AS 121 Exam 3 ACTUAL QUESTIONS
AND CORRECT ANSWERS
Standard pressure at 10000 feet is (according to the values on the FAA table) - CORRECT ANSWER
20.57 inches of mercury
Which of the following helps determine the shape of the airfoil? - CORRECT ANSWER
Purpose of the specific aircraft
As angle of attack increases, the center of pressure (CP) - CORRECT ANSWER Moves
forward
What will happen to an object immersed in fluid when pressure on one surface of the object becomes
less than pressure on the other surface of the object? - CORRECT ANSWER The object will
move in the direction of the lower pressure
The standard atmosphere at sea level is - CORRECT ANSWER 15 degrees C and 29.92 inches
of mercury
The weight of the atmosphere at 18000 feet is ______ what it is at sea level. - CORRECT ANSWER
1/2
Why is pressure altitude important to pilots? - CORRECT ANSWER It is used to determine
airplane performance
Newton and Bernoulli have stated laws that fully explain how lift is formulated. - CORRECT
ANSWER false
What are the effects of less dense air on aircraft performance? - CORRECT ANSWER
Reduces power, thrust, lift
Most of the atmosphere's oxygen is contained below ___________ feet. - CORRECT ANSWER
35,000
,Which statement relates to Bernoulli's principle? - CORRECT ANSWER Air traveling faster
over the curved upper surface of an airfoil causes lower pressure on the top surface.
When are the four forces that act on an airplane in equilibrium? - CORRECT ANSWER
During unaccelerated level flight.
What is the relationship of lift, drag, thrust, and weight when the airplane is in straight-and-level
flight? - CORRECT ANSWER Lift equals weight and thrust equals drag.
What happens when an aircraft reaches the critical angle of attack? - CORRECT ANSWER
Any further increase in angle of attack causes the wing to stall
Ground Effect becomes effective within - CORRECT ANSWER One (1) wingspan above the
surface
An aircraft always will Stall when - CORRECT ANSWER The Critical Angle of Attack is
exceeded
The penalty for a wing producing lift is called - CORRECT ANSWER Induced drag
Wingtip vortices are greatest when the generating aircraft is - CORRECT ANSWER Heavy,
clean (gear and flaps up), and slow
Aspect ratio is the ratio of - CORRECT ANSWER The wing span to the wing chord
The acronym used in class for the engine used in our Cessna 172 aircraft is - CORRECT ANSWER
HAND FL
An increase in aspect ratio with a constant velocity will - CORRECT ANSWER Decrease the
drag
, Which of the following is affected significantly by aircraft stability? - CORRECT ANSWER
Maneuverability
Induced drag is a by-product of - CORRECT ANSWER Lift
What is dihedral and what is its purpose? - CORRECT ANSWER Outer wing tips are higher
than the wing roots - helps the aircraft with roll stability
Angle of attack is defined as the acute angle between the chord line of the airfoil and - CORRECT
ANSWER The direction of the relative wind
Aircraft stability is primarily due to - CORRECT ANSWER The design characteristics of the
aircraft
In order for an airplane to maintain level flight the pilot must coordinate the - CORRECT ANSWER
Angle of attack (AOA) and thrust
In steady flight, the sum of the opposing forces is - CORRECT ANSWER Zero
Where is the CG located in most aircraft? - CORRECT ANSWER In front of the wing's CL
(Center of Lift)
What are the 4 forces acting on an airplane in flight? - CORRECT ANSWER Thrust, lift, drag,
weight
A moment is said to be equal to the product of the force applied and the - CORRECT ANSWER
Distance at which the force is applied
Low cost, low speed airplanes favor which kind of wing? - CORRECT ANSWER Rectangular
An aircraft leaving ground effect during takeoff will - CORRECT ANSWER experience an
increase in induced drag and a decrease in performance.
AND CORRECT ANSWERS
Standard pressure at 10000 feet is (according to the values on the FAA table) - CORRECT ANSWER
20.57 inches of mercury
Which of the following helps determine the shape of the airfoil? - CORRECT ANSWER
Purpose of the specific aircraft
As angle of attack increases, the center of pressure (CP) - CORRECT ANSWER Moves
forward
What will happen to an object immersed in fluid when pressure on one surface of the object becomes
less than pressure on the other surface of the object? - CORRECT ANSWER The object will
move in the direction of the lower pressure
The standard atmosphere at sea level is - CORRECT ANSWER 15 degrees C and 29.92 inches
of mercury
The weight of the atmosphere at 18000 feet is ______ what it is at sea level. - CORRECT ANSWER
1/2
Why is pressure altitude important to pilots? - CORRECT ANSWER It is used to determine
airplane performance
Newton and Bernoulli have stated laws that fully explain how lift is formulated. - CORRECT
ANSWER false
What are the effects of less dense air on aircraft performance? - CORRECT ANSWER
Reduces power, thrust, lift
Most of the atmosphere's oxygen is contained below ___________ feet. - CORRECT ANSWER
35,000
,Which statement relates to Bernoulli's principle? - CORRECT ANSWER Air traveling faster
over the curved upper surface of an airfoil causes lower pressure on the top surface.
When are the four forces that act on an airplane in equilibrium? - CORRECT ANSWER
During unaccelerated level flight.
What is the relationship of lift, drag, thrust, and weight when the airplane is in straight-and-level
flight? - CORRECT ANSWER Lift equals weight and thrust equals drag.
What happens when an aircraft reaches the critical angle of attack? - CORRECT ANSWER
Any further increase in angle of attack causes the wing to stall
Ground Effect becomes effective within - CORRECT ANSWER One (1) wingspan above the
surface
An aircraft always will Stall when - CORRECT ANSWER The Critical Angle of Attack is
exceeded
The penalty for a wing producing lift is called - CORRECT ANSWER Induced drag
Wingtip vortices are greatest when the generating aircraft is - CORRECT ANSWER Heavy,
clean (gear and flaps up), and slow
Aspect ratio is the ratio of - CORRECT ANSWER The wing span to the wing chord
The acronym used in class for the engine used in our Cessna 172 aircraft is - CORRECT ANSWER
HAND FL
An increase in aspect ratio with a constant velocity will - CORRECT ANSWER Decrease the
drag
, Which of the following is affected significantly by aircraft stability? - CORRECT ANSWER
Maneuverability
Induced drag is a by-product of - CORRECT ANSWER Lift
What is dihedral and what is its purpose? - CORRECT ANSWER Outer wing tips are higher
than the wing roots - helps the aircraft with roll stability
Angle of attack is defined as the acute angle between the chord line of the airfoil and - CORRECT
ANSWER The direction of the relative wind
Aircraft stability is primarily due to - CORRECT ANSWER The design characteristics of the
aircraft
In order for an airplane to maintain level flight the pilot must coordinate the - CORRECT ANSWER
Angle of attack (AOA) and thrust
In steady flight, the sum of the opposing forces is - CORRECT ANSWER Zero
Where is the CG located in most aircraft? - CORRECT ANSWER In front of the wing's CL
(Center of Lift)
What are the 4 forces acting on an airplane in flight? - CORRECT ANSWER Thrust, lift, drag,
weight
A moment is said to be equal to the product of the force applied and the - CORRECT ANSWER
Distance at which the force is applied
Low cost, low speed airplanes favor which kind of wing? - CORRECT ANSWER Rectangular
An aircraft leaving ground effect during takeoff will - CORRECT ANSWER experience an
increase in induced drag and a decrease in performance.
