A320 captain reports flap overspeed during wind shear event and go around at den.

Attributes
ACN	798214
Time
Date	200808
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : den.airport
State Reference	CO
Altitude	msl single value : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tower : den.tower
Operator	common carrier : air carrier
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	landing : go around
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 185 flight time type : 4000
ASRS Report	798214
Events
Anomaly	inflight encounter : weather inflight encounter other non adherence : company policies other anomaly
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance flight crew : executed go around none taken : detected after the fact
Consequence	other
Supplementary
Problem Areas	Weather Flight Crew Human Performance Airspace Structure Aircraft
Primary Problem	Ambiguous

Narrative:

On a visual approach to runway 35R in denver we had to perform a go around at approximately 6500 ft MSL due to windshear. The airport was reporting microburst conditions with rapidly changing wind speed and directions on all runways. We experienced an increase in airspeed of approximately 45 KTS with the autoplt on and in confign flaps 3 degrees. We had briefed for a windshear and decided to maintain flap/slat and landing gear confign as per fom. When we executed the go around denver tower instructed us to climb and maintain 7000 ft turn right to the heading of 095 degrees when we were at approximately 6800 ft MSL. We were in the process of trying to level at 7000 ft MSL; maintain toga thrust for the windshear; and keep the current confign as we had briefed. We never saw a drop in performance which normally is associated with a windshear. This added to rapid increase in airspeed and the overspeed of the flaps. Our time in the overspeed condition was less than 5 seconds and we did not exceed vfe +10. The difficulty was trying to comply to ATC instructions while adhering to windshear operations. The problem I see is what is the proper procedure when trying to comply with an ATC issued altitude during a go around while trying to adhere to fom windshear procedures. Over-speeding of the flaps.

Original NASA ASRS Text

Title: A320 CAPT REPORTS FLAP OVERSPEED DURING WIND SHEAR EVENT AND GAR AT DEN.

Narrative: ON A VISUAL APCH TO RWY 35R IN DENVER WE HAD TO PERFORM A GAR AT APPROX 6500 FT MSL DUE TO WINDSHEAR. THE ARPT WAS RPTING MICROBURST CONDITIONS WITH RAPIDLY CHANGING WIND SPD AND DIRECTIONS ON ALL RWYS. WE EXPERIENCED AN INCREASE IN AIRSPD OF APPROX 45 KTS WITH THE AUTOPLT ON AND IN CONFIGN FLAPS 3 DEGS. WE HAD BRIEFED FOR A WINDSHEAR AND DECIDED TO MAINTAIN FLAP/SLAT AND LNDG GEAR CONFIGN AS PER FOM. WHEN WE EXECUTED THE GAR DENVER TWR INSTRUCTED US TO CLB AND MAINTAIN 7000 FT TURN R TO THE HDG OF 095 DEGS WHEN WE WERE AT APPROX 6800 FT MSL. WE WERE IN THE PROCESS OF TRYING TO LEVEL AT 7000 FT MSL; MAINTAIN TOGA THRUST FOR THE WINDSHEAR; AND KEEP THE CURRENT CONFIGN AS WE HAD BRIEFED. WE NEVER SAW A DROP IN PERFORMANCE WHICH NORMALLY IS ASSOCIATED WITH A WINDSHEAR. THIS ADDED TO RAPID INCREASE IN AIRSPD AND THE OVERSPEED OF THE FLAPS. OUR TIME IN THE OVERSPEED CONDITION WAS LESS THAN 5 SECONDS AND WE DID NOT EXCEED VFE +10. THE DIFFICULTY WAS TRYING TO COMPLY TO ATC INSTRUCTIONS WHILE ADHERING TO WINDSHEAR OPS. THE PROB I SEE IS WHAT IS THE PROPER PROC WHEN TRYING TO COMPLY WITH AN ATC ISSUED ALT DURING A GAR WHILE TRYING TO ADHERE TO FOM WINDSHEAR PROCS. OVER-SPEEDING OF THE FLAPS.

Data retrieved from NASA's ASRS site as of May 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.