Narrative:

During approach phase of flight, as flaps were lowered, a flap asymmetry problem occurred, locking the inboard flaps at about 3 degrees. Flap asymmetry checklist was followed and remaining flaps lowered to 25 degrees with a bug speed additive of 20 KTS. At approximately 800' MSL (750' AGL) the locked set of flaps released and rapidly came down to 25 degrees. The aircraft ballooned severely and required a great deal of forward yoke pressure to control. Speed was now at least 30 KTS fast. Bug speeds were reset to normal and a normal landing was made. There should be an addition to the checklist procedure to prevent the locked out set of flaps from deploying at the wrong time and creating a possible dangerous situation if it occurs close to the ground. The problem was caused by a malfunctioning inoperative flap indicator tape that was hanging up. Supplemental information from acn 83857: on takeoff at lax, stickshaker occurred 100' AGL as gear raised. Aircraft was on speed and in trim. Lowered nose and shaker stopped at V2+12. At V2+20, flaps raised from 10 degrees to 5 degrees, asymmetry shutoff of inboard T/east flaps at 8 degrees. Nose became very heavy, required heavy abnormal back pressure and constant electric trim up to stop nose heaviness. Flap travel regained with normal control forces at flaps 0 degrees and V2+80. Later information from maintenance indicated flap transmitter problems, flap indicator problems and horizontal stabilizer misrig of approximately 3 degrees. No cockpit errors were made by crew. These incidents occurred due to poor maintenance follow-up on previously squawked control items. Supplemental information from acn 84044: during taxiout flap handle to 10 degrees. All indicator 10 degrees except left inboard flap at 0 degrees. The circuit breaker was recycled with the right inboard indicator going to off and right inboard indicator in 0 degrees. Then, the left inboard indicator started to operate intermittently. No lock out was even indicated. Normal takeoff roll. No takeoff warning horn, but a more rapid than normal rotation to 16 degrees nose up. Right after lift off, the stick shaker actuated for several seconds. Rapid xchk gave no other apparent reason for warning. Upon flap retraction the inboards appeared to lock out--0 degrees 0 degrees 7 degrees 0 degrees. Shortly thereafter, the inboards apparently broke loose and moved to up position. No noticeable control problems, flight continued uneventfully to jfk.

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Original NASA ASRS Text

Title: ACR WDB INCURRED SPLIT FLAP WHEN CONFIGURING FOR LNDG.

Narrative: DURING APCH PHASE OF FLT, AS FLAPS WERE LOWERED, A FLAP ASYMMETRY PROB OCCURRED, LOCKING THE INBOARD FLAPS AT ABOUT 3 DEGS. FLAP ASYMMETRY CHKLIST WAS FOLLOWED AND REMAINING FLAPS LOWERED TO 25 DEGS WITH A BUG SPD ADDITIVE OF 20 KTS. AT APPROX 800' MSL (750' AGL) THE LOCKED SET OF FLAPS RELEASED AND RAPIDLY CAME DOWN TO 25 DEGS. THE ACFT BALLOONED SEVERELY AND REQUIRED A GREAT DEAL OF FORWARD YOKE PRESSURE TO CTL. SPD WAS NOW AT LEAST 30 KTS FAST. BUG SPDS WERE RESET TO NORMAL AND A NORMAL LNDG WAS MADE. THERE SHOULD BE AN ADDITION TO THE CHKLIST PROC TO PREVENT THE LOCKED OUT SET OF FLAPS FROM DEPLOYING AT THE WRONG TIME AND CREATING A POSSIBLE DANGEROUS SITUATION IF IT OCCURS CLOSE TO THE GND. THE PROB WAS CAUSED BY A MALFUNCTIONING INOP FLAP INDICATOR TAPE THAT WAS HANGING UP. SUPPLEMENTAL INFO FROM ACN 83857: ON TKOF AT LAX, STICKSHAKER OCCURRED 100' AGL AS GEAR RAISED. ACFT WAS ON SPD AND IN TRIM. LOWERED NOSE AND SHAKER STOPPED AT V2+12. AT V2+20, FLAPS RAISED FROM 10 DEGS TO 5 DEGS, ASYMMETRY SHUTOFF OF INBOARD T/E FLAPS AT 8 DEGS. NOSE BECAME VERY HEAVY, REQUIRED HEAVY ABNORMAL BACK PRESSURE AND CONSTANT ELECTRIC TRIM UP TO STOP NOSE HEAVINESS. FLAP TRAVEL REGAINED WITH NORMAL CTL FORCES AT FLAPS 0 DEGS AND V2+80. LATER INFO FROM MAINT INDICATED FLAP XMITTER PROBS, FLAP INDICATOR PROBS AND HORIZ STAB MISRIG OF APPROX 3 DEGS. NO COCKPIT ERRORS WERE MADE BY CREW. THESE INCIDENTS OCCURRED DUE TO POOR MAINT FOLLOW-UP ON PREVIOUSLY SQUAWKED CTL ITEMS. SUPPLEMENTAL INFO FROM ACN 84044: DURING TAXIOUT FLAP HANDLE TO 10 DEGS. ALL INDICATOR 10 DEGS EXCEPT LEFT INBOARD FLAP AT 0 DEGS. THE CB WAS RECYCLED WITH THE RIGHT INBOARD INDICATOR GOING TO OFF AND RIGHT INBOARD INDICATOR IN 0 DEGS. THEN, THE LEFT INBOARD INDICATOR STARTED TO OPERATE INTERMITTENTLY. NO LOCK OUT WAS EVEN INDICATED. NORMAL TKOF ROLL. NO TKOF WARNING HORN, BUT A MORE RAPID THAN NORMAL ROTATION TO 16 DEGS NOSE UP. RIGHT AFTER LIFT OFF, THE STICK SHAKER ACTUATED FOR SEVERAL SECS. RAPID XCHK GAVE NO OTHER APPARENT REASON FOR WARNING. UPON FLAP RETRACTION THE INBOARDS APPEARED TO LOCK OUT--0 DEGS 0 DEGS 7 DEGS 0 DEGS. SHORTLY THEREAFTER, THE INBOARDS APPARENTLY BROKE LOOSE AND MOVED TO UP POS. NO NOTICEABLE CTL PROBS, FLT CONTINUED UNEVENTFULLY TO JFK.

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.