A B737-900 was dispatched in non compliance with the right pack deferred as inoperative per the MEL, but incorrect special procedures were applied.

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Attributes
ACN	616363
Time
Date	200405
Day	Mon
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Environment
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-900
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
Qualification	technician : powerplant technician : airframe
ASRS Report	616363
Person 2
Affiliation	company : air carrier
Function	other personnel other
Events
Anomaly	aircraft equipment problem : critical maintenance problem : non compliance with mel non adherence : published procedure non adherence : far
Independent Detector	aircraft equipment other aircraft equipment : cooling fan off light
Resolutory Action	none taken : detected after the fact
Consequence	other other
Factors
Maintenance	contributing factor : manuals contributing factor : schedule pressure performance deficiency : logbook entry performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Chart Or Publication Aircraft Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

On may/mon/04, aircraft X had a PIREP of a right 'pack trip' problem log X. I was assisting the mechanic who installed the MEL by helping perform the maintenance procedure. MEL 21-1B was installed, and the maintenance procedure for that MEL also directed you to refer to MEL 21-2 and perform its maintenance procedure for deactivation of the associated pack airflow shutoff valve in the closed position. It is in the 21-2 procedure where the problem originated. Step #6 of this procedure applies to both shutoff valves inoperative only, with sup-step directing you to pull the collar air conditioning overboard exhaust valve reconfign control circuit breaker. The qualifier for that step was missed by myself, and as a result, I pulled and collared the listed circuit breaker. The aircraft was dispatched in that condition and has resulted in 2 further discrepancies to my knowledge. Log #X and #Y both pertaining to equipment cowling exhaust fan off light illuminating in both normal and alternate position. This discrepancy was brought to my attention the next day at the start of my shift.

Original NASA ASRS Text

Title: A B737-900 WAS DISPATCHED IN NON COMPLIANCE WITH THE R PACK DEFERRED AS INOP PER THE MEL, BUT INCORRECT SPECIAL PROCS WERE APPLIED.

Narrative: ON MAY/MON/04, ACFT X HAD A PIREP OF A R 'PACK TRIP' PROB LOG X. I WAS ASSISTING THE MECH WHO INSTALLED THE MEL BY HELPING PERFORM THE MAINT PROC. MEL 21-1B WAS INSTALLED, AND THE MAINT PROC FOR THAT MEL ALSO DIRECTED YOU TO REFER TO MEL 21-2 AND PERFORM ITS MAINT PROC FOR DEACTIVATION OF THE ASSOCIATED PACK AIRFLOW SHUTOFF VALVE IN THE CLOSED POS. IT IS IN THE 21-2 PROC WHERE THE PROB ORIGINATED. STEP #6 OF THIS PROC APPLIES TO BOTH SHUTOFF VALVES INOP ONLY, WITH SUP-STEP DIRECTING YOU TO PULL THE COLLAR AIR CONDITIONING OVERBOARD EXHAUST VALVE RECONFIGN CTL CIRCUIT BREAKER. THE QUALIFIER FOR THAT STEP WAS MISSED BY MYSELF, AND AS A RESULT, I PULLED AND COLLARED THE LISTED CIRCUIT BREAKER. THE ACFT WAS DISPATCHED IN THAT CONDITION AND HAS RESULTED IN 2 FURTHER DISCREPANCIES TO MY KNOWLEDGE. LOG #X AND #Y BOTH PERTAINING TO EQUIP COWLING EXHAUST FAN OFF LIGHT ILLUMINATING IN BOTH NORMAL AND ALTERNATE POS. THIS DISCREPANCY WAS BROUGHT TO MY ATTN THE NEXT DAY AT THE START OF MY SHIFT.

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.