Narrative:

Mdt departed aspen, co bound for den. Filed route of flight was ase dbl byson den. Requested altitude was FL190. Small transport was cleared visibility den DEN234056 mtj at FL180. Sector 11 and 12 were combined at sector 12. Traffic was light to moderate. There were 2 controllers at the sector (myself and a radar controller). Aspen airport is contained within sector 11, within which is aspen approach control. Aspen TRACON issued departure clearance to mdt and by letter of agreement, assigned mdt FL190 and radar vector heading 085 degrees to join the den 213 degree right and inbound. It should be noted that the ase TRACON radar coverage is much different than center radar coverage. Ase TRACON receives its radar data from its own system on ajax mountain. Center receives its data from a mosaic of the parker and grand junction radar sites. As such, ase TRACON may not have data on the an aircraft when center does, and vice versa. Mdt data block was accepted by center almost immediately after departure (no actual beacon target). This is a widely used procedure in anticipating that once the aircraft gets high enough, a target will come up. In this case, mdt rate of climb was insufficient to reach the mia/MVA's on the 085 degree heading. Ase TRACON assigned a VFR climb through 17000' (verbal coordination required, but not accomplished). Mdt then checked on sector 11 frequency climbing 'on my own 142 to FL190.' mdt after being asked stated his position 14 NM east of dbl. Subsequently reported 20 NM southeast of dbl. Still non radar at that time, mdt was assigned sector 26's frequency. Tapes reveal mdt checked on with sector 26 leaving 17000' for FL190. Mdt then appeared in radar in sector 26's airspace (dbl 081025) head-on with small transport with 9.3 NM latitude sep at 17300'. Subsequently the aircraft passed each other. It should also be noted that more than adequate time existed from the time mdt checked on with sector 26 to take action to prevent loss of sep.

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Original NASA ASRS Text

Title: ACFT CLIMBING TO FL190 IN AN AREA OF POOR RADAR COVERAGE CAME CLOSE TO ACFT ENROUTE AT FL180.

Narrative: MDT DEPARTED ASPEN, CO BOUND FOR DEN. FILED RTE OF FLT WAS ASE DBL BYSON DEN. REQUESTED ALT WAS FL190. SMT WAS CLRED VIS DEN DEN234056 MTJ AT FL180. SECTOR 11 AND 12 WERE COMBINED AT SECTOR 12. TFC WAS LIGHT TO MODERATE. THERE WERE 2 CTLRS AT THE SECTOR (MYSELF AND A RADAR CTLR). ASPEN ARPT IS CONTAINED WITHIN SECTOR 11, WITHIN WHICH IS ASPEN APCH CTL. ASPEN TRACON ISSUED DEP CLRNC TO MDT AND BY LETTER OF AGREEMENT, ASSIGNED MDT FL190 AND RADAR VECTOR HDG 085 DEGS TO JOIN THE DEN 213 DEG R AND INBND. IT SHOULD BE NOTED THAT THE ASE TRACON RADAR COVERAGE IS MUCH DIFFERENT THAN CENTER RADAR COVERAGE. ASE TRACON RECEIVES ITS RADAR DATA FROM ITS OWN SYS ON AJAX MOUNTAIN. CENTER RECEIVES ITS DATA FROM A MOSAIC OF THE PARKER AND GRAND JUNCTION RADAR SITES. AS SUCH, ASE TRACON MAY NOT HAVE DATA ON THE AN ACFT WHEN CENTER DOES, AND VICE VERSA. MDT DATA BLOCK WAS ACCEPTED BY CENTER ALMOST IMMEDIATELY AFTER DEP (NO ACTUAL BEACON TARGET). THIS IS A WIDELY USED PROC IN ANTICIPATING THAT ONCE THE ACFT GETS HIGH ENOUGH, A TARGET WILL COME UP. IN THIS CASE, MDT RATE OF CLB WAS INSUFFICIENT TO REACH THE MIA/MVA'S ON THE 085 DEG HDG. ASE TRACON ASSIGNED A VFR CLB THROUGH 17000' (VERBAL COORD REQUIRED, BUT NOT ACCOMPLISHED). MDT THEN CHKED ON SECTOR 11 FREQ CLBING 'ON MY OWN 142 TO FL190.' MDT AFTER BEING ASKED STATED HIS POS 14 NM E OF DBL. SUBSEQUENTLY RPTED 20 NM SE OF DBL. STILL NON RADAR AT THAT TIME, MDT WAS ASSIGNED SECTOR 26'S FREQ. TAPES REVEAL MDT CHKED ON WITH SECTOR 26 LEAVING 17000' FOR FL190. MDT THEN APPEARED IN RADAR IN SECTOR 26'S AIRSPACE (DBL 081025) HEAD-ON WITH SMT WITH 9.3 NM LAT SEP AT 17300'. SUBSEQUENTLY THE ACFT PASSED EACH OTHER. IT SHOULD ALSO BE NOTED THAT MORE THAN ADEQUATE TIME EXISTED FROM THE TIME MDT CHKED ON WITH SECTOR 26 TO TAKE ACTION TO PREVENT LOSS OF SEP.

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.