Narrative:

On apr/wed/03, the main landing gear down-lock viewing mirror was found dirty, during a preflight inspection by the pilot. The mirror was cleaned, and a logbook write-up was generated. On apr/tue/03, the previous night, I was working on this aircraft performing an overnight layover check. The 'aircraft general' section (exterior) was what I was working on. The item called for a general visual inspection of the landing gear, gear doors, wheel well areas, spray deflectors, and the main landing gear down-lock viewing mirror and indicators. This paperwork requires checking the mirror for cleanliness, condition, and security. In the 5 days since my initial inspection, I have been informed that this item was possibly missed. This is an important item. If there happened to be a gear indication problem, the mirror would be required to view the indicators. This also stresses the importance of performing a double check of the checklist to make sure nothing was missed. During a normal inspection of the 'down-lock inspection mirror,' I use a flashlight to view the mirror from below, in line with the down-lock indicators. I look through the mirror to the base of the inside cover. If this is viewable, it is clean enough to view the indicators on the gear assembly, and would not require cleaning. This is up to the discretion of the person inspecting the mirror. In the future, it would be best to clean the mirror regardless of the condition, then it will always be clean. I intend to do this from now on. To prevent future occurrences, I have passed the experience on to my fellow maintenance technicians.

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Original NASA ASRS Text

Title: AN MD90 INCURRED A DELAY DUE TO PLT'S RPT OF NOSE GEAR INSPECTION MIRROR DIRTY. MIRROR CHKED OK PRIOR TO FLT ON OVERNIGHT CHK.

Narrative: ON APR/WED/03, THE MAIN LNDG GEAR DOWN-LOCK VIEWING MIRROR WAS FOUND DIRTY, DURING A PREFLT INSPECTION BY THE PLT. THE MIRROR WAS CLEANED, AND A LOGBOOK WRITE-UP WAS GENERATED. ON APR/TUE/03, THE PREVIOUS NIGHT, I WAS WORKING ON THIS ACFT PERFORMING AN OVERNIGHT LAYOVER CHK. THE 'ACFT GENERAL' SECTION (EXTERIOR) WAS WHAT I WAS WORKING ON. THE ITEM CALLED FOR A GENERAL VISUAL INSPECTION OF THE LNDG GEAR, GEAR DOORS, WHEEL WELL AREAS, SPRAY DEFLECTORS, AND THE MAIN LNDG GEAR DOWN-LOCK VIEWING MIRROR AND INDICATORS. THIS PAPERWORK REQUIRES CHKING THE MIRROR FOR CLEANLINESS, CONDITION, AND SECURITY. IN THE 5 DAYS SINCE MY INITIAL INSPECTION, I HAVE BEEN INFORMED THAT THIS ITEM WAS POSSIBLY MISSED. THIS IS AN IMPORTANT ITEM. IF THERE HAPPENED TO BE A GEAR INDICATION PROB, THE MIRROR WOULD BE REQUIRED TO VIEW THE INDICATORS. THIS ALSO STRESSES THE IMPORTANCE OF PERFORMING A DOUBLE CHK OF THE CHKLIST TO MAKE SURE NOTHING WAS MISSED. DURING A NORMAL INSPECTION OF THE 'DOWN-LOCK INSPECTION MIRROR,' I USE A FLASHLIGHT TO VIEW THE MIRROR FROM BELOW, IN LINE WITH THE DOWN-LOCK INDICATORS. I LOOK THROUGH THE MIRROR TO THE BASE OF THE INSIDE COVER. IF THIS IS VIEWABLE, IT IS CLEAN ENOUGH TO VIEW THE INDICATORS ON THE GEAR ASSEMBLY, AND WOULD NOT REQUIRE CLEANING. THIS IS UP TO THE DISCRETION OF THE PERSON INSPECTING THE MIRROR. IN THE FUTURE, IT WOULD BE BEST TO CLEAN THE MIRROR REGARDLESS OF THE CONDITION, THEN IT WILL ALWAYS BE CLEAN. I INTEND TO DO THIS FROM NOW ON. TO PREVENT FUTURE OCCURRENCES, I HAVE PASSED THE EXPERIENCE ON TO MY FELLOW MAINT TECHNICIANS.

Data retrieved from NASA's ASRS site as of July 2007 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.