May 8, 1998 2^nd flight

Crew: Streibel, Miller, Arnott, Poellot
{return}

195333 Takeoff, cirrus mission.

200330 Starting spiral climb at CART. A very faint halo around the sun.

200705 Occasional light turbulence. Climbing through 20,700'.

200816 A few ice crystals, going through 28,650'.

201340 Up through 26,500'. Getting into some larger particles. 2d concentrations 20/L, 1dp 2/L. Sizes up to 1 mm.

201600 Adjusted flow on CN.

201750 In and out of wisps at the top at 30,000'

201922 In a higher top at 31,000' Other than that weíre on top of most cloud.

202040 Note: cirrus deck is optically thin we can see the ground from 31,000'. The base was down at about 22,000'.

202635 Level for leg at 30,000'. Step down. We may have some higher cirrus just starting to overspread the site. Winds are 242/109.

202815 CART, 30,000'. The cirrus is thickening just as we passed over. That cirrus patch contains light turbulence.

203543 CART, 29,000'. In cloud, 20/L, frequent light turbulence.

203730 Turning around, getting high concentrations of larger particles, in the 300-600mm size.

204229 CART, 28,000', light turbulence. Again getting into higher concentrations. The turbulence is getting a little more significant in the turn around ñ light, occasional moderate.

204730 Seeing a halo around the sun. Particle sizes are in the 300-600 mm range to 1 mm plus.

204906 CART, 27,000'. Turbulence light, very occasional moderate. Concentrations at 1dp sizes are running 6-8/L. Particles are somewhat uniform in size.

205430 At 26,000', 2 miles from CART, turbulence now light to moderate.

205522 CART, 26,000'. Light to moderate turbulence.

210109 CART, 25,000'. Turbulence light to moderate. Particle concentrations decreasing slightly from a couple minutes ago.

210400 Changing to pitot wing the nose port has clogged up in the ice crystals. It looks like it started plugging up just under 2 minutes ago.

210820 We passed over the CART about 1 minute and 20 seconds ago. The cirrus is thinner upwind of CART now. The sun is brighter. The last pass was at 24,000'.

211045 CART, actually about a mile south of CART, southeast, at 23,000'. Turbulence is only light.

211500 We're at 22,000', 6 miles from CART. Particles are larger here, seeing more 1+ mm in size.

211713 CART, 22,000', light turbulence. The bases seem to have lowered since we started this exercise.

212242 CART, 21,000'. Still in cloud of medium density.

212756 CART, 20,000'. Weíll drop to 18,000í next, followed by a spiral up.

AT 18,000' weíre near the base, but not out of cloud. We still have significant concentrations of larger particles.

213320 (approx.) Went over CART, 18,000'. The air is fairly smooth at these lower altitudes.

213600 Weíre going down to 16,000' to see if we can get out of the base, and then spiral up. It looks like some of the images near the base are almost more plate-like, with clear areas in the center of the 2d images. Base of clouds at 16,700'.

213838 Starting spiral up from 16,000'.

214310 Back into light turbulence at about 21,400'.

214635 The cirrus is a bit thinner. Weíre at 24,400'. Still high concentrations, but the sun is more visible. Maybe it ís just because we're getting up toward cloud top. Turbulence is frequent (light turbulence). We do see a halo. Particles are rosettes, plates, at about 26,000'.We're in an area of lower cloud top. We'll continue to circle. Cirrus is somewhat patchy as we get up toward top, through 27,300' at 215008.

215430 Passed over CART. Descending to 28,000' for an upwind turbulence run.

215830 In a bit of a hole, but higher tops ahead. Heading SW, winds are 231/98.

220615 Turbulence is gradually increasing as we head SW. About 30 miles southwest of CART, turbulence is continuous light, approaching moderate.

221625 60 miles SW of CART, reversing course, 28,000'. There has been no halo on this track.

222555 On the return trip to CART, about 18 miles out, 28,000'. Winds are 215/80

222730 About 10 miles from CART. Weíve been told by ATC to descend to 24,000í for traffic.

222933 CART, descending through 26,600'. We'll start a spiral down.

223110 Descending through about 24,800', cloud is fairly thick.

224415 Leveling at 13,000' for legs. Pilot reported cloud base was about 14,300'. Weíre still in fallout at 13,000'. Particles are aggregates, several mm in size.

224856 CART, in light to moderate turbulence, 13,000'.

225140 In patches of liquid water cloud; a mixed phase cloud.

225300 Just turning King probe back on for some reason the switch had been bumped off. We're descending to do the reverse leg at 12,000'.

225356 Patch of ragged cloud ahead.

225526 CART.

230057 CART, 12,000', heading 200.

230421 CART, 12,000', in large ice crystals, light occasionally moderate turbulence. End of mission.

We had turbulence on descent until about 9,000', 230730.

231230 Landing.

3 hours, 19 minutes

3.3 hours