1、Public Lessons Learned Entry: 3256 Lesson Info: Lesson Number: 3256 Lesson Date: 2010-06-8 Submitting Organization: KSC Submitted by: Annette Pitt Subject: Orbiter Lifting Sling Damage Abstract: Lasers and targets are useful for visually aligning or leveling two objects over a significant distance.
2、Description of Driving Event: The Orbiter lifting sling was damaged when it was moved from the front of High Bay-1 to High Bay-3 for the Orbiter/External Tank mating. The damage consisted of a fractured screw-shaft on the left-hand aft stiff-leg jack-arm assembly. This delayed the roll out of OV-103
3、 (STS-117) from the Orbiter Processing Facility (OPF) by approximately 24 hours until the sling could be repaired. The screw-shaft fractured during the move when the sling was skewed beyond its structural limits. The sling is moved with the 175-ton crane connected to the aft spreader-beam and aft st
4、iff-legs; a spreader beam and forklift with fifth-wheel adapter are used to support the forward-portion of the sling. The sling will become skewed if the forklift and crane do not move in unison and in a relatively straight line. Provided by IHSNot for ResaleNo reproduction or networking permitted w
5、ithout license from IHS-,-,-Failure analysis determined the screw-shaft fracture was caused by a single bending-overload event. Lesson(s) Learned: The sling can easily become skewed if the forklift operator and the crane operator do not follow the same course. However, it was extremely difficult to
6、know if they were following the same course because there was approximately 60 feet between the forklift and the overhead crane. Recommendation(s): The use of lasers and targets is an excellent means of quantifying misalignment, skew, levelness, etc. To protect the hardware, allowable limits should
7、also be added to the operating procedure. Evidence of Recurrence Control Effectiveness: The sling was moved successfully many times using the new laser system. No hardware was damaged in the process. Documents Related to Lesson: Click here to download Orbiter Sling ERB Presentation Mission Directora
8、te(s): Space Operations Additional Key Phrase(s): Mission Operations and Ground Support Systems. Mission Operations and Ground Support Systems.Ground support systems Additional Info: Project: Space Shuttle Program Approval Info: Approval Date: 2011-02-28 Approval Name: mbell Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
