# Presentation: 543275

## 5A AOE-0588 SSQ 21654 Fiber Optic Cable Anomaly - Tiger Team Meeting

**Boeing - EEE Parts**

**12/8/99**

**David Gill**
**(714) 896-6403**

**Notes:**
This template is intended to provide guidance for preparing to present information to ISSP control panels and control boards pertaining to solutions to problems that may exist in the program.
The format is structured to present:
a clear definition of the problem, 
who/what is impacted by the problem, 
options to resolve the problem, 
how implementing the options will improve the situation, 
and what is expected from the control panel or board.

## Early FO Cable Disposition Plan

**Focus of team has been working on the root cause as well as gathering enough empirical evidence to clear early cable (Shipped during 1995-1997)**
- Early cable represents hardware which has been installed on Node 1, US Lab, Airlock, S0, and ORUs
**FO TIM Early Cable “Bubble” Disposition Plan**
- Obtain as much cable from similar dates of manufacture to determine if the bubbles existed and if they would lead to failure.  Rationale for use could then be supported by data
- Identified 9600’ of cable at SEA Wire and cable
- Identified 1000 feet of APS test harness cable
- 16 US Lab MSS Rack Links
- 6 failed links; 3 from MSS Racks and 3 from US Lab
- Investigate other programs usage, application, and experience with same optical fiber

## Early FO Cable Bubble Disposition Rationale

**Similar amounts of similar vintage cable (1996) has been tested using a proven bubble detection method  (~ 11,000’ tested vs. ~14,000’ Installed)**
- 1 bubble found which is detectable using current acceptance test techniques
- 16 US Lab MSS Rack flight links + additional test sets cables tested without detecting a single bubble
- NASA-Goddard tested 1000+’ of the same fiber (different jacketing) from similar lots and did not detect a single bubble
**Installed cables have been through handling during manufacturing build-up and installation and testing**
- 6/17 failures have been analyzed and determined to have failed due to mechanical overstress as a result of handling.  Others were not analyzed.
- Failure rate during installation (~2%) similar for current elements on ISS experience
- 700+ flight FO links have passed optical loss ATP both at assembly and post installation without a detected bubble
- 3 years has expired on the early production cables
- Zero ORU fiber optic cable failures once ORU has passed post installation ATP
**Bubble rate of later fiber optic cable builds indicate significant differences between early cable and recent**
**At least two changes in the production process have been noted during the investigation to date**

## Node 1, US Lab, Airlock and Early ORUs Bubble Disposition Plan Developed during FO Summit

**Node 1, US Lab, Airlock and Early ORUs Bubble Disposition Plan Developed during FO Summit**

- Locate HB
- Early Manufactured
- SSQ 21654 Cable

- Review
- SEA Shipping
- History

- Review
- HVL Build/Shipping
- Records

- Review
- HB Build/Shipping
-  Records

- Test Using High
- Power Laser Screen

- Review
- BICC/Spectran
- Build History

- Locate HVL
- Early Manufactured
- SSQ 21654 Cable

- Develop
- Statistical Model to Define Confidence in Not Screening US Lab Cables

- Destructive Tensile
- Testing of Limited Number
- of Samples

- Determine
- Statistical Confidence of bubble(s) in early elements and ORUs

- Present Analysis
- To ISS Program

- Present Analysis
- To ISS Chief Engineers

**10-15**

**10-18**

**10-24**

**10-24**

**11-4-99**

**11-13-99**

**11-16-99**

- Test for Optical Loss
- Using OTDR/RIFOCs
- Techniques

**11-16-99**

**11-16-99**

**10-29-99**

- Remove/Ship US Lab
- W/H Failures @ KSC

**11-3**

- Remove/Ship MSS Rack
- W/H Failures @ HVL

**11-8**

- Perform F/A of Samples

**11-10**

- Test MSS Rack
- W/H using Laser @ HVL

**11-3**

**11-18-99**

**11-19-99**

- Understand the degradation of
- Optical Loss and
- Strength Phenomena

**12-15-99**

**2nd Round of CER**
**11/24/99**

**11-29-99**

## Early FO Cable Bubble Disposition Rationale Conclusion

**High confidence has been developed by testing limited numbers of flight links, similar vintage cable on both reels and in test set applications, and analyzing limited numbers of failed flight links**
- Statistical Confidence > 99.5%has been reached
- Node 1, US Lab, Airlock, S0, and early ORUs hardware does NOT contain any bubble defects
**Residual Issues **
- Optical Degradation
- Spools retested - Closed - Testing Error
- Losses decreased post respooling
- Causes of high losses determined to improper spooling practices
- Mechanical strength and optical degradation
- Testing in progress

## FO Cable Root Cause Investigation Plan

**Investigating probable cause(s) identified in the fault tree**
**Perform Audits and discussions with supplier’s build records to analyze six unique builds over the last three years**
**Initiate in-line process inspections and tests of new product as it is being manufactured**
**Restart the production line and monitor**

## Root Cause Investigation Plan

**Root Cause Investigation Plan**

- Audit
- Findings

- BICC Build
- Record Review

- Selected Experts Product
- History Audit

- Personnel
- Changes

- Process
- Changes

- Process
- Variations not
- Controlled

- Spectran Build
- Record Review

- HB Impound
- Stock Testing

- Cut Samples
- Scrapped to
- Engineering

- Quantify Loss/
- Non-destructive
- Optical Testing

- Tensile Testing/Glass&Jacket Sectioning/Coating Removal/Other Chemical Analysis Techniques

- Optical/SEM &
- Other Evaluation

- Review Data &
- Analyze

- Determine Root Cause/
- Most Probable Cause(s)

- Laser Power
- Damages Fiber

- Identify
- Sources
- Used

- Identify
- Analysis
- Techniques

- Experimental
- Testing

- Deliver to
- NASA-Goddard/
- Bell Labs

-  Parallel Investigation

- Baseline
- Samples for future evaluation

- SEA Build
- Record Review

- Emphasis on ESD
- Effects

- Data Search/
- Analyze Contributing
- Applications/Factors

- Obtain
- Raw Fiber

- Develop Test Setup

- Test at Contributing
- Processes Steps

- Monitor Other
- Programs

- Determine
- Program Test/Inspection Criteria

- Determine
- Field Experience

- Early Cable
- Re-evaluation (See US Lab Disposition

**11-17**

**11-19**

**12-3**

**12-20**

**1-15**

**1-31**

**11-24**

**1-20**

**3-20-00**

- Monitor Restart of Production Line (See Restart Production Line)

**3-10-00**

**12-15**

**1-20**

**1-30**

- Experimentation
- of Fiber Susceptability

**1-10**

- Update SCAN with
- Closout Actions

**3-31-00**

## 5A AOE-0588 SSQ 21654 Fiber Optic Cable Anomaly Fault Tree

-  causes error(s)

- Creation of micro
- gas bubble

- Drawing tower speed
- too slow/fast

**5A AOE-0588 SSQ 21654 Fiber Optic ****Cable Anomaly Fault Tree**

- High Optical Losses
- in FO Cables

- FO W/H Design
- Error(s)

- Fiber Optic Cable Design/Manufacturing
- Error(s)

- Wire Harness Assembly
- Tools/Procedure Error(s)

- W/H Testing or Mating H/W
-  Error(s)

- Buffer Tube too Small

- Buffer Tube too Large

- Index Step Materials
- Improperly Applied

- Pre-form Processing shrinks
- material too slow/fast

- Outside Jacket Applied
- too thick

- Outside Jacket Applied
- with Too Much Heat

- Buffer Tube not
- Proper Material

- Tensile test
- mandrels not
- performing properly

- FO Cable
- Jacketing Error(s)

- Glass Fiber
- ManufacturingError(s)

- Outside Jacket Applied
- Too Much Speed

- Strength Member
- Too Many Braids

- Strength Member not
- Proper Material

- Strength Member
- Too Few Braids

- Buffer Tube not
- round enough

- Index Scrubbing Process
- improperly implemented

- FO Cable Testing
-  Error(s)

- Spectran Improperly
- Performs testing

- BICCGeneral Improperly
- Performs testing

- Fiber Draw Failure Modes

- Cladding IDSurface not
- properly prepared

- Index Step Materials
- Contamination

- Testing Performed inadequate

- Cladding Material/Supplier or Dimensional Change

- Preform/Fiber design Changes

- Etch materials/.process
- changes

- Degreasing Material/Process
- Changes

- Initial cladding processing
-  personnel error(s)

- Test Method/Procedure
- Unable to detect all anomalies

- Too Much energy
- is concentrated at
- fiber weak point

- Core Material/Supplier or Index Dimensional Changes

- Imperfections in ID

- Pre-form Lathe Processing
- temperatures not controlled
- properly

- Pre-form Lathe rotation too
- slow/fast

- Cladding wash material/
- process change

- Core material not properly
- processed

- Index processing
-  personnel changes

- Fiber Coating Material/
- Process changes

- Carbon Coating
- Material/Process
- variations

- Polyamide Coating
- Material/Process
-  variations

- Index Lathe Processing
- temperatures not controlled
- properly

- Index Lathe rotation
- too slow/fast

- Drawing tower
- furnace
- too hot/cold

- Drawing tower
- temperature/speed
- not controlled

- Drawing tower start/stops
- or speed not smooth

- Preform processing
-  personnel error(s)

- Index processing
-  personnel error(s)

- Shipping/storage
- Exposes Cables to High
- Energy

- Contamination
- in Tower

- Fiber laser mic generates
-  sufficient ESD energy

- Prejacket fiber wheels
- Damage Coatings

- Prejacket fiber wheels
- Damage Coatings

## SSQ 21654 Suppliers Production Restart Plan

**12-15**

- Audit Six Unique
- Fiber Lots from Materials to Delivery at SEA/BICC/Spectran

**11-5-99**

- Restart Production
- Line Plan

**12-10-99**

- Identify & Procure Forward Requirements

**12-15-99**

- Recommend New In-line Inspection/Test Process Requirement(s)

**2-25-00**

- Fiber Draw and Test

**3-10-00**

- Manufacture
- Cable Jacket and Test

**3-20-00**

- Receiving Inspection and Test @ Boeing

**12-31-99**

- Implement lessons learned into production
- in-line process verification

**1-31-99**

- Present to Boeing/NASA Boards for Approval

**1-5-00**

- Manufacture
- Preforms and Test

**1-15-00**

- Generated SSQ Change Language

## FO Wire Harnesses ITCE Forward Plan

- Assess Current
- Production Status

**11-10-99**

- Develop Retest/Remanufacturing Trade Options

**5-15-00**

- Re-manufacture and ATP W/Hs

**12-31-99**

- Decide Best Retest/Remanfacturing Plan

**1-31-00**

**12-10-99**

- Develop Ground Test
- Alternative Design

**1- 30-00**

- Procure/Recieve Ground Test Cable/Part Requirements

- Retest Harnesses
- In-place Using OTDR
- or other Suitable Method

**12-31-99**

**6- 30-00**

- Manufacture/Test
- Ground Support Harnesses For All ITCEs

- Remove Harnesses
- From Vehicle/Beta Cloth
- and Test using Laser

**12-31-99**

- Test Using RIFOCs

**12-31-99**

- Rebuild Harness
- by Removing existing
- FO Cable

**12-31-99**

- Repair Harness
- by Overlay All/Partial
- FO Cable then Beta Cloth

**12-31-99**

- Repair Harness by Overlay All Cable and apply Convoluted Tube Concept

**12-31-99**

**5-30-00**

- Re-install and Post Installation ATP W/Hs

**3-10-00**

- Re-screen Cables

**12-15-99**

- Disposition using
- Early Cable Disposition

**S0**

**S1/P1, S3/P3**

**2-15-00**

- Develop Design Standard Repair Drawings

**3-15-00**

- Test S0 using current
- ATP Test Methods and Techniques

**4-15-00**

- Repair, as required, using best design/manufacturing/test approach