A B737-300 first flight out of a maintenance check had a pylon panel depart the aircraft. All pylon ...

Attributes
ACN	710443
Time
Date	200608
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	ground : maintenance
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	710443
Person 2
Affiliation	company : air carrier
Function	maintenance : inspector
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other other : 3
Resolutory Action	none taken : detected after the fact
Consequence	other other other
Supplementary
Problem Areas	Maintenance Human Performance Aircraft Chart Or Publication Environmental Factor
Primary Problem	Aircraft
Situations
Publication	Maint. Manual

Narrative:

On aug/wed/06; aircraft was scheduled for a maintenance visit check in the hangar. My apprentice lead assigned me to the maintenance check that night. I do recall in the maintenance check paperwork there were figures on the fasteners or screws in question to be inspected and tightened. I accomplished this inspection by going on top of the left and right wing to access these screws per my maintenance check paperwork. Though I am an apprentice technician I am trained on these screws as well as the pylon panel fasteners. I understand also that the crews and panels are subject to lots of vibration due to the fact that they are right above a running engine. My findings were conclusive at the time; that no fasteners or screws for that matter were missing or loose. If I had found any discrepancy with the screws or pylon panels I would have done what I was trained to do. That is; generate a non-routine card to document the discrepancy on my findings. Also; I would have documented the action I took to fix the loose screws or pylon panels on the same nrc. My belief in the matter is that due to the intense vibration the screws go through day in day out; some get loose from the nut plate and could come out and go missing.

Original NASA ASRS Text

Title: A B737-300 FIRST FLT OUT OF A MAINT CHK HAD A PYLON PANEL DEPART THE ACFT. ALL PYLON PANELS WERE CHKED PER CHK JOB CARD FOR LOOSE OR MISSING FASTENERS AND ALL FASTENERS INDICATED LOCKED.

Narrative: ON AUG/WED/06; ACFT WAS SCHEDULED FOR A MAINT VISIT CHK IN THE HANGAR. MY APPRENTICE LEAD ASSIGNED ME TO THE MAINT CHK THAT NIGHT. I DO RECALL IN THE MAINT CHK PAPERWORK THERE WERE FIGURES ON THE FASTENERS OR SCREWS IN QUESTION TO BE INSPECTED AND TIGHTENED. I ACCOMPLISHED THIS INSPECTION BY GOING ON TOP OF THE L AND R WING TO ACCESS THESE SCREWS PER MY MAINT CHK PAPERWORK. THOUGH I AM AN APPRENTICE TECHNICIAN I AM TRAINED ON THESE SCREWS AS WELL AS THE PYLON PANEL FASTENERS. I UNDERSTAND ALSO THAT THE CREWS AND PANELS ARE SUBJECT TO LOTS OF VIBRATION DUE TO THE FACT THAT THEY ARE RIGHT ABOVE A RUNNING ENG. MY FINDINGS WERE CONCLUSIVE AT THE TIME; THAT NO FASTENERS OR SCREWS FOR THAT MATTER WERE MISSING OR LOOSE. IF I HAD FOUND ANY DISCREPANCY WITH THE SCREWS OR PYLON PANELS I WOULD HAVE DONE WHAT I WAS TRAINED TO DO. THAT IS; GENERATE A NON-ROUTINE CARD TO DOCUMENT THE DISCREPANCY ON MY FINDINGS. ALSO; I WOULD HAVE DOCUMENTED THE ACTION I TOOK TO FIX THE LOOSE SCREWS OR PYLON PANELS ON THE SAME NRC. MY BELIEF IN THE MATTER IS THAT DUE TO THE INTENSE VIBRATION THE SCREWS GO THROUGH DAY IN DAY OUT; SOME GET LOOSE FROM THE NUT PLATE AND COULD COME OUT AND GO MISSING.

Data retrieved from NASA's ASRS site as of January 2009 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.

A B737-300 first flight out of a maintenance check had a pylon panel depart the aircraft. All pylon panels were checked per check job card for loose or missing fasteners and all fasteners indicated locked.