A B737 encountered 19 knot gusts on short final which caused a flap blow up from 30 to 25. The egpws...

Attributes
ACN	1301224
Time
Date	201510
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Final Approach
Flight Plan	IFR
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 138 Flight Crew Type 964
Person 2
Function	First Officer Pilot Not Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 217 Flight Crew Total 13104 Flight Crew Type 2296
Events
Anomaly	Deviation - Procedural Published Material / Policy Deviation - Speed All Types Inflight Event / Encounter Unstabilized Approach Inflight Event / Encounter Weather / Turbulence

Narrative:

On approach to runway xxl; the airport was experiencing high and gusty winds; last called 220/22g33; we configured at the final approach fix at setting flaps 30 with accompanying green light at approximately 1;200 feet AGL. Autothrottles and autopilot were engaged. Passing through 1;000 feet; we got a good gust wind/airspeed increase to approximately 178-180 KIAS. This must have activated the flap blowback feature and it pushed the flaps back to approximately 26 degrees. At that point; I took the aircraft and disconnected the autopilot and autothrottles. I did not notice the flaps had been pushed back and continued to fly the approach. Passing through 200 feet we received the too low terrain warning. I verbally confirmed visual with the first officer and continued the approach. Upon receiving the aural warning a third time at approximately 50 feet; first officer noted the abnormal flap setting. The airplane was easily controllable and I had already started to flare; so I landed with 26 degrees final flap setting and taxied uneventfully from the landing runway to the gate. During taxi; we reset the flaps to 25 and then 30 degrees and the flaps worked normally; without issue.

Original NASA ASRS Text

Title: A B737 encountered 19 knot gusts on short final which caused a flap blow up from 30 to 25. The EGPWS TOO LOW alert sounded but the First Officer thought flap asymmetry. After landing the flaps were cycled with normal results.

Narrative: On approach to Runway XXL; the airport was experiencing high and gusty winds; last called 220/22G33; we configured at the final approach fix at setting flaps 30 with accompanying green light at approximately 1;200 feet AGL. Autothrottles and autopilot were engaged. Passing through 1;000 feet; we got a good gust wind/airspeed increase to approximately 178-180 KIAS. This must have activated the flap blowback feature and it pushed the flaps back to approximately 26 degrees. At that point; I took the aircraft and disconnected the autopilot and autothrottles. I did not notice the flaps had been pushed back and continued to fly the approach. Passing through 200 feet we received the too low terrain warning. I verbally confirmed visual with the First Officer and continued the approach. Upon receiving the aural warning a third time at approximately 50 feet; First Officer noted the abnormal flap setting. The airplane was easily controllable and I had already started to flare; so I landed with 26 degrees final flap setting and taxied uneventfully from the landing runway to the gate. During taxi; we reset the flaps to 25 and then 30 degrees and the flaps worked normally; without issue.

Data retrieved from NASA's ASRS site 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.

A B737 encountered 19 knot gusts on short final which caused a flap blow up from 30 to 25. The egpws too low alert sounded but the first officer thought flap asymmetry. After landing the flaps were cycled with normal results.