Reporter states a flow control problem in and out of holding by the tmu. Reporter said this unsafe c...

Attributes
ACN	361065
Time
Date	199702
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zau
State Reference	IL
Altitude	msl bound lower : 19000 msl bound upper : 19000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau tower : dtw
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 enroute airway : zau
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 8
ASRS Report	361065
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	non adherence : published procedure non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	none taken : unable
Consequence	Other
Miss Distance	horizontal : 10800 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error
Situations
ATC Facility	other physical facility

Narrative:

In sits of extensive holding, an unsafe condition needs to be addressed regarding flow control into and out of the hold. At this time the controller at the 'feeding' or arrival fix is not consulted before tmu lifts its restrs from adjacent sectors and first tier facilities. Tmu makes its decision based on the new arrival rate, DME and speed. It does not consider nor solicit information regarding sector staffing, frequency congestion, controller fatigue or the inherent difficulty and extra awareness needed when vectoring into and out of the hold. This unsafe condition recently contributed to an operational error at the bearz sector (ZAU-southeast). This unsafe condition is driven by the effort to reduce delays at all costs. Often all that is needed is an extra 5 mins of 'breathing' room to keep the operation safe. Tmu cannot lift restrs on holding aircraft without consulting and evaluating time critical information from the arrival sector. Callback conversation with reporter revealed the following information: reporter indicated the tmu was releasing traffic from the outer fixes without coordination with the inner fix controllers. Reporter felt the operational error occurred when the controller was distracted by the traffic volume and descended an air carrier to same altitude of another air carrier in the holding pattern. Reporter related that one air carrier was a B757 and did not know the make of the other aircraft only the company. Reporter felt that if a certain supervisor was on duty at the time of the incident, the less than standard separation would not have occurred as the supervisor has more initiative and would have delayed the release of traffic by the tmu from the outer fixes. Reporter alleges the problem has not been resolved but there is more discussion going on. Reporter stated the controllers are aware of the situation with the tmu and are initiating action on their own for the tmu to not release traffic.

Original NASA ASRS Text

Title: RPTR STATES A FLOW CTL PROB IN AND OUT OF HOLDING BY THE TMU. RPTR SAID THIS UNSAFE CONDITION CONTRIBUTED TO AN OPERROR. LTSS.

Narrative: IN SITS OF EXTENSIVE HOLDING, AN UNSAFE CONDITION NEEDS TO BE ADDRESSED REGARDING FLOW CTL INTO AND OUT OF THE HOLD. AT THIS TIME THE CTLR AT THE 'FEEDING' OR ARR FIX IS NOT CONSULTED BEFORE TMU LIFTS ITS RESTRS FROM ADJACENT SECTORS AND FIRST TIER FACILITIES. TMU MAKES ITS DECISION BASED ON THE NEW ARR RATE, DME AND SPD. IT DOES NOT CONSIDER NOR SOLICIT INFO REGARDING SECTOR STAFFING, FREQ CONGESTION, CTLR FATIGUE OR THE INHERENT DIFFICULTY AND EXTRA AWARENESS NEEDED WHEN VECTORING INTO AND OUT OF THE HOLD. THIS UNSAFE CONDITION RECENTLY CONTRIBUTED TO AN OPERROR AT THE BEARZ SECTOR (ZAU-SE). THIS UNSAFE CONDITION IS DRIVEN BY THE EFFORT TO REDUCE DELAYS AT ALL COSTS. OFTEN ALL THAT IS NEEDED IS AN EXTRA 5 MINS OF 'BREATHING' ROOM TO KEEP THE OP SAFE. TMU CANNOT LIFT RESTRS ON HOLDING ACFT WITHOUT CONSULTING AND EVALUATING TIME CRITICAL INFO FROM THE ARR SECTOR. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR INDICATED THE TMU WAS RELEASING TFC FROM THE OUTER FIXES WITHOUT COORD WITH THE INNER FIX CTLRS. RPTR FELT THE OPERROR OCCURRED WHEN THE CTLR WAS DISTRACTED BY THE TFC VOLUME AND DSNDED AN ACR TO SAME ALT OF ANOTHER ACR IN THE HOLDING PATTERN. RPTR RELATED THAT ONE ACR WAS A B757 AND DID NOT KNOW THE MAKE OF THE OTHER ACFT ONLY THE COMPANY. RPTR FELT THAT IF A CERTAIN SUPVR WAS ON DUTY AT THE TIME OF THE INCIDENT, THE LTSS WOULD NOT HAVE OCCURRED AS THE SUPVR HAS MORE INITIATIVE AND WOULD HAVE DELAYED THE RELEASE OF TFC BY THE TMU FROM THE OUTER FIXES. RPTR ALLEGES THE PROB HAS NOT BEEN RESOLVED BUT THERE IS MORE DISCUSSION GOING ON. RPTR STATED THE CTLRS ARE AWARE OF THE SIT WITH THE TMU AND ARE INITIATING ACTION ON THEIR OWN FOR THE TMU TO NOT RELEASE TFC.

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.

Reporter states a flow control problem in and out of holding by the tmu. Reporter said this unsafe condition contributed to an operational error. Less than standard separation.