A&P - General Oral Exam (Jeppesen)

Describe the result of adding a large positive number and a smaller negative number.

The result is a smaller positive number.

How do you convert a fraction into a decimal?

Divide the numerator by the denominator.

What is the key step that must be performed in order to add or subtract unlike fractions?

Find the lowest common denominator.

How do you divide one fraction by another?

Invert the divisor and multiply.

How can you convert a decimal into a percent?

Multiply by 100 and add the % sign.

How do you convert a fraction into a percent?

Convert into a decimal and then multiply by 100 and adding the % sign.

How do you change a decimal into the nearest equivalent fraction?

Multiply by the desired denominator to get the numerator.

What are two different ways that a ratio may be expressed?

1. As a fraction

2. By placing a colon (:) between the two numbers

3. Use the word "to" between the two numbers.

What is a proportion?

A proportion is two equal ratios

What is meant by the root of the number?

A root is a number that multiplies by itself to equal another number

How do you find the square of a number?

Multiply the number by itself.

What is the common method of making computations involving very large or very small numbers more manageable?

Convert into scientific notation using powers of 10.

How is 100,000 expressed as a power of 10?

10 to the 5th power.

What formula is used to find the area of a rectangle and a triangle?

Rectangle = L x W

Triangle = 1/2 (B x H)

Define Pi.

Pi is the number used to find the size of a circle. It's about 3.14

Describe a trapezoid.

A trapezoid is a closed, four sided figure with two parallel sides.

What is the formula for computing the area of a circle?

pi times the radius squared (A = πr²)

Define matter.

Anything that occupies space and has mass.

Matter may exist in what three states?

Solid, liquid, and gas.

Define kinetic energy?

Energy of motion.

Work is the product of what two factors?

Force and distance moved.

What are the parts of a lever?

A lever has a rigid bar and a fulcrum

A wheelbarrow is a example of what class of lever?

A second-class lever.

Are all three states of matter affected by thermal expansion and if so, which state is affected most?

All three states are affected, with gas being affected the most.

What is a British Thermal Unit?

A BTU is the amount of heat needed to raise 1 pound of water by 1°F

Name the three methods of heat transfer?

Conduction, convection and radiation.

What term defines the temperature at which all molecular motion ceases?

Absolute zero.

Can liquids be compressed?

No, liquids are generally considered incompressible.

What are the customary units used to express hydraulic or pneumatic pressure in the U.S.?

Pounds per square inch

Describe how pressure is transmitted when a force is applied to a confined liquid.

Pressure is transmitted equally in all directions.

What formula expressed the relationship between force, pressure and area?

F = P × A (Force = Pressure × Area)

What is the approximate speed of sound at sea level on a standard day?

661 knots or 340 meters per second.

What is the atmospheric pressure at sea level on a standard day?

29.92 inches of Mercury

On a standard day at sea level, what is the value for temperature?

59 deg. F or 15 deg. C

What are the factors that determine density altitude?

Temperature and atmospheric pressure.

What is the term to describe the ratio between the amount of moisture actually present in the atmosphere as compared to the amount the air could hold if it were completely saturated?

Relative humidity.

What are the four principle forces acting on an airplane in flight?

Lift, drag, thrust, and gravity.

What is the term that describes the angle between the relative wind and the chord line of airfoil?

The Angle of Attack (AOA).

What are the factors that cause the airplane wing to stall?

A wing stalls when its angle of attack becomes too high, causing the airflow to separate from the wing

What are the principle effects that result from lowering the flaps while in flight?

Lift increases, drag increases, and stall speed decreases.

What is the function of a wing mounted vortex generator?

It keeps airflow attached to the wing, helping the wing make lift at slow speeds

How does blade flapping help to compensate for dissymmetry of lift in helicopter main rotor systems?

The advancing blade flaps up and makes less lift

The retreating blade flaps down and makes more lift."

How does the airflow through the main rotor of a helicopter change during the transition from normal flight to autorotation?

During normal flight the air moves downward and during autorotation the air moves upward.

What is friction?

Friction is the resistance to motion between two surfaces in contact

One kilowatt is equal to how many watts?

1,000 watts

What law describes the most fundamental or basic relationship in an electrical circuit?

Ohm's law

What are the three elements of Ohm's law?

Voltage, current, and resistance.

How would you write the Ohms law as an equation?

E=I x R,

If the resistance in a DC circuit remains the same but the voltage doubles, what happens to the amount of current flowing in the circuit?

It also doubles.

In DC circuits, what unit measures power?

Watts

What three elements are required to form an electrical circuit?

A power source, a load, and a complete path for the current

DC circuits can take one of three forms or types, What are they?

Series, parallel, and complex (series-parallel).

A 24-volt lead-acid battery has how many cells?

12

A fully charged lead-acid battery has a specific gravity that varies between what two values?

1.275 and 1.3

You must apply a correction to the specific gravity reading of the elctrolyte of a lead-acid battery when the temp is outside of what two values?

Whenever the temperature is less than 70 deg. F or more than 90 deg. F.

What is the reason for having separate facilities for storing and servicing nickel-cadmium and lead-acid batteries?

Because the electrolytes are chemically different, and fumes from one type can contaminate the other.

The state of charge of a nickel-cadmium battery cannot be determined by measuring the specific gravity of the electrolyte for what reason?

Because the electrolyte's specific gravity doesn't change much as a nickel-cadmium battery charges or discharges."

What is the principal advantage of AC current over DC current?

AC can be transmitted long distances more efficiently because its voltage can be changed with a transformer

What are the three causes of opposition to current flow in an AC circuit?

Resistance, inductive reactance, and capacitive reactance.

Define inductance.

Inductance is the ability of a coil to oppose changes in current

What component creates capacitance in AC circuits?

A capacitor.

How does a capacitor store electricity?

A capacitor stores electricity as an electrostatic charge between two plates separated by an insulator

What property of an AC circuit is defined by the term impedance?

The total opposition to the current flow.

What are the two reasons that might cause a nickel-cadmium battery to fail to deliver its rated capacity?

Faulty cells or cell imbalance.

What electrical values are measured by a typical mulimeter?

Voltage, current, and resistance.

How many views are required to represent the important details of most aircraft parts?

One, two, or three views are usually enough.

What kind of parts can be represented by one-view drawings?

Parts with uniform thickness such as shims, plates, and gaskets.

What is the name for a part of a drawing used to bring out important details and how is it drawn?

A detailed view, which is usually drawn to a larger scale than the main drawing.

What is the purpose of schematic diagrams?

Primarily used for troubleshooting systems.

Describe an orthographic projection.

A way of drawing an object using different views at right angles to each other, such as top, bottom, front, and side view.

Why do manufacturers use symbols on aircraft drawings?

Symbols are a form of shorthand and Manufacturers use symbols to show information clearly with less drawing

Describe the appearance of lines used to show hidden views, alternate positions, and the middle of symmetrical objects, and give their name.

Hidden views are shown with "hidden lines", which are short, evenly spaced dashes.

"phantom lines" made up of light, alternating long dashes and two short dashes.

"Center lines" consisting of alternating long and short dashes, show the middle of symmetrical objects.

How can you determine if a drawing has been changed?

Check the revision block to see if the drawing has been changed

How are dimensions shown on aircraft drawings, and what is their purpose?

Dimensions are shown with dimension lines and numbers to show the size and location of a part

What is the difference between an "allowance" and a "tolerance"?

Allowance is the intended space or tightness between two mating parts.

Tolerance is how much a measurement is allowed to vary from its specified size.( extremes +/-)

What is meant by "clearance" when used in aircraft drawings?

Clearance is the allowable space between two parts

What kinds of information about an aircraft drawing can be found in the title block?

drawing number, scale, date, company, and approval information.

What information is contained in a "bill of materials"?

A list of the materials and parts needed to fabricate or assemble the component or system shown in the drawing.

If an aircraft is loaded so that the aft C.G. limit is exceeded, what undesirable flight characteristic is likely to result?

The aircraft will be tail-heavy and may be unable to recover from a stall or spin.

If all the records for an aircraft are missing, how would you determine the empty weight and empty weight C.G.?

The aircraft would have to be weighed

Define" tare weight" and describe how it is handled when weighing an aircraft.

Tare weight is anything on the scales that isn't part of the aircraft. It's subtracted from the scale reading

If a piece of equipment such as a radio is added to an aircraft, how can you determine the effect on weight andbalance without re-weighing the airccraft?

Use the weight and balance records and calculate the new weight and center of gravity

Why is control of the weight and ballance of an aircraft important?

To provide maximum safety.

What is the datum of an aircraft and what is its function?

The datum is an imaginary reference point from which all horizontal measurements are taken.

How do you determine the moment of an item of equipment?

The weight of the item is multiplied by its arm. (W.A.M)

What are two ways of determining the arm of an item of equipment?

Measure it from the datum, or use the manufacturer's data.

What should be done to obtain a positive (plus) moment aft of the datum?

Add weight.

What should be done to obtain a negative (minus) moment aft of the datum?

Remove weight.

What should be done to obtain a positive (plus) moment forward of the datum?

Remove weight

What should be done to obtain a negative (minus) moment forward of the datum?

Add weight

How does the category of an aircraft affect its loaded weight?

The category determines the allowable maximum gross weight and useful load.

As you prepare an aircraft for weighing, you determine that there is equipment aboard that is not permanently installed and recorded on the equipment list. What should you do with equipment?

Remove anything that's not permanently installed or on the equipment list.

Define the term "residual fuel"?

Any fuel that remains in the tanks, lines, and engines, after the system has been drained.

Define the term "residual oil"?

Any oil that remains in the tanks, lines, engines, after the system has been drained.

How should you account for fuel when weighing an aircraft to determine weight and balance?

Either drain the system until only unusable fuel remains, or fill the tanks full and subtract out the weight of the useable fuel.

Where are leveling instructions found, and describe one method of leveling an aircraft?

Leveling instructions are found in the Type Certificate Data Sheet, and the aircraft can be leveled with a spirit level or a plumb bob."

Define the term "Mean Aerodynamic Chord" or MAC.

Is the chord drawn through the center of the wing planform area."

Describe the two most common ways of showing the C.G. location and/or C.G. range.

In inches from the datum or in percent of MAC.

What is the purpose of an aircraft loading graph?

helps keep the center of gravity within allowable limits.

What is ballast, and why would you use it in an airplane?

Ballast is weight added to an airplane to bring its C.G. into the allowable or desired range.