In the days since Bishop killed himself, the mystery of his fatal flight has only deepened. His handwritten suicide note expressing support for Osama bin Laden didn’t seem to square with the shy and patriotic ninth grader who told friends and family he wanted to join the Air Force to fight terrorism. “I think he wrote that note just to get publicity,” Favreau says.

As investigators try to make sense of the matter, they are also faced with a larger question: how was an unlicensed 15-year-old able to take off without anyone stopping him? Flight schools are anxious to portray the Bishop incident as an isolated case. “It was not a breach of security, it was a breach of trust,” says Robert Cooper, owner of the National Aviation flight school where Bishop trained. But no one has forgotten that Osama bin Laden’s men learned to fly at U.S. schools, and the Bishop incident has made it chillingly clear just how lax security still is. Now new regulations will require the country’s 2,000 flight schools to take a hard look at aspiring pilots long before they see the inside of a cockpit.

None of the instructors at Bishop’s Clearwater, Fla., flight school saw anything suspicious about him. When Bishop’s grandmother dropped him off early for his lesson on Jan. 5, he told his teacher he wanted to work on “the pattern”–takeoffs and landings. The instructor told him to wait outside the airplane with his log books and keys. Unsupervised, Bishop hopped into the pilot’s seat and took off solo.

Bishop may not have been as carefree a kid as some post crash accounts made him out to be. His parents divorced when he was a year old. Bishop lived with his mother, Julia, a graphic artist, and the two moved frequently. Since 1998, Bishop and his mother lived at five different Tampa area addresses. Bishop never knew his father, Charles, who dropped out of sight after the divorce. The teen told schoolmates his dad was dead. Last week newspapers reported that when they were teenagers, Bishop’s parents had attempted to kill themselves in a hapless Romeo and Juliet suicide pact after being denied a marriage license. They first tried to poison themselves with car exhaust. When that failed, the lovers resolved to cut themselves with a butcher knife but called for help after Charles, stabbed in the stomach, began bleeding. (Neither parent could be reached.)

Just what effect any of this might have had on young Charles Bishop is still hazy. It’s not clear if Bishop even knew about his parents’ dramatic history. “That’s dirty laundry,” Bishop’s grandfather, Robert Bishara, told NEWSWEEK. “We don’t talk about that.” Another possible clue to his state of mind: officials say Bishop had a prescription for Accutane, an acne medication that has been anecdotally linked to depression and a small number of suicides. But investigators don’t yet know whether he took the pills.

Flight schools, already suffering a 20 percent drop in enrollment since September, worry that an overreaction to the Bishop incident could hurt the industry even more. Congress is considering a $7.5 billion bailout, but a handful of schools have already gone under. The powerful general-aviation lobby, which includes flight schools, private planes and air charters, has long enjoyed a cozy relationship with the FAA. But after September 11, flight schools feared the Feds would crack down with onerous new restrictions. A December report to Congress from Transportation Secretary Norman Mineta offered a number of ideas for improving security. Among them: requiring pilots to file detailed flight plans, and restricting airspace over 30 large metro areas.

Industry groups tried to stave off the tough rules by meeting with law-enforcement officials in September. They volunteered to beef up security on their own, arguing they’d been on the lookout for terrorists all along–it was the Pan Am school in Minnesota that flagged FBI officials about Zacarias Moussaoui’s strange behavior. There was one obstacle: flight schools feared that singling out certain students for extra scrutiny could leave them vulnerable to charges of racial profiling. Congress stepped in with a new law that requires schools to get clearance from the Justice Department whenever a foreign student applies to fly an airplane weighing more than 12,500 pounds.

The schools are now waiting for the Feds to put the new procedures in place. Meantime, the FAA issued a set of “suggestions for enhanced security” last week following the Bishop crash. Flight schools should control the keys to airplanes, provide closer supervision of student pilots and watch for suspicious activity. Any one of those obvious recommendations might have stopped Charles Bishop. But no matter how vigilant the schools become, there may be no law stringent enough to ground every pilot determined to take a one-way flight.