I think 4gb is the bare minimum for the current version of the app. Best option would be to close every background app and reduce the quality of the graphics to medium or low. If that doesn’t work, then a new device should be considered.
I’m surprised Benny didn’t already add a comment here.
Mine’s been doing the same. Just attempted 5 flights from KSFO, each time crashing right after pushback or just after taking off. I’ve already cleared out the cache, removed unnecessary apps, and lowered the quality.