REG NASA-LLIS-3116-2010 Lessons Learned - Bent Orbital Maneuvering System (OMS) Pod Rotator.pdf

1、 Public Lessons Learned Entry: 3116Lesson Info:a71 Lesson Number: 3116 a71 Lesson Date: 2010-04-21 a71 Submitting Organization: KSC a71 Submitted by: Annette Pitt Subject: Bent Orbital Maneuvering System (OMS) Pod Rotator Abstract: The Space Shuttle Orbital Maneuvering System (OMS) pod rotator (a 5-

2、ton jack screw) was bent on three occasions because of overloading. As a result, Boeing designed a system consisting of two load-sensing pins: one pin for attaching the rotator to the OMS pod lifting fixture and the other for attaching the rotator to the facility attachment point. Each sensing pin i

3、s connected to a readout unit to indicate when the rotator is under load or when the rotator load changes between tension and compression. Two load-sensing pins are used for redundancy. Description of Driving Event: The rotator is part of a lifting fixture used during OMS pod installation or removal

4、. The 73D010016-1003 OMS pod rotator was bent on three occasions: In 1991, the rotator was overdriven against the Orbiter deck, causing the screw shaft to bend. In 1992, the rotator was overdriven against the hydraset, causing the screw shaft to bend. In 2004, the lifting-fixture jack screws were ov

5、erdriven against the rotator, causing the screw shaft to bend. Lesson(s) Learned: The rotators screw shaft will bend if the rotator is overdriven. The rotators screw shaft will also bend if the jack screws of the lifting-fixture pivot shaft are overdriven. The operating personnel used several differ

6、ent indicators to determine when the rotator was unloaded; however, all of the methods depended on feel or sight. Less experienced operating personnel were not always able to make the right call. Recommendation(s): a71 Use load-sensing pins at critical connection points to indicate loading and load

7、changes as opposed to relying totally on feel or sight. a71 Include load limits in the written operating procedure to protect the hardware. Evidence of Recurrence Control Effectiveness: The new equipment was tested during the removal of RP03 from OV-103, and expectations were exceeded. It was extrem

8、ely easy to monitor the loads, and there should be no reason now for bending another rotator. The load data from the test also brought to light a problem with the safe working load of the rotator after 30 years of use. This discovery forced the design agency to redo some calculations and modeling. D

9、ocuments Related to Lesson: Certification Approval Request (CAR) Package 01-33-340247-001 Click here to download document Bent OMS Pod Rotator Engineering Review Board Presentation Click here to download document Mission Directorate(s): a71 Space Operations Additional Key Phrase(s): a71 1.Ground Equ

10、ipment a71 0.Simulators and Training Systems a71 0.Systems analysis - cost analysis a71 0.Vehicle concepts a71 1.Hardware a71 1.Lifting Devices Additional Info: a71 Project: Space Shuttle Program Approval Info: a71 Approval Date: 2010-09-30 a71 Approval Name: mbell a71 Approval Organization: HQ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-