A line aircraft maintenance technician (amt) was informed that corrosion was found on the lower aft ...

Narrative:

I work midnight shift at ZZZ airport. On the night I was assigned an a-check on a B737-800. I performed the general visual (G/V) walk around inspection on the aircraft. I was informed later on; that an area of corrosion was found on the left aft side of the fuselage; just aft of the lav motor exhaust port. I do not recall noticing evidence of corrosion on my walk around. I started the inspection at the nose of the aircraft and walked down the right side inspecting the fuselage; engine; wing; and gear; around the tail and continued on the left side inspecting fuselage; wing; engine; and gear. Conditions at the time were dark since I work midnight shift and the area of concern was painted gray. I performed my walk around using my flashlight. [Line] gate.

Original NASA ASRS Text

Title: A Line Aircraft Maintenance Technician (AMT) was informed that corrosion was found on the lower aft fuselage skin; just aft of the Lavatory Motor exhaust port on a B737-800 aircraft. He had previously accomplished an A-Check and walk around inspection on midnight shift using a flashlight.

Narrative: I work midnight shift at ZZZ airport. On the night I was assigned an A-Check on a B737-800. I performed the General Visual (G/V) walk around inspection on the aircraft. I was informed later on; that an area of corrosion was found on the left aft side of the fuselage; just aft of the lav motor exhaust port. I do not recall noticing evidence of corrosion on my walk around. I started the inspection at the nose of the aircraft and walked down the right side inspecting the fuselage; engine; wing; and gear; around the tail and continued on the left side inspecting fuselage; wing; engine; and gear. Conditions at the time were dark since I work midnight shift and the area of concern was painted gray. I performed my walk around using my flashlight. [Line] Gate.

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	1127027
Time
Date	201310
Local Time Of Day	0001-0600
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Night
Aircraft 1
Make Model Name	B737-800
Operating Under FAR Part	Part 121
Flight Phase	Parked
Component
Aircraft Component	Fuselage Skin
Person 1
Function	Technician
Qualification	Maintenance Airframe Maintenance Powerplant
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy

A line aircraft maintenance technician (amt) was informed that corrosion was found on the lower aft fuselage skin; just aft of the lavatory motor exhaust port on a B737-800 aircraft. He had previously accomplished an a-check and walk around inspection on midnight shift using a flashlight.