Upvote:7
Due to significant increase in international fare, can Airlines cancel fight for only those passengers who bought tickets at a low price economic class with the lowest subclass e.g. V?
Generally no. Cancellations are mostly due to cancellations of an entire flight which affects all passengers equally or problems with connections (schedule or route changes). I've never heard of a case where an airline kicked low-fare passengers off a flight to create space for selling more high-fare tickets.
It would probably violet their contract of carriage and it's easy enough to detect: If your flight is cancelled you can check if it's still available for booking (at a higher fare).
One related mechanism is "overbooking". That's when airlines sell more tickets than they have seats under the assumption that a certain percentage of customers don't show up. When more customers check in than expected, some don't get to go. In these cases the airline will first look for volunteers offering compensation and other incentives. There is a bit of negotiation happening. If not enough people accept, they often do raise the incentives a couple of times.
If that still doesn't produce enough seats they will start kicking people off the flight (involuntarily denied boarding) and fare class and status do indeed play a role in this selection process. The exact rules are not public as far as I know.
Overbooking has generated a lot of negative publicity and in my experience is fairly rare these days.
How can a traveler find out about the type of "sub class " at the time of on line booking and T&Cfor the fare?
These are always disclosed at time of booking and you need to actively agree to the fare rules. Of course, most people don't bother to read and/or save them. In most cases all of this is readily available on the airlines website. For example here is my online record for the flight I will take tomorrow. It's an "X" fare class.