ZOB controller experiences loss of separation between 2 aircraft X inbound to cle on wakem STAR.

Attributes
ACN	575808
Time
Date	200303
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : cle.airport
State Reference	OH
Altitude	msl single value : 10000
Aircraft 1
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	B737-500
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Route In Use	arrival : holding pattern arrival star : wakem
Flight Plan	IFR
Aircraft 2
Controlling Facilities	artcc : zob.artcc
Operator	common carrier : air carrier
Make Model Name	EMB ERJ 145 ER&LR
Operating Under FAR Part	Part 121
Flight Phase	cruise : holding
Route In Use	arrival : holding pattern arrival star : wakem
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : radar
Qualification	controller : radar
Experience	controller radar : 17
ASRS Report	575808
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance
Independent Detector	atc equipment : conflict alert other controllera
Resolutory Action	none taken : insufficient time
Consequence	faa : investigated
Miss Distance	horizontal : 24000 vertical : 200
Supplementary
Problem Areas	Flight Crew Human Performance ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Aircraft was north holding at wakem at 10000 ft. Aircraft X was approaching wakem, descending to 11000 ft with holding instructions. Approach lifted the hold and aircraft Y was cleared to fly the outbound leg. Aircraft X was cleared to cle via the wakem arrival at 110. When aircraft X was approximately 4 mi north of aircraft Y, I noticed he descended through 110 and questioned him. Since the 2 aircraft were essentially tail to tail, and by the 5 mi, separated aircraft X was told to maintain 10000 ft and switched to approach control.

Original NASA ASRS Text

Title: ZOB CTLR EXPERIENCES LOSS OF SEPARATION BTWN 2 ACFT X INBOUND TO CLE ON WAKEM STAR.

Narrative: ACFT WAS N HOLDING AT WAKEM AT 10000 FT. ACFT X WAS APCHING WAKEM, DSNDING TO 11000 FT WITH HOLDING INSTRUCTIONS. APCH LIFTED THE HOLD AND ACFT Y WAS CLRED TO FLY THE OUTBOUND LEG. ACFT X WAS CLRED TO CLE VIA THE WAKEM ARR AT 110. WHEN ACFT X WAS APPROX 4 MI N OF ACFT Y, I NOTICED HE DSNDED THROUGH 110 AND QUESTIONED HIM. SINCE THE 2 ACFT WERE ESSENTIALLY TAIL TO TAIL, AND BY THE 5 MI, SEPARATED ACFT X WAS TOLD TO MAINTAIN 10000 FT AND SWITCHED TO APCH CTL.

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.