Narrative:

I was asked to sit left seat and do the steady state break-in runs and the transient break-in runs for the no. 1 engine. Prior to doing the runs; my partner and I reviewed the procedures in the ge line maintenance manual (LMM) 72-00-00. We were confident about doing the runs being it was our first time and not familiar with the procedures. After several hours of reviewing the ge manual for the runs; we felt confident to do the runs. As we were doing the runs we came across some issues with N2 settings and interstage turbine temperature [itt] readings that could not be accomplished and required skipping the procedures that the manual did not clearly address these issues. We decided to error on the side of caution and skip these steps but added the soak times to the next available step. There were other steps requiring reduction in power when an increase in power was required. We also came across a setting to go to called approach idle. We were unsure of this setting because in the initial set up it tells you to select it to the off position in the takeoff data set in the mcdu. After completing the runs we returned to the hangar and discussed these irregularities with other mechanics as to what they would have done. We all had different interpretations of the ge manual. As we felt we did the runs correctly and to the best of what we had to go by; we cannot be certain that we did them properly to the ge manual specs. I have been in touch with powerplant engineering. They have answered most questions confirming we did do proper runs on soak times and skipping procedures. They are researching into the flight idle issues and need to be in contact with ge. We felt compelled to fill this [report] out to bring to the attention of more clarification to these runs and possibly a job card to ease the time to research all the data needed prior to doing the runs.unable to reach certain settings required by ge LMM. [Suggest] job card with all reference charts and graphs with clarifying instruction to understand the task at hand. OJT

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Original NASA ASRS Text

Title: Two maintenance technicians reported the manuals for the Embraer ERJ engine test were ambiguous and were subject to interpretation.

Narrative: I was asked to sit left seat and do the steady state break-in runs and the transient break-in runs for the No. 1 Engine. Prior to doing the runs; my partner and I reviewed the procedures in the GE Line Maintenance Manual (LMM) 72-00-00. We were confident about doing the runs being it was our first time and not familiar with the procedures. After several hours of reviewing the GE manual for the runs; we felt confident to do the runs. As we were doing the runs we came across some issues with N2 settings and Interstage Turbine Temperature [ITT] readings that could not be accomplished and required skipping the procedures that the manual did not clearly address these issues. We decided to error on the side of caution and skip these steps but added the soak times to the next available step. There were other steps requiring reduction in power when an increase in power was required. We also came across a setting to go to called approach idle. We were unsure of this setting because in the initial set up it tells you to select it to the off position in the takeoff data set in the MCDU. After completing the runs we returned to the hangar and discussed these irregularities with other mechanics as to what they would have done. We all had different interpretations of the GE Manual. As we felt we did the runs correctly and to the best of what we had to go by; we cannot be certain that we did them properly to the GE Manual specs. I have been in touch with Powerplant Engineering. They have answered most questions confirming we did do proper runs on soak times and skipping procedures. They are researching into the flight idle issues and need to be in contact with GE. We felt compelled to fill this [report] out to bring to the attention of more clarification to these runs and possibly a job card to ease the time to research all the data needed prior to doing the runs.Unable to reach certain settings required by GE LMM. [Suggest] Job card with all reference charts and graphs with clarifying instruction to understand the task at hand. OJT

Data retrieved from NASA's ASRS site 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.