7.5 Engineering Drawings

Question 1

How should you smoothe out food lines on drawings?

Answer 1

Smooth them DO NOT bend them backwards

Question 2

What are the three most common standards used for drawings?

Answer 2

International organisation for standardisation (ISO)
American National Standards Institute (ANSI)
British standard (BS8888)

Question 3

What are the three types of working drawings?

Answer 3

• detail drawings
• assembly drawings
• installation drawings

Question 4

When is a detail drawing made?

Answer 4

• during aircraft design

Question 5

What is included in a detail drawing?

Answer 5

• size and shape description
• material and heat treatment requirements
• protective finish instruction
• Machine finish if required
• part numbering and marking instructions
  (Bscly everything required for fabrication)

Question 6

What does an assembly drawing include? Where is this?

Answer 6

• reference individual parts’ by their part number
• specify type and number of fasteners needed to join them together
• found in the lower right hand

Question 7

What dimensions are included in an assembly drawing?

Answer 7

Only those needed to assemble the parts included

Question 8

What is an assembly?

Answer 8

• multi piece item that can be disassembled in to its components or units without being destroyed
• cannot perform a complete function independently

Question 9

What’s the main purpose of an installation drawing?

Answer 9

• To show exactly where certain parts or assemblies are to be permanently fixed, pertaining to the aircraft

Question 10

What does the bill of material on an installation drawing show?

Answer 10

Any instructions required for the installation
Any fasteners needed
Dimensions only given for those adjustments needed for the part to function

Question 11

What is the difference between assembly and installation drawings in terms of locating?

Answer 11

Assembly drawings give parts locations in relation with each other.
Installation drawings give their position relative to the aircraft.

Question 12

What word is in the title of all installation drawings?

Answer 12

“Installation”

Question 13

When is a sectional drawing used?

Answer 13

To show a parts internal construction or shape

Question 14

What are the four types of sectional drawings?

Answer 14

Revolved
Removed
Complete
Half section

Question 15

Revolved section drawings: where is the cutting plane?

Answer 15

Cutting plane is perpendicular through the feature/ object

Question 16

Revolved section drawings: how is the material cut with the cutting plane projected?

Answer 16

Rotated 90 degrees
Projected to the adjacent view on the adjacent view

Question 17

When is a revolved drawing used and what does it show?

Answer 17

• used when only the shape of a part needs to be shown
• shows how a part is sectioned and revolved to illustrate it from a different view

Question 18

What is a removed section drawing used for?

Answer 18

• to illustrate simple objects from another angle

Question 19

If a drawing becomes too cluttered, where can removed drawing be displayed?

Answer 19

Section can be drawn adjacent to the view

Question 20

What are complete sectional drawings used for?

Answer 20

To illustrate complex assemblies such as cable connectors

Question 21

What does a half sectional drawing show?

Answer 21

Upper half of the drawing: assembly’s internal construction
Lower half: shows the entire assembly from the outside

Question 22

Identify the drawing: All parts are in their relative positions but are extended outwards, so that each can be identified by their physical appearance or name

Answer 22

Exploded view drawings

Question 23

What does a block diagram consist of?

Answer 23

Individual blocks that represent several components
Shows how they are all connected

Question 24

What are block diagrams used for?

Answer 24

To aid troubleshooting of complex electrical and electronic systems

Question 25

What do logic flowcharts show?

Answer 25

- shows specific logic gates and their relationship to other digital devices in a system using standardised symbols - shows the inputs and outputs of individual components

Question 26

What were logic flowcharts specifically developed for?

Answer 26

For analysing digitally controlled components and systems

Question 27

What do schematic drawings show?

Answer 27

- the principle of the operation - where objects are located only in relation to each other - direction of fluid flow (if applicable)

Question 28

Can the exact image of an object be seen in a schematic drawing?

Answer 28

No

Question 29

What do electronic schematic diagrams show?

Answer 29

- show symbols for each component found in the circuit - show function and flow

Question 30

Do electronic schematic diagrams show the placement or scale of components?

Answer 30

No

Question 31

What dimensional are pictorial diagrams?

Answer 31

Two dimensional drawings

Question 32

What are schematic drawings mostly used for by engineers?

Answer 32

Fault diagnosis See how components in complex systems interact

Question 33

What do the types of projection refer to?

Answer 33

- orientation - how it’s viewed on a flat plame

Question 34

How is an orthographic projection drawing presented?

Answer 34

- Represents 3D object using several two dimensional views of the object

Question 35

In an Orthographic projection, how many possible views are there from which an object can be drawn?

Answer 35

Six views: Front Rear Top Bottom Left side Right side

Question 36

How does the first angle represent an object?

Answer 36

“Represent the side of the object that is remote from it in adjacent view” The drawing is next to the part of the object it represents

Question 37

How does the third angle present an object?

Answer 37

“Each view represents the side of the object that is nearest to it in the adjacent view” The drawing is illustrated on the side opposite of the object

Question 38

Which angle is European in origin?

Answer 38

The first angle

Question 39

What is the first angle projection symbol?

Answer 39

Rectangle : target

Question 40

What’s an isometric drawing?

Answer 40

Tilts an object forward so all three views can be seen in one view

Question 41

Where are all the edges of the object on an isometric drawing?

Answer 41

The edges of the object all form a 30 degree angle to the drawing plane

Question 42

What is an oblique drawing?

Answer 42

- An isometric drawing with one object face parallel to the drawing plane - front if the object identical to the front view of an orthographic drawing

Question 43

What is the depth axis of an oblique drawing?

Answer 43

- anything convenient - most often 45*

Question 44

What are perspective drawings?

Answer 44

- shows an object as it would appear to the observer

Question 45

Are the actual angles and dimensions in a perspective drawing accurate? Why?

Answer 45

- not accurate - lines aren’t parallel as it imitates how you’d see the object irl

Question 46

In a drawing, if no inch mark is used what is the dimension given in?

Answer 46

Inches

Question 47

What do centre lines look like?

Answer 47

Made up of alternate long and short dashes — - — - — - —

Question 48

What are dimension lines?

Answer 48

- an arrow with a vertical line on each side

Question 49

How are the dimensions of circular parts given?

Answer 49

- In terms of the circles diameter - Marked with the letter D or DIA

Question 50

How are dimensions of an arc displayed?

Answer 50

- given in terms of radius - marked w an R following the dimension

Question 51

What do section lines show?

Answer 51

Indicate the exposed surfaces of an object in a sectional view

Question 52

What do phantom lines indicate?

Answer 52

Alternate positions or layers or the object, or the relative position of a missing part

Question 53

What do phantom lines look like? Is

Answer 53

One long and two short evenly spaced dashes — - - — - -

Question 54

What do break lines indicate? What do they look like?

Answer 54

- indicate a portion if the object is not shown - short breaks are made by solid, freehand lines. Long breaks shown by solid rules lines w zigzags

Question 55

What do leader lines indicate and how do they look?

Answer 55

- indicate a part or option that a note, number or other reference applies - solid lines with one arrowhead

Question 56

What are Biden lines also referred to as?

Answer 56

Dash lines - - - -

Question 57

What do cutting plane lines indicate?

Answer 57

Indicate the plane where a sectional view of the object is taken

Question 58

What do viewing plane lines indicate?

Answer 58

Indicate the plane from where a surface is viewed

Question 59

What’s the difference in the symbol of a solid metal rod and a hollow tube?

Answer 59

Solid metal is shaded

Question 60

What are finish marks used for?

Answer 60

To indicate the surface has to be machine finished

Question 61

Surface texture: is the number bigger or smaller if the surface finish is to be smoother?

Answer 61

Smaller Smaller the number above the triangle- smoother the finish.

Question 62

What does a circle above a triangle for surface finish mean?

Answer 62

No surface finish

Question 63

When there’s a single number on the surface finish symbol, what does it mean?

Answer 63

That is the maximum degree of roughness acceptable

Question 64

What a thick lined circle portrait?

Answer 64

Drilled holes

Question 65

What do threaded holes have to show the thread crest and root?

Answer 65

Thread crest: thick circular line Root: thin circular line

Question 66

When the depth for a counterbored, countersunk or spotfaced hole aren’t given, what is the depth required?

Answer 66

The minimum depth required to achieve a flat seating

Question 67

Whats the purpose of zones in an engineering drawing?

Answer 67

makes locating items easier

Question 68

Where is the revision block?

Answer 68

upper right hand corner

Question 69

What AN?

Answer 69

Army Navy