U.S. Effectively Blocks Turkey From Operating In Syrian Airspace
"The Pentagon stated on Monday that Turkey has been removed from the “air tasking order” employed by members of the anti-Islamic State coalition operating in Syria."
"This means Turkish planes will have considerable difficulty entering Syrian airspace to support the invasion threatened by President Recep Tayyip Erdogan and will not benefit from surveillance data collected by the coalition."
If they take off and turn south then they'll eventually be in Syria. How difficult is that?