Pilot descended below his assigned altitude and came in close proximity to another aircraft.

Attributes
ACN	143469
Time
Date	199004
Day	Mon
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : avl
State Reference	NC
Altitude	msl bound lower : 5600 msl bound upper : 6000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : avl
Operator	common carrier : air carrier
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Small Transport, Low Wing, 2 Recip Eng
Flight Phase	descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach controller : departure
Qualification	controller : radar
Experience	controller radar : 1
ASRS Report	143469
Person 2
Affiliation	government : faa
Function	controller : handoff position
Qualification	controller : radar
ASRS Report	143306
Events
Anomaly	conflict : nmac non adherence : clearance non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	unspecified : 1 vertical : 300
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation Intra Facility Coordination Failure

Narrative:

Small transport X departed runway 16 with first fix sot. I gave him a left turn to 030 degree to avoid the WX west of him. He requested a right turn to 210 degree. I approved it. Small transport Y approximately 25 mi southwest inbound at 11000'. I descended small transport Y to 7000', 5 mi inside our boundary. I told him to expect visibility approach. Left traffic to runway 16 because of the WX west of the field. He said he saw the WX and left traffic was ok and acknowledged descent to 7000'. Small transport X requested direct tys. Handoff position began working on his request. Small transport Z strip came down tube. I observed route of flight and altitude on strip then determined he needed an altitude restriction of 6000'. Small transport Y was 15 mi sse of avl leaving 9000'. I turned him left to 360 degree. Small transport Z tagged up. I called him, no answer. Called local control, they said he was still on their frequency. I said switch him to me or stop him at 6000'. Local said small transport Y would have runway 34 reference. Small transport Z I said, stop small transport Z at 6000' and switch him to me. Local said is small transport Y going to take runway 34? I said stop small transport Z and switch him now! I looked over at small transport X who was in a position where he should be handed off to the center controller. Asked handoff position what was the verdict. He said he was still working on it. Small transport Z called, I verified his altitude and turned him left to direct to sug. He was leaving 3900'. Then I told smy Y about the runway 34 being available and the traffic departing runway 16, and the wind. He said runway 34 was acceptable. I then told him to reduce his airspeed. Small transport Y was approximately 10 mi southeast leaving 7400'. I looked back over at small transport X who was approximately 8 mi from our boundary still not handed off. I observed his altitude, it showed FL200. I waited another radar sweep but it still showed FL200. Looked back at small transport Y, his altitude showed 5600'. I asked small transport Y to verify level at 7000' he said he was descending to 5000'. I told him to climb and maintain 7000' immediately, issued traffic, then restr small transport Z to 5000'. Small transport Y said he had the traffic in sight. Small transport Y passed approximately 300' above and behind small transport Z. (The data blocks were overlapped).

Original NASA ASRS Text

Title: PLT DESCENDED BELOW HIS ASSIGNED ALT AND CAME IN CLOSE PROX TO ANOTHER ACFT.

Narrative: SMT X DEPARTED RWY 16 WITH FIRST FIX SOT. I GAVE HIM A L TURN TO 030 DEG TO AVOID THE WX W OF HIM. HE REQUESTED A R TURN TO 210 DEG. I APPROVED IT. SMT Y APPROX 25 MI SW INBND AT 11000'. I DSNDED SMT Y TO 7000', 5 MI INSIDE OUR BOUNDARY. I TOLD HIM TO EXPECT VIS APCH. LEFT TFC TO RWY 16 BECAUSE OF THE WX W OF THE FIELD. HE SAID HE SAW THE WX AND L TFC WAS OK AND ACKNOWLEDGED DSNT TO 7000'. SMT X REQUESTED DIRECT TYS. HDOF POS BEGAN WORKING ON HIS REQUEST. SMT Z STRIP CAME DOWN TUBE. I OBSERVED RTE OF FLT AND ALT ON STRIP THEN DETERMINED HE NEEDED AN ALT RESTRICTION OF 6000'. SMT Y WAS 15 MI SSE OF AVL LEAVING 9000'. I TURNED HIM L TO 360 DEG. SMT Z TAGGED UP. I CALLED HIM, NO ANSWER. CALLED LCL CTL, THEY SAID HE WAS STILL ON THEIR FREQ. I SAID SWITCH HIM TO ME OR STOP HIM AT 6000'. LCL SAID SMT Y WOULD HAVE RWY 34 REF. SMT Z I SAID, STOP SMT Z AT 6000' AND SWITCH HIM TO ME. LCL SAID IS SMT Y GOING TO TAKE RWY 34? I SAID STOP SMT Z AND SWITCH HIM NOW! I LOOKED OVER AT SMT X WHO WAS IN A POS WHERE HE SHOULD BE HANDED OFF TO THE CTR CTLR. ASKED HDOF POS WHAT WAS THE VERDICT. HE SAID HE WAS STILL WORKING ON IT. SMT Z CALLED, I VERIFIED HIS ALT AND TURNED HIM L TO DIRECT TO SUG. HE WAS LEAVING 3900'. THEN I TOLD SMY Y ABOUT THE RWY 34 BEING AVAILABLE AND THE TFC DEPARTING RWY 16, AND THE WIND. HE SAID RWY 34 WAS ACCEPTABLE. I THEN TOLD HIM TO REDUCE HIS AIRSPD. SMT Y WAS APPROX 10 MI SE LEAVING 7400'. I LOOKED BACK OVER AT SMT X WHO WAS APPROX 8 MI FROM OUR BOUNDARY STILL NOT HANDED OFF. I OBSERVED HIS ALT, IT SHOWED FL200. I WAITED ANOTHER RADAR SWEEP BUT IT STILL SHOWED FL200. LOOKED BACK AT SMT Y, HIS ALT SHOWED 5600'. I ASKED SMT Y TO VERIFY LEVEL AT 7000' HE SAID HE WAS DSNDING TO 5000'. I TOLD HIM TO CLB AND MAINTAIN 7000' IMMEDIATELY, ISSUED TFC, THEN RESTR SMT Z TO 5000'. SMT Y SAID HE HAD THE TFC IN SIGHT. SMT Y PASSED APPROX 300' ABOVE AND BEHIND SMT Z. (THE DATA BLOCKS WERE OVERLAPPED).

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.