Course EWIS 00-113

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 Date: October 30, 2013 Revised July 23, 2015 Revised Sept. 1, 2015 To:

All Maintenance Personnel

From: Bryan A. Sherby, Manager of Maintenance Training Re:

Electrical Wiring Interconnection Systems (EWIS) Training

A. Purpose: This MIL is required training for Electrical Wiring Interconnection Systems Training. B. General 1. EWIS training is done in accordance with AC 120-94. The objective of the EWIS training program is to ensure that proper processes, procedures, methods, techniques, and practices are used when performing maintenance, preventive maintenance, inspection, alteration, repair, and cleaning of EWIS. a. This training is divided into seven modules: 1). General EWIS Practices and Safety 2). Wiring Practices Documents and Documentation 3). Inspection Practices 4). Housekeeping 5). Wire Identification and Properties 6). Connectors and Connections 7). After Repair Tests and General Visual Inspections 2. Background a. This initiative was spurred by the investigation of the aircraft incidents, like the wreckage of TWA Flight 800. That investigation showed many AMTs and airline maintenance practices considered wiring and associated components as “install and forget”. b. TWA flight 800: 7/17/1996; Boeing 747-131, broke up in flight and crashed in Atlantic off the coast of New York. Ignition energy for center wing tank explosion most likely entered through fuel quantity indication system (FQIS) wiring. c. Swissair 111 Accident Crashed off coast of Nova Scotia on September 2, 1998. Smoke in cockpit, fire in cockpit overhead area. Metalized Mylar insulation blankets and found 23 wires with arcing damage.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 d. American Airlines: On November 29, 2000, American Airlines flight 1683, DC-9-82 aircraft departed from Reagan National Airport, Washington DC to Dallas Fort Worth, Texas. The flight crew reported smoke in the cockpit and cabin shortly after takeoff. The operator’s investigation revealed that galley power feeder wires were pinched between the edge of the galley and airplane structure. Due to normal airplane vibration, the structure eventually cut through the wire insulation and arced. 3. Standard Aircraft Wiring Practices a. Definition. 1). EWIS is [per new FAR 25.1701(a)], any wire, wiring device, or combination of these, including termination devices, installed in any area of the airplane for the purpose of transmitting electrical energy between two or more intended termination points.

b. ATSRAC (Aging Transport Systems Rulemaking Advisory Committee) originally formed to perform non-intrusive, intrusive inspections and develop recommendations to the FAA for Large Transport Aircraft. (ADs, SFAR) c. Why the need for wiring practices training? 1). Aging Systems Program. 2). Aging Transport Systems Rulemaking Advisory Committee (ATSRAC). 3).Accident Service History.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 4. Aging Systems Program a. Instituted a comprehensive aging non-structural systems program. 1). Research to identify and prioritize opportunities to enhance safety. 2). A data-driven program based on inspections and service history reviews. 3). Multi-pronged solutions developed in conjunction with aviation community. 4). Modeled after successful aging structures program.

5. NTSB a. The NTSB made several recommendations to the FAA to examine manufacturers’ design and maintenance practices and to make changes as necessary, to eliminate potential ignition hazards in transport category aircraft fuel tanks.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 b. In May 2001, the Federal Aviation Administration released a comprehensive Special Federal Aviation Regulation known as SFAR No. 88 requiring all the airframe manufacturers and Supplemental Type Certificate (STC) holders to conduct a safety review of the fuel tank system to ensure that there will be no ignition source present which could cause catastrophic failure, even with a variety of system failures. Included were requirements to prepare special maintenance inspections and procedures that operators of transport aircraft would use to prevent the development of ignition sources in order to ensure the continued safety and airworthiness of the fuel system during the life of the aircraft. c. Airworthiness Limitation Item: (ALI), as defined in Boeing Service Letter Addressing SFAR 88. 1). These are repetitive inspections which are required to help ensure that components which are subject to degradation or damage do not deteriorate to the point where they fail and create an ignition source in the fuel tanks. 2) Some Examples of Airworthiness Limitation Item Inspections: a). Inspection of wiring insulation. b). Inspections of clamping. c). Verification of fault current bonds.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2


General EWIS Practices and Safety A. Safety Practices

WARNING: Electrically bond the aircraft. Make sure you properly connect static ground cables to prevent injury to persons and damage to the equipment. B757

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 1. WARNING: De-energize electrical systems before performing work. Always inform other personnel working on or around the aircraft before re-energizing the electrical system.

2. No matter what system you are working on, “LOCK OUT, TAG OUT!”


3. Cover all open aircraft electrical connectors with the applicable protective dust caps. This will prevent entrance of unwanted materials, damage, and possible electrical shorts. Take the necessary precautions to cover exposed electrical components and avionics racks when performing any sheet metal repairs that may create metal shavings or other debris. a. Be careful to exercise extreme caution when working on any high voltage electrical systems to avoid hazardous conditions such as:

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 4. DOCUMENT what you’ve done! This is especially important for C/Bs not in the Flight Deck!

5. REMEMBER! External power can be lethal. Always turn the External power switch “OFF” and disconnect the power source before performing maintenance on External Power Systems. Use “LOCK OUT, TAG OUT”!

6. Don’t forget to make sure the Battery Switch is turned “OFF” and use “LOCK OUT, TAG OUT” to make sure that someone doesn’t turn it back on before you are finished with the repair of the DC power system.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 7. Electrostatic Sensitive Devices (ESD) and their protection from Static Electricity. a. Electronic Card Files and the connectors on LRU boxes may be sensitive to static electricity.

b. As this damage accumulates, it can result in devices which malfunction intermittently. Over time, these will damage the circuit to the point where the device may no longer function. Static induced damage is responsible for a large portion of No Fault Found (NFF) findings by shop personnel. c. Always use ESD bags to transport and store, always use a wrist grounding strap when handling cardfiles and only use conductive caps (gray) for covering connectors on electronic boxes.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 d. Use of a circuit breaker as a switch is not recommended. Repeated opening and closing of contacts can lead to damage and premature failure of circuit breakers Most circuit breaker failures are latent

OVERHEAT – damage to wiring or insulation from high operating temperature

Switches and C/Bs often deteriorate internally, causing high temperatures seen in discoloration of insulation or sleeving.

C/B held in allowed the circuit current to become excessive. This caused so much heat that the insulation failed, which started a small fire that damaged several other wires in the same harness.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 B. Tools for EWIS and their uses 1. Like every other system on an airplane, EWIS has specialized tooling. This tooling can be divided into two types, based on its purpose. EWIS Tooling is used to either maintain or repair wiring, or it is used to measure voltage, current, or resistance in the wiring. Most repairs to EWIS wiring require crimping new connectors or splices into the wire harness. We will now discuss some aspects of crimp tooling. 2. Nearly all wires in a EWIS have crimped terminations. There are three common terminals used:

3. Pins and sockets are crimped with the turret crimper. Its name comes from the turret-like adapter which is used to hold the pin or socket during crimping. The turret works with the tool to properly set the depth of the wire into the pin or socket, resulting in a mechanically tight crimp.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 4. The crimp tool used for ring terminals has two jaws. One crimps the insulation (red dot, photo below) and the other crimps the conductor (yellow dot). Like the turret crimp tool used for pins and sockets, the handle ratchets and will not release until proper crimping force is reached.

NOTE: Aviation Ring Terminals have translucent insulating sleeves. Automotive ring terminals have opaque insulating sleeves.

DO NOT USE PLIERS OR VICE-GRIPS!! C. Electrical Measuring Instrument Calibration 1. Maintenance and repair of EWIS requires the AMT to use many types of measuring devices. These include Multimeters, meggers, FQIS capacitance measuring tools, and other equipment.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 2. Meter Usage. a. It is important that to remember improper meter usage can not only damage the meter, but it can also damage the LRU, could possibly lead to injury or death and ignite fuel gases.

Probe melted by unexpected voltage

Meter damaged by improper use (set to voltage in series with source)

Ammeter melted by improperly changing settings while measuring the circuit; two workers killed

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 b. This chart provides a summary of proper meter usage. METER TYPE

USED FOR MEASURING

HOW INSERTED INTO CIRCUIT

VOLTMETER

VOLTAGE

PARALLEL WITH THE SOURCE

AMMETER (AMP METER)

CURRENT OR AMPERAGE

SERIES WITH THE SOURCE

OHMMETER

CONTINUITY

NO POWER ON CIRCUIT, BETWEEN POINTS

MEGGER

INSULATION SHORT TO GROUND

NO POWER ON CIRCUIT, BETWEEN POINTS

1). The important thing for AMTs to remember about each of these tools is that they must be calibrated and any calibrated device will have a calibration record sticker (Form 3-17) attached. It is the AMT’s responsibility to ensure the device being used is within its calibration date.

3. LRU Removal and Replacement. a. Whenever an LRU is removed and replaced, care must be used to ensure that damage is not done to the LRU or the airplane rack connector. This includes ESD damage. AMM 20-10-01 gives instructions on LRU and cardfile removals. b. Always remove power from the circuit or system before removing LRUs from the airplane. “Hot racking” not only causes unnecessary damage to the components, but it could expose you to the possibility of injury.


Wiring Practices Documents and Documentation A. Manufacturers have created specific manuals to use and to maintain the airplane’s EWIS. In this module, we will take a look at the following: 1. Wiring Diagram Manual (WDM). 2. AMM ATA 20 – Standard Practices has been superseded by the Standard Wiring Practices Manual (SWPM)

3. The Wiring Diagram Manual, or WDM, is intended to be the source document for all wiring on the airplane. In theory, the WDM contains all modifications to the airplanes’ wiring. However, be aware that not every operator has notified the manufacturer that modifications and alterations to a particular airplanes’ EWIS have taken place. Thus the WDM may not be correct in all cases.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 4. In short, the WDM is a great tool and the proper place to start when researching a suspected wiring problem, but each airplane must be treated as an individual. The AMT cannot be surprised at variations between airplanes, especially those airplanes with several past operators. 5. The WDM FRONT MATTER has a MANUAL USAGE section. It also tells you how to use the WDM. The MANUAL USAGE section gives AMTs examples to try to help gain understanding in how the WDM works.

6. The FRONT MATTER will tell you important information about how to use the manual. This is the MANUAL USAGE SECTION.

This note tells us that ATA 20 has been replaced by the Standard Wiring Practices Manual. We will look at the SWPM later in this module.


This section tells us how to identify pages that a customer has asked to be changed, say to incorporate an E.O.

This section tells us how to identify wires that a customer has added to an existing bundle or an entirely customer produced bundle


The WIRE LIST USAGE. This section explains how to read the various tables which document what each wire is actually used for. 7. The WDM has a section in Chapter 91 called the Wire List (91-21-11). Although it does not list all the same information as to wire function, it does give the location and routing of the wire bundles, as well as the disconnects, length, Wiring Diagram, wire identification number, gauge, and terminations.


The WDM FRONT MATTER Introduction has a section named CODES which lists all Vendor and terminal information.


The WDM has several pages of electrical symbols. These are found in Chapter 00 General 00-00-00 SYMBOLS

The 757 SWPM has information available in Section 20-00-13 WIRE TYPE CODES, Tables 1 and 2. Make sure you are reading the column for the 757.


The Equipment list is located in Chapter 91 of the 757 SWPM. It is an alphabetically arranged list of the Equipment by number. It gives the Part Number, the Drawing Number, the diagram number, a description of the part, its vendor, quantity, location and effectivity.

The WDM also has a Service Bulletin List. It is located in the FRONT MATTER. This lists all ATAs Service Bulletins together. The list does not describe which airplanes have incorporated the SB, only if the complete fleet has been modified.


The WDM has information at the beginning of each ATA in the CONTENTS section. The CONTENTS is broken into various topics, and all the wiring diagrams for that topic are listed along with the diagram number, date and effectivity.

Additionally, the WDM has an ALPHABETICAL INDEX at the beginning of each ATA Chapter. This index lists the titles of all the wiring diagrams in that ATA Chapter in alphabetic order, with the diagram number.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 8. Wiring Diagrams. Wiring Diagram Title

Wiring Diagram number, page and sheet information

Wiring Diagram Effectivity 9. The other manual designed to help maintain the EWIS is the Standard Wiring Practices Manual, or SWPM.


The SWPM has a Table of Contents in their FRONT MATTER.


EWIS Inspection A. This Module will briefly discuss best Inspection Practices for EWIS, types of Inspection, Inspection tools, procedures and standards, human factors in Inspection, zonal inspection practices, and the identification of typical EWIS damage. 1. Inspection of the EWIS takes the form of one of five types of inspections: a. General Visual Inspection (GVI). b. Detailed Inspection (DET). c. Special Detailed Inspection (SDI). d. Zonal Inspection (Zonal).

GVI DET SDI Zonal EZAP

e. Enhanced Zonal Analysis Procedure (EZAP). B. Inspection practices.

1. General Visual Inspection – A visual examination of the interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. The inspection is usually made from touching distance. This level of inspection uses normally available light (daylight, hangar lighting, flashlight or droplight). Removal or opening of panels or doors may be required. Stands, platforms or ladders may be required to gain access to the area being inspected.

GV I

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 2. Detailed Inspection – An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. This level of inspection uses normally available light supplemented by a direct source of good light as deemed necessary. Inspection aids such as mirrors and magnifying lenses may be necessary. Surface cleaning and elaborate access procedures may be required.

DET

3. Special Detailed Inspection – An intensive examination of a specific item, installation, or assembly to detect obvious damage, failure, or irregularity. The examination is likely to make extensive use of specialized inspection techniques and / or equipment. Intricate cleaning and substantial access or disassembly procedures may be required.

SDI

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 4. Zonal Inspection –This is a collective term comprising selected GVIs and visual checks that are applied to each zone of the airplane to check system and powerplant installations and structure for security and general condition. A zonal inspection is essentially a GVI of an area or zone to detect obvious discrepancies. Unlike a stand-alone GVI, it is not directed to any specified component or assembly.

Zonal

5. EZAP – Enhanced Zonal Analysis Procedure. This is a process used to identify tasks which will minimize the accumulation of combustible materials near EWIS, detect EWIS component defects and detect EWIS installation errors that might not be reliably detected by other inspections.

EZAP

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 C. Human Factors and Inspections. 1. It is important to understand the effect that Human Factors can play during an Inspection of an aircraft’s EWIS. The quality of the inspection performed can be greatly impacted by Human Factors.

Human Factors deals with the psychological, social, physical, biological and safety characteristics of a user and the system the user is in. 2. There could be several Human Factors responsible for this incident:  was the mechanic so tired he forgot to depressurize the system?  was the line mis-fabricated?  was there poor QA at the shop level?  was the wrong P/N line installed?

Human Factors studies incidents such as this to try and determine the root cause and introduce changes in processes and procedures to prevent them occurring again.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. There could be several Human Factors responsible for this incident:  If the area is too cold, does the Inspector need a coat? Would a coat be too bulky for the area he must inspect? If it is too warm, does he need ventilation?  does he have proper lighting? Is there a power source nearby for a drop light or stanchion light?  does he have a ladder or man-lift to gain access to the area?  is the area clean enough to allow for a proper inspection?  is the inspector physically able to enter the space?

D. Typical EWIS Damage. 1. We will now look at various forms of damage which EWIS can incur. Although the following pictures are extreme examples, they are real photos taken on commercial transport category airplanes over the past several years. Proper EWIS inspection techniques may have prevented some of these from occurring. We will look at examples of chafing, mechanically induced damage, overheat, fluid damage, corrosion and hot air damage. 2. Wiring Routing. a. Eliminate potential for chafing against structure or other components. b. Position to eliminate/minimize use as handhold or support. c. Minimize exposure to damage by maintenance crews or shifting cargo. d. Avoid battery electrolytes or other corrosive fluids.


IMPROPER

PROPER

Wire bundles that cross should be secured together to avoid chafing.

IMPROPER

PROPER

If the grommet is too short, then there is wire bundle chafing. EWIS as a HANDHOLD

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 e. Protect wires in wheel wells and other exposed areas. f. Route wires above fluid lines, if practical. g. Use drip loops to control fluids or condensed moisture. h. Keep slack to allow maintenance and prevent mechanical strain.

Path of exposed end

Broken wire shall not make contact with fluid line EWIS Bundles Above Fluid Lines

Wires improperly tied, riding on hydraulic lines, contaminated with caustic fluid


OXYGEN LINE

BEFORE

AFTER

Figure 8 loop may be located before or after tail of Y Wire bundle breakout

Head of strap shall not be located in this area or touching anything

Wire bundle breakouts. There are three basic wire bundle breakout types used in routing aircraft wiring. They are called the “Y,” “T,” and Complex types. The “Y” type of breakout is used when a portion of wiring from one direction of the wire bundle departs the bundle to be routed in another direction. Care should be taken when plastic tie wraps are used to provide wire containment at the breakout so that the tie wrap head does not cause chafing damage to the wire bundle at the breakout junction.


A Complex type of breakout is generally used to route certain wires out of a wire bundle to a terminal strip, module block, or other termination. For all types of breakouts, there should be sufficient slack in the wires that are being broken out of the bundle to avoid strain on the wire between the wire bundle and the termination. 3. Stand-offs. a. Use stand-offs to maintain clearance between wires and structure. 1). Employing tape or tubing is generally not acceptable as an alternative. b. Exception: Where impossible to install off-angle clamps to maintain wiring separation in holes, bulkheads, floors, etc.

IMPROPER

PROPER


Bundle riding on structure

Wire bundle riding on control cable 4. Clamping. a. Support wires by suitable clamps, grommets, or other devices at intervals of not more than 24 inches. b. Supporting devices should be of suitable size and type with wire and/or cables held securely in place without damage to wire or wire insulation.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 c. Wire bundles should be snug in clamp (no movement). 1). Cable not able to move axially d. RF cables: do not crush. e. Mount clamps with attachment hardware on top. f. Tying not used as alternative to clamping. Example of Correct Cable Slack

Appropriate slack

Clamp Distortion

Correct clamp position

Incorrect clamp position

Distortion of rubber on clamp is NOT acceptable


90±5°

Incorrect

Correct

Correct

Incorrect

90±5° Clamp Orientation

Clamp Distortion

support bracket

snap-in tie mount release tab Plastic Snap-in Clamp (Tie Mount)

tail


Rubber cushion

Stand off

No pinching

All wires contained in rubber cushion

Incorrect Clamp tab

Clamp slot Engage Clamp Tab in Slot

Correct


Open-faced nylon clamp with cable build-up (missing hardware)

IMPROPER

PROPER

5. Wire Bend Radii. a. Minimum bend radius - 10 times the outside diameter of the largest wire or cable in the group — unsupported. b. Exceptions: 1). Terminations/reversing direction in bundle (supported at both ends of loop) - 3 times the diameter. 2). RF cables - 6 times the diameter. 3). Thermocouple wire - 20 times the diameter.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 Minimum Bend Radii

No support at end of bend

Min. bend radius - 10 x diameter of wire or cable

Min. bend radius 3 x diameter of wire

Diameter of wire or cable

Bend radii okay- Greater than 3 times diameter (secured at both ends of loop)

Bend radii problem- Less than 3 times the diameter

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 6. Damage. a. Mechanically Induced – damage to the EWIS from items external to it.

1). Connectors broken during maintenance checks, most likely by tooling or stands being run into them.

Missing strain relief caused intermittent contact issue.

b. Overheat – damage to wiring or insulation from high operating temperature.

1). Switches and C/Bs often deteriorate internally, causing high temperatures seen in discoloration of insulation or sleeving. 2). A C/B held in allowed the circuit current to become excessive. This caused so much heat that the insulation failed, which started a small fire that damaged several other wires in the same harness.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 c. Fluid Contamination – Skydrol, some greases, and turbine oils can damage insulation.

1). Insulation dried and cracked due to exposure to turbine oil. d. Corrosion – will cause the degradation of the Cannon plug and internal pins and sockets.

1). Corroded grounding points will fail more quickly, leading to EWIS faults.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 e. High Heat – from bleed air or other sources can damage insulation.

1). Even a slightly elevated temperature acting over a long period of time can cause damage to the EWIS. f. FOD – Foreign Object Debris may take many forms already discussed. Dust, tools, food particles, etc. must be removed from the EWIS to reduce the possibilities of fires. Always use the cleaning methods called out in the SWPMs.

g. GROUNDS AND BONDING STRAPS – check that grounds are secure and free from corrosion.


Module 4 Housekeeping A. “Protect and clean as you go” philosophy. 1. This philosophy is applied to airplane EWIS through inclusion in operators’ maintenance and training programs. 2. This philosophy stresses the importance of protective measures when working on or around wire bundles, connectors, and other EWIS components. 3. It stresses how important it is to protect EWIS during structural repairs, STC installations, or other alterations by making sure that metal shavings, debris, and contamination resulting from such work are removed. 4. The “protect and clean as you go” philosophy is translated into specifics by the protection and caution recommendations described in section 15 of FAA Advisory Circular AC25-27A. B. It is important for the AMT to recognize the various types of external contamination an airplane is exposed to during operation. Examples are: 1. Deicing fluid. 2. Water and rain. 3. Snow and ice. 4. Air erosion. 5. Lavatory leaks. 6. Galley drain leaks. 7. HAZMAT spills. C. Each of these contaminants can contribute to the degradation of wiring and EWIS components. Leaks of any of the above fluids must be repaired and the EWIS cleaned properly to reduce the effects of the contaminants. Water, rain, snow, ice and air erosion damages are especially common in areas exposed to the elements such as wheel wells, wing leading and trailing edges, etc.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 D. Additionally, there are contaminants internal of the airplane which can also degrade EWIS. These include but are not limited to: 1. Hydraulic fluid. 2. Turbine oil. 3. Fuel. 4. Lint & dust. 5. Bleed air. E. Maintenance of the airplane can itself cause contamination of the EWIS and surrounding areas. This can be in the form of the following: 1. Paint. 2. Corrosion inhibitor. 3. Metal shavings (swarf). 4. Foreign objects (dropped hardware, tooling etc.).

Swarf: A term used to describe the metal particles, generated from drilling and machining operations. Such particles may accumulate on and between wires within a wire bundle.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 F. Per Advisory Circular AC 25-27A – “Do not allow debris such as drill shavings, liberated fastener pieces, broken drill bits, and so forth, to contaminate or penetrate wiring, other EWIS components, or electrical components. 1. This can cause damage to insulation and potential arcing by providing a conductive path to ground or a conductive path between two or more wires of different loads.

“Protect and clean as you go” – instructions are found in 757 SWPM 20-00-08 PROTECTION DURING MAINTENANCE.

2. Picture of generator cables that were affected by poor housekeeping.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. Like this!! Actual picture from the E & E compartment of an ATI airplane………

G. The 757 SWPM’s instructions for EWIS protection in 20-00-08 also requires the AMT to determine which types of contaminants are likely to be found during maintenance and to protect the EWIS based on this evaluation. 1. Protection consists or wrapping the EWIS with greaseproof waterproof barrier material, Kraft paper, or polyethylene film. 2. Before removing the protection, ensure all contaminates are collected from the EWIS area.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. Per Advisory Circular AC 25-27A – “Areas to be inspected should be clean enough to minimize the possibility that collected dirt, grease, or other contaminants might hide unsatisfactory conditions that would otherwise be detected during inspection. .

The 757 SWPM 20-10-04 Cleaning of Wire Harnesses based on the wiring and contamination types

H. Protection and Caution Recommendations.. 1. You should take special care to minimize disturbance of existing adjacent wiring and other EWIS components during maintenance activities. When EWIS is displaced during a maintenance activity, special attention should be given to returning it to its normal configuration in accordance with the applicable maintenance instructions. 2. Structural repairs and STC installations inevitably introduce tooling and residual debris that is harmful to airplane wiring and other EWIS components. They often require displacement or removal of EWIS to provide access to the work area. Even minor displacement of wiring, especially while clamped, can damage its insulation and result in degraded performance, leading to subsequent arcing or circuit failure.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. Avoid drilling blindly into the airplane structure. Damage to wire insulation could cause arcing, fire, and smoke. Carefully cover or displace EWIS located adjacent to drilling or riveting operations to reduce the possibility of mechanical damage.. 4. Do not allow debris such as drill shavings, liberated fastener pieces, broken drill bits, and so forth, to contaminate or penetrate wiring, other EWIS components, or electrical components. This can cause damage to insulation and potential arcing by providing a conductive path to ground or a conductive path between two or more wires of different loads.. 5. Drills equipped with vacuum aspiration can be used to minimize risk of metallic debris contaminating wire bundles or other EWIS components. When work is completed, clean electrical components, wiring, and other EWIS components in accordance with the applicable maintenance instructions.. 6. When entering the airplane or working on it, use care to prevent damage to adjacent EWIS components, including wiring or other EWIS components that may be hidden from view (for example, covered by insulation blankets). Use protective boards or platforms for adequate support and protection. Avoid using wire bundles as handholds, steps, and supports. Do not use wiring to hang or support work lights. If wiring must be displaced or removed for work area access, it should be adequately released from its clamping or other restraining provisions to allow movement without damage, and it should be returned to position after work is completed.


Module 5 Wire Identification and Properties A. Wire Identification and Properties. 1. Before beginning a repair to the EWIS, it is important for the AMT to be able to use the manufacturer’s data to determine the type of wire to be used. When performing modification or alteration to a EWIS, engineering drawings must also call out for the best wire type to be used. Thus knowledge of the different types of wire available and how to identify them is an important part of any EWIS maintenance.

2. Wire has two main components: a. Conductor – Can be several different materials such as tin coated copper, high conductivity copper alloys, sliver, aluminum, or nickel. b. Insulating Material – Kapton, Polyalkene / Kynar, Teflon / Polyimide / composite, BMS 13-48 composite.

All aircraft wire will be of the stranded conductor type

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. Many airplane wires are shielded. A shield supplies the necessary protection for the wires and equipment when it transmits unwanted energy from the conductors in the shield to the airplane electrical ground.

4. These are just a few of the many types of shield terminations available. Always use the shield connection instructions in the SWPM 20-10-15.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 5. There are many varieties of shielded wires. Some examples have: a. One layer of shield material. b. more than one layer of shield material. c. Insulation on top of the shield. d. No insulation on top of the shield. e. Insulation between the shields.

6. The energy induced from the current in the conductors passes: a. From the shield to the plug connector strain relief to the backshell. b. From the backshell to the plug connector. c. From the plug connector to the receptacle connector. d. From the receptacle connector to the ground of the airplane structure. e. Insulation between the shields.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 7. Areas on the airplane require a particular type of wire due to conditions such as: a. High temperature. b. High vibration. c. Severe Wind and Moisture Prone (SWAMP) unpressurized areas.

B757 SWPM 20-02-20 temperature areas

B757 SWPM 20-02-30 vibration areas


The 757 WDM also has a graphic which shows the SWAMP areas and the High Temperature areas. This is found in WDM 91-01-01 page 1 WIRE ZONES.

B. Insulation Identification and Properties. 1. Although there are many types of wire insulation available, there are primarily three types of wire insulation: a. Kapton. b. Cross Linked Tezel. c. TKT (Teflon/Kapton/Teflon Boeing. Note: These are the production wires used by Boeing. Modifications and engineering changes may use other types of wire. Always verify the wire type with approved data. 2. Kapton wire insulation is made of a complex aromatic polyamide. It was popular from the mid-1960’s through 1992. Kapton is a very thin, lightweight material with a high ignition temperature. a. As it ages, Kapton will dry out, forming hairline cracks which can eventually lead to short circuits. It is a very hard material, so it is prone to chafing and it will abrade other wires.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. Cross Linked Tezel. Also known as ‘Spec 55”, this insulation was developed in 1977. It is a little thicker than Kapton, but is still considered lightweight. a. It was used in 757s between 1990 and 1992. It is a soft material that will lose its mechanical strength properties at its rated temperature of 150o C. 4. TKT Boeing (Teflon/Kapton/Teflon) was introduced in 1992. It is a lightweight insulation material, with abrasion and arc-track resistance. a. It has a high heat tolerance and resists smoking while burning. It has all of Kapton’s positive qualities with none of the negatives. b. There have been no known problems with TKT Boeing. C. Inspection criterion for wire and wire bundles. 1. When inspecting wire and wire bundles there are many issues to be aware of. Any of these, if allowed to continue, can lead to damage of the EWIS, critical failure of the system, or catastrophic fire. 2. It is important understand the concept behind the proper installation of wiring and wiring bundles. There are specific methods which are used to ensure that the EWIS is not harmed and that the systems’ performance does not suffer due to the routing and installation of the bundles.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. Per the 757 SWPM 20-10-19, Aircraft wiring is designed and installed: a. To prevent the propagation of the effects of electrical faults to other independent power sources. This is accomplished by source separation, non-paralleling of generators, and break-power transfers. b. To prevent possibility that the failure of a component in a redundant system can disable another related redundant system. This is accomplished through redundant wiring circuits. c. To avoid electromagnetic interference (EMI) between electromagnetic compatibility (EMC) circuits that is not compatible. This is accomplished by physical separation of the circuits or by shielding. 4. Also per the 757 SWPM 20-10-19, Types of separation: a. Separation between independent power sources. (Functional Separation). b. Separation between redundant system circuits. (Functional Separation). c. Separation between EMC circuits that is not compatible. (Electromagnetic Separation). D. Repair of damaged Wiring or Cable. 1. When repairing wire or cable you must take into consideration several things to ensure that the correct repair method is utilized. a. Type of wire or cable needing repair. b. Location of the wire or cable on the aircraft. c. Type of aircraft system with the damaged wire/cable.


Instructions for the repair of electrical wire in the EWIS are found in the SWPM. For the757, use SWPM 20-10-13

2. Type of wire or cable needing repair: a. The environment surrounding the damaged wire or cable often times will require specific repair procedures be followed to ensure that the integrity of the wiring repair is maintained. Examples include: 1). Pressurized or unpressurized areas. 2). High vibration areas; engines, stabilizers, wings. 3). High temperature areas; engines and APU compartment. 4). SWAMP (Severe Wind and Moisture Prone) areas. 5). Fuel vapor areas: engines, APU compartment, leading and trailing edges of wings, pylons and MLG wheel wells. 3. Type of aircraft system with the damaged wire/cable: a. Repairs are not allowed to the wires or cables of some aircraft systems and the damaged wire or cable will require replacement. b. Examples include generator feeder cables and radio altimeter coax. c. Original generator feeder cable splices can be repaired or replaced, per the SWPM. d. Cable replacement is required when damage is beyond the limits of conductor strand damage.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 E. General conditions for the repair of wire or cable. 1. The condition that caused damage must be corrected. 2. Repairs must be done with clean hands/tools to prevent contamination which will cause a bad seal of the insulation materials. 3. Repairs are permanent unless specified differently. 4. Repairs in fuel vapor area must be applicable for a fuel vapor area. 5. Repairs inside a fuel tank must adhere to the Airworthiness Limitation Precautions and Critical Design Configuration Control Limitations. F. These conditions are applicable for the location of the repair. 1. Must not be in a conduit. 2. Must not be put in a connector backshell. 3. Must not be put on a bend of a wire or cable. 4. Must not be put on a wire harness where the wire harness is frequently bent. (instrument panel, etc.). G. General conditions for the selection of parts and materials for a repair: 1. Temperature grade of insulation materials for repair of wire or jacket of cable must be the same as or higher than the temperature grade of the wire or cable. 2. Temperature grade of metal components for repair of wire or cable must be the same as temperature grade of the wire or cable. 3. Temperature grade of materials used to repair wire or cable in high temperature area must be temp grade D. 4. If necessary to repair damage of wire or cable with a segment of wire or cable, segment must have same P/N as the damaged wire or cable. H. Splice Repair. 1. General conditions for repair of wire or cable with a splice: a. All splice assemblies must have a moisture resistant sealed configuration. (environmental). b. A general purpose low temp wire can have a maximum of 3 splices, not including splices installed during production.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 I. Sleeving. 1. Sleeving is used to protect wires and bundles. Sleeving may take the form of heatshrink tubing around splices. It can also be added to existing bundles in the form of spiral-wrap and fiberglass wrap.

The SWPM gives detailed instructions on how to install various types of sleeving on wire bundles.

J. Capping and Stowage of Unused Wires. 1. Many times there are unused wires in bundles. These are unused for many reasons, including: a. Provisional for future installations. b. Left in the bundle when equipment is removed or de-activated. 2. It is not uncommon for the manufacturer to include spare wires in bundles during manufacture as a means to aid in reducing aircraft on ground (AOG) time. The spare wires can be used for repairs rather than requiring the running of new wire in a harness. a. Wires that are not in use by the EWIS must be properly capped and stowed to preserve the integrity of the wire and protect it and the EWIS from damage such as corrosion.


b. The symbol for a capped and stowed wire, this is from the 757 Wiring Diagrams. c. The 757 SWPM 20-30-16 gives detailed instructions on the best methods to follow when capping and stowing wires. K. Electrical Grounds and Bonding. 1. One of the most important parts of the EWIS and one that often get over looked is grounding. A proper ground and bonding helps to ensure many aspects of the EWIS operate correctly, including: a. Reduction or elimination of radio noise. b. Reduction or elimination of interference with navigation systems. c. Reduction or elimination of corrosion at the grounding point prevention of overheating due to a high-resistance ground. 2. Proper grounding of EWIS involved in Fuel Quantity Indication Systems (FQIS) and fuel distribution systems (pumps, tubing, valves, etc.) is required by SFAR 88.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 L. Electrical Bond. 1. A stable connection between two objects that has the result of electrical conductivity between those objects. 2. Electrical bonding is very important for lightning protection as well as ensuring that certain components operate properly. 3. Bonding involves ensuring that extremely low resistance between EWIS components exists. This is usually done with a megger or a bonding meter. 4. There are three basic types of electrical bonds: a. Inherent Bond: Bonds that do not require removal of non-conductive finishes from the mating surfaces prior to bonding. When the materials that are used and the assembly procedure gives the low resistance junction without special installation procedures; included are parts that are welded, brazed, sweated, or swaged; also included are major structural components that are attached by a large number of fasteners. b. Metal to Metal Bond: Bonds that require removal of nonconductive finishes from the mating surfaces prior to bonding. c. Metal to Composite Bond: Bonds that require removal of nonconductive finishes, loose resin, and resin gloss from the mating surfaces prior to bonding. 5. You must remove all nonconductive finishes from bonded surfaces before assembly. 6. There are six classifications of bonding: a. Class A: Antenna Installation (RF). b. Class C: Current Path Return. c. Class H: Shock Hazard. d. Class L: Lightning Protection. e. Class R: RF Potentials. f. Class S: Static Charge. 7. The maximum resistance specified is not always through the same current path for each of the 6 classifications. Some are from the component to structure and others are only through the bond itself.


This chart from NASA (STD-4003) explains the different classes of bonds and their characteristics. Note that NASA does not list a CLASS A bond. 7. The SWPM lists the approved megohm meters for various bonding check tasks. Always refer to the SWPM 20-20-00 for the proper tool.


Module 6 Connector and Connections A. All EWIS utilize connectors to provide a means to hold wire sockets and pins together in mechanically tight contact, allowing the transmission of power and data from various LRUs such as sensors, displays, switches, instruments, computers, processors and illumination lamps. 1. Understanding the various types of connectors used, and how to identify damage and research repairs is an important part in maintaining the airplane’s EWIS. 2. The SWPM provides detailed instruction in the proper installation and repair of the connectors used in their EWIS. a. As there are literally dozens of different types of connectors made by nearly as many different manufacturers, this module cannot discuss every type. Always verify the proper connector type and manufacturer is being used by referencing approved data in the SWPM, IPC or Engineering Orders / Authorizations.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 3. The SWPM lists the various types of connector repair and installations beginning with SWPM 20-42 MATE-N-LOC CONNECTORS.

4. Before performing any work on a EWIS, always make sure to follow all safety guidelines as listed in the SWPM

WARNING: MAKE SURE ALL AIRCRAFT ELECTRICAL POWER IS OFF AND THE EXTERNAL POWER SOURCE IS OFF BEFORE YOU DO MAINTENANCE ON THE AIRCRAFT ELECTRICAL POWER CENTER (EPC). THE EPC HAS DANGEROUSLY HIGH VOLTAGE. HIGH VOLTAGE CAN KILL OR CAUSE INJURY TO PERSONS.


WARNING: BEFORE YOU REMOVE THE EXTERNAL POWER CONNECTOR, MAKE SURE THAT THE EXTERNAL POWER SOURCE IS SWITCHED OFF. FAILURE TO TURN OFF THE EXTERNAL POWER SOURCE CAN CAUSE INJURY TO PERSONNEL AND DAMAGE TO EQUIPMENT.

WARNING: ELECTRICALLY GROUND THE AIRCRAFT. MAKE SURE YOU PROPERLY CONNECT STATIC GROUND CABLES. THIS WILL PREVENT INJURY TO PERSONS AND DAMAGE TO THE EQUIPMENT WARNING: TAG AND USE SAFETY CLIPS TO SAFETY THE CIRCUIT BREAKERS. IF THE CIRCUIT BREAKERS ARE NOT OPENED, TAGGED AND SAFETIED, INJURY TO PERSONS AND EQUIPMENT CAN OCCUR. WARNING: MAKE SURE YOU PUT “DO NOT OPERATE” TAGS ON THE AIRCRAFT COMPONENT / SWITCH / CONTROL BEFORE YOU DO WORK ON THE AIRCRAFT. WARNING: DO NOT CLOSE THIS CIRCUIT BREAKER. THIS CIRCUIT BREAKER MUST REMAIN OPEN UNTIL COMPLETION OF MAINTENANCE WORK. WARNING: DO NOT MOVE THIS SWITCH FROM THE OFF POSITION UNTIL MAINTENANCE WORK HAS BEEN COMPLETED. WARNING: DO NOT RESET A TRIPPED CIRCUIT BREAKER UNTIL YOU KNOW THE CAUSE OF THE TRIPPED CIRCUIT BREAKER AND YOU KNOW THAT THE CIRCUIT BREAKER CAN BE SAFELY RESET. DAMAGE TO THE AIRPLANE AND INJURY TO THE PERSON CAN OCCUR.


Module 7 After Repair Tests and General Visual Inspection A. As with all maintenance actions, a ‘good fix’ must be proven by testing the repair. For EWIS, this not only means the system Operational or Functional tests, but many times it includes a check of the quality of the installation in the form of a bonding check. B. Bonding checks are performed to ensure that the components in the EWIS have little or no resistance between them. These tests are normally performed using a four probe bond meter.

1. The dual probes each have a “Potential” (red) lead and a “Current” (black) lead. It is vital to obtain a good contact on the surface being tested. Keep the probes perpendicular to the surface and press hard, especially on finished surfaces. The probe must contact the underlying metal.


2. The 757 SWPM 20-20-00 has a section called Maximum Permitted Resistance of Electrical Bonds. It has dozens of tables listing the maximum resistance values of various bonds.

The SWPM has a large number of drawings showing proper usage of the bonding meter for various assemblies and installations, even some not EWIS.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 C. After the EWIS has been repaired and the bonding tests are complete, it is likely necessary to do a functional or operational test of the affected systems. 1. Always verify the repair by performing the complete test as per the FIM and AMM as applicable. 2. Lastly, perform a GVI of the EWIS to ensure that the repaired area is secured, airworthy and has been returned to its proper configuration.

QUIZ Complete the attached examination using the answer sheet and complete the Certificate of Maintenance Training Form (M-011) and return the Training Certificate and answer sheet to ILN MX Training Department. (Scan/email or mail) 1. EWIS training is done in accordance with Advisory Circular? A. AC 120-194. B. SL 120-94. C. AC 120-94. D. EWIS is accomplished per FAR 120-94. 2. The objective of the EWIS training program is to ensure that proper processes, procedures, methods, techniques, and practices are used when performing maintenance, preventive maintenance, inspection, alteration, repair, and cleaning of EWIS. A. This statement is true. B. This statement is false. 3. EWIS is [per new FAR 25.1701(a)], any wire, wiring device, or combination of these, including termination devices, installed in any area of the airplane for the purpose of transmitting electrical energy between two or more intended termination points. A. This statement is true. B. This statement is false. 4. Why the need for wiring practices training? A. Aging Systems Program. B. Aging Transport Systems Rulemaking Advisory Committee (ATSRAC). C. All of the answers are correct. D. Accident Service History.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 5. In May 2001, the FAA released a Special Federal Aviation Regulation requiring all the airframe manufacturers and Supplemental Type Certificate (STC) holders conduct a safety review of the fuel tank system. Included were requirements to prepare special maintenance inspections and procedures that would be used to prevent the development of ignition sources in order to ensure the continued safety and airworthiness of the fuel. A. This known as FAR No. 88 requiring. B. This known as SFAR No. 88 requiring. C. This known as FAR 25.1701(a). D. This known as AC 120-94. 6. General safety practices: A. De-energize electrical systems. B. Bond the aircraft. C. All of the answers are correct. D. “LOCK OUT, TAG OUT”. 7. Nearly all wires in a EWIS have crimped terminations. There are three common terminals used. A. Sockets, pins and straight terminals. B. Rockets, pins and ring terminals. C. Pins, ring terminals and turret crimper. D. Pins, sockets and ring terminals. 8. The important thing for AMTs to remember about meters is that they must be calibrated and any calibrated device will have a calibration record sticker attached which is Form number? A. Form 3-17. B. Form 17-3. C. Form 33-117. D. Calibration sticker. 9. The Standard Wiring Practices Manual (SWPM) falls under which ATA? A. 20. B. 88. C. 06. D. The manual does not fall under the ATS system.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 10. Which section of the WDM tells you how to use the manual, identify wires, lists all vendor and terminals information, among other items……….? A. Wire usage section. B. Table of Contents. C. List of effective pages. D. Front Matter. 11. Inspection of the EWIS takes the falls into one of five types of inspections which are? A. General, Special, DET, Station and Easy. B. GVI, SDI, EZAP, Zonal and DET. C. Both B. and D. correct. D. GVI, SDI, EZAP, Zonal and Deleted. 12. Which inspection is an intensive examination of a specific item, installation, or assembly to detect obvious damage, failure, or irregularity? A. General Visual. B. Special Detailed Inspection. C. The Deleted Inspection. D. The Zonal Inspection. 13. This is a collective term comprising selected GVIs and visual checks that are applied to the airplane to check system and powerplant installations and structure for security and general condition. This inspection would be? A. General Visual. B. Special Detailed Inspection. C. The Deleted Inspection. D. The Zonal Inspection. 14. Typical EWIS Damage would consist of, but not limited to? A. Wiring Routing. B. Stand-offs. C. All of the answers are correct. D. Clamping. 15. Housekeeping pertains to? A. “Protect and clean as you go” philosophy. B. Only “Clean up after yourself”. C. “Protect and clean up after others”. D. Accounting for your tools.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 16. The correct answer to Question 15 stresses the importance of protective measures when working on or around wire bundles, connectors, and other EWIS components. A. This statement is true. B. This statement is false. 17. Wire has two main components, conductor and insulating material. And before beginning a repair to the EWIS, it is important for the AMT to be able to use the manufacturer’s data to determine the type of wire to be used A. This statement is true. B. This statement is false. 18. A component that is necessary protection for the wires and equipment when it transmits unwanted energy from the conductors in the shield to the airplane electrical ground would be? A. Bonding. B. Kapton protection. C. Shielding. D. Double wire mesh insulation. 19 When repairing wire or cable you must take into consideration several things to ensure that the correct repair method is utilized: Type of wire or cable needing repair. Location of the wire or cable on the aircraft. Type of aircraft system with the damaged wire/cable. A. This statement is true. B. This statement is false. 20. All EWIS utilize connectors to provide a means to hold wire sockets and pins together in mechanically tight contact, allowing the transmission of power and data from various LRUs such as sensors, displays, switches, instruments, computers, processors and illumination lamps. A. This statement is true. B. This statement is false. 21. It is important for the AMT to recognize the various types of external contamination an airplane is exposed to during operation. Examples are: A. Deicing fluid, water and rain. B. Snow and ice, air erosion. C. All are correct. D. Lavatory leaks, galley drain leaks.

AIR TRANSPORT INTERNATIONAL MAINTENANCE INFORMATION LETTER MIL 00-113 R2 22. Swarf…… A term used to describe? A. This term has been replaced with Housekeeping Clean As You Go. (HCYG). B. Metal particles, generated from drilling and machining operations. When not addressed, can lead to wire chaffing, arching of wires, etc. C. Swarf is not a term used in EWIS. D. Particles may accumulate on and between wires. 23. The 757 SWPM’s instructions for EWIS protection requires the AMT to determine which types of contaminants are likely to be found during maintenance and to protect the EWIS based on this evaluation. Protection consists of? A. Any material that is handy. B. Any material that will collect metal particles, generated from drilling and machining operations. C. Protection isn’t needed, just use a strong vacuum to clean the area. D. Wrapping the EWIS with greaseproof waterproof barrier material, Kraft paper, or polyethylene film is recommended. 24. Before removing the protection, ensure all contaminates are collected from the EWIS area. A. True. B. False.

25. Which of these statements are true? A. Even minor displacement of wiring, especially while clamped, can damage its insulation and result in degraded performance, leading to subsequent arcing or circuit failure. B. Drills equipped with vacuum aspiration can be used to minimize risk of metallic debris contaminating wire bundles or other EWIS components. C. Avoid drilling blindly into the airplane structure. D. You should take special care to minimize disturbance of existing adjacent wiring and other EWIS components during maintenance activities. E. Avoid using wire bundles as handholds, steps, and supports. Do not use wiring to hang or support work lights. F. All of the statements are true.

END OF QUIZ


CERTIFICATE OF MAINTENANCE TRAINING (FORM M-011) AIR TRANSPORT INTERNATIONAL NAME OF TRAINEE

EMP. NR.

JOB TITLE DATE(S): FROM

TO

AIRCRAFT/ENGINE TYPE HOURS:

OJT

ALL

3.0

LOCATION CLASSROOM

Trainee named above has received instruction as described below:

MIL 00-113 R2 Electrical Wiring Interconnection Systems (EWIS) Training

MAINTENANCE MANUAL REFERENCE(s):

ATI GMM AND THIS STUDY GUIDE

INSTRUCTOR'S COMMENTS:

NO FURTHER TRAINING REQUIRED

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SIGNATURES: (INSTRUCTOR)

(TRAINEE)

(After this form is signed, provide a copy to ILN MX Training)


MIL 00-113 R2 ANSWER SHEET NAME: ___________________________ Station ______ PRINT CLEARLY

A

B

C

D

1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. 18. 19 20. 21. 22. 23. 24 25.

E

F

Course EWIS 00-113

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