 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
A B737-800 had an engineering authority/authorized accomplished on replacement of captain's; first officer's; and observer's oxygen mask low pressure lines. Aircraft had oxygen leak reported after accomplishment.
| Attributes | |
| ACN | 715425 |
| Time | |
| Date | 200610 |
| Local Time Of Day | 0001 To 0600 |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | agl single value : 0 |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | B737-800 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | ground : maintenance |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | maintenance : lead technician |
| Qualification | technician : airframe technician : powerplant |
| Experience | maintenance lead technician : 1 maintenance technician : 3 |
| ASRS Report | 715425 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | maintenance : technician |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure |
| Independent Detector | aircraft equipment other aircraft equipment : oxygen pressure indicator other flight crewa other flight crewb |
| Resolutory Action | none taken : detected after the fact |
| Consequence | other other |
| Factors | |
| Maintenance | performance deficiency : testing performance deficiency : fault isolation performance deficiency : inspection performance deficiency : non compliance with legal requirements performance deficiency : scheduled maintenance |
| Supplementary | |
| Problem Areas | Maintenance Human Performance Environmental Factor Aircraft |
| Primary Problem | Maintenance Human Performance |
Narrative:
I replaced the captain's; first officer's; and observer's oxygen mask low pressure lines in accordance with the assigned engineering authority/authorized. After installation; when I opened the oxygen bottle shutoff valve oxygen leaked from under the valve. I asked the other mechanic I was working with to take a look and see if he could identify the problem. He had completed this engineering authority/authorized before. He went to look at it and said he had the same problem I had; but was able to get it open after a while with no leak. I was not present to watch him. We left the panel open for about 20 mins to see if the bottle would leak again. It did not. All the lines from the boxes to the 'B' nuts were tight. They were all tightened with a wrench to their maximum stopping point. I was not able to use my hand to tighten the lines of any of the position.
Original NASA ASRS Text
Title: A B737-800 HAD AN ENGINEERING AUTH ACCOMPLISHED ON REPLACEMENT OF CAPT'S; FO'S; AND OBSERVER'S OXYGEN MASK LOW PRESSURE LINES. ACFT HAD OXYGEN LEAK RPTED AFTER ACCOMPLISHMENT.
Narrative: I REPLACED THE CAPT'S; FO'S; AND OBSERVER'S OXYGEN MASK LOW PRESSURE LINES IN ACCORDANCE WITH THE ASSIGNED ENGINEERING AUTH. AFTER INSTALLATION; WHEN I OPENED THE OXYGEN BOTTLE SHUTOFF VALVE OXYGEN LEAKED FROM UNDER THE VALVE. I ASKED THE OTHER MECH I WAS WORKING WITH TO TAKE A LOOK AND SEE IF HE COULD IDENT THE PROB. HE HAD COMPLETED THIS ENGINEERING AUTH BEFORE. HE WENT TO LOOK AT IT AND SAID HE HAD THE SAME PROB I HAD; BUT WAS ABLE TO GET IT OPEN AFTER A WHILE WITH NO LEAK. I WAS NOT PRESENT TO WATCH HIM. WE LEFT THE PANEL OPEN FOR ABOUT 20 MINS TO SEE IF THE BOTTLE WOULD LEAK AGAIN. IT DID NOT. ALL THE LINES FROM THE BOXES TO THE 'B' NUTS WERE TIGHT. THEY WERE ALL TIGHTENED WITH A WRENCH TO THEIR MAX STOPPING POINT. I WAS NOT ABLE TO USE MY HAND TO TIGHTEN THE LINES OF ANY OF THE POS.
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.