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.
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.
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.
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)).
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.