If I remember correctly (I've checked and I do), that was what preceded and prepared 9/11. Hijacker-pilot and ringleader Mohamed Atta and other attackers had received training to fly planes in America, as well as elsewhere.
Were they illegals? Yes, apparently at least 11 of them had overstayed their authorized period of admission.
And this agency is called Transportation "Security" Administration. Do people ever learn?
... Eight of the attendees had entered the United States illegally, while 17 had overstayed their visas, according to a GAO audit, CNSNews.com reports. Six of the illegals obtained pilot’s licenses.
The discovery of the flight school issues began when local police — not federal authorities — stopped the school’s owner on a traffic violation and then were able to determine that he was an illegal alien, according to CNSNews.
The identities of the owner or the students were not disclosed in the GAO report, presented at a congressional hearing Wednesday into security lapses at the nation’s 935 accredited flight schools.
The report also found that some foreigners had completed flight training without a full background check and that some U.S. citizens considered a terrorist threat and banned from flying on passenger airplanes did learn to fly.
U.S. citizens are screened against terrorism databases only after flight training, when they apply for a pilot's license. More than 550 U.S. citizens are on the no-fly list, a database kept by the FBI’s Terrorist Screening Center, according to The Seattle Times…
After the Sept. 11 attacks — when al-Qaida terrorists who had attended flight schools in Florida, Arizona, and Minnesota hijacked and crashed commercial jetliners — security checks were added for people coming to the United States to enroll in flight schools, The Times reported.
But those checks were never extended to U.S. citizens despite growing concerns in recent years about “homegrown” terrorists launching attacks on U.S. soil.
According to the 911 Commission Report, four of the Sept. 11 hijackers who entered the United States with legal visas had overstayed their authorized period of admission, CNSNews reported.
U.S. flight schools are generally less expensive and more rigorous than those in other countries, and often enroll a large number of foreign students each year. About 30 percent of students enrolled in flight classes in the U.S. are foreign nationals, The Times reports.