A B737-300 had a flap asymmetry indication with no roll motion but after the Captain accidentally touched the ALTERNATE FLAPS DOWN SWITCH the flaps functioned normally and the regular landing checklist was completed. The flight crew felt rushed by TRACON and did not completely troubleshoot the problem.
Synopsis
A B737-300 had a flap asymmetry indication with no roll motion but after the Captain accidentally touched the ALTERNATE FLAPS DOWN SWITCH the flaps functioned normally and the regular landing checklist was completed. The flight crew felt rushed by TRACON and did not completely troubleshoot the problem.
Narrative
While running the Asymmetrical Trailing Edge Flaps Checklist; I bumped the flap switch to extend. The flap gauge immediately showed symmetric flaps at 2. Since we never had a rolling motion; I continued to extend the flaps to 30 per our original planned landing. I should have gone back to the Alternate Symmetric Trailing Edge Flap Checklist; and saw flaps should have been extended to 15 for landing. We asked for a vector off the localizer for inability to comply with an ATC speed restriction. I told Approach we had a flap problem we needed to work out. They sent us south for a minute and then back north to re-intercept the localizer. We had a communication problem with ATC; as they kept asking me to repeat my communication. It became a distraction as I got rushed into completing the checklist; sent over to Tower at about 6.7 miles; and then cleared to land. I've had asymmetric flaps before; and knew it was a handful. The First Officer reported no rolling motion; so I knew the flaps weren't asymmetric; even though the gauge showed they were. If the Asymmetric Flaps Checklist had a bold note at the top to redirect the crew back to the Alternate Symmetrical Trailing Edge Flaps Checklist; (in the event of no rolling motion) I might have gotten to the right checklist when things got rushed.
Second reporter narrative
ATC advised us to slow from 210 KTS to 170 KTS. I was the pilot flying and called for flaps 5. After a short period; I noticed the flaps stopped just beyond 1 with a split flap indication. Advised the Captain to inform ATC we were unable to comply with speed restriction due to flap malfunction; and called for checklist. Captain was not clear in his communication with ATC about unable to comply with speed and there was some confusion in the transmissions before we were vectored off the localizer. Captain was reading checklist at which time he momentarily bumped the alternate flap switch to down to extend the leading edge devices. At this time the asymmetry indication went away. At no time was there ever a rolling moment which led us to believe it was a gauge error. By this time; ATC gave us a heading to intercept the localizer. I mentioned to the Captain that I thought we needed more time in order to run new landing numbers with a different flap setting. He told me to continue; that the checklist was complete; and he selected the flaps to 30 with the alternate system. Upon further review of the checklist; after being informed it was done incorrectly; we should have run data for a flaps 15 landing. As I was pilot flying; I did not question the accuracy of the checklist that was run. There are no memory items on this checklist so I trusted the Captain had read it accurately. I should have insisted on taking more time to ensure the checklist was completed accurately. I think we felt rushed because ATC turned us back on the approach before we told them we were ready and should have asked for more time. I should have been more familiar with the checklist being used even though there are no memory items on it. After further review of the checklist; it can be quite confusing to apply depending on what situation you have.
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Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.