Turkish officials, including Erdogan, maintain they did their job by warning Belgium that Bakraoui could be a “foreign terrorist fighter.” The Belgian government says the warning failed to include that crucial detail.
“Turkey only explained to us in January 2016 exactly why this man was stopped,” Belgian Justice Minister Koen Geens told lawmakers, though he conceded, “we should have guessed, based on the place he had been to.”
Source: Foreign fighters are evading Europe’s security net
Turkey is signatory to international conventions and NATO security agreements that preclude any threat to airline security from boarding a plane. You simply cannot put a deported terrorist on a commercial airline, especially by himself. It is totally illegal to do so. In fact, anyone on the “no fly list,” which all terrorist suspects are supposed to be on, can never fly commercial for the rest of their lives. Finally, even if, by an unfortunate chain of errors or screw ups, a known terrorist got onto a plane; once their passport has been scanned into the airline’s computer, while they are flying along their name is being checked through every database base on the planet to catch any mistake that the boarding people made, so that “special people” can be waiting to escort the known terrorist into an interrogation room when they arrive.
Erdogan is lying. Ibrahim El Bakraoui was sent back to Belgium.