Narrative:

On approach I called for flaps 5. First officer selected flap lever to 5. The aircraft did not slow as normally expected; so I called for landing gear; which the first officer selected. The aircraft slowed a bit; but still not as normal; so I called for flaps 10. After 10 was selected and the aircraft was still not slowing properly; I noticed the flap gauge still at zero. (Note: the aircraft had been written up three times in the previous week for the same issue; which we had noted and briefed the before the flight.) we executed a go-around and notified ATC of the need for delay vectors to work the problem. We consulted the QRH; performed the trailing edge flap disagree checklist; and executed a flaps 15 landing using alternate extension.three observations in hindsight:after multiple write ups for the same problem under the same circumstances; a test flight after the second or third instance might have identified the problem better; since the problem did not occur on the ground at all.enroute; we had noticed the flap gauge showing one te (trailing edge) flap at '0' and the other indicating a little less than '0'; about a one-needle-width split (there was no other indication in terms of how the aircraft was handling that there was in fact a flap asymmetry). We figured later on that this indicated - though not factual - asymmetry may have been the cause of the failure of the flaps to move when commanded.as we looked for the proper QRH checklist; we noticed that if one went to the trailing edge flap asymmetry checklist (as opposed to the disagree checklist); based on the zero/less-than-zero indication on the flap gauge; it could lead a crew to choose to land with all flaps up; as that checklist cautions not to move the flaps with the alternate flaps switch; as there is no asymmetry protection. In reviewing the logbook; it appears one previous crew did exactly that and landed with te flaps up. The other two crews who had written up the same aircraft each had made different choices; one landed flaps 40; and one chose flaps 15 (as we did); with all three of us who landed using trailing edge flaps using the alternate extension feature. More explicit guidance might lead to more standardized decision-making in this kind of scenario; though keeping in mind all situations are fairly unique.

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Original NASA ASRS Text

Title: B737 Captain reported a trailing edge flap malfunction while on approach.

Narrative: On approach I called for flaps 5. FO selected flap lever to 5. The aircraft did not slow as normally expected; so I called for landing gear; which the FO selected. The aircraft slowed a bit; but still not as normal; so I called for flaps 10. After 10 was selected and the aircraft was still not slowing properly; I noticed the flap gauge still at zero. (Note: The aircraft had been written up three times in the previous week for the same issue; which we had noted and briefed the before the flight.) We executed a go-around and notified ATC of the need for delay vectors to work the problem. We consulted the QRH; performed the Trailing Edge Flap Disagree Checklist; and executed a flaps 15 landing using alternate extension.Three observations in hindsight:After multiple write ups for the same problem under the same circumstances; a test flight after the second or third instance might have identified the problem better; since the problem did not occur on the ground at all.Enroute; we had noticed the flap gauge showing one TE (Trailing Edge) flap at '0' and the other indicating a little LESS than '0'; about a one-needle-width split (there was no other indication in terms of how the aircraft was handling that there was in fact a flap asymmetry). We figured later on that this indicated - though not factual - asymmetry may have been the cause of the failure of the flaps to move when commanded.As we looked for the proper QRH checklist; we noticed that if one went to the Trailing Edge Flap Asymmetry Checklist (as opposed to the Disagree Checklist); based on the zero/less-than-zero indication on the flap gauge; it could lead a Crew to choose to land with all flaps up; as that checklist cautions not to move the flaps with the ALTERNATE FLAPS switch; as there is no asymmetry protection. In reviewing the logbook; it appears one previous Crew did exactly that and landed with TE flaps up. The other two Crews who had written up the same aircraft each had made different choices; one landed Flaps 40; and one chose flaps 15 (as we did); with all three of us who landed using trailing edge flaps using the alternate extension feature. More explicit guidance might lead to more standardized decision-making in this kind of scenario; though keeping in mind all situations are fairly unique.

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.