Aircraft Drawings Flashcards
- What type of line is normally used in a drawing or blueprint that indicates invisible edges or contours?
A— Medium-weight short dashes evenly spaced.
B— Medium-weight very short dashes evenly spaced.
C— Thin-weight, one long and two short dashes evenly spaced.
A— Medium-weight short dashes evenly spaced.
Explanation: A medium-weight dashed line is called a hidden line and is used to show an edge or object not visible to the viewer. A medium solid line is used as a visible outline or object line. Alternate short and long light dashes are used to show a center line.
- (Refer to Figure 27.) In the isometric view of a typical aileron balance weight, identify the view indicated by the arrow.
A— 1.
B— 3.
C— 2.
B— 3.
Explanation: View 3 shows the aileron balance weight as seen from the direction shown by the arrow. This view shows the outline of the weight and the outline of the hole. Both of these are drawn as solid lines. The two bolt holes are shown as light dashed lines (hidden lines), and there are also two hidden lines that show the break lines where the radius begins for the tip of the weight.
- (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— only 1 is true.
B— neither 1 nor 2 is true.
C— both 1 and 2 are true.
C— both 1 and 2 are true.
Explanation: Statement 1 is true. A detail drawing is a description of a single part that includes enough information to allow the part to be manufactured (fabricated). Statement 2 is also true. An assembly drawing is a drawing that shows the way various detail parts are put together to form an assembly or a subassembly. Assembly drawings refer to the various parts to be assembled by the drawing number of their detail drawings.
- (Refer to Figure 28.) Identify the bottom view of the object shown.
A— 2.
B— 3.
C— 1.
A— 2.
Explanation: View 2 shows the part as it would be seen looking up at it from the bottom. The vertical lines are hidden. View 1 is not a correct orthographic view of this part. View 3 is not a correct orthographic view of this part.
- A specific measured distance from the datum or some other point identified by the manufacturer, to a point in or on the aircraft is called a
A— zone number.
B— reference number.
C— station number.
C— station number.
Explanation: A station number is a number used to identify the number of inches from the datum or other point identified by the manufacturer to a point in or on the aircraft.
- Which statement is true regarding an orthographic projection?
A— There are always at least two views.
B— It could have as many as eight views.
C— One-view, two-view, and three-view drawings are the most common.
C— One-view, two-view, and three-view drawings are the most common.
Explanation: An orthographic projection can show as many as six views of an object. One-view, two-view, and three-view drawings are the most commonly used types of orthographic projections.
- (Refer to Figure 29.) Identify the left side view of the object shown.
A— 1.
B— 2.
C— 3.
C— 3.
Explanation: View 3 is the left side. The horizontal surface is shown as a hidden line. View 1 is the right side. We see the horizontal surface as a visible line. View 2 is the bottom view. The vertical surface is shown as a hidden line.
- A line used to show an edge which is not visible is a
A— phantom line.
B— hidden line.
C— break line.
B— hidden line.
Explanation: A phantom line is a light line made up of an alternate long dash and two short dashes. A phantom line shows the location of a part that is used as a reference. A hidden line is a medium-weight dashed line that shows a surface or a part that is not visible from the view in which it appears. A break line is a wavy or a zigzag line used to show that a part has been broken off and only part of it is shown.
8110 -1. What type of drawing line consists of alternating long and short lines?
A— Dimension.
B — Center.
C— Hidden.
B — Center.
Explanation: Centerlines are made up of alternate long and short dashes. They indicate the center of an object or part of an object. Where centerlines cross, the short dashes intersect symmetrically. In the case of very small circles, the centerlines may be shown unbroken.
- (Refer to Figure 30.) Identify the bottom view of the object.
A— 1.
B— 2.
C— 3.
A— 1.
View 1 is the bottom. The two vertical surfaces are shown as hidden lines.
View 2 is the left side. The two horizontal surfaces are shown as hidden lines.
View 3 is the top view. The two vertical surfaces are shown as visible lines.
8112 .
(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,
A— only 1 is true.
B— both 1 and 2 are true.
C— only 2 is true.
C— only 2 is true.
Explanation: Statement 1 is not true. Schematic diagrams do not indicate the location of individual components in the aircraft. Statement 2 is true. Schematic diagrams do show the location of the components with respect to each other within the system.
8113 .
(Refer to Figure 31.) What are the proper procedural steps for sketching repairs and alterations?
A— 3, 1, 4, and 2.
B— 4, 2, 3, and 1.
C— 1, 3, 4, and 2.
A— 3, 1, 4, and 2.
Explanation:
An easy way to make a sketch of a repair or alteration is to:
3 Block in the space and basic shape to be used for the sketch;
1 Add details to the basic block;
4 Darken the lines that are to show up as visible lines in the finished sketch; and
2 Add dimensions and any other information that will make the sketch more usable.
8114 .
Which statement is applicable when using a sketch for making a part?
A— The sketch may be used only if supplemented with three-view orthographic projection drawings.
B— The sketch must show all information to manufacture the part.
C— The sketch need not show all necessary construction details.
B— The sketch must show all information to manufacture the part.
Explanation: A sketch is a simple, rough drawing made rapidly and without much detail. A sketch is frequently drawn for use in manufacturing a replacement part. Such a sketch must provide all necessary information to those persons who must manufacture the part.
8115 .
(Refer to Figure 32.) What is the next step required for a working sketch of the illustration?
A— Darken the object outlines.
B— Sketch extension and dimension lines.
C— Add notes, dimensions, title, and date.
B— Sketch extension and dimension lines.
Explanation: In the sketch shown here, the part has already been blocked in, details have been added, the visible lines darkened, and the hidden lines added. The next step is to sketch in the extension lines and the dimension lines.
8116 .
For sketching purposes, almost all objects are composed of one or some combination of six basic shapes; these include the
A— angle, arc, line, plane, square, and circle.
B— triangle, circle, cube, cylinder, cone, and sphere.
C— triangle, plane, circle, line, square, and sphere.
B— triangle, circle, cube, cylinder, cone, and sphere.
Almost all objects are composed of one or some combination of the triangle, circle, cube, cylinder, cone, and sphere.
8116 -1.
In a sectional view drawing, what sections illustrate particular parts of an object?
A— Removed.
B— Revolved.
C— Half.
A— Removed.
A removed section illustrates particular parts of an object. It is similar to revolved sections, except it is placed at one side and, to bring out pertinent details, often drawn to a larger scale than the main view on which it is indicated.
- What should be the first step of the procedure in sketching an aircraft wing skin repair?
A— Draw heavy guidelines.
B— Lay out the repair.
C— Block in the views.
C— Block in the views.
In making a sketch of a repair, the first thing to do is to block in the views. As you block in the views, you are able to organize the sketch so it will clearly show the most information.
8117-1. A simple way to find the center of a circle on a sketch or drawing, or a circular piece of material is to
A— draw two non-parallel chord lines across the circle and then a corresponding perpendicular bisector line across each chord line.
B— draw two parallel chord lines across the circle and then a corresponding perpendicular bisector line across each chord line.
C— draw a single chord line across the circle and then a corresponding perpendicular bisector line across each chord line.
A— draw two non-parallel chord lines across the circle and then a corresponding perpendicular bisector line across each chord line.
An easy way to find the center of a circle on a sketch is to draw two non-parallel chord lines across the circle. Then, draw a perpendicular bisector of each of these chord lines. The bisector lines will cross at the center of the circle.
8118 .
(1) According to 14 CFR Part 91, repairs to an aircraft skin should have a detailed dimensional sketch included in the permanent records.
(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,
A— only 1 is true.
B— only 2 is true.
C— both 1 and 2 are true.
B— only 2 is true.
Statement 1 is not true. Part 91 requires that maintenance records contain “a description (or reference to data acceptable to the Administrator) of the work performed…” There is no requirement in Part 91 that a detailed dimensional sketch of a repair become a part of the aircraft’s permanent records. Statement 2 is true. A simple sketch is often needed to help a mechanic make a repair, a new design, or a modification.
- Working drawings may be divided into three classes. They are:
A— title drawings, installation drawings, and assembly drawings.
B— detail drawings, assembly drawings, and installation drawings.
C— detail drawings, orthographic projection drawings, and pictorial drawings.
B— detail drawings, assembly drawings, and installation drawings.
The three classes of working drawings are: detail drawings, assembly drawings, and installation drawings.
8119 -1.
What is the class of working drawing that is the description/depiction of a single part?
A— Installation drawing.
B— Assembly drawing.
C— Detail drawing.
C— Detail drawing.
A detail drawing is a description of a single part, given in such a manner as to describe by lines, notes, and symbols the specifications as to size, shape, material, and method of manufacture that are to be used in making the part.
- Sketches are usually made easier by the use of
A— graph paper.
B— plain white paper.
C— artist’s paper.
A— graph paper.
Sketches are easily made by using graph paper, which is available, ruled with light lines, in either four or five squares to the inch.
8120-1.
(1) Sketches are usually made with the aid of drafting instruments.
(2) Sketches are usually more complicated to make when using graph paper.
Regarding the above statements,
A— Only 1 is true.
B— Only 2 is true.
C— Neither 1 nor 2 is true.
C— Neither 1 nor 2 is true.
Sketches are simple drawings made without the use of tools. It is easier to do a sketch on graph paper where dimensions are easier to visualize without using tools such as a ruler.
- (Refer to Figure 33.) Which material section-line symbol indicates cast iron?
A— 1.
B— 2.
C— 3.
C— 3.
Section lines shown in 3 are for cast iron. Section lines shown in 1 are for rubber, plastic, or electrical insulation. Section lines shown in 2 are for steel.
- (Refer to Figure 34.) What is the dimension of the chamfer?
A— 1/16 × 37°.
B— 0.3125 + .005 − 0.
C— 0.0625 × 45°.
C— 0.0625 × 45°.
The chamfer is the tapered end of the cylindrical body of this clevis. The drawing shows that the end is chamfered at an angle of 45°, and the chamfer extends back for 1/16 inch. One-sixteenth of an inch is 0.0625 inch.
- (Refer to Figure 34.) What is the maximum diameter of the hole for the clevis pin?
A— 0.3175.
B— 0.3130.
C— 0.31255.
A— 0.3175.
The hole in this clevis through which the clevis pin fits has a diameter of 0.3125 (+0.005, -0.000) inch. The tolerance (+0.005, -0.000) allows us to make the hole anywhere between 0.3125 and 0.3175 inch in diameter.
- (Refer to Figure 34.) What would be the minimum diameter of 4130 round stock required for the construction of the clevis that would produce a machined surface?
A— 55/64 inch.
B— 1 inch.
C— 7/8 inch.
B— 1 inch.
The maximum diameter of the finished clevis is 7/8 (0.875) inch. To be sure that every part of this maximum diameter is machined, we would need to use a larger bar of material to make it. 55/64 inch = 0.859375 (this is too small) 1 inch (this is the correct choice) 7/8 inch = 0.875 (this is too small)
- (Refer to Figure 34.) Using the information, what size drill would be required to drill the clevis bolthole?
A— 5/16 inch.
B— 21/64 inch.
C— 1/2 inch.
A— 5/16 inch.
The drawing shows that the hole for the clevis bolt should have a diameter of 0.3125 (+.005, -0.000). This hole could be drilled with a 5/16 drill. The decimal equivalent of 5/16 inch is 0.3125.
- (Refer to Figure 35.) Identify the extension line.
A— 3.
B — 1.
C— 4.
A— 3.
3 is an extension line used to show the width of the paint stripe. 1 is a visible outline. 2 is a hidden line. 4 is a center line.
- (Refer to Figure 36.) The diameter of the holes in the finished object is
A— 3/4 inch.
B— 31/64 inch.
C— 1/2 inch.
C— 1/2 inch.
The two holes in this part have a finished diameter of 1/2 inch. They are made by first drilling them to a diameter of 31/64 inch and then reaming them to their final diameter of 1/2 inch. This information is found in note 1.
- Zone numbers on aircraft blueprints are used to
A— locate parts, sections, and views on large drawings.
B— indicate different sections of the aircraft.
C— locate parts in the aircraft.
A— locate parts, sections, and views on large drawings.
Large drawings used for manufacturing aircraft are zoned to make it easy to locate parts, sections, and views on large drawings. Zone identifiers are placed every foot along the edge of the drawing. The identifiers along the bottom of the drawing are numbers and those up the side of the drawing are letters.
- (Refer to Figure 37.) The vertical distance between the top of the plate and the bottom of the lowest 15/64inch hole is
A— 2.250.
B— 2.242.
C— 2.367.
C— 2.367.
The distance from the top of the plate to the center of the top hole is 3/8 inch (0.375 inch). The distance between the center of the top hole and the center of the second hole is 7/8 inch (0.875 inch). The distance between the center of the second hole and the center of the third hole is 7/8 inch (0.875 inch). The distance between the center of the third hole and the center of the lowest small hole is 1/8 inch (0.125 inch). The distance from the center of the 15/64-inch hole to its bottom edge is 15/128 inch (0.117 inch). When all of these dimensions are added together, we find the distance from the top of the plate to the bottom of the lower small hole to be 2.367 inches.
- (Refer to Figure 38.) An aircraft reciprocating engine has a 1,830 cubic-inch displacement and develops 1,250 brake-horsepower at 2,500 RPM. What is the brake mean effective pressure?
A — 217.
B— 205.
C— 225.
A — 217.
- Find the 1,250-brake-horsepower vertical line at the top of the chart, and follow this line down until it intersects the diagonal line for the 1,830-cubic-inch-displacement engine.
- Draw a horizontal line from this intersection point to the right until it intersects the diagonal line for 2,500 RPM.
- From the intersection of the horizontal line and the RPM diagonal line, draw a line vertically downward to the BMEP scale.
- You will find that the vertical line touches the BMEP scale just about on the 217 psi BMEP line.
- (Refer to Figure 38.) An aircraft reciprocating engine has a 2,800 cubic-inch displacement, develops 2,000 brake-horsepower, and indicates 270 brake mean effective pressure. What is the engine speed (RPM)?
A— 2,200.
B— 2,100.
C— 2,300.
B— 2,100.
- Find the 2,000-brake-horsepower vertical line along the top of the chart.
- Follow this line down until it intersects the diagonal line for the 2,800-cubic-inch-displacement engine.
- Draw a horizontal line from this intersection to the right of the chart.
- Find the 270-BMEP vertical line at the bottom of the chart, and follow this line up until it intersects the horizontal line you just drew.
- Find the diagonal line for the RPM that crosses the intersection of the two lines you have just drawn.
- An R-2800 engine will need to turn at 2,100 RPM to develop 2,000 brake horsepower when it has a BMEP of 270 psi.
- (Refer to Figure 38.) An aircraft reciprocating engine has a 2,800 cubic-inch displacement and develops 2,000 brake-horsepower at 2,200 RPM. What is the brake mean effective pressure?
A — 257.5 .
B— 242.5.
C— 275.0.
A — 257.5 .
- Find the 2,000-brake-horsepower vertical line at the top of the chart and follow this line down until it intersects the diagonal line for the 2,800-cubic-inch-displacement engine.
- Draw a horizontal line from this intersection point to the right until it intersects the diagonal line for 2,200 RPM.
- From the intersection of the horizontal line and the RPM diagonal line, draw a line vertically downward to the BMEP scale.
- You will find that the vertical line touches the BMEP scale just about on the 257-psi-BMEP line.
- (Refer to Figure 39.) Determine the cable size of a 40-foot length of single cable in free air, with a continuous rating, running from a bus to the equipment in a 28-volt system with a 15-ampere load and a 1-volt drop.
A— No. 10.
B— No. 11.
C— No. 18.
A— No. 10.
- Follow the 15-ampere diagonal line down until it intersects the horizontal line for 40 feet in the 28-volt column.
- This intersection occurs between the vertical lines for 12-gage and 10-gage wire.
- You would need a 10-gage wire (always use the larger of the two wires) to carry a 15-amp load for 40 feet and not have more than a 1-volt drop.
- (Refer to Figure 39.) Determine the maximum length of a 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.
A— 8 feet.
B— 10 feet.
C— 12 feet.
A— 8 feet.
- Draw a diagonal line for 25 amperes midway between and parallel to the 20-ampere and the 30-ampere diagonal lines.
- Follow this line down until it intersects the 16-gage vertical line.
- This intersection occurs just above curve 3 on the horizontal line for 8 feet of length in the 28-volt (1-volt drop) column.
- A No. 16 cable can carry an intermittent load of 25 amperes for 8 feet without exceeding a voltage drop of 1 volt
- (Refer to Figure 39.) Determine the minimum wire size of a single cable in a bundle carrying a continuous current of 20 amperes 10 feet from the bus to the equipment in a 28-volt system with an allowable 1-volt drop.
A— No. 12.
B— No. 14.
C— No. 16.
A— No. 12.
- Follow the 20-ampere diagonal line down until it intersects curve 1. This curve limits the wire sizes that can be used in a bundle.
- This intersection occurs between the vertical lines for 14-gage and 12-gage wires.
- A 12-gage wire is needed to carry a continuous current of 20 amps if the wire is routed in a bundle. 4. This wire size is chosen on the basis of the heat developed, not on the voltage drop. (If voltage drop were the limiting factor, a 16-gage wire could be used.)
- (Refer to Figure 39.) Determine the maximum length of a No. 12 single cable that can be used between a 28-volt bus and a component utilizing 20 amperes continuous load in free air with a maximum acceptable 1-volt drop.
A— 22.5 feet.
B— 26.5 feet.
C— 12.5 feet.
B— 26.5 feet.
- Follow the diagonal line for 20 amperes down until it intersects the 12-gage vertical line.
- Draw a line horizontally to the left from this point of intersection. This line meets the 1-volt drop column at the 26.5-foot mark.
- This point of intersection is above curve 1 showing that the wire can carry this load continuously without producing too much heat.
- A 12-gage wire can carry 20 amperes continuously for 26.5 feet without overheating the wire and without producing a voltage drop of more than 1 volt.
- (Refer to Figure 40.) Determine the proper tension for a 1/8-inch cable (7 × 19) if the temperature is 80°F.
A— 70 pounds.
B— 75 pounds.
C— 80 pounds.
A— 70 pounds.
- Follow the vertical line for a temperature of 80°F upward until it intersects the curve for 1/8-inch, 7 × 19 cable.
- From this point of intersection, draw a line horizontally to the right until it intersects the rigging load in pounds index. This intersection is at 70 pounds.
- (Refer to Figure 40.) Determine the proper tension for a 3/16-inch cable (7 × 19 extra flex) if the temperature is 87°F.
A— 135 pounds.
B— 125 pounds.
C— 140 pounds.
B— 125 pounds.
- Draw a line vertically upward from a temperature of 87°F until it intersects the curve for 3/16-inch, 7 × 19 cable.
- From this point of intersection, draw a line horizontally to the right until it intersects the rigging load in pounds index. This intersection is at 125 pounds.
- (Refer to Figure 41.) Determine how much fuel would be required for a 30-minute reserve operating at 2,300 RPM.
A— 25.3 pounds.
B— 35.5 pounds.
C— 49.8 pounds.
A— 25.3 pounds.
- Follow the 2,300 RPM vertical line upward until it intersects the propeller load horsepower curve.
- From the point of intersection, project a line horizontally to the left to read the brake horsepower the engine develops at 2,300 RPM. This is 110 brake horsepower.
- Follow the 2,300 RPM curve upward until it intersects the propeller load brake specific fuel consumption curve.
- From the point of intersection, project a line horizontally to the right to read the specific fuel consumption for 2,300 RPM. This is 0.46 pound of fuel burned per hour for each horsepower developed.
- The engine burns 50.6 pounds of fuel per hour when it is developing 110 brake horsepower.
- A 30-minute reserve would require one half of this, or 25.3 pounds.
- (Refer to Figure 41.) Determine the fuel consumption with the engine operating at cruise, 2,350 RPM.
A— 49.2 pounds per hour.
B— 51.2 pounds per hour.
C— 55.3 pounds per hour.
C— 55.3 pounds per hour.
- Follow the 2,350 RPM vertical line upward until it intersects the propeller load horsepower curve.
- From the point of intersection, project a line horizontally to the left to read the brake horsepower that the engine develops at 2,350 RPM. This is 118 brake horsepower.
- Follow the 2,350 RPM curve upward until it intersects the propeller load brake specific fuel consumption curve.
- From the point of intersection, project a line horizontally to the right to read the specific fuel consumption for 2,350 RPM. This is 0.47 pound of fuel burned per hour for each horsepower developed.
- Multiply 118 by 0.47 to get 55.46, the fuel consumption in pounds per hour when the engine is developing 118 brake horsepower.
