Narrative:

I was assigned to a B737-700 aircraft which had a scheduled maintenance visit in which I took part in. During the day this aircraft had a compressor stall on the #2 engine; so there was a need for a borescope inspection; this was done. There was no damage found. I then proceeded to loosen two clamps from the 5th stage bleed check valve to check it. At around this time; we were told to change the hydro-mechanical unit (hmu). I then began to re-install the clamps. After this I proceeded to begin changing the hmu. Once the hmu was completed we began our checks and tests. Once they were completed we prepared to taxi to the gate; when all of a sudden we got a # 2 engine bleed trip. We then radioed ahead and let the supervisor know of the new problem. We were told to take the aircraft back to the pad. We then came into the office for the first time since all of this began to begin paperwork. Later; a new crew was sent out to work the bleed trip. I went out to see what they had found. Apparently they found a loose clamp on the elbow to the high stage valve and also a hole in the inboard thrust reverser (T/right) insulation and the inner wall had discoloration. A temporary repair was made; which requires a permanent repair in thirty days and the clamp was resecured. The aircraft was then put back in service.on this night; the weather was particular cold with temperatures in the twenty's and wind blowing. The weather was so bad that only seven aircraft were in our station that night compared to twenty. Every so often; we had to step away from our work to warm up. I was feeling a little tired and fatigued. There was also a bit of stress trying to get the aircraft back on-line before my shift was over. There was a lot of things going on that night and quite a bit of work to be done on this aircraft. In fact; we didn't even eat till late in the night; trying to put all our efforts and priority on this aircraft for it to be ready to go.

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Original NASA ASRS Text

Title: A Line Mechanic working outside late at night on a B737-700 aircraft in very cold and windy conditions fails to properly resecure a clamp on the High Stage valve he had previously loosened; causing damage to the # 2 Engine inboard Thrust Reverser (T/R) insulation and discoloration to the T/R inner wall.

Narrative: I was assigned to a B737-700 aircraft which had a Scheduled Maintenance Visit in which I took part in. During the day this aircraft had a compressor stall on the #2 engine; so there was a need for a Borescope Inspection; this was done. There was no damage found. I then proceeded to loosen two clamps from the 5th Stage Bleed check valve to check it. At around this time; we were told to change the Hydro-Mechanical Unit (HMU). I then began to re-install the clamps. After this I proceeded to begin changing the HMU. Once the HMU was completed we began our Checks and Tests. Once they were completed we prepared to taxi to the gate; when all of a sudden we got a # 2 Engine Bleed trip. We then radioed ahead and let the Supervisor know of the new problem. We were told to take the aircraft back to the pad. We then came into the office for the first time since all of this began to begin paperwork. Later; a new crew was sent out to work the Bleed trip. I went out to see what they had found. Apparently they found a loose clamp on the elbow to the High Stage valve and also a hole in the inboard Thrust Reverser (T/R) insulation and the inner wall had discoloration. A Temporary Repair was made; which requires a Permanent Repair in thirty days and the clamp was resecured. The aircraft was then put back in service.On this night; the weather was particular cold with temperatures in the twenty's and wind blowing. The weather was so bad that only seven aircraft were in our Station that night compared to twenty. Every so often; we had to step away from our work to warm up. I was feeling a little tired and fatigued. There was also a bit of stress trying to get the aircraft back on-line before my shift was over. There was a lot of things going on that night and quite a bit of work to be done on this aircraft. In fact; we didn't even eat till late in the night; trying to put all our efforts and priority on this aircraft for it to be ready to go.

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.