B737 crew departed ord with MEL item inoperative.

Attributes
ACN	433330
Time
Date	199904
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : ord.airport
State Reference	IL
Altitude	agl single value : 0
Environment
Light	Daylight
Aircraft 1
Controlling Facilities	tower : ord.tower
Operator	common carrier : air carrier
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	ground : holding
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	433330
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : commercial pilot : instrument
ASRS Report	433329
Events
Anomaly	aircraft equipment problem : less severe maintenance problem : non compliance with mel non adherence : company policies
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : anomaly accepted
Consequence	other
Factors
Maintenance	contributing factor : manuals performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Maintenance Human Performance Aircraft Company Flight Crew Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

Prior to takeoff at ord, electric light illuminated on overhead panel. Consulted B737 procedure and it said light indicated a fault in the dc or standby electrical system. No fix procedure or guidance listed. Called maintenance and referred to MEL procedure for electric light. Through technical and maintenance representatives on radio, performed procedure for standby power check. Procedure accomplished with successful test. Decision to crew placard system was agreed. Takeoff and rest of flight uneventful. After landing at bos, was told by fleet manager that MEL referred only to inoperative light, not system. Maintenance reset system at bos with no problems on return to ord. Thus we takeoff with an electrical fault of some magnitude and were led down the path due to confusing MEL terminology and no guidance in the procedures book on system failure after gate departure. If returning to the gate was the answer, then it should be printed in bold letters in the procedure. We were not alone in interping this confusing problem. All training says that this light is a no-go item at the gate during preflight. No reference to off-gate placarding procedures.

Original NASA ASRS Text

Title: B737 CREW DEPARTED ORD WITH MEL ITEM INOP.

Narrative: PRIOR TO TKOF AT ORD, ELECTRIC LIGHT ILLUMINATED ON OVERHEAD PANEL. CONSULTED B737 PROC AND IT SAID LIGHT INDICATED A FAULT IN THE DC OR STANDBY ELECTRICAL SYS. NO FIX PROC OR GUIDANCE LISTED. CALLED MAINT AND REFERRED TO MEL PROC FOR ELECTRIC LIGHT. THROUGH TECHNICAL AND MAINT REPRESENTATIVES ON RADIO, PERFORMED PROC FOR STANDBY PWR CHK. PROC ACCOMPLISHED WITH SUCCESSFUL TEST. DECISION TO CREW PLACARD SYS WAS AGREED. TKOF AND REST OF FLT UNEVENTFUL. AFTER LNDG AT BOS, WAS TOLD BY FLEET MGR THAT MEL REFERRED ONLY TO INOP LIGHT, NOT SYS. MAINT RESET SYS AT BOS WITH NO PROBS ON RETURN TO ORD. THUS WE TKOF WITH AN ELECTRICAL FAULT OF SOME MAGNITUDE AND WERE LED DOWN THE PATH DUE TO CONFUSING MEL TERMINOLOGY AND NO GUIDANCE IN THE PROCS BOOK ON SYS FAILURE AFTER GATE DEP. IF RETURNING TO THE GATE WAS THE ANSWER, THEN IT SHOULD BE PRINTED IN BOLD LETTERS IN THE PROC. WE WERE NOT ALONE IN INTERPING THIS CONFUSING PROB. ALL TRAINING SAYS THAT THIS LIGHT IS A NO-GO ITEM AT THE GATE DURING PREFLT. NO REF TO OFF-GATE PLACARDING PROCS.

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.