Now federal prosecutors have charged Osbon following his bizarre unraveling aboard Flight 191 to Las Vegas, describing in court records a midair breakdown they say began with cockpit ramblings about religion and ended with passengers wrestling him to the cabin floor.
Witness accounts of Osbon telling his co-pilot "things just don't matter" and sprinting down the center aisle - yelling jumbled remarks about Sept. 11 and Iran - baffled longtime friends and fellow pilots who said they couldn't remember previous health or mental problems.
Osbon, 49, was instead described as an affable aviator who took his private plane for joyrides in his spare time, shied from talking politics and hosted Super Bowl parties. His father was also a pilot who died in a 1995 plane crash while on a sunken treasure hunt, according to a Wisconsin newspaper in the town where his family lived.
"I can't say whether it's shock or disbelief," said Justin Ates, a corporate jet pilot and friend who also lives in Richmond Hill. "It's hard to describe what you feel when you see something that's completely 100 percent out of character."
Osbon is charged with interfering with a flight crew following his bizarre outburst Tuesday on the flight that began in New York and was diverted to Amarillo, Texas. He was still being held at a hospital there Wednesday and being medically evaluated.
Under federal law, a conviction for interference with a flight crew or attendants can bring up to 20 years in prison. The offense is defined as assaulting or intimidating the crew, interfering with its duties or diminishing its ability to operate the plane.
One aviation expert said he couldn't remember a pilot being prosecuted on the charge, which reads as though it was written with passengers in mind.
"I've been doing this for more than 50 years, and I can't recall anything like this," said Denny Kelly, a private investigator in Dallas and former Braniff Airlines pilot.
A pilot with JetBlue since 2000, Osbon acted oddly and became increasingly erratic on the flight, worrying his fellow crew members so much that they locked him out of cockpit after he abruptly left for the cabin, according to a federal affidavit. He then started yelling about Jesus, al-Qaida and a possible bomb on board, forcing passengers to tackle him and tie him up with seat belt extenders for about 20 minutes until the planed landed.
"The (first officer) became really worried when Osbon said `we need to take a leap of faith,"' according to the sworn affidavit given by an FBI agent John Whitworth. "Osbon started trying to correlate completely unrelated numbers like different radio frequencies, and he talked about sins in Las Vegas."
Investigators said they were told that Osbon scolded air traffic controllers to quiet down, then turned off the radios altogether, and dimmed the monitors in the cockpit. He allegedly said aloud that "things just don't matter" and encouraged his co-pilot that they take a leap of faith.
"We're not going to Vegas," Osbon told his co-pilot in midflight, according to the affidavit.
Osbon, described by neighbors as tall and muscular, "aggressively" grabbed the hands of a flight attendant who confronted him and later dashed down the cabin while being chased. Passengers wrestled Osbon to the ground, and one female flight attendant's ribs were bruised during the struggle. No one on board was seriously hurt.
JetBlue spokeswoman Allison Steinberg said Osbon had been suspended pending a review of the flight. JetBlue CEO and President Dave Barger told NBC's "Today" show that Osbon is a "consummate professional" whom he has "personally known" for years. He said nothing in the captain's record indicates he would be a risk on a flight.
In Richmond Hill, a bedroom community on the Georgia coast just south of Savannah, next-door neighbor Bud Lawyer said he's having a hard time believing the man on the news is his good friend.
Osbon went to church but seldom talked about it and never seemed overly zealous, Lawyer said. And while the friends would occasionally chat about events in the Middle East, their talk never went beyond casual conversation about the events in the news, he said.
"He wouldn't intentionally hurt anyone," Lawyer said. "He's a kind-hearted, generous, loving teddy bear. It's totally out of character for this to happen to him."
Another longtime friend, Bill Curley, said Osbon is a Christian who has become "increasingly" religious but wasn't fanatical.
Osbon was also a direct marketer for health shakes sold by Visalus Sciences, a marketing company based in Troy, Mich. Ashley Guerra, a fellow Visalus marketer in Georgia, said she saw Osbon just last weekend and that he appeared friendly and helpful as usual.
In an interview last year with the local magazine Richmond Hill Reflections, Osbon said he first got in the cockpit when he was 6 or 7 and had ambitions of becoming a motivational speaker. His father and another man died after the engines in their plane failed over Daytona Beach while en route to look for treasure in Fort Lauderdale, according to 1995 story in the Washington Island Observer, a newspaper in the small Wisconsin community where Osbon's parents had a home.
Osbon's LinkedIn profile states that he received a degree in aeronautical physics from Hawthorne College and a physics degree from Carnegie Mellon University. However, Carnegie Mellon spokeswoman Teresa Thomas said Osbon attended the school for three years but never obtain his degree.
"On a Sunday morning he'd call me up and say, `Let's go for a flight,"' neighbor Erich Thorp said. "Even with that little Piper Cub, before he would take it off the ground he would spend 15 minutes checking everything out. He had a whole list he would check. He was as careful a pilot as you could imagine."