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A mechanic reports on his involvement with the removal and reinstallation of a turbine overheat thermocouple on a rolls royce trent-800; # 2 engine for a B777. The #2 engine inboard reverser cowl; inner red insulation liner; was found burnt and deteriorated. The same thermocouple was reported as not installed.
| Attributes | |
| ACN | 838242 |
| Time | |
| Date | 200905 |
| Local Time Of Day | 1201-1800 |
| Place | |
| Locale Reference | ZZZ.Airport |
| State Reference | US |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Make Model Name | B777 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | Parked |
| Component | |
| Aircraft Component | Engine Temperature Indication |
| Person 1 | |
| Function | Technician |
| Qualification | Maintenance Airframe Maintenance Powerplant |
| Events | |
| Anomaly | Aircraft Equipment Problem Critical Deviation - Procedural Maintenance Deviation - Procedural FAR Deviation - Procedural Published Material / Policy |
Narrative:
I removed the forward thermocouple per maintenance manual 77-22-11-4 ip turbine overheat thermocouples 'removal/installation' as directed by an engineering order. I did not disconnect the electrical connectors as this did not appear to be necessary; or accomplish section 1 a (2) C; because it appeared there was sufficient room for the borescope with the thermocouple in place. I removed the 2 bolts and placed them in parts bag; tied the bag to the thermocouple wiring and returned card to production control for accomplishment of inspection borescope. Card was returned to me the following day with borescope completed. When I began the reinstallation I found thermocouple removed and bent in almost a 'U' shape. Straightened thermocouple; inspected it for damage; there appeared to be none. I reinstalled the thermocouple; only the 2 bolts I had removed were in the parts bag (section 3. A; B; and C). After installation the thermocouple appeared secure.
Original NASA ASRS Text
Title: A Mechanic reports on his involvement with the removal and reinstallation of a turbine overheat thermocouple on a Rolls Royce Trent-800; # 2 engine for a B777. The #2 engine inboard reverser cowl; inner red insulation liner; was found burnt and deteriorated. The same thermocouple was reported as not installed.
Narrative: I removed the forward thermocouple per Maintenance Manual 77-22-11-4 IP TURBINE OVERHEAT THERMOCOUPLES 'REMOVAL/INSTALLATION' as directed by an engineering order. I did not disconnect the electrical connectors as this did not appear to be necessary; or accomplish Section 1 A (2) C; because it appeared there was sufficient room for the borescope with the thermocouple in place. I removed the 2 bolts and placed them in parts bag; tied the bag to the thermocouple wiring and returned card to production control for accomplishment of inspection borescope. Card was returned to me the following day with borescope completed. When I began the reinstallation I found thermocouple removed and bent in almost a 'U' shape. Straightened thermocouple; inspected it for damage; there appeared to be none. I reinstalled the thermocouple; only the 2 bolts I had removed were in the parts bag (Section 3. A; B; and C). After installation the thermocouple appeared secure.
Data retrieved from NASA's ASRS site as of April 2012 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.