PATTS- Mock Test 2022 Aircraft structures and design

Which of the following will reduce induced drag?

a. extending the flaps

b. elliptical lift distribution

c. low aspect ratio

d. flying at high angle of attack

b. elliptical lift distribution

Sweepback of a wing contribution to longitudinal stability, wing dihedrals contributes to

a. lateral stability

b. vertical stability

c. dynamics stability

d. neutral stability

a. lateral stability

Which of the following plan forms produces the lowest induced drag? (all other relevant factors are constant)

a. circular

b. elliptical

c. rectangular

d. tapered

b. elliptical

Given is an airplane wing with a rectangular planform an aspect ratio of 5, a span of 10 meters, and a NACA 4412? airfoil section. Find the camber in centimeters

a. 8.70cm

b. 8.00 cm

c. 8.26 cm

d. 8. 56 cm

b. 8.00 cm

Given is an airplane wing with a rectangular planform an aspect ratio of 5 a span of 10 meters, and a NACA 23015 airfoil section. Determination the maximum thickness of the airfoil in centimeters

a. 50cm

b. 40cm

c. 36cm

d. 30cm

d. 30cm

For a certain airfoil with infinite aspect ratio, the CL is 1.03 at 9° angle of attack and the corresponding Cd is 0.067. Find the coefficient of drag for an aspect ratio of 7, when Cl is 1.03 Assume e=10

a. 0.1029

b. 0.0902

c. 0.1152

d. 0.2109

c. 0.1152

For NACA 4 digit airfoils the first digit indicates the

a. camber as percentage of the chord

b. position of the camber from the leading edge as percentage of the chord

c. maximum thickness as percentage of the chord

a. camber as percentage of the chord

NACA airfoil designation: For NACA 5 digit airfoils, the first digit indicates the

a. camber as percentage of the chord

b. position of the camber from the leading edge as percentage of the chord divided by 2

c. position of the camber from the leading edge as percentage of the chord

a. camber as percentage of the chord

NACA Airfoil Designation: For 6 series and 7 series airfoils, the first digit indicates the

a. series designation

b. minimum pressure

c. maximum thickness as percentage of the chord

d. design lift coefficient

a. series designation

Given a NACA 4412 airfoil with chord of 2 meters. What is the camber?

a. 0.048m

b. 0.045m

c. 0.030m

d. 0.480m

a. 0.048m

For a NACA 2415 airfoil with a chord of 3 feet, what is the maximum thickness?

a. 0.13715m

b. 0.45312m

c. 0.406 ft

d. 0.44 ft

a.0.13715m

For a NACA 4412 airfoil with a chord of 1.02 meters, what is the distance from the leading edge to the position of the camber?

a. 0.408m

b. 0.048m

c. 0.456m

d. 0.046m

a. 0.408m

A 1.5m NACA 23012 airfoil was used in the design of a prototype aircraft. Calculate the position of the camber.

a. 0.225m

b. 0.215m

c. 0.135m

d.0.450m

a. 0.225m

NACA airfoil designation: for 5 digits the last two digits indicates the

a. maximum thickness as percentage of the chord

b. camber as percentage of the chord

c. position of the camber from the leading edge as percentage of the chord

a. maximum thickness as percentage of the chord

___is added to the wings for roll stability, a wing with some___will naturally return to its original position if it encourage a slight roll dsplacement.

a. dihedral angle

b. anhedral angle

c. angle of attack

d. angle of incidence

a. dihedral angle

The shape of the wing when viewed from above looking down onto the wing, is called a

a. wing planform

b. top view

c. wing shape

d. wing triangle

a. wing planform

The wing tips of some fighter aircraft are lower than the wing roots giving the aircraft a high roll rate. This is called a negative dihedral angle or

a. anhedral

b. dihedral

c. angle of incidence

d. angle of attack

a. anhedral

If an aircraft were flying at zero lift angle of attack the only drag present would be

a. parasite drag

b. induced drag

c. drag due to lift

d. wave drag

a. parasite drag

It measures the efficiency of the aerodynamic body to generate lift. This is also the lift generated by the aerodynamic body as compared to its drag

a. lift to drag ratio

b. lift to weight ratio

c. drag polar

d. ratio of drag coefficients

a. lift to drag ratio

A new aircraft is being designed at PATTS College of Aeronautics by an Aeronautical Engineering students. The selected airfoil in the design process is a NACA 2415 airfoil with a maximum thickness of 0.48 feet. Determine the chord of the airfoil in feet

a. 3.20 ft

b. 3.01 ft

c. 3.33 ft

d. 2.95 ft

a. 3.20 ft

The terms "empennage" incorporates

a. rudder, ailerons, spoilers

b. rudder, flaps, trimtabs

c. elevators, stabilizer, ailerons

d. elevators, stabilizer, rudder

d. elevators, stabilizer, rudder

For preliminary design purposes the maximum forward CG position should be kept behind

a. 15% of the Mean Aerodynamic Chord

b. 45% of the Mean Aerodynamic Chord

c. 30% of the Mean Aerodynamic Chord

d. 60% of the Mean Aerodynamic Chord

a. 15% of the Mean Aerodynamic Chord

The excess horsepower is equal to

a. Thrust horsepower minus brake horsepower

b. brake horsepower plus. Thrust horsepower

c. thrust horsepower available plus thrust horsepower required

d. thrust horsepower available minus thrust horsepower required

d. thrust horsepower available minus thrust horsepower required

The negative limit maneuvering load factor (-n) for normal category airplane, in accordance with FAR 23, need not be less than the following values

a. -0.3n

b. -0.4n

c. -0.5n

d. -0.6n

b. -0.4n

Given is aerobatic category airplane weighing 2,500 lbs with symmetrical wing loading condition I: Position high angle of attack. Determine the negative limit maneuvering load factor

a. -1.52

b. -1.608

c. -1.76

d. -2.01

d. -2.01

The positive limit maneuvering load factor (+n) for aerobatic category airplane, as provided for in the U.S. federal aviation regulation (FAR) part 23 airworthiness standards need not be less than

a. 2.5

b. 3.8

c. 4.4

d. 6.0

a. 2.5

The negative limit maneuvering load factor (-n) for normal category airplane, in accordance with FAR 23, need not be less than the following values:

a. -0.3n

b. -0.4n

c. -0.5n

d. -0.6n

b. -0.4n

The negative limit maneuvering load factor (-n) for aerobatic category airplane, in accordance with FAR 23, need not be less than the following values:

a. -0.3n

b. -0.4n

c. -0.5n

d. -0.6n

c. -0.5n

Given is a normal category airplane weighing 4,200 lb with symmetrical wing loading condition I: positive high angle of attack. Determine the positive limit maneuvering load factor

a. 3.79

b. 4.23

c. 4.44

d. 5.32

a. 3.79

Given is a utility category airplane weighing 3,500 lbs with symmetrical wing loading condition I: positive high angle of attack. Determine the negative limit maneuvering load factor

a. -1.55

b. -1.609

c. -1.75

d. -2.4

a. -1.55

The drag coefficient of a trapezoidal wing design aspect ratio corrected from aspect ratio of 6 is given by the relation Cd= 0.032-0.010 Cl^2

where Cl is wing lift coefficient. Assume elliptical lift distribution

Find

a. drag coefficient corresponding to the aspect ratio of 6

b. design aspect rati

a. 0.032 and 7.39

b. 0.035 and 7.65

0.032 and 8.23

d. 0.035 and 8.66

a. 0.032 and 7.39

A light plane has a gross weight of 1,200 lbs. It has a wing span of 30 feet and an aspect ratio 0f 6. It uses a Clark y airfoil with a maximum lift coefficient of 1.56. Computer the stalling speed in miles per hour at sea level condition.

a. 45 mph

b. 48 mph

c. 50 mph

d. 52 mph

a. 45 mph

An airfoil with aspect ratio of 6, at an angle of attack of 9°, cl= 1.067 and cd=0.0780. Find for the same airfoil shape, the angle of attack and corresponding to Cl= 1.067 for aspect ratio of 9.1 Assume e=1.0

a. 7.24 deg and 0.0682

b. 7.42 deg and 0.0633

c. 7.90 deg and 0.057

d. 7.35 deg and 0.054

b. 7.42 deg and 0.0633

The greatest air loads on an aircraft usually come from the generation of lift during high maneuvers

a. inertial loads

b. control deflection loads

c. maneuver loads

d. gust loads

c. maneuver loads

Airplanes in this category are intended for normal operation and limited aerobatic maneuvers. These airplanes are not suited for uses in snap or inverted maneuvers

a. normal category

b. utility category

c. acrobatic category

d. none of the above

b. utility category