Narrative:

At leveloff at FL350, aircraft would not accelerate and started to decelerate. Pilot in rear of aircraft indicated that left flap was extended 3 inches. Aircraft continued to decelerate. Requested immediate descent to FL310 which they could not approve immediately. Due to aircraft performance we had to initiate a shallow descent, approximately 400 ft below FL350 until clearance was received for lower. Did not feel it prudent to maintain FL350 with airspeed decreasing. Supplemental information from acn 505127: pilot in aft cabin reported left flap extended 3 inches when right retracted. Could not maintain FL350 without airspeed decreasing. Callback conversation with reporter acn 505126 revealed the following information: reporter stated the aircraft, although requiring extra power and trim, did perform adequately at FL310. While troubleshooting, the hydraulic system was repressurized in hopes the flaps would fair to their normal position. However, they remained in the extended position (3 inches) until approximately 16000 ft on descent, at which time they retracted (faired) to the up position. Flap operation was reported as normal during descent and approach. Reporter has had no feedback from maintenance as to their findings.

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Original NASA ASRS Text

Title: A DC9 CREW EXPERIENCED ACFT DECELERATION AT LEVELOFF, L TRAILING EDGE FLAP EXTENDED 3 INCHES.

Narrative: AT LEVELOFF AT FL350, ACFT WOULD NOT ACCELERATE AND STARTED TO DECELERATE. PLT IN REAR OF ACFT INDICATED THAT L FLAP WAS EXTENDED 3 INCHES. ACFT CONTINUED TO DECELERATE. REQUESTED IMMEDIATE DSCNT TO FL310 WHICH THEY COULD NOT APPROVE IMMEDIATELY. DUE TO ACFT PERFORMANCE WE HAD TO INITIATE A SHALLOW DSCNT, APPROX 400 FT BELOW FL350 UNTIL CLRNC WAS RECEIVED FOR LOWER. DID NOT FEEL IT PRUDENT TO MAINTAIN FL350 WITH AIRSPD DECREASING. SUPPLEMENTAL INFO FROM ACN 505127: PLT IN AFT CABIN RPTED L FLAP EXTENDED 3 INCHES WHEN R RETRACTED. COULD NOT MAINTAIN FL350 WITHOUT AIRSPD DECREASING. CALLBACK CONVERSATION WITH RPTR ACN 505126 REVEALED THE FOLLOWING INFO: RPTR STATED THE ACFT, ALTHOUGH REQUIRING EXTRA PWR AND TRIM, DID PERFORM ADEQUATELY AT FL310. WHILE TROUBLESHOOTING, THE HYD SYS WAS REPRESSURIZED IN HOPES THE FLAPS WOULD FAIR TO THEIR NORMAL POS. HOWEVER, THEY REMAINED IN THE EXTENDED POS (3 INCHES) UNTIL APPROX 16000 FT ON DSCNT, AT WHICH TIME THEY RETRACTED (FAIRED) TO THE UP POS. FLAP OP WAS RPTED AS NORMAL DURING DSCNT AND APCH. RPTR HAS HAD NO FEEDBACK FROM MAINT AS TO THEIR FINDINGS.

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.