Updating the comments from yesterday with news that wasn't published till late in the day, both aircraft are in fact bound for Antarctica. Kenn Borek has launched their third rescue mission into the Antarctic winter, this time to bring an employee of the Lockheed Martin Antarctic Support group out for critical medical treatment.
725 - DHC-6-300 C-GKBO Kenn Borek Air, Calgary, AB
Flew Calgary-Int'l, AB - Denver-Centennial, CO - McAllen-Miller Int'l, TX - Liberia 14/15-Jun-2016
733 - DHC-6-300 C-GKBG Kenn Borek Air, Calgary, AB