B737 has leading edge slat indication problem.

Attributes
ACN	466688
Time
Date	200003
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : sea.airport
State Reference	WA
Altitude	agl single value : 300
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tower : sea.tower
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 16r other
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	466688
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : multi engine pilot : instrument
ASRS Report	466278
Events
Anomaly	aircraft equipment problem : critical non adherence : company policies non adherence : published procedure
Independent Detector	aircraft equipment other aircraft equipment : airspeed warning other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Consequence	other other
Supplementary
Problem Areas	Flight Crew Human Performance Aircraft
Primary Problem	Aircraft

Narrative:

On final runway 16R at sea, we selected 30 degree flaps and slowed. Airspeed indicator box yellow at higher than reference airspeed. We were not sure why at the time, we selected flaps 40 degrees as was planned for landing and saw more of the yellow border around airspeed indication. At about 300 ft AGL, first officer noticed leading edge flaps transit light illuminated. Aircraft showed no abnormal tendencies -- no roll abnormalities -- and we continued to a normal landing. In retrospect we should have noticed this abnormality sooner, and gone around and set up for flaps 15 degree landing. It turned out #3 leading edge slat proximity switch was in need of adjustment. Supplemental information from acn 466278: on final runway 16R, we were visual, looking for another air carrier medical emergency on runway 16L. Captain called out what was a very narrow window on the airspeed indicator and there was a yellow border around the airspeed indicator. We were unsure for the reason for the yellow border.

Original NASA ASRS Text

Title: B737 HAS LEADING EDGE SLAT INDICATION PROB.

Narrative: ON FINAL RWY 16R AT SEA, WE SELECTED 30 DEG FLAPS AND SLOWED. AIRSPD INDICATOR BOX YELLOW AT HIGHER THAN REF AIRSPD. WE WERE NOT SURE WHY AT THE TIME, WE SELECTED FLAPS 40 DEGS AS WAS PLANNED FOR LNDG AND SAW MORE OF THE YELLOW BORDER AROUND AIRSPD INDICATION. AT ABOUT 300 FT AGL, FO NOTICED LEADING EDGE FLAPS TRANSIT LIGHT ILLUMINATED. ACFT SHOWED NO ABNORMAL TENDENCIES -- NO ROLL ABNORMALITIES -- AND WE CONTINUED TO A NORMAL LNDG. IN RETROSPECT WE SHOULD HAVE NOTICED THIS ABNORMALITY SOONER, AND GONE AROUND AND SET UP FOR FLAPS 15 DEG LNDG. IT TURNED OUT #3 LEADING EDGE SLAT PROX SWITCH WAS IN NEED OF ADJUSTMENT. SUPPLEMENTAL INFO FROM ACN 466278: ON FINAL RWY 16R, WE WERE VISUAL, LOOKING FOR ANOTHER ACR MEDICAL EMER ON RWY 16L. CAPT CALLED OUT WHAT WAS A VERY NARROW WINDOW ON THE AIRSPD INDICATOR AND THERE WAS A YELLOW BORDER AROUND THE AIRSPD INDICATOR. WE WERE UNSURE FOR THE REASON FOR THE YELLOW BORDER.

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.