1. Temperature restrictions First flight: One excursion below 189.5 K for up to 20 min Multiple excursions less than 10 min After each cold soak, warm soak 3x as long Spoiler-closed descents Temperature loggers in actuator bays Second flight: Actuator-bay temperatures will be evaluated Double times from first flight Ultimately up to 60 min at cold temperatures

2. Strategy for first flight Do not profile into cold tropopause region until cruise altitude is well above cold point Fly over cold region before profiling through tropopause Ascents/descents through cold point tropopause should result in T < 189.5 K for less than 10 min Multiple excursions less than 10 min Attempt to approach 20 min later in flight Profile near the edge of cold regions, allowing quick escape

3. Strategy for first flight

4. General flight strategies Numerous profiles through TTL Depth of profiles? Lagrangian flight paths (along wind) Survey patterns Range of latitudes to sample Sampling downstream of western Pacific convection and cold temperatures Sampling intrusions of extratropical air into TTL Takeoff time shifted to maximize daylight in tropics Suggestions would be appreciated!

5. Dissemination of flight plans Flight plans and updates will be posted on Mission Tools Suite (MTS) Email notifications will be sent for significant flight plan changes