Military

AL0966 Practice Exercise Answer Key & Review
Lesson 1, 2 & 3: Basic Aerodynamics

True - False

Select True or false for the following questions.


  1.   On an aircraft having aerodynamically clean characteristics, speed brakes are used to improve the rate of ascent.

  False
  2.   The surfaces of a wing or rotor blade are designed to produce lift when air passes over it. Two-thirds of the lift is produced by the lower pressure air passing over the wing's or blade's upper surface.

  True
  3.   The rotor system is using from 20 to 100 percent of the available power and the horizontal velocity is 10 knots or less. Under this condition a pilot may experience settling with power.

  True
  4.   The lateral axis runs from wing tip to wing tip.

  True
  5.   The man who first sketched the helicopter and referred to it as a helixopteron was Giovanni Venturi.

  False
  6.   Sir Isaac Newton's third law of motion is: for every action there is an equal and opposite reaction.

  True
  7.   Improved lift and airfoil efficiency while operating in ground effect are due to the recirculation of the main rotor tip vortex.

  False
  8.   The term "standard conditions" refers to atmospheric pressure of approximately 14.7 psi or 29.92 inches of mercury at sea level with a temperature of 15°C.

  True

Cluster True - False

NOTE:  (Each question of this kind consists of a series of statements related to the stem that precedes them. Select True or False for each question.)

 
  9.   A given volume of dry air contains a variety of gases representative of the earth's atmosphere. Indicate which of the following statements most accurately states the composition of this variety.
        a.  Nitrogen, oxygen, argon, carbon dioxide, and minute amounts of other gases.

  True
        b.  Water vapor, dust, and salt particles.

  True
        c.  A percentage of gases varying with the temperature of the air.

  False
        d.  One percent of other gases, 21 percent oxygen, and 78 percent nitrogen.

  True
        e.  Fifty percent oxygen, 48 percent nitrogen, and 2 percent argon.

  False
Matching

  10.  The proper matches are as follows:

    

(1)  Control surfaces in the empennage group.

  B. Rudder an elevator.
(2)  An imaginary line drawn from the center of the leading edge to the trailing edge of an airfoil.

  A. Chord line.
(3)  Three basic controls in a helicopter

  E. Cyclic, collective pitch and antitorque.
(4)  Control an aircraft about its bank or roll axis.

  C. Ailerons.

 

Multiple Choice

NOTE: (Each question in this group contains one and only one correct answer. Make your choice by selecting the proper letter for each question.)

  11.   The blade element located between approximately 25 and 75 percent radius is known as the auto-rotative or driving region.

  B. This region operates at a comparatively high angle of attack.
  12.   An airfoil's angle of attack is measured between the.

  C. Airfoil chord and the relative wind.
  13.   The average temperature lapse rate is:

  A. Based on the worldwide variation of temperatures with altitude.
  14.   Gyroscopic precession is the result of a force applied against a rotating body, and it occurs, approximately, at a point:

  C. Ninety degrees later in the direction of rotation from the point where force is applied.
  15.   If the pressure altitude is 7,000 feet and the temperature is +15°C the density altitude is:

  C. 8,600.
  16.   A wing that has no external supports is called a:

  A. Cantilever wing.
  17.   Lift, weight, thrust, and drag are the four forces that act on an aircraft. You are correct in making which of the following statements.

  A. Induced and parasite are two types of drag forces.
  18.   When the helicopter is moving forward at a speed of 150 knots, and the velocity of the rotor blade tip is 363 knots, the advancing and retreating blade speeds are:

  A. 513 and 213 knots.

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AL0966 Edition B Examination
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