Narrative:

Large transport X was inbound to stl from the southeast on the moduc 4 STAR descending to 100. Small transport Y reported on frequency in the vicinity of fam descending to FL240. Small transport Y was clrd to 70 and told to expect 25 south of cps at 40. At this same time there were 3 other aircraft descending to 40 landing at stl satellite airports. These 3 were low performance aircraft. Speeds less than 180 KTS. Small transport Y was placed on a heading of 030 degrees to parallel traffic and clrd to cross 25 south of cps at 40 (if possible) pilot acknowledged he would try. Small transport Y was obviously not going to make the restriction so was placed on a heading of 070 degrees to avoid stl airspace. This heading would take small transport Y across the moduc 4 STAR in front of large transport X. Large transport X was placed on a heading of 270 degrees as sep was decreasing. Small transport Y was turned left to a heading of 040 degrees. Small transport Y was clrd to maintain 150 (mode C 156), large transport X mode C (152). Small transport Y acknowledged clearance then advised he was at '14 and 1/2. Do you want us to go back?' (I thought the reply was 148, do you want us to go back.) I advised affirmative. Small transport Y was asked to say altitude and the reply was 146 climbing back to 150. After latitude sep was re-established small transport Y was clrd to 40 and issued headings back to cps. Vertical sep should have been established earlier. The ZKC/stl LOA requires us at times to have turbo jet aircraft landing at satellite airports at 4000' as much as 35 NM from the airport. This can be very difficult to accomplish, especially when the low altitude controller initially talks to the aircraft descending to FL240 only 5 mins from the crossing point. I would like to see more updates per min on data blocks. Small transport Y mode C showed 156--actual altitude 145.

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Original NASA ASRS Text

Title: CTLR VECTORED DESCENDING CPR-SMT ACROSS THE PATH OF AND INTO CONFLICT WITH AN ACR-LGT ALSO DESCENDING.

Narrative: LGT X WAS INBND TO STL FROM THE SE ON THE MODUC 4 STAR DSNDING TO 100. SMT Y RPTED ON FREQ IN THE VICINITY OF FAM DSNDING TO FL240. SMT Y WAS CLRD TO 70 AND TOLD TO EXPECT 25 S OF CPS AT 40. AT THIS SAME TIME THERE WERE 3 OTHER ACFT DSNDING TO 40 LNDG AT STL SATELLITE ARPTS. THESE 3 WERE LOW PERFORMANCE ACFT. SPDS LESS THAN 180 KTS. SMT Y WAS PLACED ON A HDG OF 030 DEGS TO PARALLEL TFC AND CLRD TO CROSS 25 S OF CPS AT 40 (IF POSSIBLE) PLT ACKNOWLEDGED HE WOULD TRY. SMT Y WAS OBVIOUSLY NOT GOING TO MAKE THE RESTRICTION SO WAS PLACED ON A HDG OF 070 DEGS TO AVOID STL AIRSPACE. THIS HDG WOULD TAKE SMT Y ACROSS THE MODUC 4 STAR IN FRONT OF LGT X. LGT X WAS PLACED ON A HDG OF 270 DEGS AS SEP WAS DECREASING. SMT Y WAS TURNED LEFT TO A HDG OF 040 DEGS. SMT Y WAS CLRD TO MAINTAIN 150 (MODE C 156), LGT X MODE C (152). SMT Y ACKNOWLEDGED CLRNC THEN ADVISED HE WAS AT '14 AND 1/2. DO YOU WANT US TO GO BACK?' (I THOUGHT THE REPLY WAS 148, DO YOU WANT US TO GO BACK.) I ADVISED AFFIRMATIVE. SMT Y WAS ASKED TO SAY ALT AND THE REPLY WAS 146 CLBING BACK TO 150. AFTER LAT SEP WAS RE-ESTABLISHED SMT Y WAS CLRD TO 40 AND ISSUED HDGS BACK TO CPS. VERT SEP SHOULD HAVE BEEN ESTABLISHED EARLIER. THE ZKC/STL LOA REQUIRES US AT TIMES TO HAVE TURBO JET ACFT LNDG AT SATELLITE ARPTS AT 4000' AS MUCH AS 35 NM FROM THE ARPT. THIS CAN BE VERY DIFFICULT TO ACCOMPLISH, ESPECIALLY WHEN THE LOW ALT CTLR INITIALLY TALKS TO THE ACFT DSNDING TO FL240 ONLY 5 MINS FROM THE XING POINT. I WOULD LIKE TO SEE MORE UPDATES PER MIN ON DATA BLOCKS. SMT Y MODE C SHOWED 156--ACTUAL ALT 145.

Data retrieved from NASA's ASRS site as of August 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.