Narrative:

Traffic was called out to us 1-2 O'clock, 18 mi. We gained visual at approximately 10 mi. At this time we were told to maintain visual separation and climb from 10000 ft to 13000 ft MSL while the traffic was cleared to descend from 13000 ft to 11000 ft MSL. The traffic was at our 2 O'clock descending and closing. I was the PF and initiated the climb. The captain said he was not comfortable with the separation and said he wanted me to descend back down to 10000 ft, which I complied with. As I begun the descent we got a TCASII RA to increase our vertical descent rate which I complied with. We never got above about 10500 ft MSL and the other aircraft was only cleared to 11000 ft MSL. As we were descending the other aircraft changed course, probably more to keep us in sight as we descended under his nose as opposed to evasive action. Contributing factors were the controllers seeming inability to perceive the potential conflict prior to issuing the clearance (he still didn't understand when we explained our deviation due to the TCASII RA). Also, the captain was indecisive in his decision making process -- continue the climb or descend? Finally, although I was hand flying the airplane, the climb rate commanded by the FMC was inadequate to provide proper separation with the closure rate between the 2 aircraft. Both of us should have recognized this sooner and climbed steeper or refused the clearance until the other aircraft was clear of our flight path.

Related reports:

Google
 

Original NASA ASRS Text

Title: A DEPARTING B737 IS ISSUED AN ARRIVING B737 AS TFC AND ADVISED TO MAINTAIN VISUAL SEPARATION AND ISSUED A CLB.

Narrative: TFC WAS CALLED OUT TO US 1-2 O'CLOCK, 18 MI. WE GAINED VISUAL AT APPROX 10 MI. AT THIS TIME WE WERE TOLD TO MAINTAIN VISUAL SEPARATION AND CLB FROM 10000 FT TO 13000 FT MSL WHILE THE TFC WAS CLRED TO DSND FROM 13000 FT TO 11000 FT MSL. THE TFC WAS AT OUR 2 O'CLOCK DSNDING AND CLOSING. I WAS THE PF AND INITIATED THE CLB. THE CAPT SAID HE WAS NOT COMFORTABLE WITH THE SEPARATION AND SAID HE WANTED ME TO DSND BACK DOWN TO 10000 FT, WHICH I COMPLIED WITH. AS I BEGUN THE DSCNT WE GOT A TCASII RA TO INCREASE OUR VERT DSCNT RATE WHICH I COMPLIED WITH. WE NEVER GOT ABOVE ABOUT 10500 FT MSL AND THE OTHER ACFT WAS ONLY CLRED TO 11000 FT MSL. AS WE WERE DSNDING THE OTHER ACFT CHANGED COURSE, PROBABLY MORE TO KEEP US IN SIGHT AS WE DSNDED UNDER HIS NOSE AS OPPOSED TO EVASIVE ACTION. CONTRIBUTING FACTORS WERE THE CTLRS SEEMING INABILITY TO PERCEIVE THE POTENTIAL CONFLICT PRIOR TO ISSUING THE CLRNC (HE STILL DIDN'T UNDERSTAND WHEN WE EXPLAINED OUR DEV DUE TO THE TCASII RA). ALSO, THE CAPT WAS INDECISIVE IN HIS DECISION MAKING PROCESS -- CONTINUE THE CLB OR DSND? FINALLY, ALTHOUGH I WAS HAND FLYING THE AIRPLANE, THE CLB RATE COMMANDED BY THE FMC WAS INADEQUATE TO PROVIDE PROPER SEPARATION WITH THE CLOSURE RATE BTWN THE 2 ACFT. BOTH OF US SHOULD HAVE RECOGNIZED THIS SOONER AND CLBED STEEPER OR REFUSED THE CLRNC UNTIL THE OTHER ACFT WAS CLR OF OUR FLT PATH.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.