Less than standard separation between two commuter flts. Operational error.

Attributes
ACN	93185
Time
Date	198807
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : pmm
State Reference	MI
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	Marginal
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	Medium Transport
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute airway : v84
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Medium Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other descent other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller non radar : 6 controller radar : 4
ASRS Report	93185
Person 2
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	atc equipment other atc equipment : unspecified
Resolutory Action	none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 22800 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Inter Facility Coordination Failure

Narrative:

Staffing at chicago center. Because I had to work the sector for over 2 1/2 hours, fatigue set in and I missed a coordinated altitude at 8000' rather than 7000' causing me to descend on top of another aircraft. Callback conversation with reporter revealed following information: reporter gave types of aircraft dir of flight, etc. Says aircraft X was showing an interim altitude of 7000 but was later coordination at 8000 prior to rho and reporter accepted climbing to 8000 while aircraft Y was descending to 8000. This sector is usually 2 man but reporter was working it as 1 man with combined position operation. Morning rush was ending and reporter felt the fatigue and may have relaxed too soon. Facility manning is a problem sometimes. System error review did not put responsibility on any other controllers, but said previous sector (aircraft X) was contributor.

Original NASA ASRS Text

Title: LESS THAN STANDARD SEPARATION BETWEEN TWO COMMUTER FLTS. OPERATIONAL ERROR.

Narrative: STAFFING AT CHICAGO CTR. BECAUSE I HAD TO WORK THE SECTOR FOR OVER 2 1/2 HOURS, FATIGUE SET IN AND I MISSED A COORDINATED ALT AT 8000' RATHER THAN 7000' CAUSING ME TO DSND ON TOP OF ANOTHER ACFT. CALLBACK CONVERSATION WITH RPTR REVEALED FOLLOWING INFO: RPTR GAVE TYPES OF ACFT DIR OF FLT, ETC. SAYS ACFT X WAS SHOWING AN INTERIM ALT OF 7000 BUT WAS LATER COORD AT 8000 PRIOR TO RHO AND RPTR ACCEPTED CLBING TO 8000 WHILE ACFT Y WAS DSNDING TO 8000. THIS SECTOR IS USUALLY 2 MAN BUT RPTR WAS WORKING IT AS 1 MAN WITH COMBINED POS OPERATION. MORNING RUSH WAS ENDING AND RPTR FELT THE FATIGUE AND MAY HAVE RELAXED TOO SOON. FAC MANNING IS A PROB SOMETIMES. SYS ERROR REVIEW DID NOT PUT RESPONSIBILITY ON ANY OTHER CTLRS, BUT SAID PREVIOUS SECTOR (ACFT X) WAS CONTRIBUTOR.

Data retrieved from NASA's ASRS site as of August 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.