Aeng 513 - Easa Part 66 Module 7

EASA Part 66 Module 7: Maintenance Practices

 Aspects of safe working practices including precautions to take when working with electricity, gases especially oxygen, oils and chemicals. Also, instruction in the remedial action to be taken in the event of a fire or another accident with one or more of these hazards including knowledge on extinguishing agents.

2. Workshop Practices

 Care of tools, control of tools, use of workshop materials;

 Dimensions, allowances and tolerances, standards of workmanship;

 Calibration of tools and equipment, calibration standards.

3. Tools

 Common hand tool types;

 Common power tool types;

 Operation and use of precision measuring tools;

 Lubrication equipment and methods.

 Operation, function and use of electrical general test equipment;

4. Avionic General Test Equipment

 Operation, function and use of avionic general test equipment.

5. Engineering Drawings, Diagrams and Standards

 Drawing types and diagrams, their symbols, dimensions, tolerances and projections;

 Identifying title block information; Microfilm, microfiche and computerized presentations;

 Specification 100 of the Air Transport Association (ATA) of America;

 Aeronautical and other applicable standards including ISO, AN, MS, NAS and MIL;

6. Fits and Clearances

 Drill sizes for bolt holes, classes of fits;

 Common system of fits and clearances;

 Schedule of fits and clearances for aircraft and engines;

 Limits for bow, twist and wear;

 Standard methods for checking shafts, bearings and other parts.

7. Electrical Cables and Connectors

 Continuity, insulation and bonding techniques and testing;

 Use of crimp tools: hand and hydraulic operated;

 Testing of crimp joints;

 Connector pin removal and insertion;

 Co-axial cables: testing and installation precautions;

 Wiring protection techniques: Cable looming and loom support, cable clamps, protective sleeving techniques including heat shrink wrapping, shielding.

8. Riveting

 Riveted joints, rivet spacing and pitch;

 Tools used for riveting and dimpling;

 Inspection of riveted joints.

9. Pipes and Hoses

 Bending and belling/flaring aircraft pipes;

 Inspection and testing of aircraft pipes and hoses;

 Installation and clamping of pipes.

10. Springs

 Inspection and testing of springs.

11. Bearings

 Testing, cleaning and inspection of bearings;

 Lubrication requirements of bearings;

12. Transmissions

 Inspection of gears, backlash;

 Inspection of belts and pulleys, chains and sprockets;

 Inspection of screw jacks, lever devices, push-pull rod systems. 13. Control Cables

 Swaging of end fittings;

 Inspection and testing of control cables;

 Bowden cables; aircraft flexible control systems.

14. Material handling 14.1 Sheet Metal

 Marking out and calculation of bend allowance; sheet metal working, including bending and forming;

 Inspection of sheet metal work. 14.2 Composite and non-metallic

 Bonding practices;

 Environmental conditions

 Inspection methods

15. Welding, Brazing, Soldering and Bonding

15.1 Soldering methods; inspection of soldered joints. 15.2 Welding and brazing methods;

 Inspection of welded and brazed joints;

 Bonding methods and inspection of bonded joints.

16. Aircraft Weight and Balance

16.1 Centre of Gravity/Balance limits calculation: use of relevant documents; 16.2 Preparation of aircraft for weighing;

17. Aircraft Handling and Storage

 Aircraft taxiing/towing and associated safety precautions;

 Aircraft jacking, chocking, securing and associated safety precautions;

 Aircraft storage methods;

 Refueling/defueling procedures;

 De-icing/anti-icing procedures;

 Electrical, hydraulic and pneumatic ground supplies.

 Effects of environmental conditions on aircraft handling and operation.

18. Disassembly, Inspection, Repair and Assembly Techniques 18.1 Types of defects and visual inspection techniques;

 Corrosion removal, assessment and re-protection. 18.2 General repair methods, Structural Repair Manual;

 Ageing, fatigue and corrosion control programs;

18.3 Non-destructive inspection techniques including, penetrant, radiographic, eddy current, ultrasonic and borescope methods.

18.4 Disassembly and re-assembly techniques. 18.5 Trouble shooting techniques

19. Abnormal Events

19.1 Inspections following lightning strikes and HIRF penetration.

19.2 Inspections following abnormal events such as heavy landings and flight through turbulence.

20. Maintenance Procedures

 Maintenance planning;

 Modification procedures; Stores procedures;

 Certification/release procedures;

 Interface with aircraft operation;

 Maintenance Inspection/Quality Control/Quality Assurance;

 Additional maintenance procedures;

1. Safety Precautions – Aircraft and Workshop

Aspects of safe working practices including precautions to take when working with electricity, gases especially oxygen, oils and chemicals. Also, instruction in the remedial action to be taken in the event of a fire or another accident with one or more of these hazards including knowledge on extinguishing agents

Negative Effects of unsafe Maintenance System 1. increase operating costs

2. reduce efficiency and effectiveness

3. additional cost for the compensation of health insurances and training of employees

Aviation Maintenance Technicians Model Code of Conduct Main Responsibilities

• make safety their highest priority, • seek excellence in workmanship,

• develop and exercise good judgment, and apply sound principles of technical decision-making, • recognize and manage risks effectively,

• adhere to prudent operating practices and personal operating parameters (e.g., tolerances, limitations, and other human factors),

• advance professionalism,

• act with responsibility and courtesy,

• adhere to applicable laws and regulations, and • comply with training and performance requirements.

Sub Responsibilities

• maintain a safe work place environment,

• manage risk and avoid unnecessary risk to aircraft occupants, people and property on the surface, and people in other aircraft,

• brief team members on maintenance procedures and inform them of any significant or unusual risk associated with the task,

• avoid operations and behavior that may alarm or disturb aircraft occupants, people on the surface, or other third-parties.

PERSONAL MINIMUM CHECKLIST

- a checklist to ensure that the job done is right.

Hazard - anything with the potential to cause harm. Types of Hazard:

1. FIRE 2. CHEMICAL 3. ELECTRICITY 4. MACHINES

HANDLING ELECTRICITY

• Must have a working knowledge of the principles of electricity, and a healthy respect for its capability to do both work and damage.

• Wearing or use of proper safety equipment.

• Avoid water at all times when working with electricity. Never touch or try repairing any electrical equipment or circuits with wet hands. It increases the conductivity of electric current.

• Never use equipment with frayed cords, damaged insulation or broken plugs. • Always use insulated tools while working.

• Never try repairing energized equipment. Always check that it is de-energized first by using a tester.

• Always be observant of electrical hazards include exposed energized parts and unguarded electrical equipment

HANDLING HAZARDOUS CHEMICAL

• Wear proper equipment (gloves, respirator, face shield, chemical suit and goggles) • Identify the chemical being used through its label

• Follow the safety guidelines when using the chemical on its MSDS *Material Safety Data Sheet • Work must be done near emergency shower in case of contact on the eyes or skin.

• Segregate chemicals when disposing through the use of color code • When accident occur refer immediately to its MSDS

NFPA HAZARD IDENTIFICATION

Personal Protective Equipment

Consists of a glove, suit, goggle and face mask that is mainly used to protect the mechanic from hazards if contact through the body has occured.

HANDLING FIRE

Personal Protective Equipment

• Work in a secured location with a fire extinguisher nearby. • Wear your PPE *PERSONAL PROTECTIVE EQUIPMENT

• Ensure the material that will be subjected to the fire is safe and stored properly • Avoid smoking near flammable areas

• Flammable materials should be out of reach • Extinguish immediately the fire when not in use • Never overload circuits or extension cords on the shop • IF ALL ELSE FAILS SOUND THE ALARM

PROPER WAYY OF EXTINGUISHING THE FIRE

P – Pull the pin and hold the extinguisher with the nozzle pointing away from you. A – Aim low. Point the extinguisher at the base of the fire.

S – Squeeze the lever slowly and evenly. S – Sweep the nozzle from side to side

2. Workshop Practices

An understanding of aircraft workshop principles and practice is a fundamental requirement for those aircraft engineering technicians or engineers, irrespective of their chosen specialization.

This presentation will give learners an understanding of the safe working practices associated with aircraft workshop activities and the care, control and safe use of aircraft workshop tools and equipment. Learners will develop the skills needed to safely carry out tasks associated with aircraft Tools and Equipment. They will also gain the skills necessary to read and interpret engineering diagrams and drawings.

Care of Tools

- Good tools can be quite an investment, but if you keeping your tools properly stored, cleaned, and maintained it will maintain its effectiveness.

- Tools and equipment on the aircraft undergo rigorous handling. These tools are exposed to large amounts of dirt and abuse. Proper maintenance of tools and equipment is critical to preserving them for future use. Failure to maintain the tools properly results in unnecessary expense.

Example

 Clean the tools and equipment after each day's work. While a thorough cleaning is not required each day, a general wipe-down and removal of the heaviest co dirt is key to extending the life of the tools.

 Keep air lines and electrical cords protected from heavy foot-traffic and vehicles or other motorized machinery, can easily cut or crush cords and hoses, preventing the tools from w orking properly, and creating potential electrical hazards. Cover the electrical cords with purpose-built ramps or casing.

 Lubricate air tools and pneumatic equipment before each day's use. Condensation in the airline creates an environment for corrosion inside pneumatic tools. Coating the internal components of these tools with air-tool oil will displace the moisture and prevent tool corrosion.

 Inspect and repair all equipment and tools at the completion of each job. Make all repairs to the equipment that are necessary for future construction work. This will prevent time being wasted repairing faulty equipment at future use.

Tool Control

- Tool control is a method to quickly determine that all tools are accounted for at the end of a maintenance task. This can only be done if each tool has a specific place where it is stored that allows for quick identification if the tool is missing. There are several ways to do this

- Tool control affects safety. Leaving a tool in an aircraft or engine is not just an

inconvenience, it is a safety risk. Realizing this, most aircraft maintenance businesses enforce some sort of tool control procedures. They realize that establishing and enforcing a tool control program can provide numerous benefits, the foremost of which is safety.

Tool shadowing

This involves specifying a specific space for each tool. It should be designed in such a way as to quickly determine if a tool is missing. A popular method is to use some type of foam product and cut out spots for each tool. In a toolroom environment, walls can be used with pegboard and hooks. The item is then outlined and shadowed.

Tool identification

Some companies require employees permanently mark their tools for tool identification purposes. This provides a way to quickly identify who a tool belongs to when it is found. Tools can be marked using a vibra-peen tool. Some other marking methods such as permanent marker may not be very effective in a hangar environment.

Marking tools serves two purposes. First of all, it ensures that if a tool is found it is returned to the owner. Second, it helps assure compliance with missing tool reporting. It makes employees become more vigilant in reporting missing tools vs. just going to the closest tool truck or store to buy a replacement.

Tool inventory

A tool inventory should be accomplished on a regular basis so that any missing tools can quickly be identified

and searched for before they affect the safety of an aircraft. This can be done after each work task or at least once a day. Many companies choose to do it at the beginning and end of each shift.

Tool inspection

An important part of tool control that can easily be overlooked is tool inspection. Tools should be inspected before and after each use to ensure they are in proper working order and no parts are missing. If this is not done, it can be easy for a piece of a tool to be left behind in a work area. David Smith, director of quality assurance, U.S. maintenance for Jet Aviation, discusses his company’s tool inspection requirement. “We require mechanics to inspect all tools and equipment before and after each use. This is written in our standard operating procedures manual. This policy helps ensure that no pieces from a broken tool are left in an aircraft or engine after maintenance is performed.”

Missing tool reporting

An important part of any tool control program is a process for missing tool reporting. In order to achieve the goal of accounting for all tools to ensure a safe product for the customer, a culture must be present that encourages employees to report any missing tool. This procedure should be clear as to how often tools need to be inventoried, how the employee should report a missing tool, and the steps to be taken once a missing tool is reported. An important part of this is the person who has the authority to release the aircraft in the event a missing tool is not found.

RFID Tool Control

3M has introduced a tool control solution using radio frequency identification (RFID) to the marketplace. This tool tracking solution was announced at the NBAA convention this past November. The RFID tool tracking system includes tracking software, RFID tags with protective labels, and RFID handheld readers. The system is currently being installed at The Nordam Group’s Tulsa, Oklahoma, facility. Dr. Sandra Tokach, general manager for 3M’s Aerospace and Aircraft Maintenance Division, says, “For aerospace manufacturers and MRO providers alike, systems that use RFID will bring much-needed efficiencies across a wide array of processes; in NORDAM’s case, for tool tracking.”

API

API recently introduced Electronic Supply Program (ESP) to the market. This is an Internet-based software program that uses and allows customers to automate inventory control and parts replenishment. As an added feature, ESP also has a tool control module. This module allows tools to be tracked according to a customer’s needs — whether it is by work order, N-number, or employee number. It can also track tool calibration requirements and send email alerts when a tool is approaching a calibration due date.

In the end, each company must select a tool control program that works

best for its needs. Whether it is a matter of shadowing toolboxes or an investment in an automated tool control system, keeping track of tools is a safety issue that shouldn’t be ignored.

Dimensions, Allowance, and Tolerance Dimensions

The dimension of an object is a topological measure of the size of its covering properties. Roughly speaking, it is the number of coordinates needed to specify a point on the object. For example, a rectangle is two-dimensional, while a cube is three-dimensional. The dimension of an object is sometimes also called its "dimensionality."

Allowance

An allowance is a planned deviation between an actual dimension and a nominal or theoretical dimension, or between an intermediate-stage dimension and an intended final dimension. The unifying abstract concept is that a certain amount of difference allows for some known factor of compensation or interference. An allowance, which is a planned deviation from an ideal, is contrasted with a tolerance, which accounts for expected but unplanned deviations.

Tolerance

Dimensions, properties, or conditions may vary within certain practical limits without significantly affecting functioning of equipment or a process. Tolerances are specified to allow reasonable leeway for imperfections and inherent variability without compromising performance.

A variation beyond the tolerance (for example, a temperature that's too hot or too cold) is said to be non-compliant, rejected, or exceeding the tolerance (regardless of if this breach was of the lower or the upper bound). If the tolerance is set too restrictive, resulting in most objects run by it being rejected, it is said to be intolerant.

Example:

All measuring devices and test equipment will:

1. Meet any requirements published by the manufacturer of the measuring device with respect to accuracy.

2. Meet any calibration requirements that are published by the tool manufacturer. 3. Be inspected before use.

4. Any tool suspected of inaccuracy or damage, despite meeting any other requirements, will be taken out of service, repaired and calibrated, or replaced.

5. Where calibration is required, be calibrated in accordance with a national standard.

6. Each precision tool will have a calibration sticker attached. Records relating to the calibration of the tool will be retained on file.

All tools and equipment requiring calibration will be listed on a status board in the organization office. The status board will contain:

 Name of tool

 Serial number of tool

 Date last calibrated

3. Tools Common hand tool types

Pounding Tools Punches Holding Tools Cutting Tools Turning Tools Inspection Tools

Common power tool types Screwdriver

Drill

Riveting gun

Precision measuring tools Vernier

Micrometer Tape measure Multimeter

Lubrication equipment and methods.

• Lubrication needle nozzles - in aircrafts many grease points are of flush type, countersunk in the construction. These flush type grease points can’t be lubricated with a standard hydraulic coupler, and a special lubrication needle nozzle is needed.

• Extension tubes - used to connect a needle nozzles or hydraulic couplers to a grease gun. The extensions are produced from heavy-wall steel tubing.

• Extension hoses - used to create a flexible connection between a needle, nozzles or hydraulic couplers to a grease gun.

• Hydraulic couplers - used to transmit rotating mechanical power. It has been used in automobile transmissions as an alternative to a mechanical clutch.

4. Avionic General Test Equipment Operation, function and use of avionic general test equipment. BASIC AVIONICS TEST EQUIPMENT

POWER SUPPLIES

Power for an avionics system is typically 14 or 28 volts DC and, for large aircraft, 400 Hz AC. When the avionics are removed from the aircraft, the appropriate bench supply is required. A power supply of about 20 amperes at 14 volts and 10 amperes at 28 volts should cover most avionics systems.

One power hungry system is the HF transceiver. Many transmitters operate at more than 100 watts output, which requires about twice that as input.

A power supply of about 20 amperes at 14 volts and 10 amperes at 28 volts should cover most avionics systems. One power hungry system is the HF transceiver. Many transmitters operate at more than 100 watts output, which requires about twice that as input.

3 COMMONLY USED AVIONIC TEST EQUIPMENT 1. SOUND – AUDIO MODULATOR

2. NAVIGATION – ADF ANTENNA TESTER 3. AUTOPILOT – TEST PANELS

AUDIO MODULATOR

• The first and most widespread use for the audio generator is to modulate radio transmitters. Another application is troubleshooting and testing audio panels and intercoms. When an audio generator provides signals for transmitters and audio equipment, the te st is called a single tone test and is not ideal for transmitter testing. This is particularly the case with SSB (single sideband), where a single tone test is virtually worthless. To effectively measure an SSB transmitter, two audio frequency tones within the speech range of 300 to 3000 Hz are applied. The tones are typically equal in amplitude and not harmonically related. The single tone test, although not ideal, is acceptable for routine amplitude modulation testing.

• No unusual features are needed for an audio source for voice transmitter testing because the transmitters are not high-fidelity and operate over a narrow range of audio frequencies. The ideal source would be two inexpensive audio frequency sine generators. The two are combined with a simple resistive network and function as a two-tone source, or one generator as a single-tone source. Shops that never repair SSB transceivers can survive with only one audio generator. ADF ANTENNA TESTER

• The Automatic Direction Finder uses a directional antenna as an integral part of the system. Without the antenna, the ADF cannot function. To operate the ADF in the shop, therefore, a signal simulator and ADF antenna are required. To simulate a received ADF signal, the antenna is placed in a known magnetic field, where the field is a signal in space with known magnitude and direction.

The ADF signal is generated by creating a magnetic field within a large aluminum box. The carrier frequency is provided by a signal generator. An ADF antenna matching the receiver to be serviced is placed within the ADF simulator and connected to the receiver.

• A repair shop may have several ADF antennas for placing within the ADF simulator so several models may be serviced. Most failures, however, occur within the receiver rather than the antenna. The antenna contains few components although it is vulnerable to environmental damage at its location. Unless the antenna is suspected of being faulty, most ADF problems involve removing only the receiver and leaving the antenna in place. If the receiver is operational, the antenna is removed from the aircraft and placed in the signal simulator.

• ADF receivers have two antennas: loop and sense. Most modern receivers locate both loop and sense antennas inside a common assembly. ADF signal simulators require a mounting plate for the specific antenna and an adapter box to couple the signal generator to the sense antenna with the correct amplitude and phase relationship.

TEST PANELS

• Once an avionics unit has been removed from an aircraft, it cannot operate unless connections are made to antennas, speakers, power supplies, indicators, microphones, etc. These items are provided by a test panel and test harness. The panel provides hardware such as speakers, volume control, frequency setting, etc., while a wire harness makes connection to the unit under test (UUT).

• A test panel generally covers a number of products but not all. As an example, a panel will handle one or more brands of navigation receiver or communications transceivers.

• Another test panel may handle DMEs and transponders or just DMEs or only transponders. Each model has a unique harness for signal connections via a mating connector.

5. Engineering Drawings, Diagrams and Standards Types of Technical Drawings

The two types of technical drawings are based on graphical projection. This is used to create an image of a three-dimensional object onto a two-dimensional surface:

Two-dimensional representation

- Uses orthographic projection to create an image where only two of the three dimensions of the object are seen.

Three-dimensional representation

- In a three-dimensional representation, also referred to as a pictorial, all three dimensions of an object are visible.

Engineering Drawing

An engineering drawing, a type of technical drawing, is used to fully and clearly define requirements for engineered items.

Engineering drawing (the activity) produces engineering drawings (the documents). More than just the drawing of pictures, it is also a language—a graphical language that communicates ideas and information from one mind to another. Most especially, it communicates all needed information from the engineer who designed a part to the workers who will make it.

Systems of dimensioning and Tolerancing

Almost all engineering drawings (except perhaps reference-only views or initial sketches) communicate not only geometry (shape and location) but also dimensions and tolerances for those characteristics. Several systems of dimensioning and tolerancing have evolved. The simplest dimensioning system just specifies distances between points (such as an object's length or width, or hole center locations). Since the advent of well-developed interchangeable manufacture, these distances have been accompanied by tolerances of the plus-or-minus or min-and-max-limit types. Coordinate dimensioning involves defining all points, lines, planes, and profiles in terms of Cartesian coordinates, with a common origin. Coordinate dimensioning was the sole best option until the post-World War II era saw the development of geometric dimensioning and tolerancing (GD&T), which departs from the limitations of coordinate dimensioning (e.g., rectangular-only tolerance zones, tolerance stacking) to allow the most logical tolerancing of both geometry and dimensions (that is, both form [shapes/locations] and sizes).

Dimensions

The dimension of an object is a topological measure of the size of its covering properties. Roughly speaking, it is the number of coordinates needed to specify a point on the object. For example, a rectangle is two-dimensional, while a cube is three-dimensional. The dimension of an object is sometimes also called its "dimensionality."

Tolerance

Dimensions, properties, or conditions may vary within certain practical limits without significantly affecting functioning of equipment or a process. Tolerances are specified to allow reasonable leeway for imperfections and inherent variability without compromising performance.

A variation beyond the tolerance (for example, a temperature that's too hot or too cold) is said to be non-compliant, rejected, or exceeding the tolerance (regardless of if this breach was of the lower or the upper bound). If the tolerance is set too restrictive, resulting in most objects run by it being rejected, it is said to be intolerant.

Three basic tolerances Limit Dimension

Are two dimensional values stacked on top of each other? The dimensions show the largest and smallest values allowed anything in between these values is acceptable.

Unilateral Tolerance

A unilateral tolerance exists when a target dimension is given along with a tolerance that allows variation to occur in only one direction.

Bilateral Tolerance

A bilateral tolerance exists if the variation from a target dimension is shown occurring in both the positive and negative directions.

Systems of dimensioning and tolerancing

In most cases, a single view is not sufficient to show all necessary features, and several views are used. Types of views include the following:

Orthographic projection

The orthographic projection shows the object as it looks from the front, right, left, top, bottom, or back, and are typically positioned relative to each other according to the rules of either first-angle or third-angle projection. The origin and vector direction of the projectors (also called projection lines).

Auxiliary projection

An auxiliary view is an orthographic view that is projected into any plane other than one of the six principal views. These views are typically used when an object contains some sort of inclined plane. Using the auxiliary view allows for that inclined plane (and any other significant features) to be projected in their true size and shape. The true size and shape of any feature in an engineering drawing can only be known when the Line of Sight (LOS) is perpendicular to the plane being referenced. It is shown like a three-dimensional object.

Isometric projection

The isometric projection show the object from angles in which the scales along each axis of the object are equal. Isometric projection corresponds to rotation of the object by ± 45° about the vertical axis, followed by rotation of approximately ± 35.264° [= arcsin(tan(30°))] about the horizontal axis starting from an orthographic projection view. "Isometric" comes from the Greek for "same measure". One of the things that makes isometric drawings so attractive is the ease with which 60 degree angles can be constructed with only a compass and straightedge.

Isometric projection is a type of axonometric projection. The other two types of axonometric projection are:

Oblique projection

An oblique projection is a simple type of graphical projection used for producing pictorial, two-dimensional images of three-two-dimensional objects:

It projects an image by intersecting parallel rays (projectors) from the three-dimensional source object with the drawing surface (projection plan).

In both oblique projection and orthographic projection, parallel lines of the source object produce parallel lines in the projected image.

Perspective

Perspective is an approximate representation on a flat surface, of an image as it is perceived by the eye. The two most characteristic features of perspective are that objects are drawn:

Smaller as their distance from the observer increases Foreshortened: the size of an object's dimensions along the line of sight are relatively shorter than dimensions across the line of sight.

Section Views

Projected views (either Auxiliary or Orthographic) which show a cross section of the source object along the specified cut plane. These views are commonly used to show internal features with more clarity than may be available using regular projections or hidden lines. In assembly drawings, hardware components (e.g. nuts, screws, washers) are typically not sectioned.

Identifying title block information;

- The title block (T/B, TB) is an area of the drawing that conveys header-type information about the drawing, such as:

 Drawing title (hence the name "title block")

 Drawing number

 Part number(s)

 Name of the design activity (corporation, government agency, etc.)

 Identifying code of the design activity (such as a CAGE code)

 Address of the design activity (such as city, state/province, country)

 Measurement units of the drawing (for example, inches, millimeters)

 Default tolerances for dimension callouts where no tolerance is specified

 Boilerplate callouts of general specs

 Intellectual property rights warning

 Traditional locations for the title block are the bottom right (most commonly) or the top right or center.

Specification 100 of the Air Transport Association (ATA) of America; ATA Spec 100: Manufacturers' Technical Data

The then Air Transport Association released the newest version of ATA Spec 100 in 1999. According to the A4A website, this information will not be revised and has been combined with ATA Spec 2100 to produce the ATA iSpec 2200: Information Standards for Aviation Maintenance manual.

This specification defines a widely used numbering scheme for aircraft parts and the appearance of printed aircraft maintenance information. The Federal Aviation Administration's JASC (Joint Aircraft System/Component) code table provides a modified version of ATA Spec 100.

ATA Spec 100 contains format and content guidelines for technical manuals written by aviation manufacturers and suppliers, and is used by airlines and other segments of the industry in the maintenance of their respective products. This document provides the industrywide standard for aircraft systems numbering, often referred to as the ATA system or ATA chapter numbers. The format and content guidelines define the data prepared as conventional printed documentation. In 2000 ATA Spec 100 and ATA Spec 2100 were incorporated into ATA iSpec 2200: Information Standards for Aviation Maintenance. ATA Spec 100 and Spec 2100 will not be updated beyond the 1999 revision level.

Aeronautical and other applicable standards Example:

ISO

The International Organization for Standardization, known as ISO, is an international standard-setting body composed of representatives from various national standards organizations.

ANSI

The American National Standards Institute is a private non-profit organization that oversees the development of voluntary consensus standards for products, services, processes, systems, and personnel in the United States.[3] The organization also coordinates U.S. standards with international standards so that American products can be used worldwide. For example, standards ensure that people who own cameras can find the film they need for that camera anywhere around the globe.

MIL

A United States defense standard, often called a Military Standard, "MIL-STD", "MIL-SPEC", or (informally) "MilSpecs", is used to help achieve standardization objectives by the U.S. Department of Defense. Standardization is beneficial in achieving interoperability, ensuring products meet certain requirements, commonality, reliability, total cost of ownership, compatibility with logistics systems, and similar defense-related objectives.

Defense standards are also used by other non-defense government organizations, technical organizations, and industry. This article discusses definitions, history, and usage of defense standards. Related documents, such as defense handbooks and defense specifications, are also addressed.

Wiring diagrams and schematic diagrams. Wiring diagrams

A wiring diagram is a simplified conventional pictorial representation of an electrical circuit. It shows the components of the circuit as simplified shapes, and the power and signal connections between the devices.

A wiring diagram usually gives more information about the relative position and arrangement of devices and terminals on the devices, to help in building the device. This is unlike a schematic diagram, where the arrangement of the components' interconnections on the diagram usually does not correspond to the components' physical locations in the finished device. A pictorial diagram would show more detail of the physical appearance, whereas a wiring diagram uses a more symbolic notation to emphasize interconnections over physical appearance.

A wiring diagram is used to troubleshoot problems and to make sure that all the connections have been made and that everything is present.

Schematic diagrams

A schematic, or schematic diagram, is a representation of the elements of a system using abstract, graphic symbols rather than realistic pictures. A schematic usually omits all details that are not relevant to the information the schematic is intended to convey, and may add unrealistic elements that aid comprehension. For example, a subway map intended for riders may represent a subway station with a dot; the dot doesn't resemble the actual station at all but gives the viewer information without unnecessary visual clutter. A schematic diagram of a chemical process uses symbols to represent the vessels, piping, valves, pumps, and other equipment of the system, emphasizing their interconnection paths and suppressing physical details. In an electronic circuit diagram, the layout of the symbols may not resemble the layout in the physical circuit. In the schematic diagram, the symbolic elements are arranged to be more easily interpreted by the viewer.

6. Fits and Clearances Tolerance Dimensioning

 Tolerance is the total amount that a specific dimension is permitted to vary;

 It is the difference between the maximum and the minimum limits for the dimension.

 For Example a dimension given as 1.625 ± .002 means that the manufactured part may be 1.627” or 1.623”, or anywhere between these limit dimensions.

Size Designations

 Nominal Size: It is the designation used for general identification and is usually expressed in common fractions. For Ex. In the previous figure, the nominal size of both hole and shaft, which is 11/4” would be 1.25” in a decimal system of dimensioning.

 Basic Size or Basic dimension: It is the theoretical size from which limits of size are derived by the application of allowances and tolerances.

 Actual Size: is the measured size of the finished part.

 Allowance: is the minimum clearance space (or maximum interference) intended between the maximum material conditions of mating parts.

Fits between Mating Parts

 Fit is the general term used to signify the range of tightness or looseness that may result from the application of a specific combination of allowances and tolerances in mating parts.

There are four types of fits between parts

1. Clearance Fit: an internal member fits in an external member (as a shaft in a hole) and always leaves a space or clearance between the parts.

Minimum air space is 0.002”. This is the allowance and is always positive in a clearance fit

2. Interference Fit: The internal member is larger than the external member such that there is always an actual interference of material. The smallest shaft is 1.2513” and the largest hole is 1.2506”, so that there is an actual interference of metal amounting to at least 0.0007”. Under maximum material conditions the interference would be 0.0019”. This interference is the allowance, and in an interference fit it is always negative.

3. Transition Fit: may result in either a clearance or interference condition. In the figure below, the smallest shaft 1.2503” will fit in the largest hole 1.2506”, with 0.003” to spare. But the largest shaft, 1.2509” will have to be forced into the smallest hole, 1.2500” with an interference of metal of 0.009”.

4. Line Fit: the limits of size are so specified that a clearance or surface contact may result when mating parts are assembled.

Basic Hole System

 Minimum hole is taken as the basic size, an allowance is assigned, and tolerances are applied on both sides of and away from this allowance.

1. The minimum size of the hole 0.500” is taken as the basic size.

2. An allowance of 0.002” is decided on and subtracted from the basic hole size, making the maximum shaft as 0.498”.

3. Tolerances of 0.002” and 0.003” respectively are applied to the hole and shaft to obtain the maximum hole of 0.502” and the minimum shaft of 0.495”.

Minimum clearance: 0.500”-0.498” = 0.002” Maximum clearance: 0.502” – 0.495” = 0.007”

Basic Shaft System

 Maximum shaft is taken as the basic size, an allowance is assigned, and tolerances are applied on both sides of and away from this allowance.

1. The maximum size of the shaft 0.500” is taken as the basic size.

2. An allowance of 0.002” is decided on and added to the basic shaft size, making the minimum hole as 0.502”.

3. Tolerances of 0.003” and 0.001” respectively are applied to the hole and shaft to obtain the maximum hole of 0.505” and the minimum shaft of 0.499”.

Minimum clearance: 0.502”-0.500” = 0.002” Maximum clearance: 0.505” – 0.499” = 0.006”

Specifications of Tolerances

In single-line note form, the low limit precedes the high limit separated by a dash

2. Plus-or-minus Dimensioning

 Unilateral Tolerance

 Bilateral Tolerance

 Basic Size: is the size from which limits or deviations are assigned. Basic sizes, usually diameters, should be selected from a table of preferred sizes.

 Deviation: is the difference between the basic size and the hole or shaft size.

 Upper Deviation: is the difference between the basic size and the permitted maximum size of the part.

 Lower Deviation: is the difference between the basic size and the minimum permitted size of the part.

 Fundamental Deviation: is the deviation closest to the basic size.

7. Electrical Cables and Connectors Continuity, insulation and bonding techniques and testing;

Electrical Continuity. Metal raceways, cables, boxes, fittings, cabinets, and enclosures for conductors must be metallically joined together to form a continuous, low-impedance fault current path capable of carrying any fault current likely to be imposed on it

Continuity refers to being part of a complete or connected whole. In electrical applications, when an electrical circuit is capable of conducting current, it demonstrates electrical continuity. It is also said to be “closed,” because the circuit is complete. In the case of a light switch, for example, the circuit is closed and capable of conducting electricity when the switch is flipped to "on." The user can break the continuity by flipping the switch to "off," opening the circuit and rendering it incapable of conducting electricity. Electrical bonding is the practice of intentionally electrically connecting all exposed metallic items not designed to carry electricity in a room or building as protection from electric shock. If a failure of electrical insulation occurs, all bonded metal objects in the room will have substantially the s ame electrical potential, so that an occupant of the room cannot touch two objects with significantly different potentials. Even if the connection to a distant earth ground is lost, the occupant will be protected from dangerous potential differences.

An insulator, also called a dielectric, is a material that resists the flow of electric charge. In insulating materials valence electrons are tightly bonded to their atoms. These materials are used in electrical equipment as insulators or insulation. Their function is to support or separate electrical conductors without allowing current through themselves. The term also refers to insulating supports that attach electric power transmission wires to utility poles or pylons.

Use of crimp tools: hand and hydraulic operated;

Handheld , manual

Handheld tools are portable,

inexpensive, and effective. They typically have interchangeable die -sets. A manually actuated ratchet crimper can yield up to 180 terminations per hour.

Hydraulic, handheld

Hydraulic crimp tools are hand operated and pump hydraulic fluid into the device to compress the die. Despite being hand-driven, effort is

Testing of crimp joints; Crimp Testing

There are several destructive tests an operator can utilize to ensure the quality of the crimp.

Bend test: A quality connection will be able to accommodate 90° bends in several directions without misplacing the insulation or wire crimps.

Crimp height testing: Measured from the top surface of the formed crimp to the bottom radial surface, this provides a metric for the mechanical and electrical reliability of the connection. A caliper or crimp micrometer is used for this test, and it provides a good measure of terminal compression and process control.

Pull test: Attaching hanging weights to the wire for one minute, or using a mechanical pull tester, are means of testing the tensile strength--and crimp quality--of a wire termination.

Connector pin removal and insertion; D-sub (d-subminiature) connectors

– For use with low-current circuits such as data signals, position sensor feedback, micro-switches, and trim motors. These are used on the Control Unit and Display Unit. Each d-sub connector is unique to minimize the risk of a miss-match.

D-sub Terminal Install

Step 1: Mark the pin numbers on both sides of the d-sub with a Sharpie Step 2: Strip the end of the wire

Step 3: Install terminal into crimper tool, ensuring crimp tool is adjusted to the proper height. The head of the terminal should be flush with the top of the tool.

Step 4: Crimp terminal to wire.

Step 5: Insert terminal into connector assembly until you hear a slight click. Give the wire a tug to make sure it is fully seated. Visually inspect the other face of the connector to verify proper placement of the terminal.

D-sub Pin Removal

Step 1: Insert white side of removal tool into connector. Carefully wrap metal prongs around the wire. Step 2: Push down on tool until you feel it seat around the terminal. Note: you may have to fish around for a bit until it seats properly.

Co-axial cables: testing and installation precautions;

Coaxial cable, or coax (pronounced 'ko.æks), is a type of cable that has an inner conductor surrounded by a tubular insulating layer, surrounded by a tubular conducting shield.

RG-59 flexible coaxial cable composed of: A. Outer plastic sheath

B. Woven copper shield C. Inner dielectric insulator D. Copper core

1. Choose the right cable: there are many coaxial cables on the market and the type you buy can depend on whether you are using it for commercial or domestic purposes

2. Weatherproof: very important because moisture can damage the cable. Seal the end of the cable and make sure the cable's outer sheath is not damaged during installation. Loop the cable up and down to help prevent water from entering.

3. General installation rule of thumb: make sure your cables are not bent or crushed. If coax is bent beyond its limit, then internal damage will occur.

4. Connections: the connections to the connectors must be made correctly and the right quality connectors should be used. Some cheap versions of connectors can take away from the coaxial cable's performance.

CAUTION 1: Avoid Torque Forces (Twisting)

While individual coaxial cables within the test adapter have some rotational freedom, twisting the TPA as a unit, with one end held stationary, in excess of +/- 90° may damage or severely degrade

performance. Adherence to Caution 5 (below) helps to avoid exceeding twist limits. CAUTION 2: Avoid Sharp Cable Bends

Never bend coaxial cables into a radius of 26 mm (1 -inch) or less. Never bend cables greater than 90°. Single or multiple cable bends must be kept within this limit. Bending the TPA cables less than a 26mm (1-Inch) radius will permanently damage or severely degrade test adapter performance.

CAUTION 3: Avoid Cable Tension (Pull Forces)

Never apply tension (pull forces) to an individual coaxial cable that is greater than 2.3 kg (5 lbs.). To avoid applying tension, always place accessories and equipment on a surface that allows adjustment to eliminate tension on the TPA and cables. Use adjustable elevation stands or apparatus to accurately place and support the TPA.

Wiring protection techniques: Cable looming and loom support, cable clamps, protective sleeving techniques including heat shrink wrapping, shielding.

A cable harness, also known as a wire harness, cable assembly, wiring assembly or wiring loom, is an assembly of cables or wires which transmit signals or electrical power. The cables are bound together by straps, cable ties, cable lacing, sleeves, electrical tape, conduit, a weave of extruded string, or a

combination thereof. Wire clamps

Wire clamps consist of a piece of heavy wire, typically steel, first bent into a tight U, then formed into a ring shape with one end overlapping the other, and finally the ends bent outwards and cut. A captive nut is attached to one end, and a captive screw to the other. When the screw is tightened, the overlapped ends of the wire are pushed apart, tightening the wire loop around the hose. For an explanation of why this design is used, see the section on sealing the connection.

Braided sleeving is a great way to keep hoses, wires and cables safe from abrasion, temperature, chemicals and other damage. Expandable sleeving adds an extra layer of versatility by conforming to bundles of odd shapes & sizes.

High temperature and flame retardant sleeves are built for the most extreme conditions. Most are made of fiberglass, and less commonly from ceramic and material blends. Some of these sleevings operate with no problems in temperatures up to 3000°F. In addition, many models can protect cables from abrasion, moisture, chemicals and fungus.

Side entry braided sleeving makes installation a breeze by allowing you to easily wrap cables, hoses and wires for maximum convenience. The semi-rigid construction of F6 provides an extra layer of flexibility for clean and fast implementation.

Abrasion Resistant Sleeving

These sleevings will protect cables from cuts, scratches and other abrasions. Several types are available, including stainless steel, Nylon and Kevlar examples, but all feature woven designs that allow for

flexibility while keeping cables, wires, and hoses free from damage, and most are expandable to allow for maximum versatility.

Treated fiberglass sleeve

These protective sleevings are ideal for automotive and industrial applications, as well for use in generators, transformers, or any setting where resistance to heat, abrasion, moisture, chemicals or weather corrosion is required.

10. Springs Inspection of springs

1. Inspect spring free length

2. Inspect spring compression force 3. Inspect for bends

4. Inspect for pitting 5. Inspect coils for rubbing

Because there are many different types of spring carrying out different functions, the answer is not always easy. Normally it is not necessary to NDT springs since the time between crack initiation and breakage is extremely short.

NDT assumes that cracks can exist benignly until the next inspection interval allowing one to find the crack before the part breaks in half. The following inspection and replacement criteria is suggested as a general aid to be used when the maintenance manual is lacking:

 If the spring is inexpensive - replace it.

 If the spring works hard and hot - replace it during major maintenance. For example, valve springs.

 If the spring is in a corrosive environment - replace it.

 If the spring serves some critical or safety function - replace it. 11. Bearings

Maintenance Instructions:

1. Keep your bearings dirt-free, moisture free, and lubricated.

2. Clean your bearings when they become dirty or noisy with the most environmentally friendly cleaner you can find that is suitable for dissolving oil, grease, and removing dirt from the steel, plastic and rubber surfaces.

3. If you use a solvent cleaner, please wear appropriate rubber gloves and work in a safe well-ventilated area.

4. Do not add oil to dirty bearings. It will not clean the bearing, but merely flush the existing dirt further into the bearing.

Cleaning Instructions:

1. Gently remove the non-contact rubber shield with a push pin or the edge of a small knife by prying the shield upwards from under the shield at the inner race.

2. Optional Cage Removal: You can clean your bearings more thoroughly by removing the ball retainer or “cage.”

3. Clean your bearings and your ball retainers 4. Dry your bearings

5. Reinstall your cages 6. Lubricate your bearings

7. Reinstall your clean rubber shields 8. Reinstall your bearings

12. Transmissions

 Inspection of gears, backlash;

Gear - is a rotating machine part having cut teeth, or cogs, which mesh with another toothed part in order to transmit torque, in most cases with teeth on the one gear being of identical shape, and often also with that shape on the other gear. Two or more gears working in tandem are called a transmission and can produce a mechanical advantage through a gear ratio and thus may be considered a simple machine.

Backlash - Its clearance or lost motion in a mechanism caused by gaps between the parts. It can be defined as "the maximum distance or angle through which any part of a mechanical system may be moved in one direction without applying appreciable force or motion to the next part in mechanical sequence.

Factors affecting the amount backlash required in a gear train include errors in profile, pitch, tooth thickness, helix angle and center distance, and run-out. The greater the accuracy the smaller the backlash needed. Backlash is most commonly created by cutting the teeth deeper into the gears than the ideal depth. Another way of introducing backlash is by increasing the center distances between the gears.

 Inspection of belts and pulleys, chains and sprockets

Belts and Pulleys - is a loop of flexible material used to mechanically link two or more rotating shafts, most often parallel. Belts may be used as a source of motion, to transmit power efficiently, or to track relative movement. Belts are looped over pulleys and may have a twist between the pulleys, and the shafts need not be parallel. In a two pulley system, the belt can either drive the pulleys normally in one direction (the same if on parallel shafts), or the belt may be crossed, so that the direction of the driven shaft is reversed (the opposite direction to the driver if on parallel shafts). As a source of motion, a conveyor belt is one application where the belt is adapted to continuously carry a load between two points.

How to check Belts:

1. Listen for squealing sounds from the engine. 2. Check belts for signs of wear

3. Check you belts for places where the rubber is slick or glazed in appearance 4. Inspect the pulleys

5. Check the belt tension Chains and Sprockets

Sprocket - is a profiled wheel with teeth or cogs that mesh with a chain, track or other perforated or indented material. The name "sprocket" applies generally to any wheel upon which are radial projections that engage a chain passing over it. It is distinguished from a gear in that sprockets are never meshed together directly, and differs from a pulley in that sprockets have teeth and pulleys are smooth. The word "sprockets" may also be used to refer to the teeth on the wheel.

Chain Inspection

 Chain cleanliness and proper lubrication are vital to your chains long life

 Check for evidence of wear

 Inspect chain for flexibility

 Inspect the amount of chain stretch or elongation

 Check for any signs of physical damage to the chain, such as broken or cracked parts, loose pins and bushings, or indications of corrosion.

Sprocket Inspection

 The sprocket teeth should be inspected for signs of wear, indicating a possible alignment problem.

 Check the teeth for signs of wear, indicated by a “hooked” shaped

 Inspect for signs of physical damage to the sprocket, such as broken or chipped teeth, or excessive corrosion.

 Check the sprocket run out on the shaft, and inspect the keys and keyw ays for wear or damage.

Inspection of Screw Jacks, Push-pull rod systems

Jack Screw - is a type of jack that is operated by turning a lead screw. In the form of a screw jack it is commonly used to lift heavy weights, such as the foundations of houses, or large vehicles.

An advantage of jackscrews over some other types of jack is that they are self-locking, which means when the rotational force on the screw is removed, it will remain motionless where it was left and will not rotate backwards, regardless of how much load it is supporting.

Push-pull Rod Systems - A stiff rod in an aircraft control system that moves a control surface by either pushing or pulling on it.

13. Control Cables

 Swaging of End Fittings

Swaging - is a forging process in which the dimensions of an item are altered using dies into which the item is forced. Swaging is usually a cold working process; however, it is sometimes done as a hot working process.

 Inspection and Testing of Control Cables Maintenance:

 Moisture Management - Wipe off the control cable as you draw the probe up on the last run of the day.

 Cable - When necessary, rinse cable (but not connectors) in clean water or wash the cable in a laboratory-grade detergent, such as Liquinox.Do not use solvents to clean the cable.

 Connectors - If it is necessary to clean the connector, use a cotton swab moistened with alcohol. Sockets can be cleaned with a brush.Do not use spray lubricants or electric contact cleaners. Solvents contained in such products will attack the neoprene inserts in the connectors.  Storing Control Cable - Improper coiling of any electrical cable twists conductors and can cause

reliability problems. There are several ways to control twisting:

 Use a cable reel with hub diameter of at least 200mm or 8 inches.

 Coil cable in a figure-eight.

Inspection:

Cuts or Gouges - Deep cuts or gouges allow water to enter cable. In both cases, bad section of cable must be removed, either by shortening the cable or replacing the cable.

 Bowden Cables; Aircraft Flexible Control Systems

Bowden Cable - is a type of flexible cable used to transmit mechanical force or energy by the movement of an inner cable (most commonly of steel or stainless steel) relative to a hollow outer cable housing. The housing is generally of composite construction, consisting of a helical steel wire, often lined with nylon, and with a plastic outer sheath.

Transmission

1. A chain removed for routine inspection, it does not need proof loading 2. An aircraft control chain is connected using nuts and bolts

3. If a control chain can be lifted clear of a tooth, it should be removed and an elongation check carried out.

4. In removing a tight link from a chain, it should tap it lightly with a hammer. 5. The initial lubricant on a new chain should not be removed

6. Control chains should be fitted in an aircraft with the minimum of slack in the chain. 7. Backlash is a type of wear associated with gears.

8. After a chain has been cleaned in paraffin it should be dried in hot air.

9. What fraction of the minimum breaking load should be the proof load for a chain? 1/3 10. If corrosion is found on a chain, replace the chain.

11. The three principle dimensions specified for a chain is the diameter of the rollers and the pitch and width between inner plates.

12. The distance between the centers of the rollers and chain is called pitch.

13. The maximum allowable extension of a chain assembly over a normal length is 2%. 14. A feather key locates a gear on a shaft and permits a positive drive and axial movement. 15. A chain is removed by nuts and bolts.

16. To check a chain for elongation, lay flat on a table, apply tensile load and measure.

Control Cables

1. When a control cable is contaminated with acid, it should be rejected or replaced. 2. A balanced cable is installed in a control system to enable the cable to be tensioned 3. The aileron balance cable equalizes the control cable tension.

4. How would you inspect a cable for fraying? Run a rag the full length of the cable. 5. A cable is replaced if a chemical spillage is suspected.

6. The proof loading for cables after swaging is 50% minimum breaking strain.

7. The best way to check control cables for broken wires is to run a rag along the cable in both directions.

8. If the turnbuckles in a control system is being tightened extensively, the aircraft will be heavy on controls

14. Material Handling Bending

Is a manufacturing process that produces a V-shape, U-shape, or channel shape along a straight axis in ductile materials, most commonly sheet metal.

Bend Allowance

The length of the arc through the bend area at the neutral axis. Bend Angle

The included angle of the arc formed by the bending operation. Bend Compensation

The amount by which the material is stretched or compressed by the bending operation. All stretch or compression is assumed to occur in the bend area.

K-factor

Defines the location of the neutral axis. It is measured as the distance from the inside of the material to the neutral axis divided by the material thickness.

Mold Lines

For bends of less than 180 degrees, the mold lines are the straight lines where the surfaces of the flange bounding the bend area intersect. This occurs on both the inside and outside surfaces of the bend. Neutral Axis

Looking at the cross section of the bend, the neutral axis is the theoretical locati on at which the material is neither compressed nor stretched.

Set Back

For bends of less than 180 degrees, the set back is the distance from the bend lines (see above) to the mold line.

Composite materials (also called composition materials or shortened to composites)

Are materials made from two or more constituent materials with significantly

different physical or chemical properties, that when combined, produce a material with characteristics different from the individual components. The individual components remain separate and distinct within the finished structure. The new material may be preferred for many reasons: common examples include materials which are stronger, lighter or less expensive when compared to traditional materials.

17. Aircraft Handling and Storage Aircraft taxiing/towing and associated safety precautions;

Taxiing, also sometimes written "taxying", is the movement of an aircraft on the ground, under its own power, in contrast to towing or push-back where the aircraft is moved by a tug. The aircraft usually moves on wheels, but the term also includes aircraft with skis or floats (for water-based travel).

Safety

When taxiing, aircraft travel slowly. This ensures that they can be stopped quickly and do not risk wheel damage on larger aircraft if they accidentally turn off the paved surface. Taxi speeds are typically from 5 to 20 knots (9 to 37 km/h; 6 to 23 mph).

Rotor downwash limits helicopter hover-taxiing near parked light aircraft.

The use of engine thrust near terminals is restricted due to the possibility of jet blast damage.

Towing is necessary to enable the aircraft to be moved without engine power. The procedure required will vary greatly dependent on the type of aircraft to be moved.

Safety

(a) Aircraft must not exceed walking pace while being towed (in closed area).

(b) Oleo-leg and tyres must be correctly inflated prior to moving the aircraft, and sufficient brake pressure available for an emergency stop.

(c) Undercarriage ground locks must be fitted prior to towing (d) At night Aircraft navigation lights must be “ON”

(e) By-pass pin or towing pin must be fitted before connecting the tow bar. (f) A person in charge with all other team members in his sight.

(g) Personnel must be stationed on the wing tip and tail to ensure clearance round obstacles.

(h) There must be a competent person occupying the pilot set to operate the aircraft brakes in case of emergency.

Aircraft jacking, chocking, securing and associated safety precautions;

Jacking Procedure - Raising

The general procedure for raising the complete aircraft on jacks is as follows: 1 Place Safety Barriers in position around the aircraft.

2 Place warning notices in the aircraft cockpit.

3 Ensure that Ground Safety Locks are fitted to all Landing Gears. 4 Ensure Wheel Chocks are fitted.

5 Ensure the Brakes are applied.

6 Ensure that the aircraft is balanced and stable.

7 Ensure that the aircraft is in the ‘Clean Flight Configuration’. (Flaps/Slats are housed)

8 Deactivate the relevant circuit breakers to ensure that there will be no movement of flight controls or the operation of other in-flight systems. NB: As the aircraft is raised it moves from the ‘Ground Configuration’ to the ‘Flight Configuration’.

9 Fit Jacking Pads and Adaptors.

10 Position the jacks under the aircraft, just taking a little of the aircraft’s weight. 11 Remove Wheel Chocks.

12 Release the Brakes.

13 Ensure that all the passenger/crew doors, the emergency exits and the cargo doors are closed and locked or fully open and locked.

14 Remove access ladders and platforms.

15 Clear the area around the aircraft of all ground support and maintenance e quipment and ensure that no other work is being carried out.

16 Operate the nose jack if necessary to ensure the aircraft is longitudinally stable.

17 Slowly operate the jacks at the same time to keep the aircraft level until the appropriate clearance is achieved between the main landing gear wheels and the ground.

18 Ensure that throughout the jacking operations the jack Safety Locking Collars are kept approximately 2.5 cms clear of the jack body.

19 On completion of all jack raising operations the aircraft should be levelled to the ‘datum position’, the jack Safety Locking Collars tightened and the aircraft made stable by the fitting of trestles or a safety stay.

Aircraft storage methods;

Categories of Storage. The length of time that the aircraft will be inactive will determine which of the following categories of storage will be used.

Flyable Storage

Flyable storage is the prescribed procedure to maintain a stored aircraft inoperable condition. Next to daily use, this category of storage keeps the aircraft in the best possible condition. All scheduled preventative maintenance will be performed on aircraft in flyable storage, and periodic operation of the aircraft and all systems is required. There is no time limit on flyable storage.

Short Term Storage

Short term storage issued to store an aircraft for a period not to exceed 45days. Aircraft in short term storage require extensive preservation but very little periodic attention.

Intermediate Storage

Intermediate storage issued to store aircraft for a period of 46 to 180 days. Aircraft in intermediate storage require very extensive preservation but minimal periodic attention. Long Term Storage

Procedures for long term storage are not available for the storage of Army aircraft if storage beyond 180 days is required, the aircraft will be depreserved, returned to flyable status, operated, and represerved in accordance with this chapter.