Doppler/Dropsonde Scientist | Sim Aberson |
Doppler/Dropsonde Scientist | Rob Rogers |
IWRAP Scientists | Zorana Jelenak
Dani Esteban-Fernandez Joe Manus |
Pilots | Carl Newman |
Flight Director | Tom Shepherd |
Navigator | Tim Gallagher |
Flt. Eng. | Steve Wade |
Data Tech | Sean McMillan John Hill |
Elec. Tech | Bill Olney |
Mission Plan :
This was the third planned flight in a series of flights into Felix to gather 3-dimensional Doppler wind data during the entire life cycle of a tropical cyclone. The plan was to approach Felix from the northeast and do 105 nm legs, each rotated 45 degrees downwind from the previous leg's endpoint, for a total of four passes. Since the last of the four passes ended on the west side, the plane was to turn around and perform one final pass, then return to St. Croix.
Due to fix responsibility, at least two of the passes were to require hunting for the center and releasing a dropwindsonde in the eye. The plan was to accomplish this on the seond and fourth passes (north-south and east-west) from 10,000 ft, with dropwindsondes released at the endpoints and midway between the endpoints and the center. Due to IWRAP interests, the two other passes would be done at 7000 ft, and the final pass at 5000 ft if flight felt this was safe. Eyewall soundings were planned for each eyewall penetration.
N42RF will leave St. Croix, USVI at 04:00 PM AST, and recover at St. Croix, USVI at 11:00 PM AST.
Mission summary and evaluation:
Takeoff was planned for 2000 UTC. However, the inertial navigation was not set properly before takeoff, and the plane had to return to allow the navigation to reset. Takeoff occurred about 40 minutes late. Because of operational responsibility within a set time, the 10,000 ft legs were switched to the first and third. Upon approach to the center, the endpoint and midpoint dropwindsondes were released and provided good data. It was apparent from both TA and nose radars that the storm had a very small eye surrounded by a high-reflectivity ring, with purple on the nose radar. Close to the eye, the flight-level and surface (SFMR) wind speeds were relatively low, then began to spike rapidly. Upon penetration of the eyewall, at 10,000 ft, the aircraft was pelted with hail, encountered constant cloud-to-cloud lightning, and an updraft downdraft couplet that caused the accelerometers to read +4G/-4G, higher than safe operations allow, so the decision was made to abort the mission.
Sim Aberson
Mission Data:
SFMR temp brightness |
SFMR wind speed and rain rate |
SFMR Felix winds vs. Katrina winds |
Temperature and Moisture |
Wind |
Track |
Track detail |