Radar controller had one aircraft at wrong altitude for direction of flight and later had less than ...

Attributes
ACN	186206
Time
Date	199108
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : msp
State Reference	MN
Altitude	msl bound lower : 4800 msl bound upper : 5300
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	cruise other descent other
Route In Use	enroute airway : zmp
Flight Plan	IFR
Aircraft 2
Make Model Name	Any Unknown or Unlisted Aircraft Manufacturer
Flight Phase	climbout : initial cruise other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar oversight : supervisor
Qualification	controller : radar
Experience	controller supervisory : 18
ASRS Report	186206
Person 2
Affiliation	government : faa
Function	controller : handoff position
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Miss Distance	horizontal : 15000 vertical : 500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Traffic was fairly heavy in the sector. On the west side of the sector arrs from the southwest were being rerted to the northwest fix due to thunderstorms. Wbound departures were restr by area supervisor to 20 mi in trail from msp departure. The departure traffic began to deviate farther north than anticipated and one of the departures turned due north to avoid the WX. When he did he was head on with the arrival traffic descending into msp. Traffic on the last side of the sector was routine. All concentration was directed at west side of sector. Most of the traffic and all of the deviating was on the west side. On the east side there was an aircraft proceeding from eau to rzn non radar. An aircraft was appreq at 6000, but because of the non radar traffic was approved at 5000 wrong altitude for direction. The appreq occurred approximately 28 mins before the incident occurred. As the radar controller I was not concentrating on the strips in the sector because I was too busy watching the traffic in the sector deviating and there was a manual controller and a handoff controller assisting at the sector. After listening to the tape I heard the swbound 5000 traffic make an initial call. I did not hear the call sign and asked the aircraft to say again. There was no response from that aircraft. Due to the activity going on in the sector, I did not ask a second time. Aircraft #2 called and checked in at 5000 and I acknowledged the call. A few moments later I observed a limited data block 6 or 7 mi northeast of aircraft #2. The handoff controller advised me that it was the non radar traffic at 5000. I immediately descended aircraft #1, climbed aircraft #2 and then turned aircraft #2. In addition to the above activity, the overlying high altitude sector would not accept any departure traffic because they were saturated. That caused a tremendous increase in workload because we then put interim altitudes in the computer so there weren't so many conflict alerts. Then the aircraft were reaching the point that they were soon to be leaving the lateral limits of our airspace so it was necessary to reassign the altitudes so the adjacent low altitude sector would get strips.

Original NASA ASRS Text

Title: RADAR CTLR HAD ONE ACFT AT WRONG ALT FOR DIRECTION OF FLT AND LATER HAD LTSS WITH XING TFC.

Narrative: TFC WAS FAIRLY HVY IN THE SECTOR. ON THE W SIDE OF THE SECTOR ARRS FROM THE SW WERE BEING RERTED TO THE NW FIX DUE TO TSTMS. WBOUND DEPS WERE RESTR BY AREA SUPVR TO 20 MI IN TRAIL FROM MSP DEP. THE DEP TFC BEGAN TO DEVIATE FARTHER N THAN ANTICIPATED AND ONE OF THE DEPS TURNED DUE N TO AVOID THE WX. WHEN HE DID HE WAS HEAD ON WITH THE ARR TFC DSNDING INTO MSP. TFC ON THE LAST SIDE OF THE SECTOR WAS ROUTINE. ALL CONCENTRATION WAS DIRECTED AT W SIDE OF SECTOR. MOST OF THE TFC AND ALL OF THE DEVIATING WAS ON THE W SIDE. ON THE E SIDE THERE WAS AN ACFT PROCEEDING FROM EAU TO RZN NON RADAR. AN ACFT WAS APPREQ AT 6000, BUT BECAUSE OF THE NON RADAR TFC WAS APPROVED AT 5000 WRONG ALT FOR DIRECTION. THE APPREQ OCCURRED APPROX 28 MINS BEFORE THE INCIDENT OCCURRED. AS THE RADAR CTLR I WAS NOT CONCENTRATING ON THE STRIPS IN THE SECTOR BECAUSE I WAS TOO BUSY WATCHING THE TFC IN THE SECTOR DEVIATING AND THERE WAS A MANUAL CTLR AND A HDOF CTLR ASSISTING AT THE SECTOR. AFTER LISTENING TO THE TAPE I HEARD THE SWBOUND 5000 TFC MAKE AN INITIAL CALL. I DID NOT HEAR THE CALL SIGN AND ASKED THE ACFT TO SAY AGAIN. THERE WAS NO RESPONSE FROM THAT ACFT. DUE TO THE ACTIVITY GOING ON IN THE SECTOR, I DID NOT ASK A SECOND TIME. ACFT #2 CALLED AND CHKED IN AT 5000 AND I ACKNOWLEDGED THE CALL. A FEW MOMENTS LATER I OBSERVED A LIMITED DATA BLOCK 6 OR 7 MI NE OF ACFT #2. THE HDOF CTLR ADVISED ME THAT IT WAS THE NON RADAR TFC AT 5000. I IMMEDIATELY DSNDED ACFT #1, CLBED ACFT #2 AND THEN TURNED ACFT #2. IN ADDITION TO THE ABOVE ACTIVITY, THE OVERLYING HIGH ALT SECTOR WOULD NOT ACCEPT ANY DEP TFC BECAUSE THEY WERE SATURATED. THAT CAUSED A TREMENDOUS INCREASE IN WORKLOAD BECAUSE WE THEN PUT INTERIM ALTS IN THE COMPUTER SO THERE WEREN'T SO MANY CONFLICT ALERTS. THEN THE ACFT WERE REACHING THE POINT THAT THEY WERE SOON TO BE LEAVING THE LATERAL LIMITS OF OUR AIRSPACE SO IT WAS NECESSARY TO REASSIGN THE ALTS SO THE ADJACENT LOW ALT SECTOR WOULD GET STRIPS.

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.

Radar controller had one aircraft at wrong altitude for direction of flight and later had less than standard separation with crossing traffic.