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

Attributes
ACN	175947
Time
Date	199104
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : dca
State Reference	DC
Altitude	agl bound lower : 0 agl bound upper : 200
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : dca
Operator	other
Make Model Name	Small Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	landing : go around
Route In Use	approach : straight in
Flight Plan	IFR
Aircraft 2
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	ground other : taxi
Person 1
Affiliation	government : faa
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 10500 flight time type : 300
ASRS Report	175947
Person 2
Affiliation	government : faa
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	conflict : airborne less severe conflict : ground critical non adherence : published procedure non adherence : required legal separation
Independent Detector	other flight crewa
Resolutory Action	other
Consequence	Other
Miss Distance	horizontal : 0 vertical : 200
Supplementary
Primary Problem	ATC Human Performance
Air Traffic Incident	Operational Error Intra Facility Coordination Failure

Narrative:

PF government X, making a low approach to runway 15 using the lda/DME runway 18 approach. The WX was 1600' thin broken, 2200' overcast and 9 mi visibility. We were light checking the lda/DME 18 all day. On this approach, dca tower cleared us to land on runway 18. Then we told the tower it was a low approach to 15 and the tower cleared us for a low approach to runway 15. At 1 mi on final, the PIC instructed me to start a missed approach due to air carrier Y taxiing on runway 15. The crossing altitude was approximately 200'. The tower and approach control were working a large amount of traffic plus our flight check. Earlier we had made a low approach and circled to land on 18, which probably led to the confusion.

Original NASA ASRS Text

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

Narrative: PF GOV X, MAKING A LOW APCH TO RWY 15 USING THE LDA/DME RWY 18 APCH. THE WX WAS 1600' THIN BROKEN, 2200' OVCST AND 9 MI VISIBILITY. WE WERE LIGHT CHKING THE LDA/DME 18 ALL DAY. ON THIS APCH, DCA TWR CLRED US TO LAND ON RWY 18. THEN WE TOLD THE TWR IT WAS A LOW APCH TO 15 AND THE TWR CLRED US FOR A LOW APCH TO RWY 15. AT 1 MI ON FINAL, THE PIC INSTRUCTED ME TO START A MISSED APCH DUE TO ACR Y TAXIING ON RWY 15. THE XING ALT WAS APPROX 200'. THE TWR AND APCH CTL WERE WORKING A LARGE AMOUNT OF TFC PLUS OUR FLT CHK. EARLIER WE HAD MADE A LOW APCH AND CIRCLED TO LAND ON 18, WHICH PROBABLY LED TO THE CONFUSION.

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.