Narrative:

Aircraft XXX experienced an air return due to right gear retraction failure as a result of the omission of proper maintenance installation procedures of the spoiler speed brake interlock cable. Several problems; in my opinion; contributed to the mishap. Here is the sequence of events that occurred prior to the air return. Fellow technicians mr. X and mr. Y and myself worked the first 7 hours of the shift clamping; safetying and installing panels per the work card tasks for the right-hand main gear. At approximately XA30 we routed the interlock cable through its respective position alongside the gear. Knowing we would not have time to install the cable; we signed our work completed. I then proceeded to write a work interruption for swing shift as to what was required to be completed next; that data included the installation and adjustment of the speed brake interlock cable. I also gave an oral summary of our work activity and what was necessary for the next technicians to do; directly to the swing shift lead technician. No signoff of the interlock was made at this time by myself. The next day; I observed the gear prior to my shift start. I noticed the cable was attached and safetied. When the shift began; I thumbed through the work card and observed the speed brake interlock cable adjustment was signed for as completed. With this information at hand; we proceeded to install the gear doors and set out to rig them during the swinging of the gear portion of the work card. Now late in the shift; I signed off the several sections pertaining to gear door installation and rigging. In retrospect; I concluded that my biggest failure in the task was not short signing my work on the first step of the door installation. This section also contained a step to install the interlock cable. There is no inspection buyback on that particular part of the work card. In retrospect; I know I should have short signed the door installation and left the installation step of the interlock to swing to complete. This would have alerted the next technicians to check the installation and readjust the cable. In my defense; I feel the work card is poorly written and should have a separate signoff with inspection buyback on the cable installation; instead of being part of the doors which has no relevance to the cable procession of tasks. I certainly have learned a lesson regarding checking every sentence of each task before signing off. I should always remember to short sign any work performed and have inspection sign; too; on my work performed. Fortunately; no one was injured due to my mistake; but I regret the time; money and inconvenience I put our company (and its passenger) through. The work card is poorly written and should be modified to have a separate step for maintenance and inspection to buy back. It should not be part of the door installation. Perhaps if communication between the swing lead technician and myself had been cleared; this might not have happened. In addition; if our air carrier had provided a better overlap of inspectors during the shift change this could have meditated the problem as well. Supplemental information from acn 828980: at the beginning of my shift; I was assigned from my lead to work on right-hand main landing gear. I received a brief verbal only turnover from day shift mechanic that the spoiler interlock cable was completely installed and that it's ready to rig. I then performed the next step on the work card to adjust/test the cable. I followed the aircraft maintenance manual and made 1 turn to the eye bolt at the cable end to make the rig pin south/B 3 fit freely through the yoke of the interlock valve. Then I conducted the test of jacking up the strut a minimum of 1.5 inches up to a maximum 3.0 inches -- the spoilers deployed at about 2.25 inches. The test was good; so we lowered the plane and I instructed mechanic to tighten the jam nuts and safety wire everything. He did and I had a quick look at everything; and it looked

Related reports:

Google
 

Original NASA ASRS Text

Title: Two Mechanics report a B737-800 experienced an air turnback due to a right gear retraction failure caused by the omission of proper maintenance installation procedures of the spoiler speed brake interlock cable.

Narrative: Aircraft XXX experienced an air return due to right gear retraction failure as a result of the omission of proper maintenance installation procedures of the spoiler speed brake interlock cable. Several problems; in my opinion; contributed to the mishap. Here is the sequence of events that occurred prior to the air return. Fellow technicians Mr. X and Mr. Y and myself worked the first 7 hours of the shift clamping; safetying and installing panels per the work card tasks for the right-hand main gear. At approximately XA30 we routed the interlock cable through its respective position alongside the gear. Knowing we would not have time to install the cable; we signed our work completed. I then proceeded to write a work interruption for swing shift as to what was required to be completed next; that data included the installation and adjustment of the speed brake interlock cable. I also gave an oral summary of our work activity and what was necessary for the next technicians to do; directly to the swing shift Lead Technician. No signoff of the interlock was made at this time by myself. The next day; I observed the gear prior to my shift start. I noticed the cable was attached and safetied. When the shift began; I thumbed through the work card and observed the speed brake interlock cable adjustment was signed for as completed. With this information at hand; we proceeded to install the gear doors and set out to rig them during the swinging of the gear portion of the work card. Now late in the shift; I signed off the several sections pertaining to gear door installation and rigging. In retrospect; I concluded that my biggest failure in the task was not short signing my work on the first step of the door installation. This section also contained a step to install the interlock cable. There is no inspection buyback on that particular part of the work card. In retrospect; I know I should have short signed the door installation and left the installation step of the interlock to swing to complete. This would have alerted the next technicians to check the installation and readjust the cable. In my defense; I feel the work card is poorly written and should have a separate signoff with inspection buyback on the cable installation; instead of being part of the doors which has no relevance to the cable procession of tasks. I certainly have learned a lesson regarding checking every sentence of each task before signing off. I should always remember to short sign any work performed and have inspection sign; too; on my work performed. Fortunately; no one was injured due to my mistake; but I regret the time; money and inconvenience I put our company (and its passenger) through. The work card is poorly written and should be modified to have a separate step for maintenance and inspection to buy back. It should not be part of the door installation. Perhaps if communication between the swing Lead Technician and myself had been cleared; this might not have happened. In addition; if our air carrier had provided a better overlap of inspectors during the shift change this could have meditated the problem as well. Supplemental information from ACN 828980: At the beginning of my shift; I was assigned from my Lead to work on right-hand main landing gear. I received a brief verbal only turnover from day shift Mechanic that the spoiler interlock cable was completely installed and that it's ready to rig. I then performed the next step on the work card to adjust/test the cable. I followed the Aircraft Maintenance Manual and made 1 turn to the eye bolt at the cable end to make the rig pin S/B 3 fit freely through the yoke of the interlock valve. Then I conducted the test of jacking up the strut a minimum of 1.5 inches up to a maximum 3.0 inches -- the spoilers deployed at about 2.25 inches. The test was good; so we lowered the plane and I instructed Mechanic to tighten the jam nuts and safety wire everything. He did and I had a quick look at everything; and it looked

Data retrieved from NASA's ASRS site as of April 2012 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.