Onur Air has ceased operations as of December 2021
They declared bankruptcy in April 2022.
I've flown with Onur Air several times, and they were fine flights: comfortable, professional, on time.
Onur's fleet of aircraft (mostly Airbus) has been flying tour groups to and from Germany and Switzerland since 1992 in association with Ten Tour, a major Turkish tour operator.
In the last few years Onur has been expanding its Turkish domestic flights. Its routes from Istanbul include flights to:
It's not quite as easy to make reservations on Onur Air flights as it is on Turkish Airlines flights because fewer travel agencies work with Onur Air. (Two that do areEfendi Travel near Istanbul's Sultanahmet Square; and Argeus Tourism in Cappadocia.)
You can try making your own reservations onlineusing the Onur Air website: look for the tiny, colorless British flag in the upper right-hand corner of the homepage and click on it to reach the English-language version of the site.
Try to concentrate with all the unnecessary flashing, blinking, moving baloney on the page.
You can also try to contact Onur Air by email, telephone or fax, but some TTP users have found it difficult to get an answer:
Tel (Istanbul) +90 212 662 9797 or +90 212 663 9176
Fax (Istanbul) +90 212 6630773
Domestic routes: email@example.com
Call center: firstname.lastname@example.org
Atatürk Airport (Istanbul): email@example.com