Air carrier X had less than standard separation from air carrier Y. System error.

Attributes
ACN	138824
Time
Date	199003
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : bwi
State Reference	MD
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : bwi
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	cruise other
Route In Use	departure other
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Light Transport, Low Wing, 2 Turboprop Eng
Flight Phase	cruise other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	government : faa
Function	controller : departure
Qualification	controller : radar
Experience	controller radar : 10
ASRS Report	138824
Person 2
Affiliation	government : faa
Function	controller : approach
Qualification	controller : radar
Events
Anomaly	conflict : airborne less severe non adherence : published procedure non adherence : required legal separation other anomaly other
Independent Detector	atc equipment other atc equipment : unspecified other controllera
Resolutory Action	controller : issued new clearance other
Consequence	faa : investigated
Miss Distance	horizontal : 3000 vertical : 100
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error

Narrative:

During a period of peak traffic a departure aircraft air carrier X nearly hit an arrival aircraft air carrier Y. Air carrier X was held at 5000' as an intermediate altitude because of overhead traffic. Air carrier Y arrival aircraft for whatever reason was on a 7 mi final at 5000'. The conflict was detected by an adjacent controller and the C/a. The departure aircraft was issued traffic and a climb clearance. The 2 aircraft had already passed at the same altitude. Callback conversation with reporter revealed the following: reporter stated he was working departure control. WX was VMC. Aircraft types were medium large transport and light transport. FAA investigated incident. Approach controller had issued descent to air carrier Y, but transmission was covered. Reporter issued traffic to air carrier X, but the aircraft had already passed. Approach controller had penetrated departure control airspace west/O coordination.

Original NASA ASRS Text

Title: ACR X HAD LESS THAN STANDARD SEPARATION FROM ACR Y. SYSTEM ERROR.

Narrative: DURING A PERIOD OF PEAK TFC A DEP ACFT ACR X NEARLY HIT AN ARR ACFT ACR Y. ACR X WAS HELD AT 5000' AS AN INTERMEDIATE ALT BECAUSE OF OVERHEAD TFC. ACR Y ARR ACFT FOR WHATEVER REASON WAS ON A 7 MI FINAL AT 5000'. THE CONFLICT WAS DETECTED BY AN ADJACENT CTLR AND THE C/A. THE DEP ACFT WAS ISSUED TFC AND A CLB CLRNC. THE 2 ACFT HAD ALREADY PASSED AT THE SAME ALT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: RPTR STATED HE WAS WORKING DEP CTL. WX WAS VMC. ACFT TYPES WERE MLG AND LTT. FAA INVESTIGATED INCIDENT. APCH CTLR HAD ISSUED DSCNT TO ACR Y, BUT XMISSION WAS COVERED. RPTR ISSUED TFC TO ACR X, BUT THE ACFT HAD ALREADY PASSED. APCH CTLR HAD PENETRATED DEP CTL AIRSPACE W/O COORD.

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.