Approach controller allowed a DC8 and an FA27 to have less than legal separation.

Attributes
ACN	416226
Time
Date	199809
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : dqn airport : day
State Reference	OH
Altitude	msl bound lower : 8000 msl bound upper : 8000
Environment
Flight Conditions	Mixed
Light	Night
Aircraft 1
Controlling Facilities	tracon : day
Operator	common carrier : air carrier
Make Model Name	Heavy Transport, Low Wing, 4 Turbojet Eng
Flight Phase	descent other
Flight Plan	IFR
Aircraft 2
Make Model Name	Medium Transport, High Wing, 2 Turboprop Eng
Flight Phase	cruise other
Person 1
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Experience	controller radar : 35
ASRS Report	416226
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe non adherence : required legal separation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance
Consequence	Other
Miss Distance	horizontal : 5460 vertical : 0
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

Aircraft a, an H/DC8 out of 13000 ft descending to 4000 ft 30 mi west of day inbound runway 6L visual approach. Aircraft B, an F27 8000 ft wbound. Aircraft a drifted left from direct course to airport. Controller's attention distracted in conversation with developmental controller. Allowed aircraft a flight trajectory to encroach on 3 mi horizontal of aircraft B. Aircraft a descent profile inconsistent. Rate not continuous, leveled off at 8000 ft. Traffic issued at 4.94 mi and turned to ensure flight paths did not cross. Aircraft a entered clouds did not see aircraft B. Aircraft B issued turn to further ensure separation. Aircraft B did not see aircraft a. Flight paths never did cross. Nearest point .91. Aircraft a -- last min of flight prior to encroachment lost only 200 ft (500-1500 ft expected). Summation: controller made error in course/rate, attention diverted, instruction too late to avoid airspace intrusion.

Original NASA ASRS Text

Title: APCH CTLR ALLOWED A DC8 AND AN FA27 TO HAVE LESS THAN LEGAL SEPARATION.

Narrative: ACFT A, AN H/DC8 OUT OF 13000 FT DSNDING TO 4000 FT 30 MI W OF DAY INBOUND RWY 6L VISUAL APCH. ACFT B, AN F27 8000 FT WBOUND. ACFT A DRIFTED L FROM DIRECT COURSE TO ARPT. CTLR'S ATTN DISTRACTED IN CONVERSATION WITH DEVELOPMENTAL CTLR. ALLOWED ACFT A FLT TRAJECTORY TO ENCROACH ON 3 MI HORIZ OF ACFT B. ACFT A DSCNT PROFILE INCONSISTENT. RATE NOT CONTINUOUS, LEVELED OFF AT 8000 FT. TFC ISSUED AT 4.94 MI AND TURNED TO ENSURE FLT PATHS DID NOT CROSS. ACFT A ENTERED CLOUDS DID NOT SEE ACFT B. ACFT B ISSUED TURN TO FURTHER ENSURE SEPARATION. ACFT B DID NOT SEE ACFT A. FLT PATHS NEVER DID CROSS. NEAREST POINT .91. ACFT A -- LAST MIN OF FLT PRIOR TO ENCROACHMENT LOST ONLY 200 FT (500-1500 FT EXPECTED). SUMMATION: CTLR MADE ERROR IN COURSE/RATE, ATTN DIVERTED, INSTRUCTION TOO LATE TO AVOID AIRSPACE INTRUSION.

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.