Mock AC STRUC and DESIGN Terms

Distributed load intensity

The slope of the shear diagram of the different structure is equal to

a. Rotational moment

b. Bending moment

c. Total weight

d. Distributed load intensity

Proportional Limit

Which of the following parameters can be obtained by tension test of a standard specimen?

a. Proportional Limit

b. Yield Strength

c. Percentage Reduction in area

d. All of the mentioned

Bulkheads

The pressure is contained within the fuselage by two pressure

a. Longerons

b. Formers

c. Bulkheads

d. Frames

Spar

The construction of an aircraft's wing is centred around a main member. What is that member called?

a. Rib

b. Frame

c. Spar

d. Longerons

PD/2t

Tangential stress in a cylinder is given by [symbols have their usual meanings].

a. PD/2t

b. 2PD/t

c. PD/4t

d. 4PD/t

A part of the empty weight

When determining the empty weight of an aircraft, certificated under current airworthiness standards (14 CFR Part 23), the oil contained in the supply tank is considered

a. A part of the empty weight

b. A part of the useful load

c. The same as the fluid contained in the water injection reservoir

d. None of the above

Station Numbers

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?

a. Zone numbers

b. Reference numbers

c. Station numbers

d. Tolerances

longerons and stringers

Longitudinal (fore and aft) structural members of a semi monocoque fuselage are called

a. spars and ribs.

b. longerons and stringers.

c. spars and stringers.

d. ribs and longerons.

Only shear force is correct

The forces that cause one section of the body to slide past its adjacent section are the Axial force and the Shear force. Which of these forces is correct?

a. Only axial force is correct

b. Only shear force is correct

c. Both are correct

d. Both are incorrect

Shear Center

It is the point where the resultant shear load is applied without producing any torsional deflection or twist in the section.

a. centroid

b. center of gravity

c. shear center

d. moment center

Shear Panels

Structural members which transmits in-plane shear loads only.

a. Membranes

b. Thin-shells

c. Shear panels

d. Thin-plates

Distributed Load

A type of load measured by their intensity.

a. Concentrated load

b. Distributed load

c. Couple

d. Surface load

Body Loads

Inertial loads & loads due to gravity are examples of what type of load?

a. Surface loads

b. Body loads

c. Dynamic loads

d. Distributed load

Tension, compression, bending and twisting

What are the four basic forms of deformation of solid bodies?

a. Tension, compression, bending and twisting

b. Tension, compression, elongation and bending

c. Tension, compression, plastic and elastic

d. Tension, compression, elongation and torsion

Poisson's ratio

What is the ratio of the transverse strain to the corresponding axial strain in a body subjected to uniaxial stress?

a. Poisson's ratio

b. Euler's ratio

c. Refractive index

d. Dielectric index

Centroidal distance

What is the mean position of all the points in all of the coordinate directions?

a. Centroidal distance

b. Shear center

c. Center of gravity

d. Aerodynamic center

Modulus of rigidity

Within elastic limit, the shear stress is proportional to shear strain. What is the constant of proportionality of this statement called?

a. Modulus of rigidity

b. Modulus of elasticity

c. Young's modulus

d. Bulk modulus

Static Load

A mechanical force applied slowly to an assembly or object.

a. Dynamic Load

b. Concentrated Load

c. Static Load

d. Distributed Load

at the top of the surface

The shear stress at any section of a shaft is maximum

a. at the center of the section

b. at the top of the surface

c. at a distance r/2 from the center

d. at a distance 3/4 r from the center

A - c; B - a; C - d; D - b

Match each force or couple (A - D) w/ the deformation it would cause when applied to a bar (a - d).

A. Normal Force a. Slides one bar segment relative to another.

B. Shear Force b. Bends the bar.

C. Torque c. Elongates or shortens the bar.

D. Bending Moment d. Twist the bar.

a. A - a; B - d; C - c; D - b

b. A - c; B - d; C - a; D - b

c. A - c; B - a; C - d; D - b

d. A - a; B - c; C - d; D - b

None of the above

Which is not a type of vibration?

a. Noise

b. Flutter

c. Buffet

d. None of the above

21

Pressurization is a type of a slowly applied load. What is the ATA chapter for pressurization?

a. 20

b. 21

c. 22

d. 23

mass balancing control surfaces

Flutter can be prevented by _____ to alter the moment of inertia of the surface.

a. weight reduction

b. pulling back on the control

c. mass balancing control surfaces

d. fuel jettisoning

3.8 and 6.0

The maximum positive maneuvering load factors for a normal and an acrobatic airplane are _____, respectively.

a. 3.8 and 3.8

b. 3.8 and 4.4

c. 1.2 and 3.8

d. 3.8 and 6.0

to improve stability about the longitudinal axis

An airplane's center of lift is usually located aft of its center of gravity

a. so that the airplane will have a tail-heavy tendency

b. to improve stability about the longitudinal axis

c. so that the airplane will have a nose-heavy tendency

d. to improve stability about the vertical axis

Hinge support

A support designed to allow only rotation at the point of connection, and thus reactive forces (reactions) are developed in the other directions where movements

are not allowed.

a. Fixed support

b. Hinge support

c. Hinge-roller support

d. Wedge support

Negative High Angle of Attack

It occurs in intentional flight maneuvers in which the air loads on the wing are down or when the airplane strikes sudden downdrafts while in level flight.

a. Positive High Angle of Attack

b. Positive Low Angle of Attack

c. Negative High Angle of Attack

d. Negative Low Angle of Attack

Airframe

It is the basic structure of an aircraft and is designed to withstand all

aerodynamic forces, as well as the stresses imposed by the weight of the fuel,

crew, and payload.

a. Aircraft component

b. Airframe

c. Cabin system

d. Landing Gear

Modulus of Elasticity

It is the slope of the initial straight portion of the stress-strain diagram.

a. Modulus of Elasticity

b. Hooke's constant

c. Modulus of Rigidity

d. Poisson's ratio

Resilience

The capacity of a material to absorb energy in the elastic range.

a. Toughness

b. Resilience

c. Hardness

d. Permeability

2.2

The limit load factor of a utility aircraft when its flaps are down is

a. 4.4

b. 3.8

c. 1.2

d. 2.2

Water Line

It is known as the measurement of height in inches. It is perpendicular from a horizontal plane located at a ground, cabin floor, or some other easily referenced

location.

a. Aileron Station

b. Butt Line

c. Wing Station

d. Water Line

Positive High Angle of Attack

It is obtained in a pullout at the highest possible angle of attack on the wing. It

is where lift and forces are perpendicular and parallel to the relative wind, respectively.

a. Positive High Angle of Attack

b. Positive Low Angle of Attack

c. Negative High Angle of Attack

d. Negative Low Angle of Attack

VA

About a V-n diagram, it is the slowest speed at which the maximum load factor can be reached without stalling.

a. VA

b. VB

c. VSX

d. VS1

Overturn Angle

When looking the aircraft's front view, the angle between the vertical line passing through the aircraft C.G. and the line between aircraft C.G. and the one of the main wheels is the _____.

a. Angle of Incidence

b. Overturn Angle

c. Tipback Angle

d. Tipforward Angle

Static

Loads that are gradually applied and cause no appreciable shock or vibration of structure.

a. Static

b. Dynamic

c. Continuous

d. Shock-resistant

Blunt gust

Which is not a type of gust?

a. Sharp-edged gust

b. Graded gust

c. Blunt gust

d. 1-cosine gust

Gussets

It is a flat sheet triangular shape used to reinforce the corners of structure.

a. Webs

b. Fittings

c. Caps

d. Gussets

friction

The tangent of this angle where the opposite side is the frictional force and the adjacent side is the normal force is called _____.

a. bank

b. friction

c. incidence

d. attack

Wings

It is essentially a beam which transmits and gathers all the applied airload to the central attachment to the fuselage.

a. Wings

b. Horizontal stabilizer

c. Landing gear

d. Dorsal fin

Supported at one end only with no external bracing

Which among the following statements best describes a cantilever wing?

a. Externally braced with either struts and /or bracing wires

b. Supported at one end only with no external bracing

c. Braced at both the upper and lower section of the airfoil

d. Able to be folded at the root section to ease storage in confined spaces

Tipback Angle

It is the maximum aircraft nose-up attitude with the tail touching the ground and strut fully extended.

a. Angle of Incidence

b. Overturn Angle

c. Tipback Angle

d. Tipforward Angle

Hooke's Law

Which among the following choices articulates the relationship of stress to strain?

a. Young's Modulus law

b. Hooke's Law

c. Poisson's ratio

d. Varignon's Law

Fixed support

Normally designed to provide restraints against rotation and all translations; therefore, reactive forces and moments (reactions) are developed along the directions where movements are not permitted.

a. Fixed support

b. Hinge-roller support

c. Wedge support

d. Hinge support

2.5

The positive limit maneuvering load factor (+n) for an acrobatic category airplane shall not be less than ____.

a. 2.5

b. 3.8

c. 4.4

d. 6.0

Cruciform

This tail design is chosen to keep the tail out of the engines' wake or to avoid complex interference drag.

a. Conventional

b. Cruciform

c. Dual-tail

d. T-tail

VNO

It is the maximum structural cruising speed that should not be exceeded except in smooth air, and then only with caution.

a. VS0

b. VS1

c. VFE

d. VNO

Wrench

It is the simplest system that can represent any general force and couple moment system acting on a body.

a. Beam

b. Truss

c. Lever

d. Wrench

three

There are _____ unknowns for a cantilever support.

a. two

b. three

c. four

d. five

High

Compared with the other types of wing vertical location, this type has more lateral dynamic stability

a. Parasol

b. Low

c. Mid

d. High

Tipforward Angle

It is the angle between the vertical and the line passing through the aircraft most forward C.G. and the contact point between tire and the ground.

a. Angle of Incidence

b. Overturn Angle

c. Tipback Angle

d. Tipforward Angle

80%-95%

The main gear carries about _____ of the aircraft load.

a. 60%

b. 70%-75%

c. 80%-95%

d. 100%

equivalent

Airspeed corrected for instrument error, position error, and adiabatic compression flow for the altitude is called _____ airspeed.

a. true

b. indicated

c. equivalent

d. calibrated

Outer pane

Which part of the window is the primary pressure-carrying pane?

a. Outer pane

b. Middle pane

c. Inner pane

d. Middle third pane

specific design

The following are phases of Aircraft design except?

(a) Detailed design (c) conceptual design

(b) Preliminary design (d) specific design

elliptical

Which of the following wing design has the best aerodynamic efficiency?

(a) rectangular (c) elliptical

(b) tapered (d) sweptback

Flaps

Which of the following is not a primary control surface?

(a) Aileron (c) Flaps

(b) Elevators (d) Rudder

Summation of forces = 0

Which of the following statement is true

(a) during straight level unaccelerated flight lift = drag.

(b) during straight level unaccelerated flight lift = thrust.

(c) during straight level unaccelerated flight lift = weight.

(d) Summation of forces = 0

stability

It is the ability of an aircraft to maintain its flight path without the help or being controlled by the pilot.

(a) stability (c) controllability

(b) maneuverability (d) operability

resistance to bending

The higher the moment of inertia the greater the ______ in that orientation

(a) stress (c) strength

(b) resistance to bending (d) possibility of buckling

Goose

Canard which is a French word meaning?

(a) Goose (c) Flaps

(b) Wings (d) direction

span over chord

Aspect ratio is

(a) Chord over span (c) span over chord

(b) Chord over swept (d) span over lift

lighter than modern design

Which of the following is an advantage of conventional landing gear arrangement?

(a) good pilot field of view (c) reduced ground looping tendency

(b) lighter than modern design (d) less affected by P-Factor

P-Factor

It is responsible for the asymmetrical relocation of the propeller's center of thrust when an aircraft is at a high angle of

attack.

(a) Critical engine (c) P-Factor

(b) Aerodynamic Twisting (d) Dutch Roll

Positive Stagger

Moving the upper wing forward relative to the lower one is called

(a) Negative Stagger (c) Decalage

(b) Positive Stagger (d) Cabane

Sesquiplane

A common variation on the biplane where one wing (usually the lower) has not more than half the surface area of the

other.

(a) Parasol (c) Gull Wing

(b) Sesquiplane (d) Cabane

Yaw dampers

Which of the following can be sued to prevent Dutch roll?

(a) Dihedral (c) Yaw dampers

(b) Wing Swept (d) Low Wing design

Anhedral

A wing design wherein the tips are lower than the root

(a) Dihedral (c) Anhedral

(b) Unhedral (d) inverted gull

Krueger Flaps

Which of the following flaps is commonly found on the leading edge

(a) Krueger Flaps (c) Slotted Flaps

(b) Fowler Flaps (d) Spoiler

Modulus of Elasticity

It is the ratio of stress to strain

(a) Euler's ratio (c) Poisson's ratio

(b) stress to strain ratio (d) Modulus of Elasticity

lifting canard

A design having their elevators in ahead of the wings and at the same time contributes to lift.

(a) Sweptback design (c) Control Canard

(b) swept front design (d) lifting canard

lateral stability

The primary purpose of wing dihedral is to improve?

(a) longitudinal stability (c) vertical stability

(b) lateral stability (d) overall stability

decision speed

During take-off roll V1 stands for?

(a) initial speed (c) decision speed

(b) take off speed (d) cruise speed

longitudinal offset of the two wings relative to each other

In biplane wing design, stagger means?

(a) longitudinal offset of the two wings relative to each other

(b) lateral offset of the two wings relative to each other

(c) vertical offset of the two wings relative to each other

(d) angle between two wings relative to each other

angle between two wings relative to each other

In biplane wing design, decalage means.

(a) longitudinal offset of the two wings relative to each other

(b) lateral offset of the two wings relative to each other

(c) vertical offset of the two wings relative to each other

(d) angle between two wings relative to each other

swept back

Which of the following wing geometry and/or design is best to reduce the adverse effect of supersonic and transonic

flow.

(a) wing dihedral (c) anhedral

(b) swept back (d) taper

parasol

A wing design of monoplane where it is raised clear above the top of the fuselage.

(a) mid wing (c) parasol

(b) sesquiplane (d) inverted parasol

minimum upstick speed

Vmu stands for?

(a) maximum upstick speed (c) maximum upturn speed

(b) minimum upstick speed (d) minimum upturn speed

elliptical wing

The most efficient way to create lift on a fixed wing is to use?

(a) wing taper (c) elliptical wing

(b) wing tip (d) vortex generator

stalling speed landing configuration

VS0 stands for

(a) stalling speed clean configuration (c) stalling speed specific configuration

(b) stalling speed landing configuration (d) minimum landing speed

Fuel

ATA 28 is?

(a) Hydraulic Power (c) Flight Controls

(b) Fuel (d) Landing gears

14 CFR

The Federal Aviation Regulations are under what CFR?

(a) 12 CFR (c) 15 CFR

(b) 14 CFR (d) 13 CFR

19,000 lbs

The maximum take-off weight of commuter category under FAR 23 is?

(a) 12,500 lbs (c) 22,000 lbs

(b) 19,000 lbs (d) 17,500 lbs

Method of Shears

In the solution of trusses, if two of the unknown forces are parallel, forces may be summed perpendicular to the direction of these unknowns to determine directly the third unknown force. This method is known as:

a. Method of Joints

b. Method of Shears

c. Method of Section

d. Method of Members

3.0

A design airplane has a weight of 2,200 lb and a wing area of 90 ft2 It is to be certified as acrobatic category under FAR part 23. What is

the negative limit maneuvering load factor in which the airplane must be designed for?

a. 2.1

b. 2.5

c. 3.8

d. 3.0

3.8

A design airplane intended to be certified as a commuter category under FAR part 23 has the following specifications: design gross weight is 3,100 lb, wing span is 34 ft, MAC is 4.75 ft, and maximum lift coefficient is 1.35 with flaps retracted. What is the required positive limit maneuvering load factor?

a. 3.8

b. 2.1

c. 3.93

d. 4.4

Increasing directional stability

The swept back wing design is primarily intended to increase the critical Mach number of a supersonic aircraft but also useful in:

a. Reducing induced drag

b. Improving L/D ratio

c. Increasing directional stability

d. Reduce parasite drag

No external bracing is needed

Which statement is true regarding a cantilever wing?

a. No external bracing is needed.

b. It requires only one lift strut on each side.

c. It has nonadjustable lift struts.

d. All of the choices

the rear wing or tail to stall first

As a rule of thumb in designing an aircraft, the designer must not allow

a. the left wing to stall first

b. the rear wing or tail to stall first

c. the canard wing to stall late

d. the vertical stabilizer to stall only

good pilot field of view

Which of the following is not an advantage of conventional landing gear arrangement?

a. good pilot field of view

b. better propeller clearance

c. lighter than modern design

d. automatic positive angle of attack

ceiling

Which of the following is a performance requirement?

a. ceiling

b. maximum take-off weight

c. cost of material

d. wing span

mean aerodynamic center

It is approximately located at the quarter chord point for subsonic wings.

a. mean aerodynamic chord

b. mean aerodynamic center

c. center of pressure

d. center of gravity

reverse delta planform

Which of the following is the least attractive wing design feature

a. delta planform

b. taper

c. reverse delta planform

d. reverse taper

low wing

Which of the following wing vertical position is adapted by most commercial jets?

a. high wing

b. low wing

c. mid wing

d. parasol wing

high wing

Which of the following wing vertical position is adapted by most cargo aircraft?

a. high wing

b. low wing

c. mid wing

d. parasol wing

mid wing

Which of the following wing vertical position is adapted by most aerobatic aircraft?

a. high wing

b. low wing

c. mid wing

d. parasol wing

mid wing

Which wing vertical position has the least interference drag?

a. high wing

b. low wing

c. mid wing

d. parasol wing

butterfly tail

Which of the following empennage

configuration has the least interference drag?

a. t-tail

b. cross tail

c. h-tail

d. butterfly tail

delta wing

Which of the following has the most induced

drag, if each one is producing the same lift?

a. tandem wing

b. biplane

c. monoplane

d. delta wing

biplane

Which of the following is producing the most drag at high speeds?

a. tandem wing

b. biplane

c. monoplane

d. delta wing