A mechanic reports he misread a circuit breaker panel modification task card and installed a 22-gaug...

Narrative:

I was given the job of working on an upgraded landing light system in march 2010; specifically the circuit breaker (circuit breaker) panel modification task card. The wire had been run out of the circuit breaker panel by the previous shift and my task was to install the circuit breaker and terminate the wiring to it. I installed the circuit breaker and installed the wires to it. I misread the step that says 'lead wire should be military-west-89044/12.' I read it as a 22-gauge wire instead of a 12- gauge wire. The lead wire installed is a 22-gauge wire which is incorrect. Misread the task card. I was tasked to do the exact same step on the next Q-400 aircraft modification. When I reviewed the task for the current job; I noticed the error. I notified my lead and supervisor immediately and my lead contacted maintenance control.

Original NASA ASRS Text

Title: A Mechanic reports he misread a circuit breaker panel modification Task Card and installed a 22-gauge wire instead of a larger 12-gauge type as the Lead wire. Some of the wing landing lights were being replaced on their DHC-8-Q400's with a pulse type landing light system.

Narrative: I was given the job of working on an upgraded landing light system in March 2010; specifically the circuit breaker (CB) panel modification Task Card. The wire had been run out of the CB panel by the previous shift and my Task was to install the circuit breaker and terminate the wiring to it. I installed the CB and installed the wires to it. I misread the step that says 'Lead wire should be MIL-W-89044/12.' I read it as a 22-gauge wire instead of a 12- gauge wire. The Lead wire installed is a 22-gauge wire which is incorrect. Misread the Task Card. I was tasked to do the exact same step on the next Q-400 aircraft modification. When I reviewed the Task for the current job; I noticed the error. I notified my Lead and Supervisor immediately and my Lead contacted Maintenance Control.

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.

Attributes
ACN	878151
Time
Date	201003
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Aircraft 1
Make Model Name	Q400
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Electrical Wiring & Connectors
Person 1
Function	Technician
Qualification	Maintenance Airframe Maintenance Powerplant
Events
Anomaly	Aircraft Equipment Problem Critical Deviation - Procedural Maintenance Deviation - Procedural Published Material / Policy

A mechanic reports he misread a circuit breaker panel modification task card and installed a 22-gauge wire instead of a larger 12-gauge type as the lead wire. Some of the wing landing lights were being replaced on their dhc-8-Q400's with a pulse type landing light system.