“How it Works” is part of a continuing series from the Central Air Safety Committee (CASC). On today’s episode, First Officer Jerimy Maclellan from CASC explains how Latest Allowable Takeoff Time (LATT) works. While seemingly simple, LATT is more complex and dynamic than most think. Did you know there are two LATTs? An FDP LATT and a Block LATT. Ever get rerouted? Your LATTs are likely incorrectly updated on your paperwork. As a FAR 117 requirement, LATT violations can create significant issues for pilots. On this episode, Jerimy explains what LATT is, how it affects pilots, and how to calculate and update LATT with rolling delays and operational challenges. (Recorded July 21, 2023)