A B737-300 in cruise with #1 slat indications deferred had #2 leading edge flap indicate extended on...

Attributes
ACN	577943
Time
Date	200303
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : zzz.artcc
State Reference	US
Altitude	msl single value : 31000
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zzz.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	577943
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : annunciator panel 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:

We received the aircraft with the #1 leading edge slat overhead and forward in-transit indicator deferred. The in-transit lights were deferred, because they remained illuminated after flap retraction even though the flaps and slats were all retracting normally. During the climb after flap retraction, the in-transit lights remained illuminated as we expected. At some point during cruise, we noticed the overhead indicator had gone to green on the #2 leading edge flap (the forward in-transit light was also still illuminated). The captain notified maintenance. We had no reason to believe the flap was extended. We had no yaw, bank, or vibration to indicate the flap was actually extended. At one point, the indication went from green to yellow and back to green again. We continued to treat the indications as erroneous due to the deferral of the in-transit lights. After landing, the flaps were raised during taxi and the #2 leading edge flap overhead indicator was showing green. After parking at the gate, we looked at the flap, and it was indeed fully extended. We notified maintenance. During flight, we complied with the deferral speed restrs of .65 mach/300 KTS at all times. Other than the indication problems, the flaps appeared to be working normally at all times during flight.

Original NASA ASRS Text

Title: A B737-300 IN CRUISE WITH #1 SLAT INDICATIONS DEFERRED HAD #2 LEADING EDGE FLAP INDICATE EXTENDED ON BOTH PANELS. ON GND, VERIFIED FLAP WAS EXTENDED.

Narrative: WE RECEIVED THE ACFT WITH THE #1 LEADING EDGE SLAT OVERHEAD AND FORWARD IN-TRANSIT INDICATOR DEFERRED. THE IN-TRANSIT LIGHTS WERE DEFERRED, BECAUSE THEY REMAINED ILLUMINATED AFTER FLAP RETRACTION EVEN THOUGH THE FLAPS AND SLATS WERE ALL RETRACTING NORMALLY. DURING THE CLB AFTER FLAP RETRACTION, THE IN-TRANSIT LIGHTS REMAINED ILLUMINATED AS WE EXPECTED. AT SOME POINT DURING CRUISE, WE NOTICED THE OVERHEAD INDICATOR HAD GONE TO GREEN ON THE #2 LEADING EDGE FLAP (THE FORWARD IN-TRANSIT LIGHT WAS ALSO STILL ILLUMINATED). THE CAPT NOTIFIED MAINT. WE HAD NO REASON TO BELIEVE THE FLAP WAS EXTENDED. WE HAD NO YAW, BANK, OR VIBRATION TO INDICATE THE FLAP WAS ACTUALLY EXTENDED. AT ONE POINT, THE INDICATION WENT FROM GREEN TO YELLOW AND BACK TO GREEN AGAIN. WE CONTINUED TO TREAT THE INDICATIONS AS ERRONEOUS DUE TO THE DEFERRAL OF THE IN-TRANSIT LIGHTS. AFTER LNDG, THE FLAPS WERE RAISED DURING TAXI AND THE #2 LEADING EDGE FLAP OVERHEAD INDICATOR WAS SHOWING GREEN. AFTER PARKING AT THE GATE, WE LOOKED AT THE FLAP, AND IT WAS INDEED FULLY EXTENDED. WE NOTIFIED MAINT. DURING FLT, WE COMPLIED WITH THE DEFERRAL SPD RESTRS OF .65 MACH/300 KTS AT ALL TIMES. OTHER THAN THE INDICATION PROBS, THE FLAPS APPEARED TO BE WORKING NORMALLY AT ALL TIMES DURING FLT.

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.

A B737-300 in cruise with #1 slat indications deferred had #2 leading edge flap indicate extended on both panels. On ground, verified flap was extended.