While working an airworthiness directive to change the gamble plates on the outboard flap #8 aft fla...

Attributes
ACN	784500
Time
Date	200807
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Make Model Name	B777-200
Operating Under FAR Part	Part 121
Person 1
Affiliation	company : air carrier
Function	maintenance : technician
ASRS Report	784500
Events
Anomaly	aircraft equipment problem : critical maintenance problem : improper maintenance non adherence : far non adherence : published procedure
Independent Detector	other other : 1
Resolutory Action	none taken : detected after the fact
Consequence	other
Factors
Maintenance	contributing factor : engineering procedure performance deficiency : non compliance with legal requirements performance deficiency : scheduled maintenance performance deficiency : installation
Supplementary
Problem Areas	Chart Or Publication Maintenance Human Performance Aircraft
Primary Problem	Maintenance Human Performance

Narrative:

While I was working on an airworthy directive for changing the gimbal plates on aircraft X; I realized I had put the 12-point head bolts in the wrong location on aircraft Y. I mistakenly installed them on the #8 aft flap support gamble plates on aircraft Y. Contributing factors: while working on an airworthy directive; on the gamble plate mode on aircraft X; I realized I had installed the 2 12-point head bolts in the wrong location on aircraft Y. I mistakenly installed them on the #8 flap support mechanism on aircraft Y. Callback conversation with reporter revealed the following information: reporter stated the most outboard left and right flap jack screw gamble plates were being replaced with a beefier plate per an airworthiness directive (ad). Part of the ad; required removing the old six-point head bolts at this location and installing two new twelve-point type head bolts; to allow for bolt clearance when flaps are retracted; due to the thicker gamble plates. A fellow mechanic had noticed that reporter had installed the two bolts in the wrong direction on the aircraft he was working at the time. Reporter stated he then realized he had incorrectly installed the same type bolts; at the same location; on the previous aircraft he worked.

Original NASA ASRS Text

Title: WHILE WORKING AN AIRWORTHINESS DIRECTIVE TO CHANGE THE GAMBLE PLATES ON THE OUTBOARD FLAP #8 AFT FLAP SUPPORT ON A B777-200 ACFT; MECHANIC REALIZES HE INSTALLED THE REQUIRED TWELVE POINT BOLTS IN THE WRONG DIRECTION.

Narrative: WHILE I WAS WORKING ON AN AIRWORTHY DIRECTIVE FOR CHANGING THE GIMBAL PLATES ON ACFT X; I REALIZED I HAD PUT THE 12-POINT HEAD BOLTS IN THE WRONG LOCATION ON ACFT Y. I MISTAKENLY INSTALLED THEM ON THE #8 AFT FLAP SUPPORT GAMBLE PLATES ON ACFT Y. CONTRIBUTING FACTORS: WHILE WORKING ON AN AIRWORTHY DIRECTIVE; ON THE GAMBLE PLATE MODE ON ACFT X; I REALIZED I HAD INSTALLED THE 2 12-POINT HEAD BOLTS IN THE WRONG LOCATION ON ACFT Y. I MISTAKENLY INSTALLED THEM ON THE #8 FLAP SUPPORT MECHANISM ON ACFT Y. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE MOST OUTBOARD LEFT AND RIGHT FLAP JACK SCREW GAMBLE PLATES WERE BEING REPLACED WITH A BEEFIER PLATE PER AN AIRWORTHINESS DIRECTIVE (AD). PART OF THE AD; REQUIRED REMOVING THE OLD SIX-POINT HEAD BOLTS AT THIS LOCATION AND INSTALLING TWO NEW TWELVE-POINT TYPE HEAD BOLTS; TO ALLOW FOR BOLT CLEARANCE WHEN FLAPS ARE RETRACTED; DUE TO THE THICKER GAMBLE PLATES. A FELLOW MECHANIC HAD NOTICED THAT REPORTER HAD INSTALLED THE TWO BOLTS IN THE WRONG DIRECTION ON THE ACFT HE WAS WORKING AT THE TIME. REPORTER STATED HE THEN REALIZED HE HAD INCORRECTLY INSTALLED THE SAME TYPE BOLTS; AT THE SAME LOCATION; ON THE PREVIOUS ACFT HE WORKED.

Data retrieved from NASA's ASRS site as of May 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.

While working an airworthiness directive to change the gamble plates on the outboard flap #8 aft flap support on a B777-200 aircraft; mechanic realizes he installed the required twelve point bolts in the wrong direction.