 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
An MD81 returned to the field due to throttle split out of limits to maintain equal EPR indications. Caused by a leaking PT2 line.
| Attributes | |
| ACN | 572009 |
| Time | |
| Date | 200301 |
| Day | Sat |
| Place | |
| Locale Reference | airport : zzz.airport |
| State Reference | US |
| Altitude | agl single value : 0 |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | MD-81 |
| 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 |
| Experience | maintenance technician : 2 |
| ASRS Report | 572009 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Events | |
| Anomaly | aircraft equipment problem : critical maintenance problem : improper documentation maintenance problem : improper maintenance non adherence : published procedure non adherence : far |
| Independent Detector | aircraft equipment other aircraft equipment : eng press ratio indications other flight crewa other flight crewb |
| Resolutory Action | flight crew : diverted to another airport |
| Consequence | faa : investigated other other Other |
| Factors | |
| Maintenance | contributing factor : work cards contributing factor : manuals performance deficiency : non compliance with legal requirements performance deficiency : installation performance deficiency : scheduled maintenance performance deficiency : testing |
| Supplementary | |
| Problem Areas | Maintenance Human Performance Aircraft Chart Or Publication |
| Primary Problem | Maintenance Human Performance |
Narrative:
On jan/sat/03, aircraft had an air turn-back due to throttle split for EPR difference. When the aircraft was in for a c-chk, a .063 doubler was installed where the 3 main hydraulic lines and PT2 and PT7 lines for the engine come through the fuselage. I reinstalled the line. I used the same hardware that was removed, but the doubler pushed everything back .063 and I bottomed out the PT2 line on the washers not knowing it. I leak-checked the hydraulic lines but overlooked the PT2 and PT7 lines. I think this could have been avoided by making separate line items in the paperwork for lines removed and for the leak checks.
Original NASA ASRS Text
Title: AN MD81 RETURNED TO THE FIELD DUE TO THROTTLE SPLIT OUT OF LIMITS TO MAINTAIN EQUAL EPR INDICATIONS. CAUSED BY A LEAKING PT2 LINE.
Narrative: ON JAN/SAT/03, ACFT HAD AN AIR TURN-BACK DUE TO THROTTLE SPLIT FOR EPR DIFFERENCE. WHEN THE ACFT WAS IN FOR A C-CHK, A .063 DOUBLER WAS INSTALLED WHERE THE 3 MAIN HYD LINES AND PT2 AND PT7 LINES FOR THE ENG COME THROUGH THE FUSELAGE. I REINSTALLED THE LINE. I USED THE SAME HARDWARE THAT WAS REMOVED, BUT THE DOUBLER PUSHED EVERYTHING BACK .063 AND I BOTTOMED OUT THE PT2 LINE ON THE WASHERS NOT KNOWING IT. I LEAK-CHKED THE HYD LINES BUT OVERLOOKED THE PT2 AND PT7 LINES. I THINK THIS COULD HAVE BEEN AVOIDED BY MAKING SEPARATE LINE ITEMS IN THE PAPERWORK FOR LINES REMOVED AND FOR THE LEAK CHKS.
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.