The T-39, DC-8 and ER-2 flew a coordinated mission over the CART site, with the DC-8 and T-39 sampling each others exhaust plume while the ER-2 flew a racetrack pattern above them. The T-39 measured the DC-8 plume at distances from 0.8km-8.0km. The DC-8 reported that the tropopause was too warm for contrail formation, however, the T-39 observed short lived contrails (1km-2km) from commercial aircraft at 32kft west of the CART site. Clear skies/low level cumulus was reported by all three aircraft.

Highlights

ER-2 lidar data from 04/15

Flight Reports

ER-2 Flight: 96103

Date: April 15, 1996

Mission: Non-persistent contrails/Radiation measurement mission over ARM CART Site. Aircraft (ER-2, DC-8, T-39) coordination exercise.

Mission Objectives

Observe T-39 non-persistent contrails, if present. Exercise T-39, DC-8, and ER-2 coordinated flight over ARM CART site checkpoint. Overfly ground-based instrumentation at the ARM CART site for comparison of ER-2 downlooking with surface based uplooking instruments.

Flight Track

Flight Summary

ER-2 launch at 1745 UTC; ER-2 recovery at 2045 UTC. ER-2 flew 2 1/2 revolutions of racetrack pattern (headings 345 and 165 degrees true north, ~100 nm flight lines) starting on eastern leg (heading 165). ER-2 overflew ARM CART site (36 36.6'N 97 34.8'W) at center of eastern leg. Total of 3 overpasses of ARM CART site. Aircraft coordination (ER-2, DC-8, T-39) checkpoint at ARM CART site.

Skies mostly clear at ARM CART site with increasing scattered boundary layer cloud formation on 2nd and 3rd overpass. DC-8 (on racetrack oriented 330/150 degrees) was unable to complete it's racetrack pattern due to air traffic control (ATC) vectoring of DC-8. This complicated aircraft coordination exercise, however ER-2 pilot reported verbal exchange placed ER-2 and DC-8 within about 30 seconds (~ 3 nm) of each other at CART site.

ARM CART site Central Facility coordinates provided for DC-8 and ER-2 flight plans did not agree. Coordinates being verified for next flight.

Highlights

Aircraft coordination was complicated by ATC. Verbal exchange placed ER-2 and DC-8 within 30 seconds of each other on ARM CART site overpass (1854 UTC). Mostly clear sky conditions useful for ARM science objectives. Three overpasses of ARM CART site (approximately1854, 1926; and 2001 UTC)).

Instrument Status

• Modis Airborne Simulator (MAS): Operated. Good data collected.
• Cloud Aerosol Lidar System (CALS): Operated. Good data collected.
• High-Resolution Interferometer Sounder (HIS): Operated. Good data collected.
• Millimeter-wave Imaging Radiometer(MIR): Operated. Good data collected.
• Tilt Scan CCD Camera (TSCC): Operated in non-data collection mode.
• Radiation Measuring System (RAMS): Operated. Status unknown at time of report.
• RC-10 Camera: Operated (black and white visible film- 6 inch lens).

Additional Pilot Notes:. No visual of DC-8 aircraft at coordination point. ER-2 pilot performed several loops to time arrival at CART site with DC-8 arrival.

Mission Summary

DC-8 SUCCESS flight #203 (scientist: Eric Jensen)

SUMMARY: The basic flight went very well. All of the instruments are functioning, with mainly small problems left to be worked out. We met all of our major objectives, testing instruments, calibrating the MMS and coordinating flight maneuvers with the T-39 and the ER-2.

Mission Objective

DC-8 TEST-FLIGHT

• practice coordinated flight maneuvers for DC-8 and T-39
• attempt a coordinated overpass of the ER-2 and DC-8/T-39
• test the Valero radiaometers on the ER-2, third test-flight
• evaluate how long after takeoff the DC-8 instruments become operational
• repeat a few of the calibration maneuvers for the MMS system

Flight Track

Flight Log

OPERATIONS
FLIGHT PLAN:
Planned takeoff: 17.00 UTC (12.00 local time)
The DC-8 and T-39 will climb out in formation and head to the CART site. Over the CART site racetrack patterns will be flown aligned with the wind (predicted to be 330 deg.). The DC-8 and T-39 will practice following one another. If possible, the DC-8 and T-39 will coordinate with the ER-2 to pass over a particular waypoint simultaneously. The success of the coordinated overpass will be determined visually by the ER-2 pilot. At the end of the flight, we will fly maneuvers to calibrate MMS.

TAKEOFF/LANDING
The DC-8 left Salina at 17.00 UTC (12.00 am local time) and returned to Salina at 20.30 UTC

FLIGHT REPORT
Circled over KSLP then headed south to WP 2. Climbed through stratocu at about 3-5 K'. Lost power to systems on converter 1, possibly due to short in 3-stage hygrometer pump. Climbed to 31 K'. T-39 flew off right wingtip, then flew in front. No coning. Tropopause Temp about -50 C. Indications from Twohey and DeMott/Rogers that we were intersecting plume: 60 s of enhanced CN number density with numbers as high as about 15000/cc. Most of the CN were involatile based on Twohey's heated inlet measurements. T-39 about 0.75 miles ahead. T-39 exhaust was also detected in H2O and CO2 measurements. Next, the T-39 pulled in behind and stayed behind. When T-39 used radar, MTP was fouled. Short contrail was observed during a few brief periods by T-39 while following. Laid contrail over CART site at T of about -50 C, low RHI. This contrail was not visible on video or looking back. Didn't begin racetrack over CART site until about 1.5 hours into flight. Air traffic problems forced turn in first leg of racetrack. T-39 headed home after waypoint 5 was reached. Started coning visibly at -53 C, 30% RHI. Descended to 25 K' to do MMS maneuvers. Did box and yaw maneuvers at 25 K'. Did pitch maneuvers at 23 K'. Attempted to repeat pattern at 17 K'. Air traffic forced one leg of box to be a couple of minutes. Yaw maneuver at 17K', and pitch maneuver at 16K'.

METEOROLOGY-REPORT
FORECAST: No clouds, tropopause too warm for even transient contrails.
OBSERVATIONS: As expected, tropopause was low and warm: near 10 km and -50 C. Popcorn cumulous was present at about 3-5 K'.

INSTRUMENT STATUS
All instruments are functioning.

• BALLENTHIN: No problems
• BAUMGARDNER: No major problems. Minor datasystem problems.
• BRUNE: ATHOS functioned well. Added NO and got good HO2 signal. Still need improved sensitivity. Need a few down days soon.
• CHAN: No problems. Expect to need some maeuvers every flight.
• COGGIOLA: No problems
• COOPER: Water dripped on instrument, but no major problem.
• DADS: Fine. Lost data in power failure.
• FERRY: Worked fine.
• GARY: Worked except maybe when T-39 radar was on.
• GERBER: Temperature, airspeed - dependent offset discovered.
• HAGEN: Worked OK.
• HALLET: Replicator worked, no clouds.
• HEYMSFIELD: VIPS and 2D-C, worked well.
• HUDSON: Pump failed near end of flight. Need replacement.
• LAWSON: Not on board
• RODGERS: Good data
• SACHSE: Hygrometer worked well. Alignment problem with CO instrument.
• TALBOT: No problems
• TWOHY: Good shape
• UTHE: Lidar worked well. Still adjusting displays.
• VALERO: Worked well. One chanel on TDDR still down.
• WEINHEIMER: Everything fine

Mission Highlights

• strong east-west O3 gradient observed near CART site
• T-39 plume was observed with high CN (up to 10000/cc, mostly involatile) and in CO2 and H2O measurements.
• background CN number densities were about 150 - 200/cc with about 50-80% non-volatile.

Mission Objective

T-39 Flight 02

• Practice aircraft coordination with DC-8 and ER-2.
• Establish ``comfort range'' of separation between the T-39 and DC-8 for plume/vortex penetrations.

Flight Log

TAKEOFF/LANDING:
The T-39 departed Salina at 17:03UT and returned at 19:28

FLIGHT REPORT:
The T-39 and DC-8 aircraft took off together and flew in formation to the experiment area. Once there, the DC-8 dropped back into the T-39 trail and sampled its exhaust emissions while the DC-8 pilots practiced coordinated maneuvers with the T-39. After completing a racetrack course, the T-39 dropped into the DC-8 trail and sampled as the DC-8 flew a series of racetracks over the CART site.

METEOROLOGY-REPORT:
Observed low level cumulus on takeoff and landing with clear skies in the mid to upper troposphere. Short contrails (1-2km) formed to the west of the CART site at 32k ft.

INSTRUMENT STATUS:

• CIMS - Not yet installed
• MS - Met/Nav system - worked (except for GPS)
• AMS - Air motion system - WORKED
• NDIR - CO2 - WORKED
• 3760 - fine CN - WORKED
• 3025 - ultra fine CN - WORKED
• FSSP - 0.3-20um aerosols - WORKED
• PCASP - 0.1-3um aerosols - WORKED

Highlights

• Accomplished low altitude rendezvous with the DC-8 and satisfactory formation flight.
• Made several dozen crossings of the DC-8 plume at separations of 0.8 to 8 miles.
• Observed large concentrations of volatile ultra fine particles at all distances behind the DC-8.