Widebody transport crew had a section of the right inboard flap vane fall off the aircraft.

Attributes
ACN	610996
Time
Date	200403
Day	Wed
Local Time Of Day	0001 To 0600
Place
Locale Reference	airport : ord.airport
State Reference	IL
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	MD-10 Conversion
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 57 flight time total : 5100 flight time type : 209
ASRS Report	610996
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : less severe
Independent Detector	other other : 3
Resolutory Action	none taken : detected after the fact
Consequence	other other
Supplementary
Problem Areas	Aircraft
Primary Problem	Aircraft

Narrative:

The captain was flying the aircraft on approach to runway 14R at chicago ohare. When extending the flaps to 35 degrees we felt a slight bump. The captain disconnected the autoplt and hand flew the airplane with no control difficulty. He then cycled the flaps from 35-50 degrees and back, noting normal operation and position indications. We continued the approach to a normal landing. The next morning we were informed that our maintenance had discovered a section of the right inboard flap vane missing from the aircraft. We had no idea this had occurred. We attributed the bump to possible turbulence and felt it was insignificant. Looking back, this slight bump was the only thing unusual about the flight. This may have been when the separation of the flap vane occurred. We had some crosswind until close to the runway. This may have made it more difficult for the captain to notice any aerodynamic effects.

Original NASA ASRS Text

Title: WDB CREW HAD A SECTION OF THE R INBOARD FLAP VANE FALL OFF THE ACFT.

Narrative: THE CAPT WAS FLYING THE ACFT ON APCH TO RWY 14R AT CHICAGO OHARE. WHEN EXTENDING THE FLAPS TO 35 DEGS WE FELT A SLIGHT BUMP. THE CAPT DISCONNECTED THE AUTOPLT AND HAND FLEW THE AIRPLANE WITH NO CTL DIFFICULTY. HE THEN CYCLED THE FLAPS FROM 35-50 DEGS AND BACK, NOTING NORMAL OP AND POS INDICATIONS. WE CONTINUED THE APCH TO A NORMAL LNDG. THE NEXT MORNING WE WERE INFORMED THAT OUR MAINT HAD DISCOVERED A SECTION OF THE R INBOARD FLAP VANE MISSING FROM THE ACFT. WE HAD NO IDEA THIS HAD OCCURRED. WE ATTRIBUTED THE BUMP TO POSSIBLE TURB AND FELT IT WAS INSIGNIFICANT. LOOKING BACK, THIS SLIGHT BUMP WAS THE ONLY THING UNUSUAL ABOUT THE FLT. THIS MAY HAVE BEEN WHEN THE SEPARATION OF THE FLAP VANE OCCURRED. WE HAD SOME XWIND UNTIL CLOSE TO THE RWY. THIS MAY HAVE MADE IT MORE DIFFICULT FOR THE CAPT TO NOTICE ANY AERODYNAMIC EFFECTS.

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.