Ten years after the 9/11 attacks, government screening has made it harder for foreign students to enroll in civilian flight schools like a handful of the hijackers had done, banking on America being inviting and a place to learn quickly.

But the most rigorous checks don't apply to all students and instructors, so schools and trainers have to be especially alert to weed out would-be terrorists.

"Prior to 9/11, I wouldn't have had the phone number and name of my local FBI agent posted on my wall. I do," said Patrick Murphy, director of training at Sunrise Aviation in Ormond Beach, Fla., near Daytona Beach.

Hundreds of U.S. flight schools fiercely compete for students. In Florida, some still pitch the good weather as a way for students to fly more often and finish programs faster. The 9/11 hijackers sought out U.S. schools partly because they were seen as requiring shorter training periods.

Florida schools have reason to be careful: Three of the 9/11 hijackers were simulating flights in large jets within six months of arriving for training in Venice, Fla., along the Gulf Coast. Mohamed Atta, the operational leader of the hijackings, and Marwan al Shehhi enrolled in an accelerated pilot program at Huffman Aviation, while Ziad Jarrah entered a private pilot program nearby.

The terrorists obtained licenses and certifications despite rowdy behavior and poor performance at times.

The U.S. commission that investigated the attacks said in its report that Atta and Shehhi quickly took solo flights and passed a private pilot airman test. The two later enrolled at another school, where an instructor said the two were rude and aggressive, and sometimes even fought to take over the controls during training flights. They failed an instruments rating exam. Undeterred, they returned to Huffman. Meanwhile, Jarrah received a single-engine private pilot certificate.

Hani Hanjour obtained his private pilot license after about three months of training in Arizona.

Several more months of training yielded a commercial pilot certificate, issued by the Federal Aviation Administration. In early 2001, he started training on a Boeing 737 simulator. An instructor found his work substandard and advised him to quit, but he continued and finished the training just 5 1/2 months before the attacks, the commission said.

Today, it would be tougher for the four men to enter U.S. flight schools.

There is a stricter visa process for foreign students seeking flight training in the U.S. They cannot start until the Transportation Security Administration, created after Sept. 11 to protect U.S. air travel, runs a fingerprint-based criminal background check and runs their names against terrorist watch lists. TSA inspectors visit FAA-certified flight schools at least once a year to make sure students have proper documentation verifying their identities and haven't overstayed their visas.

Plus, TSA shares intelligence with other agencies and has other layers of security to catch people before they can do harm even if they slipped through the cracks and were able to get flight training in the U.S.

The stepped-up measures involving flight schools are not foolproof or uniform, however.

There are numerous flight instructors with access to planes and simulators who don't all get an annual TSA visit, and are subject only to random TSA inspections if they train only U.S. citizens.

The TSA has access to a database of all student pilots that is maintained by the FAA. But TSA said it only runs the names of U.S.-citizen students against watch lists, and not necessarily before those students can start their programs.

TSA said the fingerprinting and criminal background checks done on foreign students before they can enter U.S. flight schools are not done on U.S. citizens. TransPac Aviation Academy in Phoenix tells domestic applicants they need proof of citizenship, a high school diploma or college transcripts, a medical card, a driver's license and any pilot licenses already held. Other schools do the same, said Tom Lippincott, TransPac's vice president of business development.

And one security measure never employed by the government, despite interest from the 9/11 commission, was requiring that transponders that help officials locate commercial planes can't be turned off as the hijackers did. The FAA said if there is an electrical fire or malfunction, pilots must be able to turn off the transponder for safety reasons.

The shortcomings have led schools to self-police.

Andre Maye, vice president of administration at Phoenix East Aviation in Daytona Beach, pays attention to red flags including inconsistencies in addresses applicants provide and discrepancies on financial statements. He monitors the size of wire transfers from students when they pay for their tuition, which can total $46,000 or more, and looks for consistency in the transactions.

James Coyne, president of the National Air Transportation Association, a trade group for aviation service businesses including flight training companies, said the industry is open to more rigorous and uniform vetting of students.

The safeguards in place haven't deterred foreign students from flocking to the U.S. -- Sunrise Aviation's Murphy said the majority of students are international at many flight schools, including his.

They come because the training industry is more developed and efficient than programs at home.

Also, pilot hiring in the U.S. is stagnant, while growth in Asia has fueled a need for pilots there.

Students often come to the U.S. with their own money or financing.

Akshai Stephen, 27, of New Delhi, has been at Sunrise about five months. He said the month it took him to go through the approval process and start training didn't discourage him.

"What I thought was, just tell the truth, `I want to fly. I want to fly,"' he said. "If you are truthful and have good intentions, you have nothing to worry about."

Of the 41 recommendations in the 9/11 commission's report, none specifically addressed flight schools. Thomas Kean, the former New Jersey governor who chaired the commission, told The Associated Press the feeling at the time was that the federal government already was working to close that loophole.

Huffman Aviation, where Atta and Shehhi trained, closed after the attacks. Owner Rudi Dekkers said in a recent interview that considering what he knew 10 years ago, there is nothing he could have seen that would have alerted him to what his students were planning.

And despite the enhanced government screening today, he isn't convinced the same thing couldn't happen at another school.

"You have someone who doesn't behave, you think that makes them a terrorist?" Dekkers asked.

"Then half the country is a terrorist."