Narrative:

While on ILS runway 36L at dfw tripped trailing edge and leading edge flap disagree over OM; executed a go around. Ran trailing edge flap disagree checklist; all lights extinguished (leading edge disagree lights extinguished with trailing edge disagree checklist); landed with flaps 20 degrees. The WX was 100 and 1/4 3000 ft RVR; we had approximately 12.0 fuel remaining. Traffic was heavy with around 3 mi spacing. We were instructed to maintain 170 KTS to the OM. At GS intercept the first officer called for flaps 30 degrees; I then selected flaps 30 degrees and noticed the flaps had stopped at 25 degrees and that our airspeed was around 165-170 KTS at which time I moved the flap lever back to 25 degrees. Either I missed the flap 25 degree detent or I was moving the handle while the flap relief system was in operation. Either way we got both leading edge and trailing edge flap disagree lights and EICAS messages at which time we executed a go around from around 1200 ft. We leveled off at 3000 ft; accelerated to 190 KTS then reduced back to 170 KTS. During the go around the flap handle was moved to 20 degree position out of instinct and to silence the gear horn. By the time we ran the checklist the flaps were indicating 20 degrees and we elected to land with flaps 20 degrees per the checklist. The first officer flew the aircraft while I ran the checklist. The workload was extremely heavy with ATC instructions; heavy traffic; bad WX; fuel considerations and flying the plane. After I had completed the checklist I assumed control of the aircraft for landing and instructed the first officer to review the checklist for any mistakes I might have made in the heat of the battle. There was some confusion with the checklist as to whether we could re-extend the flaps to 30 degrees with alternate; however we decided not to move the flight control in question not being exactly sure what had taken place. We had 20 degree flaps; the runway was 12500 ft long; the WX was at minimums; we were low on fuel and the traffic was heavy; so we landed uneventful. There was never any indication of flap limit on the ADI throughout the whole event. After landing we left the flaps at 20 degrees for maintenance to inspect; entered the sequence of events in the aircraft log; and notified a maintenance supervisor and my fleet supervisor of what had taken place.

Related reports:

Google
 

Original NASA ASRS Text

Title: B757 LEADING EDGE AND TRAILING EDGE FLAP DISAGREE MESSAGES APPEAR WHEN FLAP EXTENSION TO 30 DEGS IS ATTEMPTED ABOVE LIMIT SPD.

Narrative: WHILE ON ILS RWY 36L AT DFW TRIPPED TRAILING EDGE AND LEADING EDGE FLAP DISAGREE OVER OM; EXECUTED A GAR. RAN TRAILING EDGE FLAP DISAGREE CHKLIST; ALL LIGHTS EXTINGUISHED (LEADING EDGE DISAGREE LIGHTS EXTINGUISHED WITH TRAILING EDGE DISAGREE CHKLIST); LANDED WITH FLAPS 20 DEGS. THE WX WAS 100 AND 1/4 3000 FT RVR; WE HAD APPROX 12.0 FUEL REMAINING. TFC WAS HVY WITH AROUND 3 MI SPACING. WE WERE INSTRUCTED TO MAINTAIN 170 KTS TO THE OM. AT GS INTERCEPT THE FO CALLED FOR FLAPS 30 DEGS; I THEN SELECTED FLAPS 30 DEGS AND NOTICED THE FLAPS HAD STOPPED AT 25 DEGS AND THAT OUR AIRSPD WAS AROUND 165-170 KTS AT WHICH TIME I MOVED THE FLAP LEVER BACK TO 25 DEGS. EITHER I MISSED THE FLAP 25 DEG DETENT OR I WAS MOVING THE HANDLE WHILE THE FLAP RELIEF SYS WAS IN OP. EITHER WAY WE GOT BOTH LEADING EDGE AND TRAILING EDGE FLAP DISAGREE LIGHTS AND EICAS MESSAGES AT WHICH TIME WE EXECUTED A GAR FROM AROUND 1200 FT. WE LEVELED OFF AT 3000 FT; ACCELERATED TO 190 KTS THEN REDUCED BACK TO 170 KTS. DURING THE GAR THE FLAP HANDLE WAS MOVED TO 20 DEG POS OUT OF INSTINCT AND TO SILENCE THE GEAR HORN. BY THE TIME WE RAN THE CHKLIST THE FLAPS WERE INDICATING 20 DEGS AND WE ELECTED TO LAND WITH FLAPS 20 DEGS PER THE CHKLIST. THE FO FLEW THE ACFT WHILE I RAN THE CHKLIST. THE WORKLOAD WAS EXTREMELY HVY WITH ATC INSTRUCTIONS; HVY TFC; BAD WX; FUEL CONSIDERATIONS AND FLYING THE PLANE. AFTER I HAD COMPLETED THE CHKLIST I ASSUMED CTL OF THE ACFT FOR LNDG AND INSTRUCTED THE FO TO REVIEW THE CHKLIST FOR ANY MISTAKES I MIGHT HAVE MADE IN THE HEAT OF THE BATTLE. THERE WAS SOME CONFUSION WITH THE CHKLIST AS TO WHETHER WE COULD RE-EXTEND THE FLAPS TO 30 DEGS WITH ALTERNATE; HOWEVER WE DECIDED NOT TO MOVE THE FLT CTL IN QUESTION NOT BEING EXACTLY SURE WHAT HAD TAKEN PLACE. WE HAD 20 DEG FLAPS; THE RWY WAS 12500 FT LONG; THE WX WAS AT MINIMUMS; WE WERE LOW ON FUEL AND THE TFC WAS HVY; SO WE LANDED UNEVENTFUL. THERE WAS NEVER ANY INDICATION OF FLAP LIMIT ON THE ADI THROUGHOUT THE WHOLE EVENT. AFTER LNDG WE LEFT THE FLAPS AT 20 DEGS FOR MAINT TO INSPECT; ENTERED THE SEQUENCE OF EVENTS IN THE ACFT LOG; AND NOTIFIED A MAINT SUPVR AND MY FLEET SUPVR OF WHAT HAD TAKEN PLACE.

Data retrieved from NASA's ASRS site as of January 2009 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.