Narrative:

Approaching five miles from FAF; first officer requested flaps 1. I noted speed 210 KTS. Selected flaps 1; left flap needle never moved; right flap needle moved to half way between 0 and 1 then stopped. Flap in transit light remained amber. Requested hold at FAF from tower; and informed them of flap problem and declared an emergency. Proceeded to 'trailing edge flap disagree' checklist which led me to 'flap asymmetry' checklist. Completed 'flap asymmetry' checklist extending leading edge devices through alternate means and found ref speed for landing condition. Referred to abnormal landing configuration landing distance in performance section to assure sufficient landing distance; and completed emergency landing checklist. Sent dispatch a free text of our condition and our intentions to land. First officer and I began final approach segment from 3;000 feet and 10 miles from runway to assure long stable approach.with auto brakes set at maximum; touch down was firm but not hard. Auto brakes gradually applied maximum brake pressure; and stopped aircraft on center line. Requested aarf personnel to inspect aircraft; paying particular attention to wheels; brakes and tires. Approach speed target was 180 KTS. No problems found; preceded to gate. First officer and I inspected exterior of aircraft and found left flap up and right flap down approximately 2' down from flush with wing; as indicated on flap gauge. Inspected brakes and wheels and temperatures seemed to be normal.we had communication with aarf only through relay from tower staff. Spoke with airport safety coordinator after this event and he said they would solve that issue.

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Original NASA ASRS Text

Title: B737-800 flight crew experienced a flap asymmetry; ran the checklist and landed without incident.

Narrative: Approaching five miles from FAF; First Officer requested flaps 1. I noted speed 210 KTS. Selected flaps 1; Left flap needle never moved; Right flap needle moved to half way between 0 and 1 then stopped. Flap in transit light remained amber. Requested hold at FAF from Tower; and informed them of Flap problem and declared an emergency. Proceeded to 'Trailing Edge Flap Disagree' checklist which led me to 'Flap Asymmetry' checklist. Completed 'Flap Asymmetry' checklist extending leading edge devices through alternate means and found Ref speed for landing condition. Referred to Abnormal landing configuration landing distance in Performance section to assure sufficient landing distance; and completed Emergency Landing checklist. Sent Dispatch a free text of our condition and our intentions to land. First Officer and I began final approach segment from 3;000 feet and 10 miles from runway to assure long stable approach.With auto brakes set at MAX; touch down was firm but not hard. Auto brakes gradually applied MAX brake pressure; and stopped aircraft on center line. Requested AARF personnel to inspect aircraft; paying particular attention to wheels; brakes and tires. Approach speed target was 180 KTS. No problems found; preceded to gate. First Officer and I inspected exterior of aircraft and found left flap up and right flap down approximately 2' down from flush with wing; as indicated on flap gauge. Inspected brakes and wheels and temperatures seemed to be normal.We had communication with AARF only through relay from Tower staff. Spoke with airport safety coordinator after this event and he said they would solve that issue.

Data retrieved from NASA's ASRS site as of July 2013 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.