Narrative:

On a flaps 5 departure from oma runway 36 at an approximately takeoff weight of 149000 pounds, a normal climb profile and a turnout to an assigned heading of 300 degrees was established. Reaching 1000 ft AGL, a command for flaps 2 degrees was given. A split flap condition occurred, as noticed by the flight engineer, with the inboard flaps remaining at the 5 degree position and the outboard flaps retracting to a 2 degree position with all leading edge devices remaining fully extended. While retrieving the split trailing edge flaps checklist, smoke began to fill the cockpit. Oxygen masks were donned by the first officer and flight engineer. An emergency was declared to ATC and an immediate right turn was initiated back toward the airport. A steep bank turn of approximately 45 degrees was used to expedite the course reversal while at an altitude of approximately 3000 ft MSL. This established a final approach course for runway 14R. We were handed off to tower who then cleared us for landing on any runway. Due to the nature of the emergency it was decided a landing on runway 14R would be made with an approximately tailwind of 15 KTS. The flaps were left in the split condition due to the malfunction and close proximity to the ground. On final approach, the aircraft became laterally unstable requiring many control inputs and power applications to maintain control. An approach speed of approximately 220 KIAS was required to prevent excessive sink rate and maintain control stability. Touchdown occurred approximately 2500 ft down the runway at an approximately speed of 195 KIAS and an overweight condition due to the short flight duration (approximately 4 mins). Speed brakes were extended, maximum reverse thrust established and maximum braking effort applied to decelerate the aircraft on the runway. We exited the runway, shut down the aircraft and evacuate/evacuationed to safety on a large taxiway. Fire crews met the aircraft but the source of the smoke could not be found. It was also noticed that the 1, 4, 5, 8 slats and kruger flaps had retracted and the flaps remained in a split condition. Human factors related to the urgency and nature of the flight include a dual emergency condition and short duration of flight. The split trailing edge flap checklist was interrupted due to the cockpit filling with smoke and the immediate turn toward the runway not allowing the completion of the checklist. After donning oxygen masks and establishing communications, the aircraft was laterally unstable requiring much attention and effort by the captain to maintain aircraft control not allowing checklists to be used on final. Fuel was also not dumped due to the short duration of flight after discovery of the smoke. The alternate flap system was not used due to the possibility of worsening the situation with an asymmetrical flap condition and close proximity to the ground. Overall, the performance of the crew was excellent considering the circumstances. Callback conversation with reporter revealed the following information: reporter said that the source of the smoke was not determined, but that the area around the air conditioning packs was charred and the ducts in that area showed the evidence of excess heat. The level of smoke was not so severe that the captain took the time to don his oxygen mask because of the difficulty he had controling the aircraft. The leading edge flap position was 1, 4, 5, and 8 extended when it should have been 2, 3, 6, and 7 extended. Reporter has no feedback on what caused the flap condition.

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Original NASA ASRS Text

Title: B727-100 CREW EXPERIENCED SPLIT FLAPS DURING FLAP RETRACTION FOLLOWED BY SMOKE IN THE COCKPIT ON DEP FROM OMA, NE.

Narrative: ON A FLAPS 5 DEP FROM OMA RWY 36 AT AN APPROX TKOF WT OF 149000 LBS, A NORMAL CLB PROFILE AND A TURNOUT TO AN ASSIGNED HDG OF 300 DEGS WAS ESTABLISHED. REACHING 1000 FT AGL, A COMMAND FOR FLAPS 2 DEGS WAS GIVEN. A SPLIT FLAP CONDITION OCCURRED, AS NOTICED BY THE FE, WITH THE INBOARD FLAPS REMAINING AT THE 5 DEG POS AND THE OUTBOARD FLAPS RETRACTING TO A 2 DEG POS WITH ALL LEADING EDGE DEVICES REMAINING FULLY EXTENDED. WHILE RETRIEVING THE SPLIT TRAILING EDGE FLAPS CHKLIST, SMOKE BEGAN TO FILL THE COCKPIT. OXYGEN MASKS WERE DONNED BY THE FO AND FE. AN EMER WAS DECLARED TO ATC AND AN IMMEDIATE R TURN WAS INITIATED BACK TOWARD THE ARPT. A STEEP BANK TURN OF APPROX 45 DEGS WAS USED TO EXPEDITE THE COURSE REVERSAL WHILE AT AN ALT OF APPROX 3000 FT MSL. THIS ESTABLISHED A FINAL APCH COURSE FOR RWY 14R. WE WERE HANDED OFF TO TWR WHO THEN CLRED US FOR LNDG ON ANY RWY. DUE TO THE NATURE OF THE EMER IT WAS DECIDED A LNDG ON RWY 14R WOULD BE MADE WITH AN APPROX TAILWIND OF 15 KTS. THE FLAPS WERE LEFT IN THE SPLIT CONDITION DUE TO THE MALFUNCTION AND CLOSE PROX TO THE GND. ON FINAL APCH, THE ACFT BECAME LATERALLY UNSTABLE REQUIRING MANY CTL INPUTS AND PWR APPLICATIONS TO MAINTAIN CTL. AN APCH SPD OF APPROX 220 KIAS WAS REQUIRED TO PREVENT EXCESSIVE SINK RATE AND MAINTAIN CTL STABILITY. TOUCHDOWN OCCURRED APPROX 2500 FT DOWN THE RWY AT AN APPROX SPD OF 195 KIAS AND AN OVERWT CONDITION DUE TO THE SHORT FLT DURATION (APPROX 4 MINS). SPD BRAKES WERE EXTENDED, MAX REVERSE THRUST ESTABLISHED AND MAX BRAKING EFFORT APPLIED TO DECELERATE THE ACFT ON THE RWY. WE EXITED THE RWY, SHUT DOWN THE ACFT AND EVACED TO SAFETY ON A LARGE TXWY. FIRE CREWS MET THE ACFT BUT THE SOURCE OF THE SMOKE COULD NOT BE FOUND. IT WAS ALSO NOTICED THAT THE 1, 4, 5, 8 SLATS AND KRUGER FLAPS HAD RETRACTED AND THE FLAPS REMAINED IN A SPLIT CONDITION. HUMAN FACTORS RELATED TO THE URGENCY AND NATURE OF THE FLT INCLUDE A DUAL EMER CONDITION AND SHORT DURATION OF FLT. THE SPLIT TRAILING EDGE FLAP CHKLIST WAS INTERRUPTED DUE TO THE COCKPIT FILLING WITH SMOKE AND THE IMMEDIATE TURN TOWARD THE RWY NOT ALLOWING THE COMPLETION OF THE CHKLIST. AFTER DONNING OXYGEN MASKS AND ESTABLISHING COMS, THE ACFT WAS LATERALLY UNSTABLE REQUIRING MUCH ATTN AND EFFORT BY THE CAPT TO MAINTAIN ACFT CTL NOT ALLOWING CHKLISTS TO BE USED ON FINAL. FUEL WAS ALSO NOT DUMPED DUE TO THE SHORT DURATION OF FLT AFTER DISCOVERY OF THE SMOKE. THE ALTERNATE FLAP SYS WAS NOT USED DUE TO THE POSSIBILITY OF WORSENING THE SIT WITH AN ASYMMETRICAL FLAP CONDITION AND CLOSE PROX TO THE GND. OVERALL, THE PERFORMANCE OF THE CREW WAS EXCELLENT CONSIDERING THE CIRCUMSTANCES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID THAT THE SOURCE OF THE SMOKE WAS NOT DETERMINED, BUT THAT THE AREA AROUND THE AIR CONDITIONING PACKS WAS CHARRED AND THE DUCTS IN THAT AREA SHOWED THE EVIDENCE OF EXCESS HEAT. THE LEVEL OF SMOKE WAS NOT SO SEVERE THAT THE CAPT TOOK THE TIME TO DON HIS OXYGEN MASK BECAUSE OF THE DIFFICULTY HE HAD CTLING THE ACFT. THE LEADING EDGE FLAP POS WAS 1, 4, 5, AND 8 EXTENDED WHEN IT SHOULD HAVE BEEN 2, 3, 6, AND 7 EXTENDED. RPTR HAS NO FEEDBACK ON WHAT CAUSED THE FLAP CONDITION.

Data retrieved from NASA's ASRS site as of July 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.