An air carrier MD11 had to return land with an aircraft equipment problem, the aileron droop system would not raise the ailerons to the faired position.

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Attributes
ACN	322202
Time
Date	199511
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : anc
State Reference	AK
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : anc
Operator	common carrier : air carrier
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	climbout : intermediate altitude other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain instruction : instructor oversight : pic
Qualification	pilot : instrument pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 210 flight time total : 14000 flight time type : 2400
ASRS Report	322202
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 83 flight time total : 8000 flight time type : 2
ASRS Report	322211
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

MD11 aircraft, received 'aileron deflect disagree' alert on flap/slat retraction. Performed abnormal procedures in accordance with flight manual by returning lever to '0 degree/ext.' required fuel dump to preclude overweight landing. Approach and landing normal, -- (manual procedures are specific to 'land at suitable airport'). Callback conversation with reporter of acn 322211 revealed the following information: the reporter is flying a later model of the MD11 than did analyst. The latest aircraft have an aileron droop system that droops the ailerons when slats are in the extend position so that there will be greater lift for climb out. If the ailerons do not come up to their normal position when the slats are retracted, the drag penalty is so great that the aircraft must return/land. The aileron droop system is now deactivated. The reporter is quite new to the aircraft and was not aware that the earlier models did not have this feature. Airspeed is also restr when the ailerons do not fair with the slats up.

Original NASA ASRS Text

Title: AN ACR MD11 HAD TO RETURN LAND WITH AN ACFT EQUIP PROB, THE AILERON DROOP SYS WOULD NOT RAISE THE AILERONS TO THE FAIRED POS.

Narrative: MD11 ACFT, RECEIVED 'AILERON DEFLECT DISAGREE' ALERT ON FLAP/SLAT RETRACTION. PERFORMED ABNORMAL PROCS IN ACCORDANCE WITH FLT MANUAL BY RETURNING LEVER TO '0 DEG/EXT.' REQUIRED FUEL DUMP TO PRECLUDE OVERWT LNDG. APCH AND LNDG NORMAL, -- (MANUAL PROCS ARE SPECIFIC TO 'LAND AT SUITABLE ARPT'). CALLBACK CONVERSATION WITH RPTR OF ACN 322211 REVEALED THE FOLLOWING INFO: THE RPTR IS FLYING A LATER MODEL OF THE MD11 THAN DID ANALYST. THE LATEST ACFT HAVE AN AILERON DROOP SYS THAT DROOPS THE AILERONS WHEN SLATS ARE IN THE EXTEND POS SO THAT THERE WILL BE GREATER LIFT FOR CLB OUT. IF THE AILERONS DO NOT COME UP TO THEIR NORMAL POS WHEN THE SLATS ARE RETRACTED, THE DRAG PENALTY IS SO GREAT THAT THE ACFT MUST RETURN/LAND. THE AILERON DROOP SYS IS NOW DEACTIVATED. THE RPTR IS QUITE NEW TO THE ACFT AND WAS NOT AWARE THAT THE EARLIER MODELS DID NOT HAVE THIS FEATURE. AIRSPD IS ALSO RESTR WHEN THE AILERONS DO NOT FAIR WITH THE SLATS UP.

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.