Flight crew of A320 received microburst alert during flare at den elected to land.

Attributes
ACN	579390
Time
Date	200304
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : den.airport
State Reference	CO
Altitude	agl single value : 30
Environment
Weather Elements	Windshear other
Light	Night
Aircraft 1
Controlling Facilities	tower : den.tower
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 1500 flight time total : 11000 flight time type : 150
ASRS Report	579390
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	inflight encounter : turbulence inflight encounter other
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted other
Supplementary
Problem Areas	Weather Flight Crew Human Performance Environmental Factor
Primary Problem	Weather

Narrative:

WX in the denver area was virga all quadrants -- no convective activity. Numerous windshear and microburst alerts caused delays for an approach. Denver approach re-established approachs to runway 17R. Virga was 5-7 mi north of the airport. The aircraft in front of us reported a maximum of 15 KT airspeed loss on the approach. We configured and used the recommended flaps 3 confign. At 1000 ft afe, we were within stabilized parameters. A report was made of a 35 KT loss of airspeed by an aircraft 5 NM north of runway 17R (approximately where the virga was located). An aircraft behind us went around. At approximately 1500 ft AGL, the predictive windshear system became inoperative (it doesn't monitor anything until below 2300 ft AGL). We attempted 3 times to get a windshear advisory update for runway 17R and kept getting 'stepped on' with other aircraft and tower xmissions. Airspeed fluctuations were within +/- 10 KTS. Winds displayed on our navigation display were variable 5-10 KTS. In the flare, at approximately 30 ft AGL, the tower reported a microburst alert. We felt the safest course of action was to land instead of spooling up to go around thrust and climbing into it.

Original NASA ASRS Text

Title: FLT CREW OF A320 RECEIVED MICROBURST ALERT DURING FLARE AT DEN ELECTED TO LAND.

Narrative: WX IN THE DENVER AREA WAS VIRGA ALL QUADRANTS -- NO CONVECTIVE ACTIVITY. NUMEROUS WINDSHEAR AND MICROBURST ALERTS CAUSED DELAYS FOR AN APCH. DENVER APCH RE-ESTABLISHED APCHS TO RWY 17R. VIRGA WAS 5-7 MI N OF THE ARPT. THE ACFT IN FRONT OF US RPTED A MAX OF 15 KT AIRSPD LOSS ON THE APCH. WE CONFIGURED AND USED THE RECOMMENDED FLAPS 3 CONFIGN. AT 1000 FT AFE, WE WERE WITHIN STABILIZED PARAMETERS. A RPT WAS MADE OF A 35 KT LOSS OF AIRSPD BY AN ACFT 5 NM N OF RWY 17R (APPROX WHERE THE VIRGA WAS LOCATED). AN ACFT BEHIND US WENT AROUND. AT APPROX 1500 FT AGL, THE PREDICTIVE WINDSHEAR SYS BECAME INOP (IT DOESN'T MONITOR ANYTHING UNTIL BELOW 2300 FT AGL). WE ATTEMPTED 3 TIMES TO GET A WINDSHEAR ADVISORY UPDATE FOR RWY 17R AND KEPT GETTING 'STEPPED ON' WITH OTHER ACFT AND TWR XMISSIONS. AIRSPD FLUCTUATIONS WERE WITHIN +/- 10 KTS. WINDS DISPLAYED ON OUR NAV DISPLAY WERE VARIABLE 5-10 KTS. IN THE FLARE, AT APPROX 30 FT AGL, THE TWR RPTED A MICROBURST ALERT. WE FELT THE SAFEST COURSE OF ACTION WAS TO LAND INSTEAD OF SPOOLING UP TO GAR THRUST AND CLBING INTO IT.

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.