Not sure if this is the place to ask, but I'm trying to price out a specific routing using a TK codeshare (on Aegean). I'm a Matrix novice, but can't seem to force the routing I would like. The specific flights I'd like are:

June 6: TK80 SFO-IST
June 22: TK9190 (AE 990 codeshare) ATH-IST/TK79 IST-SFO

All the tools I try use TK1844 for the ATH-IST segment; if I try to force Matrix to use TK9190 it can't put together a routing. I'd rather use the earlier TK1844/A3 990 to add some cushion to an otherwise tight 1:10 connection in IST - I know it's nominally safe, but TK1844 seems to have a history of running late, often enough to misconnect in IST which would lead to something like (at best) being put on IST-BOS-SFO or IST-SEA-SFO instead of the nonstop (and we might lose the business class seats).

Any suggestions (or pointers to other places on FT to ask) greatly appreciated.

Even though this doesn't really answer your question... are you aware that any TK availability shown on Matrix is stale or simply incorrect?

Try to put it together with something that is bookable. Google Flights, the TK website, etc.

Contact your local ticket office to see if your preferred itinerary is possible to book, and in the affirmative whether you like the fare.

Anyway, I wouldn't hesitate to book the later TK1844 with only 1h10min at IST. Most likely you will make it. In the event of missing TK79 to SFO you most likely will be put on the next available TK flight to SFO (in business class) (same day or the following morning?) rather than via BOS or BOS (unless you specifically ask for this, but no guarantee that it will be granted). There is no reason to take the risk of loosing business class seats into the equation.

Anyway for flights 5 months out there is a significant risk of schedule changes or cancellations (TK is notorious for sch. changes and cancellations) which may play in your favour later (any cancellation or sch. change more than 15min will alllow you to rebook -7 / + 30 days and even to change destination and origin).

I would agree that TK is notorious for schedule changes and cancellations but they are back to their pre-COVID way of handling things, where the majority of the summer schedule for 2023 ( travel until last week of October 2023 ) was already adjusted back this fall.

Of course this doesn't mean that there wouldn't be any schedule changes but the risk is not high for this case unless TK decides to make major operational changes in their network at the last minute, which of course is possible within the world of TK.

I have a very tight connection in late May, 1:05 and 1h respectively, I don't think there's any chance of making it if I have to go through security. If there is a schedule change that is less than 15 minutes but will cut the connections to even shorter time, would I get a notification that I can change my flights?

Yes you get notified by email (and SMS) also of schedule changes of less than 15min. If you then check your reservation in the app or TK website it will tell you if a free rebooking is available.

At least for the flight from CPH you will be able to proceed directly to departures level from the aerobridge at IST, so 1 hour connection shouldn't be a problem.

It's 1h connection arriving from SIN, so it wouldn't be a clean arrival. Once I got in from YVR and it wasn't clean either.

The early morning arrival from SIN/Asia often gets in a bit early and if you miss the CPH flight, the next is 2-3 hours later. Nothing to worry about.

I really don't mind waiting in the lounge to catch the last flight back to CPH

I'm hoping for a schedule change