Date: 201507
Local time of day: 1801-2400
Location: DEN.Airport, CO
Flight conditions: VMC
Weather elements / visibility: Windshear
Light: Night
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B DEN
ATC / advisory: Tower DEN
Reporter organization: Air Carrier
Reporter function: First Officer; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Anomaly: Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Executed Go Around / Missed Approach
Contributing factors: Aircraft; Weather
Primary problem: Weather

Narrative: I am submitting this report to document a windshear encounter; two go-arounds; and a flap overspeed that occurred on approach into DEN.Most of our flight to DEN was uneventful. We were late due to baggage loading issues; and we circumnavigated some minor weather; but nothing unusual. The weather at DEN was forecast to be VFR (night); with the usual change of arrival procedures that one encounters when flying into DEN. Our first hint of a problem was a report of moderate turbulence on approach between 10;000 FT and 7000 FT MSL. We were on downwind for a visual approach to 16L. I flew a dogleg to the final approach fix and configured normally. We encountered some bumps; but nothing terrible. I had some difficulty slowing down because of the shifting winds; but I was able to get configured. The Captain bumped up my final approach speeds for me by a few knots which I agreed with. Entering the landing flare; I had a significant gain in airspeed. I tried to put the aircraft down; but I could not get it to touch down. The Captain called for a go-around and I complied. A couple of other aircraft had also gone around at those few moments. We executed a normal go-around (very turbulent) and now were told to prepare for an approach to Runway 34R. We set up and quickly briefed that visual approach.It was extremely turbulent at this time; and I configured early on the final for 34R. At 1000 FT AGL; I was fully configured and on-speed and glideslope. The Tower was reporting a low level wind shift from a tailwind on final to a significant headwind. Shortly thereafter (before 500 FT AGL); I experienced a significant wind shift and rapid increase in airspeed; which caused me to overspeed the flaps 30 setting by approximately 10 knots. I executed a second go-around. We conducted our third approach to Runway 34R with the Captain now flying; as we started to get concerned about fuel. We did not experience any issues (other than some bumps) on the third approach. We taxied to the gate and contacted Maintenance.Although this event happened suddenly and was not forecast; I do think that some improvements could be made to provide an additional margin of safety. We did not receive any windshear warnings from the aircraft at any time during this event. I reviewed my FRM and learned that this aircraft does not provide any cautionary reactive windshear alerts (i.e.; CAUTION WINDSHEAR or HEADWIND SHEAR) as other aircraft that I have flown provide. This would provide an additional level of situational awareness that would greatly enhance safety.




Synopsis: B737 First Officer reported two weather related go-arounds and a flap overspeed on approach to DEN.