While separating the engine core from the fan case of a pratt whitney 2000 engine; one bolt was acci...

Attributes
ACN	788171
Time
Date	200804
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B757 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	788171
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure
Independent Detector	other other : 1
Resolutory Action	none taken : detected after the fact
Consequence	other Other
Factors
Maintenance	contributing factor : briefing performance deficiency : non compliance with legal requirements
Supplementary
Problem Areas	Maintenance Human Performance
Primary Problem	Maintenance Human Performance

Narrative:

While separating an engine core from the fan case; 1 bolt was accidentally left in; resulting in damage to the fan case. In the process of removing bolts; I stopped and walked away from the area for a min. When I returned; my work partner was removing the remaining bolts. We thought we had removed all of them. This engine was under investigation because it blew up in the test cell after an overhaul. There were many people looking at the disassembly; which added some distraction. Leaving my area for a min actually broke up my work flow; also causing me to miss the bolt and not doublechk my work. My work partner looked at the work also; causing me not to doublechk my work. Callback conversation with reporter revealed the following information: reporter stated this was a pratt whitney 2000 engine. This engine was being disassembled after exploding in the engine test cell during final runs after coming out of a complete overhaul. The cause of the engine failure in the test cell has not been disclosed; at this time.

Original NASA ASRS Text

Title: WHILE SEPARATING THE ENGINE CORE FROM THE FAN CASE OF A PRATT WHITNEY 2000 ENG; ONE BOLT WAS ACCIDENTALLY LEFT IN; RESULTING IN DAMAGE TO THE FAN CASE.

Narrative: WHILE SEPARATING AN ENG CORE FROM THE FAN CASE; 1 BOLT WAS ACCIDENTALLY LEFT IN; RESULTING IN DAMAGE TO THE FAN CASE. IN THE PROCESS OF REMOVING BOLTS; I STOPPED AND WALKED AWAY FROM THE AREA FOR A MIN. WHEN I RETURNED; MY WORK PARTNER WAS REMOVING THE REMAINING BOLTS. WE THOUGHT WE HAD REMOVED ALL OF THEM. THIS ENG WAS UNDER INVESTIGATION BECAUSE IT BLEW UP IN THE TEST CELL AFTER AN OVERHAUL. THERE WERE MANY PEOPLE LOOKING AT THE DISASSEMBLY; WHICH ADDED SOME DISTR. LEAVING MY AREA FOR A MIN ACTUALLY BROKE UP MY WORK FLOW; ALSO CAUSING ME TO MISS THE BOLT AND NOT DOUBLECHK MY WORK. MY WORK PARTNER LOOKED AT THE WORK ALSO; CAUSING ME NOT TO DOUBLECHK MY WORK. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THIS WAS A PRATT WHITNEY 2000 ENGINE. THIS ENGINE WAS BEING DISASSEMBLED AFTER EXPLODING IN THE ENG TEST CELL DURING FINAL RUNS AFTER COMING OUT OF A COMPLETE OVERHAUL. THE CAUSE OF THE ENGINE FAILURE IN THE TEST CELL HAS NOT BEEN DISCLOSED; AT THIS TIME.

Data retrieved from NASA's ASRS site as of May 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.

While separating the engine core from the fan case of a pratt whitney 2000 engine; one bolt was accidentally left in; resulting in damage to the fan case.