|37000 Feet||Browse and search NASA's
Aviation Safety Reporting System
|Local Time Of Day||1801 To 2400|
|Locale Reference||airport : zzz.airport|
|Altitude||msl single value : 30000|
|Controlling Facilities||artcc : zzz.artcc|
|Operator||common carrier : air carrier|
|Make Model Name||MD-80 Series (DC-9-80) Undifferentiated or Other Model|
|Operating Under FAR Part||Part 121|
|Flight Phase||climbout : initial|
|Affiliation||company : air carrier|
|Function||flight crew : captain|
oversight : pic
|Affiliation||company : air carrier|
|Function||flight crew : first officer|
|Anomaly||aircraft equipment problem : critical|
|Independent Detector||other flight crewa|
other flight crewb
|Resolutory Action||flight crew : landed in emergency condition|
flight crew : declared emergency
flight crew : regained aircraft control
flight crew : overcame equipment problem
The first officer was climbing out of FL260 for FL320 with dfgc selected to #2; when both FMA's went blank along with flight director command bars going out of view; followed by an autoplt and autothrottle disconnect. As we were leveling at FL320 the QRH was being reviewed and the aircraft was being hand flown by the first officer. The aircraft flight controls momentarily over powered the first officer by a left hard over control force. The first officer regained control; followed by a second left hard uncommanded control movement. I then took the controls in an attempt to try to figure out what was happening. We declared an emergency; and returned to the airport landing 3000 pounds overweight with no further uncommanded flight control inputs and an uneventful landing.supplemental information from acn 740386: we were unable to connect the autoplt using either dfgc. We continued the climb without autoflt. At this point I was hand flying using raw data. After leveling off at FL320; the aircraft made a brief; but pronounced; uncommanded yaw/roll to the left. I regained control using opposite aileron.callback conversation with reporter revealed the following information: the captain; who was the PNF during both instances of the uncommanded left roll was uncertain whether the roll was the result of rudder or aileron deflection. He was also unable to describe the force required to correct it. He did state the first officer; a smaller individual; appeared to be exerting a significant amount of effort which caused him to assume control. The roll did not recur while he was at the controls. A maintenance byte check produced 47 error codes; the nature of which the reporter was unclear. Maintenance wanted to replace a 'black box' and re-dispatch the aircraft. The reporter refused stating the problem appeared flight control related and; in his opinion; would require a flight test before being released for revenue flight. He made a log entry to that effect; effectively grounding the aircraft. Reporter was unaware of the outcome of any subsequent maintenance action.
Original NASA ASRS Text
Title: MD80 FLT CREW EXPERIENCES UNCOMMANDED ROLL FOLLOWING FAILURE OF THE FMS FMA AND THE ACCOMPANYING DISCONNECT OF THE AUTOPLT AND FLT DIRECTORS.
Narrative: THE FO WAS CLBING OUT OF FL260 FOR FL320 WITH DFGC SELECTED TO #2; WHEN BOTH FMA'S WENT BLANK ALONG WITH FLT DIRECTOR COMMAND BARS GOING OUT OF VIEW; FOLLOWED BY AN AUTOPLT AND AUTOTHROTTLE DISCONNECT. AS WE WERE LEVELING AT FL320 THE QRH WAS BEING REVIEWED AND THE ACFT WAS BEING HAND FLOWN BY THE FO. THE ACFT FLT CTLS MOMENTARILY OVER POWERED THE FO BY A L HARD OVER CTL FORCE. THE FO REGAINED CTL; FOLLOWED BY A SECOND L HARD UNCOMMANDED CTL MOVEMENT. I THEN TOOK THE CTLS IN AN ATTEMPT TO TRY TO FIGURE OUT WHAT WAS HAPPENING. WE DECLARED AN EMER; AND RETURNED TO THE ARPT LNDG 3000 LBS OVERWEIGHT WITH NO FURTHER UNCOMMANDED FLT CTL INPUTS AND AN UNEVENTFUL LNDG.SUPPLEMENTAL INFO FROM ACN 740386: WE WERE UNABLE TO CONNECT THE AUTOPLT USING EITHER DFGC. WE CONTINUED THE CLB WITHOUT AUTOFLT. AT THIS POINT I WAS HAND FLYING USING RAW DATA. AFTER LEVELING OFF AT FL320; THE ACFT MADE A BRIEF; BUT PRONOUNCED; UNCOMMANDED YAW/ROLL TO THE LEFT. I REGAINED CTL USING OPPOSITE AILERON.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE CAPT; WHO WAS THE PNF DURING BOTH INSTANCES OF THE UNCOMMANDED L ROLL WAS UNCERTAIN WHETHER THE ROLL WAS THE RESULT OF RUDDER OR AILERON DEFLECTION. HE WAS ALSO UNABLE TO DESCRIBE THE FORCE REQUIRED TO CORRECT IT. HE DID STATE THE FO; A SMALLER INDIVIDUAL; APPEARED TO BE EXERTING A SIGNIFICANT AMOUNT OF EFFORT WHICH CAUSED HIM TO ASSUME CTL. THE ROLL DID NOT RECUR WHILE HE WAS AT THE CTLS. A MAINT BYTE CHK PRODUCED 47 ERROR CODES; THE NATURE OF WHICH THE RPTR WAS UNCLEAR. MAINT WANTED TO REPLACE A 'BLACK BOX' AND RE-DISPATCH THE ACFT. THE RPTR REFUSED STATING THE PROB APPEARED FLT CTL RELATED AND; IN HIS OPINION; WOULD REQUIRE A FLT TEST BEFORE BEING RELEASED FOR REVENUE FLT. HE MADE A LOG ENTRY TO THAT EFFECT; EFFECTIVELY GROUNDING THE ACFT. RPTR WAS UNAWARE OF THE OUTCOME OF ANY SUBSEQUENT MAINT ACTION.
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.