According to a declassified CIA intelligence report from December 4, 1998: “Reporting [redacted] suggests Bin Ladin and his allies are preparing for attacks in the US, including an aircraft hijacking to obtain the release of [World Trade Center bombing conspirator] Shaykh ‘Umar ‘Abd al-Rahman, [World Trade Center bomber] Ramzi Yousef, and [U.S. embassy bombing suspect] Muhammad Sadiq ‘Awda. One source quoted a senior member of the Gama’at al-Islamiyya (IG) saying that, as of late October, the IG had completed panning for an operation in the US on behalf of Bin Ladin, but that the operation was on hold. A senior Bin Ladin operative from Saudi Arabia was to visit IG counterparts in the US soon thereafter to discuss options–perhaps including an aircraft hijacking.”
– CIA, “Bin Ladin Preparing to Hijack US Aircraft and Other Attacks,” (CIA Intelligence Report), The Central Intelligence Agency’s 9/11 File:, The National Security Archive, Dec. 4, 1998