Aircraft Drawings
1. Schematic diagrams indicate the location of individual components in the aircraft. 2. Schematic diagrams indicate the location of components with respect to each other within the system. Regarding the above statements
C. Only #2 is true Schematic diagrams show the location of components with respect to each other within a system, not their actual location in the aircraft.
Using the information, what size drill would be required to drill the clevis bolt hole? Refer to figure 4-8 below
A. 5/16 The drawing below notes that the clevis bolt hole should have a diameter of .3125 The drill bit size decimal equivalents are: 5/16=.3125, 21/64=.3281, and 1/2=.5, therefore the 5/16th would be the correct drill bit to use.
M. These lines are made up of alternate long and short dashes.
A. Center Line
The measurements showing the ideal or "perfect" sizes of parts on drawings are called
C. Dimensions Although not specifically defined, dimensions are the preferred (ideal/perfect) measurements for a part. Allowances and tolerances define deviations from these preferred measurements, if acceptable.
Where are title blocks normally located on an aircraft drawing?
C. Lower right hand corner Title blocks are normally located in the lower right hand corner, but may also extend along the entire distance across the bottom of a drawing.
B. Using figure 4-33 on page 4-27 of the textbook "Electrical Wiring Chart". In a 28 volt system with a required 50 feet of bundled wire and a 15 amp load, determine the required wire size.
14-16 Gauge Wire
B. Based on the chart of figure 4-32 on page 4-26 of the textbook, "Nomogram". What is the specific weight of Jet A at 10°C in lbs per gal?
6.800 + or - .02 lbs per gal
The -100 in the title block (Area 1) is applicable to which doubler part number(s) diagrams in the figure 4-1 below?
A. -101 Locate the specific information in the title block pertaining to -100 (see figure 4-1). Locate the doubler. There are two doublers required; reading to the left will tell you which part number is applicable to -100 part assemblies.
What is the allowable manufacturing tolerance for a bushing where the outside dimensions shown on the blueprint are: 1.0625 +.0025 - .0003?
A. .0028 Tolerance is the sum of the plus and minus allowable deviation of the dimensions. Therefore, in this example you would add the maximum allowable deviation of. 0025 and the minimum allowable deviation of. 0003 (ignoring the negative sign) for a tolerance of .0028.
What is the maximum diameter of the hole for the clevis pin? Refer to figure 4-8 below.
A. 0.3175 The diameter of the clevis hole is 0.3125 with an allowance of +0.005 and -0.000, which means the maximum size the hole can be 0.3175
B. Use the figure below to identify the lines used in the drawing
A. Phantom Line B. Center Line C. Outline D. Hidden Line E. Cutting Plane Line F. Break Line G. Dimension Line H. Extension Line I. Sectioning Line J. Leader Line
A sectional drawing depicts
A. an object by cutting away part of the object to show the shape and construction at the cutting plane. A sectional drawing depicts an object by cutting away part of the object to show the shape and construction at the cutting plane, they can be full, half, revolved and removed section drawings depending on the objective of the drawing.
Zone numbers on aircraft blueprints are used to
A. locate parts, sections, and views on large drawings. Zone numbers on drawings are there to help you locate a specific area on the drawing. To locate the referenced area on a drawing, locate the letter and number and then mentally draw horizontal and vertical lines from the letter and number to where they intersect on the drawing. This is the location where you will find the referenced point.
Refer to figure 4-3; identify the bottom view of the object shown.
B. 2 View 2 in figure 4-3 is the correct orthographic view for this part. The bottom of the object is solid, remembering that dashed vertical lines represent features of the part that are hidden from the view being represented, here the bottom.
M. A light solid line broken at the midpoint for insertion of measurement indications and having opposite pointing arrowheads at each end.
B. Dimension Line
Which statement is applicable when using a sketch for making a part?
B. The sketch must show all information to manufacture the part The degree to which a sketch is complete will depend on its intended use. However, it must show all information necessary for its intended use. In the example, for making a part, it must have all the information to manufacture the part.
The diameter of the holes in the finished object in the diagram (Figure 4-2) are
C. 1/2 inch. Refer to the notes in the figure 4-2. Answer: They state the holes are to be drilled to diameter of 31/64 and then reamed to 1/2 inch.
Refer to figure 4-12 below. Which material section-line symbol indicates cast iron?
C. 3 Item #3 in figure 4-12 on the previous page represents cast iron, #2 is steel, and #1 represents rubber, plastic, or electrical insulation.
M. This type of line is composed of one long and two short evenly spaced dashes.
C. Phantom Line
List 8 pieces of information contained in the title block of a drawing: __________ __________ __________ __________ __________ __________ __________ __________
Drawing Number, Number of Part, Scale Name of Checker, Date, Firm Name, Name of Draftsman, Name of Person Approving Drawing
M. These type of lines are used for all lines on the drawing representing visible lines on the object.
G. Outline or Visible Line
M. This type of line indicates invisible edges or contours.
H. Hidden Line
__________ use a combination of the views of an orthographic projection and tilts the object forward so that portions of all three views can be seen in one view.
Isometric View
B. Explain tolerances as they pertain to drawings.
It is the allowable variation from the given dimension on the drawing. A + Figure indicates the maximum and a - indicates the minimum variation from the given dimension.
M. This line indicates stitching or sewing lines and consist of a series of evenly spaced dashes.
J. Stitch Line
B. In figure 4-20 on page 4-17 of the textbook " Block diagram". If the voltage selector was completely inoperative, would the power amplifier receive any signal?
No
A __________ drawing shows an object as it appears to an observer.
Perspective
Every __________ must have some means of identification.
__________ diagrams are used mainly in troubleshooting.
Schematic
B. Using figure 4-18 on page 4-15 of the textbook " Example of Installation Drawing",what component secures the altitude/vertical speed selector?
Screw
O. Define tolerance as it relates to aircraft drawings.
Tolerance is the allowable variation, the plus (+) figure indicates the maximum, and the minus (-) figure indicates the minimum allowable variation. The sum of the plus and minus allowance figures is called tolerance
T or F? Troubleshooting flowcharts are frequently used for the detection of faulty components.
True
B. What does the term scale refer to on a drawing.
When parts or objects are much larger than the area available for the drawing it must be drawn to some scale. If it was small enough to fit on the drawing paper it could be drawn to a scale of 1:1. But if it is larger it must be drawn to scale, such as 1 inch on the drawing represents 1 foot on the object.
Explain a dimension line and what is it used for.
A dimension line is a light solid line, broken at the midpoint for insertion of measurement indications, and having opposite pointing arrowheads at each end to show origin and termination of a measurement. They are generally parallel to the line for which the dimension is given, and are usually placed outside the outline of the object and between views if more than one view is shown.
Refer to figure 4-6. Identify the bottom view of the object shown.
A. 1 View 1 in figure 4-6 is the correct orthographic view for this part. The bottom of the object is solid, remembering that dashed vertical lines represent features of the part that are hidden from the view being represented.
An aircraft reciprocating engine has a 1,830 cubic inch displacement and develops 1,250 brake horsepower at 2500 RPM. What is the brake mean effective pressure? Refer to figure 4-13 below.
A. 217 Start at the 1,250 brake-horsepower vertical line, follow it to where it intersects with the diagonal line representing the 1830 cubic inch displacement engine. Then, follow the vertical line from this intersection to the diagonal line for 2,500 RPM, at this intersection follow the vertical line to the bottom to read the brake mean effective pressure. The graph is hard to read but the closest answer is 217 BMEP.
Identify the extension line in figure 4-9 below.
A. 3 Extensions are used to extend the line showing the side or edge of a figure for placing a dimension to that side or edge. They are very narrow and have a short break where they extend from the object and extend a short distance past the arrow of the dimensioning line. Item #3 in figure 4-9 from the previous page represents extension lines.
Determine the maximum length of No. 16 cable to be installed from a bus to the equipment in a 28-volt system with a 25-ampere intermittent load and a 1-volt drop. Refer to figure 4-14 below.
A. 8 feet Utilizing Figure 4-14 on the previous page, first draw a line mid-way between the 20 and 30 amperes lines to use as a guide to represent the 25 amperes in this question. Find the 16-gage wire size we will be using, follow this line until it intersects with the 25-ampere line drawn, draw a line from this intersection to the left column for a 28-volt circuit with a 1-volt drop and the answer is 8 feet.
In what type of electrical diagram are images of components used instead of conventional electrical symbols?
A. A pictorial diagram This is not specifically addressed within the text. However based on your knowledge of the three answers determine the one that best fits the question. Block diagrams used blocks to simplify the relationship between components of a more complex system and do not use electrical systems. Schematic diagrams show the location of components with respect to each other within a system and do not use electrical systems. Pictorial drawings are similar to photographs. The question refers to images of the components, therefore this would be the most correct answer.
Refer to figure 4-7. In the isometric view of a typical aileron balance weight, identify the view indicated by the arrow.
B. 3 An isometric view uses a combination of the views from an orthographic projection and tilts the object forward so that portions of three views are seen at once.
For sketching purposes, almost all objects are composed of one or more combinations of six basic shapes. These include:
B. Triangle, circle, cube, cylinder, cone, and sphere. The six basic shapes used in sketching include the triangle, circle, cube, cylinder, cone, and sphere.
Refer to figure 4-5; Identify the left side of the object shown.
C. 3 View 3 in figure 4-5 on previous page is the correct view of the left side of the object.
What do flowcharts illustrate?
C. The flow of events or a particular sequence. Flowcharts illustrate a particular sequence or flow of events. There are troubleshooting flowcharts used to aid you in detecting a faulty component. You will find these in the fault isolation manuals. Another flowchart you will use in your career is the logic flowchart that uses standardized symbols to indicate specific types of logic gates and their relationship to other digital devices in a system. This type of flowchart is also used for troubleshooting by illustrating decisions and reactions. By using standardized symbols, decisions and actions can be indicated.
M. These lines are used to extend the line showing the side or edge of a figure for the purpose of placing a dimension to that side or edge.
E. Extension Line
__________ are used to illustrate a particular sequence or flow of events.
Flowcharts
B. Using figure 4-19 on page 4-16 of the textbook "Air Conditioning System for B-737". What are the two sources of cooling air when in flight?
Left and Right Engine Bleed Air
O. What information can you find on the title block of an aircraft drawing?
The information found in a title block is as follows: A drawing number to identify the print for filing purposes and to prevent confusing it with any other print. 1. The name of the part or assembly. 2. The scale to which it is drawn. 3. The date. 4. The name of the firm. 5. The name of the draftsman, the checker, and the person approving the drawing.
T or F? Drawings and prints are the link between the engineers who design an aircraft and the workers who build, maintain, and repair it.
True
T or F? The universal numbering system provides a means of identifying information standard drawing sizes.
True
O. Define clearance as it relates to aircraft drawings.
The dimensions given for tolerances signify the amount of clearance allowable between moving parts. A positive allowance is indicated for a part that is to slide or revolve upon another part. A negative allowance is one given for a force fit.
B. When using a digital image for transmitting information to others what type of information should be included to help define the damaged area.
The exact location of the damage should be referenced by station, waterline and so forth. Using a measuring scale also will help determine the extent of the damage.
List the 4 basic types of drawings: __________ ___________ __________ __________
Detailed, Assembly, Installation, Sectional View
What would be the minimum diameter of 4130 round stock required for the construction of the clevis that would produce a machined surface? Refer to figure 4-8 below.
B. 1 inch The question is stating that all the surfaces of the clevis are machined. Therefore the part needs to be larger than its largest finished dimension which is 7/8 inch. 55/64 is equivalent to 0.859375 which is too small, and 7/8 is also too small, and 7/8 is also too small if it must be machined. Therefore the minimum diameter of 4130 round stock must be 1 inch.
Determine the proper tension for a 3/16 inch cable (7x19 extra flex) if the temperature is 87 degrees F. Refer to figure 4-15 below.
B. 125 pounds Utilizing figure 4-15 below, from the 87° mark on the bottom of the graph, draw a vertical line up until it intersects with the 3/16 7 x 19 cable curve. From this intersection draw a horizontal line to the right scale on the graph to read the proper rigging load in pounds, 125 is the closest answer.
An aircraft reciprocating engine has a 2,800 cubic inch displacement and develops 2,000 brake horsepower, and indicates 270 brake mean effective pressure. What is the engine speed RPM? Refer to figure 4-13 on the previous page.
B. 2,100 Utilizing figure 4-13 on the previous page, start at the 2,000 brake-horsepower vertical line, follow it to where it intersects with the diagonal line representing the 2,800 cubic inch displacement engine. Draw a horizontal line from this intersection to the right of the chart. Locate the 270 brake mean effective pressure on the bottom scale, draw a vertical line up until it intersects with the horizontal line you drew previously; from here, you can determine that the RPM for this engine will be 2100.
What type of diagrams is used to explain a principle of operation, rather than show the parts as they actually appear?
B. A schematic diagram Schematic diagrams show functional location of components within a system, and by studying the various components and how they are related within the system the AMT can learn how the system operates. Schematic diagrams of this type are often used in troubleshooting.
A drawing in which the subassemblies or parts are shown as brought together on the aircraft is called
B. An installation drawing Installation drawings are used extensively in aircraft maintenance and repair manuals. They provide the AMT a visual representation of how the various parts and/or subassemblies are assembled.
M. This line indicates that a portion of the object is not shown on the drawing.
F. Break Line
T or F? Drawings may be divided into three classes detail, assembly, full section.
False
T or F? Half sections are used to advantage with symmetrical objects to show only exterior views.
False
M. This line uses a solid line with one arrowhead and indicate apart or portion to which a note, number, or other reference applies
I. Leader Line
What are the proper procedural steps for sketching repairs and alterations? Refer to figure 4-10 below.
A. 3, 1, 4, and 2 To make a sketch, first determine what views are necessary to portray the object, then block in the views, using light construction lines. Next, complete the details, darken the object outline, and sketch extension and dimension lines. Complete the drawing by adding notes, dimensions, title, date, and when necessary, the sketcher's name.
1. A detail drawing is a description of a single part. 2. An assembly drawing is a description of an object made up of two or more parts. Regarding the above statements,
A. Detail drawings depict single parts, providing information for construction of the part including specifications on size, shape, material, and method of construction. Assembly drawings depict objects made up of two or more parts. They can display the various dimensions of the part; however, the primary purpose is to show how the various parts are assembled.
The drawings often used in illustrated parts catalogs/manuels are
A. Exploded view An exploded view is a pictorial drawing of two or more parts that fit together as an assembly. The view shows the Individual parts and their relative position to other parts before assembled.
One purpose for schematic drawings is to show the
A. Functional location of components within a system. Schematic diagrams show the location of components with respect to each other within a system. In other words, their functional location not necessarily their actual location within the system.
1. A measurement should not be scaled from an aircraft print because the paper shrinks or stretches when the print is made. 2. When a detail drawing is made, it is carefully and accurately drawn to scale, and is dimensioned. Regarding the above statements:
B. Both #1 and #2 are true Scaled drawings are representations drawn in the same proportions as the original. They can be the same (1:1), smaller (1/4 inch), or larger (2:1). Never re-measure the paper drawing to determine a measurement, even if noted as scaled 1:1. The paper can shrink or stretch and with today's technology, copies are easily reduced or enlarged yet will still note a scale of 1:1. ALWAYS use the dimensions on the drawing.
What material symbol is frequently used in sectional drawings to represent all metals?
B. Cast iron Section line symbols show the kind of material from which the part is to be constructed. The material may not be indicated symbolically if its exact specification is shown elsewhere on the drawing. In this case, the more easily drawn symbol for cast iron is used for the sectioning, and the material specification is listed in the bill of materials or indicated in a note.
A schematic diagram of a hydraulic system would indicate the
B. Direction of fluid flow through the system. Schematic diagrams show the location of components with respect to each other within a system. In other words, their functional location. In this question, the direction of fluid flow with the system would be depicted as part of its functionality. Actual location, type, and quantity of hydraulic fluid would not be found in a Schematic diagram.
When reading aircraft blueprints, the term "tolerance" used in association with aircraft parts or components
B. Is the difference between extreme permissible dimensions that a part may have and still be acceptable. Tolerance is defined as the difference between extreme permissible dimensions that a part may have and still be acceptable. This definition is equivalent to "the sum of the plus and minus allowance figures" used in the text. In the text definition, you ignored the signs and added the numbers. For this definition, you keep the signs. Difference in this context means subtraction; remember that subtracting a negative is the same as adding a positive.
1. According to FAR Part 91, repairs to an aircraft skin should have a detailed dimensional sketch included in the permanent record. 2. On occasion, a mechanic may need to make a simple sketch of a proposed repair to an aircraft, a new design, or a modification. Regarding the above statements,
B. Only #1 is true To determine this answer you have to know the FARs. Although statement 1 appears logical, not all repairs need to have detailed dimensional sketches included.
Refer to figure 4-11 below. What is the next step required for a working sketch of the illustration?
B. Sketch extension and dimension lines. To make a sketch, first determine what views are necessary to portray the object; then block in the views, using light construction lines. Next, complete the details, darken the object outline, and sketch extension and dimension lines. Complete the drawing by adding notes, dimensions, title, date, and when necessary, the sketchers name.
Which of the following terms is/are used to indicate specific measured distances from the datum and/or other points identified by the manufacturer to points in or on the aircraft?
B. Station numbers A station number is a reference measure from a reference point. For aircraft, these reference points are the datum for fuselage measurement, the buttock line for measurements left and right of the aircraft's longitudinal axis, and the waterline for measurements below and above a reference line running from the nose of the aircraft to the tail.
When reading a blueprint, a dimension is given as 4.387 inches +.005 -.002, which statement is true?
B. The minimum acceptable size is 4.385 inches. When a given dimension on a print shows an allowable variation, the plus (+) figure indicates the maximum allowable acceptable dimension, the negative (-) figure indicates the minimum allowable/acceptable dimension. In this example the following are true: Maximum allowable/acceptable dimension is 4.387 + .005 = 4.392 Minimum allowable/acceptable dimension is 4.387 - .002 = 4.385
According to figure 4-4 the vertical distance between the top of the plate and the bottom of the lowest 15/64 inch hole is?
C. 2.367 Add the following dimensions from figure 4-4: Distance from the top of the plate to center of the top hole is 3/8" or 0.375" Distance from the center of first hole to the center of the center of second hole is 7/8" or 0.875" Distance from the center of the second hole to the center of the third hole is 7/8" or 0.875" Distance from the center of the third hole to the center of the fourth hole is 1/8" or 0.125" Distance from the center of the fourth hole to the bottom edge is 15/128" or 0.117" 0.375 + 0.875 + 0.875 + 0.125 + 0.117 = 2.367"
What should be the first step of the procedure in sketching an aircraft wing repair?
C. Block in the views. Blocking in the views is the first step for this type of sketching. The second step is to complete the drawing details, the third step is to sketch extension and dimension lines and the fourth step is to add notes and dimensions.
What is the class of working drawing that is the description/depiction of a single part?
C. Detail drawing Detail drawings depict single parts, providing information for construction of the part including specifications on size, shape, material, and method of construction.
In an aircraft drawing, what type of line would be drawn if it was composed of one long and two short evenly spaced dashes indicating the alternate position of parts of an object or relative position of a missing part
C. Phantom Line Phantom lines composed of one long and two short evenly spaced dashes indicate the alternate position of parts of the object or the relative position of a missing part.
Which statement is true regarding an orthographic projection?
C. The most common are 1 view, 2 view, and 3 view drawings. An orthographic projection is a two-dimensional representation of a three-dimensional object. Three-dimensional objects can be viewed from six sides: front, top, bottom, rear, right side, and left side. Rarely are all views necessary to portray an object clearly, therefore one, two, and three views are the most commonly drawn.
The Process in which a computer is used in the design and drafting process is known as __________
Computer Aided Design Drafting
The Process in which a computer is used in the engineering of a product is known as __________
Computer Aided Engineering
Drawings made with the use of a computer are known as __________
Computer Graphics
M. These lines indicate the exposed surfaces of an object in a sectional view.
D. Sectioning Line
B. Describe the information that a drawing conveys to the person reading the drawing.
Drawing must provide information such as size and shape of the object and all of its parts, specifications for material to be used, how the material is to be finished, how the parts are to be assembled, and any other information essential to making and assembling the particular object.
