Operational error occurred when a cpr LR35 at FL200 conflicted with a climbing WW24. The controller had issued a descent clearance to the LR35 which had not been acknowledged nor was descent begun before the controller moved on to other duties.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	371133
Time
Date	199706
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : mod
State Reference	CA
Altitude	msl bound lower : 20000 msl bound upper : 20000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zoa
Operator	general aviation : corporate
Make Model Name	Learjet 35
Operating Under FAR Part	Part 91
Flight Phase	cruise other
Route In Use	arrival star : star
Flight Plan	IFR
Aircraft 2
Operator	general aviation : corporate
Make Model Name	IAI1124/1124A/Westwind
Operating Under FAR Part	Part 91
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : flight data
Qualification	controller : radar pilot : instrument
Experience	controller non radar : 3 controller radar : 3 flight time total : 1800
ASRS Report	371133
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation
Independent Detector	other other : unspecified
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 18000 vertical : 400
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Radar controller was working alone and needed help. Right before I got there to help, the radar controller took a pointout on an aircraft climbing through our sector sbound. Shortly thereafter issued a clearance to an aircraft #1 to descend, aircraft #1 did not acknowledge descent clearance and remained at FL200. Controller was busy and was going to get back to aircraft #1 for readback but never did even though the data block indicated that it was to descend. I (the d-side) was on land line and did not hear the lack of readback. When it became apparent that aircraft #1 was not descending it was too late. The effect separation and standard IFR separation was lost. Cause: controllers should not have moved on until readback was received. Also controller was too busy to give me a relief briefing and I had to get the picture on my own. Get help as traffic is building, not at the peak level.

Original NASA ASRS Text

Title: OPERROR OCCURRED WHEN A CPR LR35 AT FL200 CONFLICTED WITH A CLBING WW24. THE CTLR HAD ISSUED A DSCNT CLRNC TO THE LR35 WHICH HAD NOT BEEN ACKNOWLEDGED NOR WAS DSCNT BEGUN BEFORE THE CTLR MOVED ON TO OTHER DUTIES.

Narrative: RADAR CTLR WAS WORKING ALONE AND NEEDED HELP. RIGHT BEFORE I GOT THERE TO HELP, THE RADAR CTLR TOOK A POINTOUT ON AN ACFT CLBING THROUGH OUR SECTOR SBOUND. SHORTLY THEREAFTER ISSUED A CLRNC TO AN ACFT #1 TO DSND, ACFT #1 DID NOT ACKNOWLEDGE DSCNT CLRNC AND REMAINED AT FL200. CTLR WAS BUSY AND WAS GOING TO GET BACK TO ACFT #1 FOR READBACK BUT NEVER DID EVEN THOUGH THE DATA BLOCK INDICATED THAT IT WAS TO DSND. I (THE D-SIDE) WAS ON LAND LINE AND DID NOT HEAR THE LACK OF READBACK. WHEN IT BECAME APPARENT THAT ACFT #1 WAS NOT DSNDING IT WAS TOO LATE. THE EFFECT SEPARATION AND STANDARD IFR SEPARATION WAS LOST. CAUSE: CTLRS SHOULD NOT HAVE MOVED ON UNTIL READBACK WAS RECEIVED. ALSO CTLR WAS TOO BUSY TO GIVE ME A RELIEF BRIEFING AND I HAD TO GET THE PICTURE ON MY OWN. GET HELP AS TFC IS BUILDING, NOT AT THE PEAK LEVEL.

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.