I wasn't talking about protecting the TK flight but rather options to get to BOS. B6 is limited during irrops compared to other airlines. Capacity & frequency are more constrained in B6 operations while AA can have more slack. Rerouting or putting on a different flight if a plane goes tech or there is a weather issue can save the situation.
Originally Posted by
LondonElite
Whilst this is generally true, it is of limited use to the OP as AA won't protect his TK flight destination (if that is the benefit you were referring to.)