An approach controller and a flight crew arriving slc describe the circumstances surrounding a desce...

Attributes
ACN	983794
Time
Date	201112
Local Time Of Day	0601-1200
Place
Locale Reference	SLC.Airport
State Reference	UT
Environment
Light	Daylight
Aircraft 1
Make Model Name	Regional Jet 900 (CRJ900)
Operating Under FAR Part	Part 121
Flight Phase	Descent
Flight Plan	IFR
Aircraft 2
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Climb
Flight Plan	IFR
Person 1
Function	Approach
Qualification	Air Traffic Control Fully Certified
Person 2
Function	Pilot Flying Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Conflict Airborne Conflict Deviation - Altitude Excursion From Assigned Altitude Deviation - Procedural Published Material / Policy Deviation - Procedural Clearance

Narrative:

A CRJ9 was on the leehy arrival to slc. I cleared the crj direct dryer with a descent to 17;000 ft to sequence in front of traffic over jamin. I then issued a descent to 15;000 ft to the crj. I needed more room; so I re-cleared the crj direct to pittt and resumed the arrival for runway 16R with the last assigned altitude of 15;000 ft. There was a departure off slc level at 13;000 ft southbound. I was briefing the handoff controller with the sector information and traffic when I noticed the crj leaving 13;900 ft crossing in front of the departure. I turned the crj to 250 heading; climbed to 15;000 ft; and issued traffic. The departure had my arrival in sight and was instructed to maintain visual separation. The conflict alert never went off. The crj went down to 13;100 ft on a 250 heading to get more separation before climbing back up to 15;000 ft. The crj was never cleared to descend via the leehy 3 arrival. I think when I re-cleared the crj direct pittt they assumed they had a descent to 11;000 ft; which is the altitude they would descend to with restrictions if they were cleared to descend via the leehy 3 arrival.when I re-clear an aircraft that was on a RNAV arrival direct a new fix on that arrival; [I should] restate an altitude no matter if it is the same altitude that was previously issued.

Original NASA ASRS Text

Title: An Approach Controller and a flight crew arriving SLC describe the circumstances surrounding a descent below assigned altitude and a conflict with a departing aircraft.

Narrative: A CRJ9 was on the LEEHY Arrival to SLC. I cleared the CRJ direct DRYER with a descent to 17;000 FT to sequence in front of traffic over JAMIN. I then issued a descent to 15;000 FT to the CRJ. I needed more room; so I re-cleared the CRJ direct to PITTT and resumed the arrival for Runway 16R with the last assigned altitude of 15;000 FT. There was a departure off SLC level at 13;000 FT southbound. I was briefing the Handoff Controller with the sector information and traffic when I noticed the CRJ leaving 13;900 FT crossing in front of the departure. I turned the CRJ to 250 heading; climbed to 15;000 FT; and issued traffic. The departure had my arrival in sight and was instructed to maintain visual separation. The conflict alert never went off. The CRJ went down to 13;100 FT on a 250 heading to get more separation before climbing back up to 15;000 FT. The CRJ was never cleared to descend via the LEEHY 3 Arrival. I think when I re-cleared the CRJ direct PITTT they assumed they had a descent to 11;000 FT; which is the altitude they would descend to with restrictions if they were cleared to descend via the LEEHY 3 Arrival.When I re-clear an aircraft that was on a RNAV arrival direct a new fix on that arrival; [I should] restate an altitude no matter if it is the same altitude that was previously issued.

Data retrieved from NASA's ASRS site as of April 2012 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.

An approach controller and a flight crew arriving slc describe the circumstances surrounding a descent below assigned altitude and a conflict with a departing aircraft.