REG NASA-LLIS-0528-1994 Lessons Learned Improperly Conceived Acceptance Tests and Original Specifications.pdf

1、Lessons Learned Entry: 0528Lesson Info:a71 Lesson Number: 0528a71 Lesson Date: 1994-10-05a71 Submitting Organization: LARCa71 Submitted by: Bernard LewisSubject: Improperly Conceived Acceptance Tests and Original Specifications Description of Driving Event: In preparation for a test in the tow tank,

2、 Naval Underwater Systems Center personnel, who operate the facility under an MOU, sought the recommendations of IRD for the purchase of thirteen wet/wet pressure transducers with amplified outputs. The IRD recommended manufacturer was Druck and the appropriate specifications for transducers in thei

3、r product line were provided to NUSC personnel. When the PR reached purchasing, the facility was informed that a GSA contract manufacturer would be the supplier. The GSA contract manufacturer was contacted by both NUSC and the instrument support section, IRD, since the needed items were not part of

4、the GSA contract manufacturers product line. The GSA contract manufacturer gave assurances that they could custom build the transducers to the required specifications. Twelve of the ordered thirteen transducers were delivered more than two months behind schedule and the thirteenth one-two weeks late

5、r. All the transducers passed acceptance tests and met or exceeded the original specifications. The first time the facility introduced a wet test medium (fresh water) into the transducers, the output of two transducers became very erratic and a third leaked water through welded seams in the transduc

6、er case. The two with erratic output were returned to the GSA contract manufacturer. The leaking transducer cannot be sent back without shutting down the in-progress test. Before the PR went out, ISS advised purchasing of the questionable quality of the GSA contract manufacturers products, but accor

7、ding to purchasing, because of the GSA contract system, the GSA contract manufacturer had to be the supplier.Lesson(s) Learned: Improperly conceived acceptance tests and original specifications led NASA Langley Research Center to accept parts, which failed in use.Recommendation(s): Provided by IHSNo

8、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-When used, the output of two transducers became very erratic while a third one leaked water through welded seams in the transducer case.Evidence of Recurrence Control Effectiveness: N/ADocuments Related to Lesson: N/AMi

9、ssion Directorate(s): N/AAdditional Key Phrase(s): a71 Hardwarea71 Procurement Small Business & Industrial Relationsa71 Test & VerificationAdditional Info: Approval Info: a71 Approval Date: 1997-04-02a71 Approval Name: Elijah C. Kenta71 Approval Organization: 421a71 Approval Phone Number: 757-864-3345Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-