EWIS Training

8/12/2019 EWIS Training

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EWISEWIS

Electrical Wiring Interconnect SystemNot Just Another Acronym!

Technical Committee

Special Project ATSRAC


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What is EWIS?

All wiring related components connecting

LRUs such as: Wiring

Cannon Plugs

Modular Blocks

Clamps

Terminal Strips

Etc.


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Why the concerns about EWIS?

History

NTSB, following the TWA 800 accident,determined that wiring inside a fuel tank

developed a short causing an explosion which

downed the aircraft. Vice Presidential Committee Gore

Commissioned detailed study be performed on

the health of aircraft wiring in regards to aging ofan aircraft.


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Why the concerns about EWIS?

History (cont.) The FAA in conjunction with regulatory agencies

worldwide and industry developed a focus group to

study the potential problem. ATSRAC (Aging Transport Systems Rulemaking

Advisory Committee)

Originally formed to perform non-intrusive,intrusive inspections and developrecommendations to the FAA for LargeTransport Aircraft. (ADs, SFAR)

After the Payne Stewart incident, NTSBrecommended that all Transport Aircraft beincluded in ATSRAC study - STA


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ATSRAC HWG10 - STA

WIRING EVALUATIONS - Summary

39 privately owned in-service a/c

No Safety of Flight Concern

2256 discrepancies

73 of them are considered as significant*items

*Significant items need to be rectified/repaired forcontinued airworthiness throughout aircraft operational

life


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ATSRAC - STA

WIRING EVALUATIONS (Cont'd) No aging issue specific to wire insulation and

conductor were detected 29 % of discrepancies are inadequate clearance

with structure, racks, equipments 43 % of discrepancies are bad clamp

conditionning/sizing/spacing

68 % of significant items are due to inadequate

clearance or bad clamp conditionning: sizing /

spacing.


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Aircraft Type

Findings Summary AC Mode l A AC Mode l B AC Mode l C AC Mode l D AC Mode l E AC Mode l F AC Mode l G AC Mode l H Summary

Number of Aircraft Inspected 5 5 5 5 4 5 5 5 39

% of the Model Fleet 5.90% 2.90% 0.61% 0.90% 2.10% 2.10% 1.05% 0.80% 0.6% to 6%

Age Range 19 to21 11 to 24 10 to 18 18 to 25 11 to 12 20 to 30 12 to 15 11 to 32 10 to 32

Hour Range 4785 to 7835 4130 to 12001 3258 to 8413 7223 to 12408 4130 to 8083 8770 to 17389 4271 to 5904 3572 to 13014 3258 to 17389

Landing (Cycles) Range 4846 to 5684 3473 to 8558 2682 to 5692 5709 to 9873 2746 to 7498 4843 to 8500 2638 to 3389 3187 to 13252 2638 to 13252

Inspections Performed By WG & OEM WG & OEM WG & OEM WG & OEM WG & OEM WG & OEM OEM WG & OEM WG & OEM

0

73

1.9

2256

58

Evaluation Findings % to Specific M odel Totalsby Appendix A Categories:

Connectors 3.20% 1.90% 5.40% 3.30% 1.70% 1.80% 0% 2.30% 2.75%

Terminations 2.30% 0.60% 0.30% 6.70% 0 0.40% 0% 5.50% 1.99%

Installations (General) 80% 79.50% 87% 87% 90.50% 86.40% 97.40% 80.70% 84.53%

Wiring Condition 14.40% 18% 7.30% 2.90% 7.80% 11.40% 2.60% 11.50% 10.73%

Significant Items

% of Significant Items(73Items) to All Model (2256

Items) Evaluation Findings3.24%

Findings per AC (Avg.)

Immediate Fleet Wide Safety

Total Findings

Significant Items

Significant Items per AC (Avg.)


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Damaged Clamp

Zone: 310 Aft equipmentcompartment below APU


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Oxygen line


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Installation invertedTeflon shim


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Disabled system connectors pulled from rack

Tied to environmental system duct


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Conduit rubbing on connector hardware


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Wires pinched in clamp


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ImproperlyInstalled Clamp

(pinching wire)

Zone: 140 Under floor area above wing box


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Chaffed through


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Bend Radius

Zone: 220 Flight compartment above floor

behind circuit breaker panel (copilots feet)


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Bend radius

Improper installation

ll i d i i d i d l


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Installation deterioration and inadequate clearances

Inadequate clearance


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Inadequate clearance


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Inadequate Clearanceto Structure

Zone: 114/115 Flight compartment

under floor bottom of fuselage


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Damaged ConduitZone: 143/144 Main landinggear wheel well


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Improper

Repair

Zone: 143/144 Main landing gear wheel well


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Debris on Power Wires

(Metal Shavings)

Zone: 240/250 Cabin area above floor


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Contaminated

Wires

Zone: 250 Cabin area above floornear luggage compartment door


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ATSRAC HWG10

General Comments - From a/c evaluations

Aircraft in good overall condition

Reasons of Discrepancies

Wiring Repair

Training Issues

Lack of use of OAM Standard Practice Manuals

Routing of Modification Wiring

Training Issues

Lack of use of Industry Standard Guidelines (AC 43.13)

and OAM Standard Practice Manuals


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ATSRAC HWG10

General Comments (cont'd)

Clamping and Structural Contact

Training Issues Instructions for Continued Airworthiness Issues

Protect, Clean as you go philosophy

Training Issue

ICA possible no mention

Industry cultural concerns


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ATSRAC HWG10

Organizational Differences

STA = Smaller Organizations within eachDepartment

Dispatch

Flight Maintenance (35%)

STA Owner/Operators tend to be more

interdependent with TC and STC Holders


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NBAA Operator Demographics

669

2358

314

362588

237

0

500

1000

1500

2000

2500

3000

3500

1 2 >2

W/O MX

With MX

Operators

Aircraft Operated


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ATSRAC HWG10

Lessons Learned

Before April of 2002 the Majority of theWorking Group was not Aware of EWIS -Concepts

Based on the review of: Aircraft Evaluations

Service History/ADs

Intrusive Inspection Report

HWG-6 through HWG-9 Final Reports


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ATSRAC HWG10

Lessons Learned

HWG-10 determined areas of need: Awareness and Training

Installation Guidance (FAA driven

Standardization Issues)

Inspection Criteria

Maintenance Procedures Enforcement of Current Regulations


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HWG-10 Recommendations

FAA

FAR Part 147 Appendix E is revised to

include the concepts of AC 120-YY(EWIS, Detailed Inspection (DET),General Visual Inspection (GVI), andSpecial Detailed Inspection (SDI)).

Rationale

To fully effect a culture change, in theaviation industry, this should include aground up approach (e.g. future technicians

are trained from day one on EWIS concepts)

d i


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FAA The following Advisory Circulars be revised

to include EWIS concepts: 43.13

43.204

65-9A

65-11B

65-12A 65-15A

* concepts and language with standardized criteria forEWIS


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Rationale

These Advisory Circulars are the basis forcertification, maintenance, and training of industry

personnel.

EWIS concepts revision would generateawareness to a large group of existing and future

approvers, designers, installers, and technicians.


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I i C i i


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Inspection Criteria

Rationale

There is a lack of Inspection Criteria forwiring and its subcomponents.

Development of this Criteria will ensure

that inspectors know what is to be

inspected.


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Maintenance Procedures

Recommendations

Review existing manufacturerinspection/maintenance programs and

enhance for EWIS considerations

Manufacturer standards - wiring

practices

pass fail criteria

Training program


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Maintenance Procedures

OEMs and STC Holders to enhance thecurrent Maintenance Procedures

Enhancement doesnt necessarily drive toEZAP.

Maintenance Program DevelopmentPhilosophies of the Various STA OEMs shouldbe capable of enhancing current programsincorporating concepts of EWIS

Future Small Transport Aircraft Designs willmost likely follow the version of MSG-3 of that

time period or applicable analytical logic processof that time period.


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ATSRAC - STA

Whats next?

HWG 13 New Tasks - further define anddevelop for STA

Criteria for enhanced wiring inspectionprocedures

Means of compliance


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So now we know

Installation of wiring (EWIS) has not had the

awareness of the Approvers & Maintainers itrequires

Concerns for installation & functionality ofequipment was the priority not wiring

Current practices will not be allowed to

continue as is


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Future - demands an EWIS

priority

Communicate through existingindustry venues and forums available

(i.e. AEA, GAMA, PAMA,

NBAA) and through FAA and state

DOT sponsored activities (i.e. D.E.R

renewals, IA renewal)

d d


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Future - demands an EWIS

priority Enhance Maintenance Procedures

Instructions for Continuous Airworthiness

both TC and STC Holders

Enhancement of Advisory Material bothCurrent and Future Development of EWIS

Installation Guidance

Inspection Criteria Pass/Fail Inspection

Criteria for go/no-go decisions


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EWIS Reference Information

Websites Official ATSRAC Website:

www.mitrecaasd.org/atsrac/index.html

FAA Wiring Training Website:

www.academy.jccbi.gov/AIRDL/wiringcourse


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Thank You!Thank You!Eli [email protected]

Questions?Questions?

Documents

EWIS Training