Narrative:

First officer landed the aircraft (30 degree flap landing) and called for 'flaps 25' after T/D (normal procedure to avoid FOD ingestion during landing/reversing). I (captain) moved the flap handle toward the '25 flap safety gate,' but flap handle passed unobstructed to flaps 2 safety gate. Flap lever should have been prevented from moving past 25 safety gate until lever passed under safety gate. From flaps 2 position, I attempted to re-select 25 degree flaps and lever once again passed by the '25 safety gate' and went into flaps detent. Flap handle finally would up at flaps 20 position. Stopped on taxiway inbound to terminal gate and attempted 25 degree flap selection 8-10 times, on 5 or 6 times flap handled passed freely by the 25 flap safety gate. It is not so critical for the 25 flap safety gate to malfunction on landing, but our air carrier go around procedure calls for selection of flaps 25 degrees initially until 40 reference + 5 KTS are attained before selecting 15 degree flaps, and continuing the missed approach climb out procedure. Where this malfunction may be significant is during a low minimum missed approach when the flap handle advances past the 25 degree flap position safety gate and the crew becomes distracted while attempting to successfully go around. This 25 flap worn safety gate appears to only be apparent on the large transport advanced airplanes.

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Original NASA ASRS Text

Title: WING FLAP CONTROL AHNDLE SAFETY GATE INOPERATIVE INEFFECTIVE.

Narrative: F/O LANDED THE ACFT (30 DEG FLAP LNDG) AND CALLED FOR 'FLAPS 25' AFTER T/D (NORMAL PROC TO AVOID FOD INGESTION DURING LNDG/REVERSING). I (CAPT) MOVED THE FLAP HANDLE TOWARD THE '25 FLAP SAFETY GATE,' BUT FLAP HANDLE PASSED UNOBSTRUCTED TO FLAPS 2 SAFETY GATE. FLAP LEVER SHOULD HAVE BEEN PREVENTED FROM MOVING PAST 25 SAFETY GATE UNTIL LEVER PASSED UNDER SAFETY GATE. FROM FLAPS 2 POS, I ATTEMPTED TO RE-SELECT 25 DEG FLAPS AND LEVER ONCE AGAIN PASSED BY THE '25 SAFETY GATE' AND WENT INTO FLAPS DETENT. FLAP HANDLE FINALLY WOULD UP AT FLAPS 20 POS. STOPPED ON TXWY INBND TO TERMINAL GATE AND ATTEMPTED 25 DEG FLAP SELECTION 8-10 TIMES, ON 5 OR 6 TIMES FLAP HANDLED PASSED FREELY BY THE 25 FLAP SAFETY GATE. IT IS NOT SO CRITICAL FOR THE 25 FLAP SAFETY GATE TO MALFUNCTION ON LNDG, BUT OUR ACR GAR PROC CALLS FOR SELECTION OF FLAPS 25 DEGS INITIALLY UNTIL 40 REF + 5 KTS ARE ATTAINED BEFORE SELECTING 15 DEG FLAPS, AND CONTINUING THE MISSED APCH CLBOUT PROC. WHERE THIS MALFUNCTION MAY BE SIGNIFICANT IS DURING A LOW MINIMUM MISSED APCH WHEN THE FLAP HANDLE ADVANCES PAST THE 25 DEG FLAP POS SAFETY GATE AND THE CREW BECOMES DISTRACTED WHILE ATTEMPTING TO SUCCESSFULLY GO AROUND. THIS 25 FLAP WORN SAFETY GATE APPEARS TO ONLY BE APPARENT ON THE LGT ADVANCED AIRPLANES.

Data retrieved from NASA's ASRS site as of August 2007 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.