T. The angle of attack is the angle between the chord of the wing (which is the distance between the leading edge and the trailing edge of the wing) and the direction of the relative wind.
S. I can draw it.
Fig.1.3.4. The angle of attack
Is that right?
T. Quite right. We have already mentioned that the wing creates lift. In what way can lift be increased?
S. To my mind by increasing the angle of attack.
T. Right. There is one more wing angle. It is the angle of incidence (“кут установки крила/угол установки крыла“). It is the angle between the longitudinal axis of the airplane and the wing chord. The angle of incidence is fixed. It cannot be changed by the pilot.
Now look at Figure I.3.5. The airplane may have parasol, low-wing, mid-wing and high-wing construction. (Fig.I.3.5.)
T. That’s correct. Depending on the design of the aircraft the wing may be made of metal, wood or fabric.
Exercise 3. Read, translate and give the gist of text 1.
Text 1. Wing Design
The wing is the principal structural unit of an airplane. It is designed to produce lift when moved rapidly through the air. So, the function of the wing is to provide lift and to support the airplane in the air. The wing has a leading edge, a trailing edge, tips and a root.
The length of the wing between its tips is called the span. The chord is the distance between the leading edge and the trailing edge of the wing.
The shape of the wing may be rectangular, triangular, elliptical and swept back. The amount of the sweepback angle depends upon the type of the airplane and its design. The sweepback angle is the angle between the wing and a perpendicular to the longitudinal axis of the airplane. High-speed jet aircraft have greater sweepback angle.
The dihedral angle is the angle between the wing and a horizontal plane. The angle of attack is the angle between the chord of the wing and the direction of the relative wind. When an airplane’s angle of attack is so steep that the airflow over the upper surface of the wing breaks, lift is lost and drag increases. The angle of incidence is the angle between the longitudinal axis of the airplane and the wing chord. The angle of incidence is measured by the angle at which the wing is attached to the fuselage. The angle of incidence is fixed and cannot be changed by the pilot. The position of the wing may vary. The airplane may have a parasol, high-wing, mid-wing and low-wing construction.
The airplanes may be divided according to the number of wings into monoplanes, biplanes and multi-planes. Monoplanes have one wing, biplanes have two wings and multi-planes have more than two wings.
The wing may be made of metal, wood, fabric or composite material which depends on the design of the airplane.
Exercise 4. Translate the following universal words without a dictionary. Mind the difference in spelling, pronunciation and meanings of such words in English and Ukrainian/Russian.
i) The distance from the leading to the trailing edge of a wing
10. wing tip
j) An airplane with only one wing
11. sweepback angle
k) The angle between the longitudinal axis of the airplane and the chord of the wing
l) The rearmost edge of the airfoil
m) The outer end of the outboard panel
Exercise 10. Answer the questions on text 1.
1. Is the wing a principal structural unit of the airplane? 2. What is the function of the wing? 3. What does the wing consist of? 4. What shapes can the wing have? 5. What is the sweepback angle? 6. What is the dihedral angle? 7. What angle is the angle between the longitudinal axis of the airplane and the wing chord? 8. What is the angle of attack? 9. Does the position of the wing vary? 10. What types of airplanes do we distinguish according to the number of wings? 11. What materials is the wing usually made of?
Exercise 11. Give definitions to the following terms:
monoplane, wing tip, biplane, leading edge, angle of attack, chord, span, trailing edge, dihedral angle, sweepback angle, drag, angle of incidence, wing root.
Exercise 13. Practise out the dialogue.
Т. The main structural member of the wing is a wing spar or beam. It is shown in Figure I.3.6.
Fig.I.3.6. A spar
The terms “spar” and "beam" are synonyms. They mean “лон-жерон / лонжерон”. The spar runs along the length of the wing from the fuselage to the wing tip. The word "long" is an adjective. The correspondent noun is "length". Will you translate the phrase “to run along the length”, please.