Date: 201205
Local time of day: 1201-1800
Location: MIA.Airport, FL
Flight conditions: VMC
Weather elements / visibility: Rain; Thunderstorm
Aircraft: B737-800
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Initial Approach
Airspace: Class B MIA
ATC / advisory: TRACON MIA
Aircraft component: Flap/Slat Control System
Component problem: Malfunctioning; Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Second reporter function: First Officer; Pilot Not Flying
Anomaly: Aircraft Equipment Problem Less Severe; Deviation - Speed All Types; Inflight Event / Encounter Weather / Turbulence
Detector: Person Flight Crew
When detected: In-flight
Result: Aircraft Equipment Problem Dissipated; General Maintenance Action
Contributing factors: Human Factors; Weather; Aircraft
Primary problem: Ambiguous

Narrative: We were on final approach to land in MIA; ILS 9 approach in VMC. During the arrival we had basically flown radar vectors in lieu of the arrival to navigate around thunderstorms and isolated cells in the area. Weather and visibility was clear from base leg to final and on the arrival corridor. At approximately 1;400 FT MSL; I verified airspeed and called for flaps 30. As the First Officer began to move the flap handle from 25 to 30; we experienced a sudden increase of airspeed which quickly/eventually ended up to be an increase of 30 KTS. Upon noting this; the First Officer moved the flap lever back to the 25 position and then up to the 15 degree position. I continued flying the aircraft on the glideslope with adjustments to pitch and power. After the airspeed decreased from a high of 180-185 KTS; we attempted to extend the flaps back to 25. Although the handle moved; the flap indicator remained at 15. There were no signs of a split or skew. The First Officer moved the Ground Proximity Flap Inhibit Switch to Inhibit as per the QRH and we increased the bug speed. I continued flying the approach at flaps 15 to a normal landing. After clearing all runways; we raised the flaps and they retracted normally.


Second narrative: We were on final approach to land in MIA; ILS 09 approach in VMC. At approximately 1;400 FT MSL; The Captain called for flaps 30 degrees. After verifying the speed was below 175; I moved the handle from 25 to 30 degrees. Looking up I noticed the airspeed trend vector rapidly moving to an increasing speed trend and knowing that a possible airspeed exceedence was about to happen; I moved flap handle back to 25 degrees and then 15 degrees. The Captain continued to fly the aircraft on the glide slope with adjustments to pitch and power. After the airspeed decreased from a high of 180-185 KTS; we attempted to extend the flaps back to 25 degrees. Although the handle moved; the flap indicator remained at 15. There were no indications of a split or skew. The 'Too Low Flaps' audible warning sounded and I moved the Ground Proximity Flap Inhibit Switch to 'Inhibit' as per the QRH and we reset the bug speed to the flaps 15 speed. The Captain continued to fly the approach at flaps 15 to a normal landing. Upon clearing the runway I reported to the Tower an airspeed increase of approximately 30 KTS at about 1;300 MSL. After clearing all runways; we raised the flaps and they retracted normally to 0 degrees. We notified maintenance via radio.


Synopsis: B737-800 flight crew experiences stuck flaps during approach when the flap lever is first selected from 25 to 30 then quickly retracted to 25 then 15 as a wind gust threatens to overspeed the flaps when the flaps cannot be extended; bug speeds are adjusted and a flaps 15 landing ensues. Flaps retract normally after landing.