Aircraft drawing

Working drawings

- detail drawings - assembly drawings - installation drawings

Line types

- visible lines - hidden lines - center lines - extension lines - dimension lines - cutting-plane line - phantom lines - break lines - leader lines

What is the ATA code for "Electrical Power"?

24

What is the ATA code for "Equipment/ Furnishings"?

25

What is the ATA code for "Fuel"?

28

What is the ATA code for " Lights/ Lighting"?

33

What is the ATA code for "Navigation"?

34

Title block

A table located in the bottom right-hand corner of an engineering drawing that identifies, in an organized way, all of the necessary information that is not given on the drawing itself. Also referred to as a title strip. Includes the Title Box, Drawing Number, Scale, Page, Standards, Material List, and Application. revision is a different block

Zone

Aircraft drawings can be quite large, therefore, a grid reference with letters and numbers is utilized to locate particular items.

Center line

Alternating long and short dashes, lightweight - Used to show the center of a symmetrical part. Exact center is marked by the intersection of two short dashes.

Fuel consumption

Another type of performance chart. Example: How much fuel is being consumed at a cruise of 2000 RPM? Locate 2400 RPM on the bottom of the chart, move up to "Propeller Load-Specific Fuel Consumption" curve. Move to the right to show 0.47 Lb/BHP/Hr. Go back to 2400 RPM and move upward to the "propeller Load Horsepower" curve. Move left to give 127 Brake Horsepower. Calculate 0.47 x 127 = 59.69 Lb/Hr

Graphic representation of calculations:

Bar graphs, pictographs, broken-line graphs, and pie charts.

Wire chart

Block 1: System voltage (28v) Block 2: Length of wire in feet (25ft) Block 3: Max intermittent current (125A in this case) Block 4: Shows the maximum allowed in a bundle. (this example is in a bundle so we must be at or above line 1) Block 5: Follow the diagonal (125A) up to line 1 (bundle line) Block 6: Drop straight down to show wire size required (this one falls between 0 and 1 so choose the largest...0) ***NOTE: "0" wire is known as "aught". "00" size is "double-aught"*** curve one represents the continuous rating of a wire when routed in bundles or conduit. if the intersection of the current and wire length lines are above this curve, the wire can carry the current without generating excessive heat. if the intersection of the current and wire length lines falls between curve one and two, the wire can only be used to carry current continuously in free air. if the intersection falls between curves two and three, the wire can only be used to carry current intermittently.

Hidden line

Dashed line, medium weight - indicates invisible edges or contours.

Assembly drawing

Depicts the relationship between 2 or more parts. *** No materials are specified and only those dimensions needed to assemble a part are included.***

Dimensioning/ Dimension

Dimensioning - Basic or nominal dimensions represent the perfect size of a part. Dimensions - must be placed on a drawing in a uniform manner to promote clarity.

Fin style

Equipment on the A/C is generally allocated a unique identifier known as a Functional Item Number (FIN). The basic element of the FIN is a two letter code indicating to which system and circuit the equipment belongs. To this code are added prefixes and/or suffixes which provide the unique identification for individual equipment

Horse power

Find % of "Sea Level Horsepower" generated at 7000 ft...an engine can create more horsepower at sea level due to denser air. Luckily, much less horsepower is required at a higher altitude due to less drag.

Sectional/ half-sectional

Half sectional (top item) - Identifies the external and internal details...basically illustrates a part cut in half. Sectional view - Used to identify individual parts within a complex assembly.

Phantom line

Lightweight consists of long dashes and two short dashes - Indicates the presence of another part, included for reference.

Leader line

Lightweight line with arrowheads - extends from a note, number, or information box to a part. These lines should never cross a dimension line, an extension line, or another leader line.

Cutting-plane line

Medium weight, alternating long/short dashes, Arrowheads show the direction in which the view is taken and have letters to identify the section shown - Used to indicate the plane in which a sectional view of an object is taken.

Break line

Medium weight, usually drawn freehand - Indicates that a part continues.

NHA

Next higher assembly

Revolved/ Removed section

Revolved section - Used to illustrate simple items. Shows a rotated view of the same part. Removed section - The object illustrated is cut and a section is removed to illustrate another angle.

Installation drawing

Shows the general arrangement or position of parts with respect to the aircraft and provides the information necessary to install them. *** Dimensions are given only for those adjustments necessary for the part to function.***

Dimension line

Solid line with broken center, arrowheads at ends - A dimension number is inserted in the break.

Extension line

Solid line, lightweight - Extend from a point where a measurement can be made. A 1/16th inch from the part's edge.

Visible line

Solid line, medium weight - used to illustrate a visible part.

Detail drawing

Supplies all the information required to construct a part. Includes all dimensions, materials, and type of finish (buffed, painted, etc). Enlarged sections (views) are normally provided when required to facilitate understanding. ***All dimensions should be derived from the dimensions given on the diagram.***

Allowance

The difference between the nominal dimension and the upper or lower limit. Example - 0.3125 +/- 0.0005 means the allowance is between 0.3125 and 0.3130 and the Tolerance is 0.0010 or +/- 0.0005

Wire numbering

The most standard system uses the ATA 100 codes.

Revision block

This is an information block located in the upper right-hand corner of a drawing and indicates the number of revisions since the drawing was new.

Station number

This type of drawing shows distances from a fixed points on the aircraft along all axes. Datum point: the point of initial measurement along the longitudinal axis. There is no fixed rule for its location, and it may be located forward of the nose of the aircraft, at the nose, or aft of the nose. (will be stated in the maintenance manual). A point forward of the Datum point will have a "-" number.

Brake horsepower

Type of performance chart developed by engineers. Example: 2000 cubic inch displacement, 2400 RPM, 1500 brake horsepower. What is the Brake Mean Effective Pressure? Answer: Start at 1500 bhp, drop down to 2000 cid, move horizontally to 2400 RPM, intersects with 248 BMEP

What type of drawing supplies complete information for the construction of a single part?

a detail drawing

What type of chart may be used to keep troubleshooting time to a minimum?

a logic flowchart

Isometric drawing

a projection of a 3-dimensional object on a flat plane. the object is rotated until 3 sides are visible.

What type of drawing is made to show the internal construction or shape of a part?

a sectional drawing

Auxiliary view

a type of rotational view that is used when it is necessary to view the object at an angle different than 90 degrees.

Note

added to a drawing to identify a deviation from the norm, give additional information, list alternatives, call attention to an item, or specify modifications to the norm.

_________ is the difference between the nominal dimensions and the upper or lower limit.

allowance

What type of drawing is often used in illustrated parts breakdowns to show every part that is in an assembly?

an exploded drawing

Oblique drawing

an isometric drawing with one face perpendicular to the drawing plane. ex) cabinet drawing, cavalier drawing

A(n) _________ drawing depicts the assembled relationships between two or more parts.

assembly

Simplified functional diagram

basically a cross between a block diagram and a schematic diagram. it has characteristics of both and is used to help in understanding the function of a circuit.

Distance to the right or left of the centre line of the fuselage are measured by __________ lines.

buttock

Sectional drawing

drawings that indicate construction or shape of a part.

(electrical) Schematic diagram

electrical schematics are intended to supplement the wiring diagrams and are used to explain the systems particular to the aircraft installation. they are also used as aids when tracing wires for trouble shooting and continuity checks.... this is a much simpler representation of a system that allows someone to follow the logical operation without having to trace wiring through a lot of other components that are not shown.

Name six views that are possible to have using orthographic projection. ______, ______, ______, ______, ______, ______.

front top bottom left side right side rear

A ______ line is used to represent an edge of a part that would not be visible in the view illustrated.

hidden

Electrical wiring diagram

identify the wire size, terminal types, part numbers, connections, and gives the ident code for the wires, terminals, bundles, ground studs, etc.

Exploded view

illustrated parts drawings use exploded views to show every part in the assembly. This is to be used for reference and does not supersede direction from the maintenance manual for "remove/ install".

A(n) _______ drawing shows the general arrangement of the parts or their position, and the information to install the items.

installation

The form of pictorial presentation that is most used for aircraft drawing and sketching is the __________ drawing.

isometric

NLA

next lower assembly

Circuit breaker

only one time reset allow

A ______ drawing shows an object more like the human eye sees it than either an isometric or oblique drawing.

perspective

An alternate position of a part may be shown using ________ lines.

phantom

Pictorial diagram

pictures of components are used instead of conventional electrical symbols. these diagrams help a person visualize the operation of a specific system.

Logic flowchart

represents the mechanical, electrical, or electronic action of a system without expressing construction or engineering.

The title block will be found in the lower _________ hand corner of every aircraft drawing.

right

A ________ diagram is used to explain a principle of operation, rather than to show the parts as they actually appear, or as they actually function.

schematic

Locations fore and aft along the fuselage, measured from a datum are called ________ _________.

station numbers

Orthographic projection

there are 6 possible views of orthographic projection from which an object can be drawn.

What information may be found in the title block? ______, ______, ______, ______, ______, ______, ______, ______, ______.

title size drawing scale page responsibility standards bill of materials application

The ________ is the difference between the extreme permissible dimensions.

tolerance

Block diagram

troubleshooting manuals utilize this type of drawing to aid the technician in locating problems.

(mechanical) Schematic diagram

used to illustrate a principle of operation and therefore, does not show parts as they actually appear.

Section line

used to show the difference in types of materials or exposed surfaces.

Perspective drawing

used when the view must depict what the human eye sees. the lines on the drawing converge or meet at the "vanishing point".

What line is used to show any edge of a part that is visible in the view represented by the drawing?

visible

Vertical measurements on aircraft fuselage are made along _________ lines.

water

______________ stations are measured from the center line of the fuselage, and indicate the distance out along the wing toward the tip.

wing

________ numbers on aircraft blueprints are used to locate parts, sections, and views on large drawings.

zone