has not made a public statement. He was in New York, speaking with officials about the incident, his mother said.
After the incident, the flight made the emergency landing in Amarillo, Texas.
Osbon's stepmother said Thursday she has flown with him several times.
"He loved to fly, a love which he got from his dad," Judy Osbon said in a statement. "He also took his piloting very seriously and was very good at it. I've only known Clayton to be a cheerful, conscientious and caring person."
Her stepson was upbeat the last time they spoke, she said.
Osbon's father, Ronald, who was a pilot, and a passenger were killed in a 1995 airplane crash in Florida, according to the National Transportation Safety Board. The pilot radioed he was losing power on both engines and was out of gas. The aircraft crashed near Daytona Beach Regional Airport.
CNN's Aaron Cooper, Mike M. Ahlers and Carol Cratty contributed to this report.