General information for passengers coming from outside Istanbul: 

• You are required to obtain a Domestic Travel Permit document from the relevant authorities and you must carry this with you at all times. You may obtain permission for one person to accompany you. 
• We kindly recommend that you arrive in Istanbul before the curfew begins, if possible. 
• We kindly recommend that you stay overnight at the Istanbul Airport hotel, if arriving in Istanbul the day before your flight. Alternatively, we recommend that you stay overnight in areas, such as Taksim, Aksaray and Kadıköy, that are close to the HAVAIST bus departure points. 

How to get to the airport during the curfew 

• You can use the HAVAIST bus to get to the airport. Please check the HAVAIST page for the timetables and routes. 
• If you wish to take a taxi to the airport, please call the Istanbul Airport Taxi Coop. via +90 850 780 7734 or +90 533 315 7133 to arrange for a pick-up at your address. Please note that these taxis can only provide transportation to the airport. Note: Other taxi companies may not be able to provide service during the curfew. 

Other necessary information: 

• You are required to have your international flight ticket with you at all times. You may be asked to present this ticket at various checkpoints. 
• You are not required to obtain a Domestic Travel Permit document if you are traveling to the airport from Istanbul via local transportation and we kindly request that you keep your international flight ticket with you at all times. Passengers are permitted to have one person accompany them. (That person should retain a copy of the flight ticket to present at checkpoints, if necessary, upon returning from the airport). 
• You must be at the airport 4 (four) hours before the scheduled flight time. 
• Passengers who cannot attend their flight will have the right to change their tickets and refund. 
• If you need assistance, please call 444 0 849.

https://www.turkishairlines.com/en-tr/announcements/evacuation-flights-during-curfew/