A319 flight crew executes a go around due to a runway incursion at dia.

Attributes
ACN	722729
Time
Date	200701
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : den.airport
State Reference	CO
Altitude	agl single value : 100
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : den.tower tower : den.tower
Operator	common carrier : air carrier
Make Model Name	A319
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Aircraft 2
Controlling Facilities	tower : den.tower
Operator	common carrier : air carrier
Make Model Name	Metro Undifferentiated or Other Model
Operating Under FAR Part	Part 135
Flight Phase	ground : position and hold
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 210 flight time type : 4200
ASRS Report	722729
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	conflict : airborne critical incursion : runway
Independent Detector	other controllera
Resolutory Action	controller : issued alert controller : issued new clearance flight crew : executed go around flight crew : took precautionary avoidance action
Supplementary
Problem Areas	Weather ATC Human Performance Flight Crew Human Performance
Primary Problem	Ambiguous

Narrative:

We were cleared to land on runway 35L at dia. The WX was 600 ft overcast with a visibility of between 1/2 and 1 mi. The approach was briefed for CAT 1; with the first officer as the PF. While the aircraft descended crossing the threshold; the denver tower instructed us to go around. Both pilots at that same time observed the metroliner aircraft in the touchdown zone of runway 35L. The PF advanced the throttles to toga and applied full back pressure on the controls. A successful go around was completed and we landed on runway 35R. Due to the aircraft size; low visibility and blowing snow; the metroliner was impossible to see until we were directly upon it. The saving factors were good training; flying the approach as CAT 1; not CAT 3 where pilot's attentions are more inside focused and an alert tower controller. I feel that the crew could not have done anything different. The other party should not have been on the runway without proper clearance.

Original NASA ASRS Text

Title: A319 FLT CREW EXECUTES A GAR DUE TO A RWY INCURSION AT DIA.

Narrative: WE WERE CLRED TO LAND ON RWY 35L AT DIA. THE WX WAS 600 FT OVCST WITH A VISIBILITY OF BTWN 1/2 AND 1 MI. THE APCH WAS BRIEFED FOR CAT 1; WITH THE FO AS THE PF. WHILE THE ACFT DSNDED XING THE THRESHOLD; THE DENVER TWR INSTRUCTED US TO GO AROUND. BOTH PLTS AT THAT SAME TIME OBSERVED THE METROLINER ACFT IN THE TOUCHDOWN ZONE OF RWY 35L. THE PF ADVANCED THE THROTTLES TO TOGA AND APPLIED FULL BACK PRESSURE ON THE CTLS. A SUCCESSFUL GAR WAS COMPLETED AND WE LANDED ON RWY 35R. DUE TO THE ACFT SIZE; LOW VISIBILITY AND BLOWING SNOW; THE METROLINER WAS IMPOSSIBLE TO SEE UNTIL WE WERE DIRECTLY UPON IT. THE SAVING FACTORS WERE GOOD TRAINING; FLYING THE APCH AS CAT 1; NOT CAT 3 WHERE PLT'S ATTENTIONS ARE MORE INSIDE FOCUSED AND AN ALERT TWR CTLR. I FEEL THAT THE CREW COULD NOT HAVE DONE ANYTHING DIFFERENT. THE OTHER PARTY SHOULD NOT HAVE BEEN ON THE RWY WITHOUT PROPER CLRNC.

Data retrieved from NASA's ASRS site as of January 2009 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.