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Aircraft Coordinator Summary

This was primarily a test flight, for shakedown of procedures,

instrumentation, communications. One specific objective was to circle the

1100L radiosonde ascent from Kwaj. In addition, there were significant

convective bands and large stratiform precip areas in the vicinity, so a

large portion of the flight was in cloud physics sampling mode.

As the scheduled 1100 launch time approached, so did a strong

convective band, with 40-50 dBZ echoes and some lightning. TRMM Ops so

notified the a/c and suggested holding off to the NW of Kwaj. The 11L

launch was postponed to 12L to await the passage of a second convective

band. Both bands were oriented NNW-SSE and moved across Kwaj from ~060

degrees at 40-50 km/hour. The a/c came over TRMM Ops at 1200L at 500' and

successfully followed the balloon up to about 20Kft. (Later, we looked at

the sounding, noting that it was very moist but with an apparent subsident

drying area from about 600-700 mb (0C to +10C))

The convective bands were rapidly going to stratiform after 12L,

and the strat area covered about 200 X 100 km with long axis E-W centered

about 30 km N of Kwaj. The a/c was given a short S-N flight line through

significant stratiform echoes at 1240L. That area weakened rapidly, so a

longer line was sent to the a/c at 1307L through the best remaining echoes

farther to the WNW. That was flown while slowly descending and the

aircraft returned to Kwaj.

Issues. This was a good shakedown for Ops Center procedures.

Communications worked well, with help from Carl Sweetland. The aircraft

tracks were brought up on the screen soon after takeoff. We learned some

lessons about keeping aware of updates to the radar screens; this is

crucial if we are to anticipate the best locations for flight tracks with

sufficient lead time. In today's flight, TRMM Ops should have seen the

decay of the strat area quicker than we did.

Overall, this was a worthwhile first mission.

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UNIVERSITY OF WASHINGTON FLIGHT FOR KWAJEX

DATE: 26 July 1999

UW FLIGHT #: 1783