Так вот почему тур. визы почти перестали продлевать - унификация с шенгеном:
Holders of type C visa can apply to the local authorities -Department of Migration for an extension of their visa for a period of up to 90 days from the date of entry, within any 180-day period. A condition for the extension of a visa is that the visa holder is able to provide evidence of force majeure or humanitarian reasons preventing him from leaving the territory of the Member States before the expiry of the period of validity of or the duration of stay authorised by the visa. Such an extension shall be granted free of charge.

Отмена рейса подходит.

AI пишет только что только last-minute:
A last-minute flight cancellation or schedule change caused by severe weather conditions, sudden airline strikes, airport closures, or technical/security emergencies typically counts as force majeure. (Note: Routine cancellations or personal scheduling mistakes generally do not qualify).

Ясно. Раньше визы выдавали с запасом на несколько дней, а сейчас строго по билетам. И стать нарушителем легко.

шенген всё ближе