Mission Briefing:
This mission was designed to inter-compare aircraft flight level instrumentation between the two NOAA aircraft, to flight test new CBLAST instrumentation, to test the hurricane planetary boundary layer (PBL) flight pattern and to execute BAT probe calibration maneuvers.

Mission Synopsis
Detailed mission briefings were held with AOC flight directors the day before the flight to discuss any problems with the calibration flight segments being planned. A detailed briefing on CBLAST, air sea and ocean winds hurricane flight patterns followed with AOC flight crew. Two hours prior to the flight, a second briefing with the flight crew was held to discuss the flight profile.
The flight, delayed for two days by a defective prop hub, departed AOC at MacDill AFB at 1400 UTC, Aug 23 and landed at MacDill AFB at 19:45 UTC, Aug 23, a duration of 5.75 hours. Flight altitudes were 10,000, 5,000 and 1,000 ft for formation flying during the two-aircraft inter-comparison portion of the flight. The aircraft flew 5-6 min legs outbound and inbound from NDBC buoy 42003 in the east-central Gulf at two values of the indicated airspeed: 220 kt (penetration airspeed) and 190 kt (ocean probe deployment airspeed). The aircraft then descended to 600 ft during the cross wind flight legs of the PBL flight pattern followed by legs at 3,500, 2,000, 1,000, 600, 400 and 200 ft during the along wind portion of the PBL pattern. The flight altitude for the BAT wind circle and box calibration maneuvers was 2,000 ft.
There were scattered cumulus congestus clouds in the area during the mission. The surface wind was 5 kt from 110 deg.
Following the first downwind leg, 43RF departed the area to fly through rain cells about 50-100 nm away. However, their mission had to be cut short following failure of the UMASS IWRAP system. Two problems were encountered: 1) a failed motor for rotating the antenna systems and 2) a failure of the communications between the processor and data recording systems.
The formation flying portion of the flight was executed flawlessly. The aircraft approached to within about 100 ft of each other with 42 just below and trailing 43 for the first two altitudes and then switched positions for the final altitude. The formation was held even in turns- a very impressive performance.
The boundary layer pattern was also executed extremely well. However, one premature altitude change pointed to the need to more clearly lay out the flight altitude and probe deployment sequence. The aircraft coordination was carried out flawlessly as was the sequence of GPS sonde, AXBT and sonobuoy deployments. This included coordinating channel numbers for both AXBTs and GPS sondes to prevent any probe transmission interference.
The main CBLAST instruments being tested on this flight were the NOAA FRD BAT probe and IRGA systems for turbulence measurement and the Scripps suite of instruments: the laser altimeter, the downward digital camera system and the sonobuoy receiver. The BAT probe and IRGA performed perfectly as did the Scripps systems. The digital camera system was impressive to watch as it captured images at a nominal 10 hz at the higher levels and at 20 hz at the lower levels. All cad-launched and internal free-fall launched sonobuoys functioned for the duration of the flight following deployment. This was a pleasant surprise as previous AOML users of the Navy surplus units had reported 70% failure. This may have been due to improper hand-launching from a ship.
The Scripps data will be analyzed for any problems the coming week. The BAT and IRGA data were written to a zip disc and will be sent to Jeff French in Australia and Ed Dumas in Oak Ridge for analysis.
The HRD SFMR still appeared to exhibit biases in near-zero wind brightness temperatures. However, Pro Sensing had not yet provided calibration updates from the previous weeks initial test. Empirical biases were applied that will be used in high wind environments as a default.
The real-time transmission of AXBT ocean temperature profiles and computed ocean heat content were transmitted to NHC for the first time. The system of real time despiking, smoothing and significant level computation will continue to be tested this season in high wind environments.

Problems:
All aircraft systems performed flawlessly, including expendable probe deployment and processing systems. The HRD workstation failed to communicate with AVAPS dropsonde system, AXBT system or radar systems despite having done so during pre-flight checks. This problem will be addressed on Monday or Tuesday following arrival of HRD computer personnel.
The SRA system for directional ocean wave spectra, surface elevation (storm surge) and low rain rates was not operated despite intermittent data dropouts due to flawed automatic frequency control (AFC). Ed Walsh had to return to base in Boulder before the twice-delayed flight could be conducted.
The PMS and CIP particle measurement probes were not installed. All are awaiting completion of the new wing pylon to mount the probes. All electronics is installed and also awaiting pylon completion and installation, now expected about Sept 15.
As mentioned above, the IWRAP system on NOAA42 failed. UMASS engineers will continue working on the system during the coming week.
One miscommunication resulted in a premature climb in the flight pattern. Format and content of flight leg and expendable probe deployment sequences will be revised to clarify these maneuvers.

Return to Mission page.