ARTCC radar controller assigns an air carrier B737 to a holding pattern that nearly placed the aircraft in conflict with an A320 arriving on a STAR route, descending through the holding aircraft's altitude.

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Attributes
ACN	406900
Time
Date	199807
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : pdz
State Reference	CA
Altitude	msl bound lower : 17000 msl bound upper : 17000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : approach controller : handoff position
Qualification	controller : radar
Experience	controller radar : 8
ASRS Report	406900
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	non adherence other other anomaly other
Independent Detector	other controllera
Resolutory Action	none taken : detected after the fact
Consequence	Other
Miss Distance	horizontal : 30000 vertical : 1500
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Deviation Intra Facility Coordination Failure
Situations
ATC Facility	procedure or policy : unspecified

Narrative:

Aircraft #1 instructed to hold at paradise on the paradise 2 arrival as published at 17000 ft by ZLA sector 19. This holding pattern is in direct conflict with aircraft descending via the civet 4 arrival from ZLA sector 20. Callback conversation with a facility specialist revealed the following information: facility specialist advised that published holding at pdz VORTAC, 10 mi leg lengths is procedurally separated from aircraft descending on the civet arrival. 10 mi leg lengths are specified by the controller to ensure separation with the civet arrival, beyond 10 mi leg lengths, procedural separation is not ensured and there is potential for conflict. Internal ZLA coordination procedures are for sector 19 to point out pdz holding traffic to sector 20. Primary holding for lax on the pdz 2 arrival is konzl intersection. Pdz is used only as a safety valve for last min holding. Since this is a complex traffic volume area, radar procedures are utilized to their maximum.

Original NASA ASRS Text

Title: ARTCC RADAR CTLR ASSIGNS AN ACR B737 TO A HOLDING PATTERN THAT NEARLY PLACED THE ACFT IN CONFLICT WITH AN A320 ARRIVING ON A STAR RTE, DSNDING THROUGH THE HOLDING ACFT'S ALT.

Narrative: ACFT #1 INSTRUCTED TO HOLD AT PARADISE ON THE PARADISE 2 ARR AS PUBLISHED AT 17000 FT BY ZLA SECTOR 19. THIS HOLDING PATTERN IS IN DIRECT CONFLICT WITH ACFT DSNDING VIA THE CIVET 4 ARR FROM ZLA SECTOR 20. CALLBACK CONVERSATION WITH A FACILITY SPECIALIST REVEALED THE FOLLOWING INFO: FACILITY SPECIALIST ADVISED THAT PUBLISHED HOLDING AT PDZ VORTAC, 10 MI LEG LENGTHS IS PROCEDURALLY SEPARATED FROM ACFT DSNDING ON THE CIVET ARR. 10 MI LEG LENGTHS ARE SPECIFIED BY THE CTLR TO ENSURE SEPARATION WITH THE CIVET ARR, BEYOND 10 MI LEG LENGTHS, PROCEDURAL SEPARATION IS NOT ENSURED AND THERE IS POTENTIAL FOR CONFLICT. INTERNAL ZLA COORD PROCS ARE FOR SECTOR 19 TO POINT OUT PDZ HOLDING TFC TO SECTOR 20. PRIMARY HOLDING FOR LAX ON THE PDZ 2 ARR IS KONZL INTXN. PDZ IS USED ONLY AS A SAFETY VALVE FOR LAST MIN HOLDING. SINCE THIS IS A COMPLEX TFC VOLUME AREA, RADAR PROCS ARE UTILIZED TO THEIR MAX.

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.