Narrative:

Maintenance technician and I completed the task of pressure dome bolt, nut, and washer replacement. I now realize that we installed the wrong washers (flat washers) under the head of the bolts instead of the conical washer that should have been installed. I realized this mistake after being assigned the same task on aircraft. Callback conversation with the reporter revealed the following information: the reporter stated the wrong washers were installed in the pressure dome at every hole between the stringers on the unpressurized side. The reporter said, 'this was the first time my partner and I worked this engineering change order.' the reporter stated the kit of parts looked ok but failed to notice the washers were flat not conical as required. The reporter said the job was completed and inspected. The reporter said the airplane was released for service. The reporter stated the next night we were assigned to another airplane to work the pressure dome and the error was discovered. The reporter said engineering was alerted and the airplane was set up to return and have the conical washers installed.

Related reports:

Google
 

Original NASA ASRS Text

Title: A B767-300 PRESSURE DOME ENGINEERING CHANGE ORDER WAS ACCOMPLISHED INCORRECTLY. THE WRONG WASHERS WERE INCLUDED IN THE ACCOMPLISHMENT KIT AND WERE INSTALLED

Narrative: MAINT TECHNICIAN AND I COMPLETED THE TASK OF PRESSURE DOME BOLT, NUT, AND WASHER REPLACEMENT. I NOW REALIZE THAT WE INSTALLED THE WRONG WASHERS (FLAT WASHERS) UNDER THE HEAD OF THE BOLTS INSTEAD OF THE CONICAL WASHER THAT SHOULD HAVE BEEN INSTALLED. I REALIZED THIS MISTAKE AFTER BEING ASSIGNED THE SAME TASK ON ACFT. CALLBACK CONVERSATION WITH THE RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE WRONG WASHERS WERE INSTALLED IN THE PRESSURE DOME AT EVERY HOLE BETWEEN THE STRINGERS ON THE UNPRESSURIZED SIDE. THE RPTR SAID, 'THIS WAS THE FIRST TIME MY PARTNER AND I WORKED THIS ENGINEERING CHANGE ORDER.' THE RPTR STATED THE KIT OF PARTS LOOKED OK BUT FAILED TO NOTICE THE WASHERS WERE FLAT NOT CONICAL AS REQUIRED. THE RPTR SAID THE JOB WAS COMPLETED AND INSPECTED. THE RPTR SAID THE AIRPLANE WAS RELEASED FOR SVC. THE RPTR STATED THE NEXT NIGHT WE WERE ASSIGNED TO ANOTHER AIRPLANE TO WORK THE PRESSURE DOME AND THE ERROR WAS DISCOVERED. THE RPTR SAID ENGINEERING WAS ALERTED AND THE AIRPLANE WAS SET UP TO RETURN AND HAVE THE CONICAL WASHERS INSTALLED.

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.