Federal authorities have been aware for years that suspected terrorists with ties to Osama bin Laden were receiving flight training at schools in the United States and abroad, according to interviews and court testimony. Three days after the attack on the Pentagon and the World Trade Center, FBI Director Robert S. Mueller III described reports that several of the hijackers had received flight training in the United States as news, quite obviously," adding, "If we had understood that to be the case, we would have -- perhaps one could have averted this." A senior government official yesterday acknowledged law enforcement officials were aware that ... a dozen people with links to bin Laden had attended U.S. flight schools. Abdul Hakim Murad ... was arrested in Manila in 1995 and later convicted in New York of plotting to blow up a dozen U.S. airliners over the Pacific, then crash a suicide plane into CIA headquarters. According to law enforcement officials and press reports, the 19 suspected terrorists received flight training from at least 10 U.S. flight schools. At least 44 people sought by the FBI for questioning received some flight instruction.