Mechanic was informed he failed to collar the left engine start circuit breakers (C/B) he had previo...

Narrative:

I was prepping the aircraft for a borescope inspection of the left engine. I pulled the engine start circuit breakers (C/B) as per the aircraft maintenance manual (amm) to make the aircraft safe prior to performing the maintenance task; but forgot to collar the circuit breakers. I went to the cockpit to check the temperature of the left engine from the EICAS. I pulled the breakers (C/bs) as required by the amm for safetying the engine for maintenance; but then got involved in removing the cowlings; shifting equipment and cooling the engine to below required minimum temperatures to enable the borescope to occur. I did not return to the cockpit to attach maintenance 'do not close' C/B collars as I should have. The only response is follow procedures as outlined in the amm. The task in the amm states to pull the required circuit breakers/install safety collars.

Original NASA ASRS Text

Title: Mechanic was informed he failed to collar the Left Engine Start Circuit Breakers (C/B) he had previously pulled while prepping an EMB-145 aircraft for a Boroscope Inspection.

Narrative: I was prepping the aircraft for a Borescope Inspection of the left engine. I pulled the Engine Start Circuit Breakers (C/B) as per the Aircraft Maintenance Manual (AMM) to make the aircraft safe prior to performing the maintenance task; but forgot to collar the Circuit Breakers. I went to the cockpit to check the temperature of the left engine from the EICAS. I pulled the Breakers (C/Bs) as required by the AMM for safetying the engine for maintenance; but then got involved in removing the cowlings; shifting equipment and cooling the engine to below required minimum temperatures to enable the borescope to occur. I did not return to the cockpit to attach maintenance 'Do Not Close' C/B collars as I should have. The only response is follow procedures as outlined in the AMM. The task in the AMM states to pull the required Circuit Breakers/install safety collars.

Data retrieved from NASA's ASRS site as of July 2013 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.

Attributes
ACN	1008464
Time
Date	201204
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	EMB ERJ 145 ER/LR
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Engine Starting System
Person 1
Function	Technician
Qualification	Maintenance Powerplant Maintenance Airframe
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Published Material / Policy

Mechanic was informed he failed to collar the left engine start circuit breakers (C/B) he had previously pulled while prepping an emb-145 aircraft for a boroscope inspection.