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A B737-200 #2 engine pressure regulator and shutoff valve was deferred as inoperative per the MEL. Technician checked wiring and connector; reset circuit breaker. Cleared deferred item but failed to unlock valve per MEL.
| Attributes | |
| ACN | 696994 |
| Time | |
| Date | 200605 |
| Local Time Of Day | 1801 To 2400 |
| 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 | B737-300 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : maintenance |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| Qualification | technician : powerplant technician : airframe |
| ASRS Report | 696994 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | maintenance : lead technician |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : improper documentation maintenance problem : improper maintenance maintenance problem : non compliance with mel non adherence : far non adherence : published procedure non adherence : company policies |
| Independent Detector | other flight crewa |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other other |
| Factors | |
| Maintenance | contributing factor : schedule pressure performance deficiency : non compliance with legal requirements performance deficiency : fault isolation performance deficiency : unqualified personnel performance deficiency : repair |
| Supplementary | |
| Problem Areas | Maintenance Human Performance Environmental Factor Aircraft Chart Or Publication |
| Primary Problem | Maintenance Human Performance |
Narrative:
I normally work B & C checks. I was working line routine overnight checks on overtime and had a service check with an MEL that #2 engine bleed valve circuit breaker would not reset. I worked along with other mechanic and ohmed out the wiring. Disconnected wiring to check condition of wiring and reconnected. Reset circuit breaker and cycled #2 engine bleed switch several times. Circuit breaker stayed set and solenoid operated normally. I closed engine up and cleared MEL stating that I ohmed out wiring and noted no faults in system. I copied the discrepancy from MEL sticker to green sheet; but did not see that SP36 was performed which is to lock out the prsov. The aircraft flew to las and took a delay where the prsov was found locked out. I failed to catch that SP36 was performed due to it being noted above the discrepancy on the MEL sticker. It was oversight on my part.
Original NASA ASRS Text
Title: A B737-200 #2 ENG PRESSURE REGULATOR AND SHUTOFF VALVE WAS DEFERRED AS INOP PER THE MEL. TECHNICIAN CHKED WIRING AND CONNECTOR; RESET CIRCUIT BREAKER. CLRED DEFERRED ITEM BUT FAILED TO UNLOCK VALVE PER MEL.
Narrative: I NORMALLY WORK B & C CHKS. I WAS WORKING LINE ROUTINE OVERNIGHT CHKS ON OVERTIME AND HAD A SVC CHK WITH AN MEL THAT #2 ENG BLEED VALVE CIRCUIT BREAKER WOULD NOT RESET. I WORKED ALONG WITH OTHER MECH AND OHMED OUT THE WIRING. DISCONNECTED WIRING TO CHK CONDITION OF WIRING AND RECONNECTED. RESET CIRCUIT BREAKER AND CYCLED #2 ENG BLEED SWITCH SEVERAL TIMES. CIRCUIT BREAKER STAYED SET AND SOLENOID OPERATED NORMALLY. I CLOSED ENG UP AND CLRED MEL STATING THAT I OHMED OUT WIRING AND NOTED NO FAULTS IN SYS. I COPIED THE DISCREPANCY FROM MEL STICKER TO GREEN SHEET; BUT DID NOT SEE THAT SP36 WAS PERFORMED WHICH IS TO LOCK OUT THE PRSOV. THE ACFT FLEW TO LAS AND TOOK A DELAY WHERE THE PRSOV WAS FOUND LOCKED OUT. I FAILED TO CATCH THAT SP36 WAS PERFORMED DUE TO IT BEING NOTED ABOVE THE DISCREPANCY ON THE MEL STICKER. IT WAS OVERSIGHT ON MY PART.
Data retrieved from NASA's ASRS site as of January 2009 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.