REG NASA-LLIS-0006-1991 Lessons Learned - Orbiter Exterior Panel Separation During Flight due to Incorrect Installation (Washers not Provided Under Fasteners).pdf

1、Lessons Learned Entry: 0006Lesson Info:a71 Lesson Number: 0006a71 Lesson Date: 1991-04-29a71 Submitting Organization: JSCa71 Submitted by: L. UnderwoodSubject: Orbiter Exterior Panel Separation During Flight due to Incorrect Installation (Washers not Provided Under Fasteners) Description of Driving

2、Event: Following the shuttle mission STS-27, the right side orbital maneuvering system (OMS) pod carrier panel on the orbiter OV-104 was missing. It was concluded that the panel was installed incorrectly. Six flat washers were not installed under the mounting fasteners. This caused damage to the bas

3、e panel material upon installation. The panel became loose during flight, produced a gap, and was pulled off by the air flow. No additional damage was sustained by the orbiter thermal protection system or other orbiter components. The panel installation procedures did not clearly identify the requir

4、ement for the washers. The procedures were revised to include the steps for installing the washers. Approximately 100 orbiter panels of similar configuration were recommended for inspection to assure this anomaly was not present elsewhere within the orbiter fleet.Lesson(s) Learned: Incomplete assemb

5、ly or installation instructions (no reference to the use of washers) can result a in poorly fastened exterior mounted component (orbiter OMS carrier panel) causing loss of the component and potentially hazardous debris.Recommendation(s): Procedures were changed to include detailed instructions for i

6、nstalling washers. All similar orbiter panels were inspected to preclude recurrence of the anomaly.Evidence of Recurrence Control Effectiveness: N/AProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Documents Related to Lesson: N/AMission Directorate(s)

7、: a71 Exploration Systemsa71 Sciencea71 Space Operationsa71 Aeronautics ResearchAdditional Key Phrase(s): a71 Configuration Managementa71 Flight Operationsa71 Flight Equipmenta71 HardwareAdditional Info: Approval Info: a71 Approval Date: 1993-09-09a71 Approval Name: Ron Montaguea71 Approval Organization: JSC/NS3a71 Approval Phone Number: 281-483-8576Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-