The second problem we wish to bring to your attention concerns passengers holding nonrefundable tickets or tickets that require the payment of a penalty for a change of flight time or travel date. It is our understanding that at least one carrier has been applying its nonrefundability/penalty provisions in situations in which the change of flight time or travel date has been necessitated by carrier action or "an act of god", e.g., where the carrier cancels a flight for weather or mechanical reasons. Imposing monetary penalties on passengers in these kinds of situations is grossly unfair and it violates 49 U.S.C. 41712, as would any contract of carriage or tariff provision mandating such a result. We will aggressively pursue any cases of this type that come to our attention.