7.5 Engineering Drawings Flashcards
Why are drawings used in engineering?
Drawings convey the designer’s requirements clearer than words and provide sufficient information for manufacture, assembly, production planning, testing, and inspection.
Drawings are essential for effective communication in engineering.
What are the components identified in engineering drawings?
Diagrams, symbols, dimensions, tolerances, projections
These components are crucial for accurately interpreting the drawings.
What are the dimensions of a drawing sheet?
The dimensions are specified by drawing standards.
These standards vary by organization and region.
What is the purpose of scale in drawings?
Scale allows for the accurate representation of objects in a reduced or enlarged format.
It is crucial for ensuring that the drawing can be used for practical applications.
What are the types of aircraft engineering drawings?
- Detail drawings
- Assembly drawings
- Installation drawings
- Exploded view drawings
- Schematic drawings
- Sectional drawings
Each type serves a specific purpose in the engineering process.
What is the use of lines in engineering drawings?
Lines are used to represent edges, boundaries, and other features; break lines indicate interruptions, and repetitive information is simplified.
Understanding line types is essential for interpreting drawings correctly.
Why are symbols used in engineering drawings?
Symbols provide a concise way to convey information about features and specifications.
This reduces clutter and enhances clarity.
What do the following symbols represent in drawings?
- Holes
- Recessed holes
- Conventions
- Surface texture
These symbols standardize the representation of various features.
What is the purpose of a perspective drawing?
Perspective drawings provide a three-dimensional view of an object to better visualize its form and structure.
They are often used in presentations and design concepts.
What are sketches in the context of engineering drawings?
Sketches are informal drawings used to quickly convey ideas or concepts.
They are typically not to scale and serve as preliminary designs.
What is ‘orthographic projection’?
Orthographic projection is a method of representing three-dimensional objects in two dimensions, including first angle and third angle projection.
This technique is essential for accurately depicting dimensions and relationships.
What precautions should be taken when handling drawings?
- Handle carefully to prevent damage
- Open slowly to avoid tearing
- Smooth out fold lines
- Keep hands clean
- Never make unauthorized marks
- Return to proper place when finished
Proper care extends the lifespan of valuable engineering drawings.
What do drawing standards cover?
- Paper sizes
- Notes
- Numbering systems
- Geometric dimensions and tolerances
- Abbreviations
- Welding symbols
- Roughness symbols
- Electrical symbols
Adhering to these standards ensures consistency and clarity in engineering documentation.
Which organizations publish common drawing standards?
- International Organization for Standardization (ISO)
- American National Standards Institute (ANSI)
- British Standard (BS8888)
These standards facilitate international collaboration and understanding in engineering.
True or False: Only authorized individuals can make notes or changes on engineering prints.
True
This protocol prevents confusion and maintains the integrity of engineering documents.
What is the most common type of drawing used in aircraft engineering?
Working drawing
Working drawings are essential for conveying specific information in aircraft engineering.
What are the three types of working drawings?
- Detail drawings
- Assembly drawings
- Installation drawings
These types are crucial for different stages of aircraft design and construction.
What is a detail drawing?
A drawing that supplies all information required to construct a part, including dimensions, materials, and type of finish.
Detail drawings may also be referred to as FAB (fabrication) drawings.
What does an inseparable assembly refer to?
Items or parts that are permanently joined, such as welded or riveted parts.
Inseparable assemblies are not subject to disassembly.
What information do detail drawings NOT provide?
Location, position, or fastening method.
They primarily instruct fabrication personnel.
What is included in detail information for a part?
- Size and shape description
- Material and heat treatment requirements
- Protective-finish instruction
- Machine finish requirements
- Part numbering and marking instructions
This information ensures accurate part fabrication.
What is the purpose of assembly drawings?
To depict the relationship between two or more parts and guide their assembly.
Assembly drawings reference individual parts by their part number.
How do installation drawings differ from assembly drawings?
Installation drawings describe where parts are to be permanently fixed on the aircraft, while assembly drawings focus on part relationships.
Installation drawings include a bill of materials for installation instructions.
What are the four types of sectional drawings?
- Revolved section drawings
- Removed section drawings
- Complete section drawings
- Half section drawings
Each type serves to illustrate different aspects of a part’s internal construction.
What is a revolved section drawing?
A drawing that shows a cutting plane perpendicular through the feature, rotated 90° to illustrate the shape.
This type is useful for simple items without interior parts.
What is the purpose of exploded view drawings?
To show every part in an assembly in their relative position, expanded outwards for identification.
They often include a parts list for reference.
What is a block diagram used for?
As an aid for troubleshooting complex electrical and electronic systems.
Block diagrams represent components as individual blocks.
What are the two types of flowcharts commonly used in aviation?
- Troubleshooting flowcharts
- Logic flowcharts
Both types assist in diagnosing and analyzing systems.
What do troubleshooting flowcharts consist of?
A series of yes or no questions to detect faulty components.
This method helps in logically determining solutions.
What do logic flowcharts analyze?
Digitally controlled components and systems using standardized symbols.
They help determine outputs based on binary inputs.
What do schematic drawings illustrate?
The principle of operation and the relationship of objects in a system.
They are useful for troubleshooting complex systems.
What is the difference between schematic diagrams and pictorial diagrams?
Schematic diagrams use symbols for function and flow, while pictorial diagrams show a visual layout of components.
Pictorial diagrams provide a two-dimensional representation.
What are schematic diagrams used for in aircraft engineering?
To provide an overview representation of the complete aircraft system for fault diagnosis.
They illustrate how components in complex systems interact.
What is the purpose of projection in illustrated representations?
To represent parts in various orientations on a flat plane
What are the six possible views in orthographic projection?
- Front
- Rear
- Top
- Bottom
- Left side
- Right side
How does an orthographic projection represent a three-dimensional object?
Using several two-dimensional views
What is the principal view in an orthographic projection?
The front view
What is the first angle projection?
A projection method where each view represents the side of the object that is remote from it in the adjacent view
What is the third angle projection?
A projection method where each view represents the side of the object that is nearest to it in the adjacent view
Which projection is more common in Europe?
First angle projection
Which projection is widely used in the USA and the UK?
Third angle projection
What is a sketch?
A simple drawing made quickly and without much detail
What are the four steps in sketching?
- Determine necessary views
- Block in views using light construction
- Darken object view lines and add dimension lines
- Include title, date, and sketcher’s name
What is an isometric view?
A view that combines three orthographic views into one, tilting the object forward
What angle do edges form in an isometric drawing?
30° to the drawing plane
How are distances represented in an isometric drawing?
All distances are the same length as the actual sides
What characterizes an oblique drawing?
One face of the object is parallel to the drawing plane, with two axes perpendicular
What is a key feature of perspective drawings?
They show an object as it appears to the observer, resembling a photograph
True or False: Perspective drawings maintain accurate angles and dimensions.
False
Fill in the blank: A sketch is usually drawn for _______ or for manufacturing a replacement part.
repairs
What is essential for aircraft engineers when interpreting drawings?
A working knowledge of the information conveyed by the drawings
What should be the first step when opening a drawing?
Read the drawing number and the description of the article
When reading a multi-view drawing, what is the initial approach?
Scan all views to get a general idea of the object’s shape
True or False: A single view is sufficient to understand all details of an object in a multi-view drawing.
False
What units are commonly used in drawings for new aircraft and components?
Millimetre (mm)
Fill in the blank: The dimension of an angle is indicated by placing the degree of the angle in its _______.
arc
What do dimension lines indicate in a drawing?
Measurements of an object
What is the purpose of extension lines in a drawing?
To extend the line showing the side or edge of a figure for placing a dimension
What do sectioning lines indicate in a sectional view?
The exposed surfaces of an object
What do phantom lines represent?
The alternate position of parts of the object or the relative position of a missing part
What do break lines indicate in a drawing?
That a portion of the object is not shown
What do hidden lines indicate?
Invisible edges or contours
What are stitch lines used for in drawings?
To indicate the stitching or sewing lines on an article
What do cutting plane lines indicate?
The plane where a sectional view of the object is taken
What do viewing plane lines indicate?
The plane from where a surface is viewed
What are material symbols used for in drawings?
To show the kind of material from which the part is to be constructed
What do finish marks indicate on a drawing?
The surface that must be machine finished
How is surface texture specified on a drawing?
By numbers above a triangle indicating smoothness
What types of holes can be represented in a drawing?
- Plain-drilled
- Reamed
- Threaded
What characterizes a counterbore hole?
A larger diameter hole, concentric to the primary hole, with a flat shoulder
What is a spotface used for?
To provide a flat, smooth seating for a mating part or fastener head
What is a countersunk hole designed to accommodate?
The tapered head of a fastener
True or False: The surface texture number on a drawing can indicate a rough finish.
True
What must be observed during the finishing process of a surface?
The required limits and tolerances
What does a title block provide in engineering drawings?
Identification for the print
It helps prevent confusion with other prints.
What information is typically included in a title block?
- Drawing number
- Name of the part or assembly
- Scale
- Date
- Name of the firm
- Names of drafter, checker, and approver
Where is the title block usually located on a print?
Lower right-hand corner
What is the purpose of the drawing number in a title block?
Quick identification of a print
What are the standard sizes of A-size and B-size drawings?
- A-size: 8 ½ x 11 in (22 x 28 cm)
- B-size: 11 x 17 in (28 x 43 cm)
What scale is used for drawings made to the same size as the part?
1:1
How is tolerance represented in technical drawings?
With plus (+) and minus (−) figures indicating maximum and minimum allowable variations
What does the sum of the plus and minus allowance figures represent?
Tolerance
What is the tolerance if the plus and minus allowances are ± 0.0025?
0.0050
What names are typically included in the title block?
- Firm’s name
- Engineer
- Drafter
- Checker
- Approver
Where are revisions recorded in an engineering drawing?
Upper-right hand corner
What information is included in the revision block?
- Revision letter
- Description
- Release date
- Initials of approver
What system is used to define zones in large aircraft drawings?
A grid system with vertical divisions marked with letters and horizontal with numbers
What is the term for the process of updating engineering drawings as modifications occur?
Raising-in-issue
What is the Bill of Materials?
A list of materials and parts necessary for fabrication or assembly
What does an electronic schematic drawing provide?
Detailed information about a circuit
True or False: Electronic schematics are the easiest type of drawing to read.
False
Fill in the blank: The _______ block starts in the top right-hand corner of each sheet.
revision
What are the documentation systems used for maintenance data?
Computer Aided Design, Microfilm/microfiche, Digital images
What is Computer Aided Design (CAD)?
The use of computers to aid in the creation, modification, and analysis of a design
What does Computer Aided Design Drafting (CADD) refer to?
A computer is used in the design and drafting process
What is the purpose of Computer Aided Manufacturing (CAM)?
A computer is used in the manufacturing of a part or product
What does Computer Aided Engineering (CAE) involve?
A computer is used in the engineering of a part or product
What are the benefits of using Computer Aided Engineering (CAE)?
Product analysis, assembly, simulations, and maintenance information
What is microfilm?
An analog storage system using film reels to store photographic records
What is microfiche?
A card with pages laid out in a grid format for storing documents
How has the aviation industry changed in terms of document storage?
Nearly all aircraft manufacturers have replaced microfilm and microfiche with digital storage methods
What is a significant advantage of using digital images in aircraft maintenance?
Provides an instant picture of defects/damage for quicker response
Fill in the blank: Digital images can be rapidly transmitted over the _______.
internet
True or False: Microfilm and microfiche are still widely used in the aviation industry today.
False
What is the common size for microfilm used in the aviation industry?
16 mm or 35 mm film
What software is commonly used for aircraft design and manufacturing?
Computer Aided Three Dimensional Interactive Application (CATIA)
What is one method to emphasize the size of damage in a digital image?
Place a rule or a coin near the area of concern
What are the applications of computer software in the context of aircraft design?
Increase productivity, improve quality, improve communications, create a database for manufacturing
What are the key terms associated with computer graphics in design?
- Computer Aided Design (CAD)
- Computer Aided Design Drafting (CADD)
- Computer Aided Manufacturing (CAM)
- Computer Aided Engineering (CAE)
What is the purpose of Specification 100 of the Air Transport Association (ATA) of America?
To standardise the format for how aircraft maintenance information is presented in Aircraft Maintenance Manuals (AMM)
This ensures consistency across different manufacturers.
What does the ATA 100 System classify?
Maintenance data subjects by standardised numbered chapters
This helps organize maintenance information systematically.
Why is the ATA 100 System necessary?
It allows aircraft personnel to access maintenance information without needing to learn each manufacturer’s data organization system
This enhances efficiency and reduces training time.
What does the chapter numbering system in ATA 100 consist of?
A three-element number (XX-XX-XX) that divides material into chapters, sections, and subjects
Each element contains two digits.
What are the components of the six-digit numerical breakdown in ATA Specification 100?
- System/Chapter Identification 2. Section 3. Sub-Section 4. Subject
Each component is represented by a two-digit number.
Provide an example of a chapter number in the ATA 100 system.
79-21-41
This represents the Fuel Oil Heat Exchanger under the Engine Oil system.
What is the significance of the page block number following the six-digit number in ATA iSpec 2200?
It provides information on how to perform a specific maintenance task
Page blocks are reserved for different subject matters.
List the page block numbers reserved for specific subjects in the ATA iSpec 2200.
- Description and Operation: 1 – 99
- Fault Isolation: 101 – 199
- Maintenance Practices: 201 – 299
- Servicing: 301 – 399
- Removal and Installation: 401 – 499
- Adjustment and Test: 501 – 599
- Inspection and Check: 601 – 699
- Cleaning and Painting: 701 – 799
- Repairs: 801 – 899
These page block numbers categorize maintenance tasks for easy reference.
True or False: The ATA iSpec 2200 is an evolution of the ATA Spec 100 and ATA Spec 2100.
True
It combines specifications for both traditional and electronic documentation.
What does ATA iSpec 2200 identify?
Maintenance data chapters by a standardised numbering system
This aids engineers in locating relevant information systematically.
Fill in the blank: The first two numbers in the ATA 100 chapter numbering system identify the _______.
[System/Chapter Identification]
List some systems included in the titles of ATA SPEC 100/i2200.
- Time Limits/Maintenance Checks
- Dimensions & Areas
- Lifting & Shoring
- Fire Protection
- Fuel
These titles represent various maintenance categories across aircraft.
What is the chapter for fire-protection systems according to ATA 100 specifications?
Chapter 26
This chapter includes all technical information related to fire-protection.
How does the ATA 100 chapter structure benefit different types of aircraft?
It provides a consistent framework for similar information to be found across different aircraft types
This is crucial for maintenance personnel working on various models.
What is the ATA spec 100?
A standard for the organisation of data in the aerospace industry
This standard is one of many that facilitate data management and compatibility.
What is the role of government-controlled institutions in standard development?
They develop standards for various industries, facilitating business and technology
These institutions play a critical role in ensuring the effectiveness of industry standards.
What is the International Organization for Standardisation (ISO)?
One of the world’s largest developers of global standards, comprised of national standards organisations from 156 member countries
ISO promotes international standardization to enhance efficiency and trade.
What benefits do ISO standards provide?
- Efficiency in development and manufacturing
- Easier and fairer international trade
- Technical base for government legislation
- Aids technology transfer to developing countries
- Safeguards consumers and simplifies their lives
ISO standards are voluntary but widely adopted due to their benefits.
How does ISO gather consensus for its standards?
Through technical committees consisting of expert representatives from various sectors
This process includes public review before adoption to ensure comprehensive input.
What is the significance of the AN system in aviation?
It is one of the most widely used standards in aircraft hardware, ensuring quality and uniformity
Items manufactured to this standard are used across all aircraft classifications.
What does the MS/MIL standard encompass?
It incorporates most of the same hardware as the AN system and is used in all aspects of aviation
Care must be taken when substituting MS hardware for AN hardware to ensure compatibility.
What does NAS stand for, and what is its purpose?
National Aerospace Standard; it approves military hardware for use in the civilian aerospace industry
This standard covers various hardware components like screws, nuts, and rivets.
What is the British Standards Institution (BSI)?
The national standards institute for the UK, controlling British Standards and representing the UK in ISO matters
BSI has standards for hardware and codes of practice relevant to aviation.
True or False: ISO standards are mandatory for member countries.
False
ISO standards are voluntary but are often complied with due to their recognized benefits.
Fill in the blank: The EASA aviation maintenance professional is exposed to ________ work of the ISO.
standardisation
This exposure includes various standards relevant to aviation engineering and maintenance.
What is the primary purpose of diagrams in an electrical context?
To provide a graphic representation of an assembly or system, illustrating various parts and expressing methods or principles of operation.
What is a schematic diagram?
A schematic shows the plan and function for an electrical circuit without detailing physical layout or cable specifics.
What does a wiring diagram illustrate?
How wires are connected and their locations within the actual system, including physical connections between components.
List the three types of schematic diagrams based on detail level.
- Block diagrams
- Simplified schematics
- System schematics
What do block diagrams provide?
A general overview of a system, showing major functions, components, functional groups, and relevant interfaces.
How do simplified schematics differ from block diagrams?
They provide a more detailed view of functions and components without regard to their physical location.
What is the function of system schematics?
To show the system in sufficient detail for fault isolation to the Line Replacement Unit (LRU) level.
What is indicated in schematic diagrams regarding component locations?
The general location of components with respect to each other, including main components, their interfaces, and associated system messages.
True or False: Schematic diagrams include information for testing.
False
What do wiring diagrams typically identify?
Each component within a system by its part number and serial number, including production changes.
What is the purpose of wiring diagrams in troubleshooting?
To isolate faults in wiring and in-line disconnects.
What does the wiring diagram numbering follow?
The ATA Specification conventions.
What does the Wiring Diagram Manual (WDM) for Boeing aircraft include?
- Wiring diagrams
- Wire lists
- Hook-up lists
- Equipment lists
What types of lists may be found within wiring diagrams?
- Terminal strip lists
- Splice lists
- Ground lists
- Master bundle lists
- Spare wire lists
- Circuit breaker lists
What is the SWPM?
Boeing’s Standard Wiring Practices Manual containing important data and tables for wiring.
What information do home diagrams indicate?
All connections on a termination, referencing the diagram that shows the connection.
What does effectivity refer to in wiring diagrams?
The applicability of a wiring diagram manual to specific aircraft listed on the effective aircraft page.
What is indicated by a suffix in a page number (e.g., 1A, 2A)?
A post-delivery configuration for the same aircraft.
What do customer assigned and manufacturer assigned equipment item numbers facilitate?
Reference within drawings and diagrams, linked to effectivity data.
