1、Lessons Learned Entry: 0856Lesson Info:a71 Lesson Number: 0856a71 Lesson Date: 2000-02-04a71 Submitting Organization: ARCa71 Submitted by: Anthony BricenoSubject: SOFIA B747 Aircraft Upper Rudder Incident Description of Driving Event: The SOFIA B747 upper rudder was dropped after it was removed from
2、 the tail of the aircraft and was in the process of being placed on a flat bed trailer.Maintenance personnel attempted to rotate the removed rudder from the vertical to the horizontal position. This task was performed without the use of a holding/transport fixture as defined within the specific task
3、 job card and utilizing only two of the four attach points called out in the written procedures. Prior to removal, the procedures were reviewed and found adequate to perform this task. While the procedures addressed the equipment and the process for removal of the rudder, they did not address the pr
4、ocess beyond installation of the vertical rudder on a dolly. Though telephone calls were made in an attempt to locate equipment required by the procedures, there was none available when the decision was made to proceed with the rudder removal. The production supervisor admitted responsibility for th
5、e decision to proceed without all of the equipment required by the procedures and he proceeded to transition the rudder from a vertical to a horizontal position.The transition was attempted by unfastening the two harness support brackets on one side of the rudder. As the crew began the transition, t
6、he loading was multiplied by approximately 800 lbs. of counterweights on the rudders leading edge, a condition for which the sling assembly and attach points were not designed to carry. Of the three bolts at the point of failure, one bolt stripped the threads on exit, another pulled the attachement
7、receptacle through and out, and the third bolt pulled the attachment receptacle and surrounding structure loose from the rudder.Lesson(s) Learned: Perform adequate planing prior to performing the task.Verify that adequate resources are available.Provided by IHSNot for ResaleNo reproduction or networ
8、king permitted without license from IHS-,-,-Recommendation(s): 1. Implement procedures to require identification of critical tasks where human error can result in pesonnel death/injury and/or substantial damage to equipment.2. Implement procedures to require adequate planing including verification t
9、hat required resources (personnel experience, procedures, and tooling) are available.3. Require management signature on a critical task planing checklist to indicate adequate planing of resouces has been accomplished.4. Perform periodic audit to verify implementation of the procedure.Evidence of Rec
10、urrence Control Effectiveness: Audit was performed by NASA to verify adequacy of corrective action.Documents Related to Lesson: N/AMission Directorate(s): a71 Exploration Systemsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Aircrafta71 Ground Operationsa71 Hardwarea71 Lifting DevicesAdditional Info: Approval Info: a71 Approval Date: 2000-06-5a71 Approval Name: Eric Raynora71 Approval Organization: QSa71 Approval Phone Number: 202-358-4738Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
