Unit 5: Fabrication of powered Gliders - Practice Quiz

1 What does RC stand for in RC flying?

2 Which device does the pilot use to send commands to an RC airplane?

3 What is the main purpose of the receiver in an RC airplane?

4 Which component usually moves an RC airplane's control surfaces?

5 Which control surface primarily makes an airplane roll left or right?

6 Which control surface primarily raises or lowers the airplane's nose?

7 What force is mainly produced by the propeller of a powered RC airplane?

8 Why is a flight simulator useful for a beginner RC pilot?

9 Which simulator exercise is most useful before attempting advanced maneuvers?

10 What should be done before switching on a powered RC airplane?

11 Why is balsa wood commonly used to build RC airplanes?

12 Which tool is commonly used to make precise cuts in thin balsa wood?

13 What is the main purpose of a wing spar?

14 What is the main body of an RC airplane called?

15 Why should matching wing parts be made symmetrical?

16 Which material is generally more resistant to water than untreated balsa wood?

17 Why should excess adhesive be avoided during fabrication?

18 What should be checked after attaching the tail surfaces?

19 What does the center of gravity indicate on an RC airplane?

20 Why is sanding used when shaping balsa airplane parts?

21 During a simulator flight, an RC glider repeatedly pitches upward and stalls when power is increased. Which adjustment should be tested first?

22 A powered glider has a mass of and a wing area of . What is its wing loading?

23 In a simulator, the glider drops its left wing near the top of a slow climb. What is the best immediate recovery action?

24 A pilot wants to compare two propellers fairly in a flight simulator. Which variables should remain unchanged during the comparison?

25 When the transmitter stick is moved right, the rudder moves left. What should the pilot do before flight?

26 Why is exponential control commonly added to an RC glider's elevator channel?

27 A glider flies straight with power off but rolls right whenever the motor starts. Which cause is most likely?

28 In calm simulated conditions, a glider requires continuous up-elevator to maintain a level glide. Which trim change is appropriate?

29 Which simulator exercise best prepares a beginner for an RC glider flying toward the pilot?

30 A powered glider travels in during a level simulator test. What is its average ground speed?

31 A balsa wing spar must resist bending along the span. How should the wood grain be oriented?

32 Two balsa wing panels must be joined at the center. Which method best strengthens the joint without excessive mass?

33 A plastic fuselage part has a smooth, glossy bonding surface. What preparation will usually improve adhesive grip?

34 After assembly, the right wingtip is higher than intended while the left wingtip is correct. What should be done before the glue cures?

35 Why should only a small amount of adhesive be used on well-fitted balsa joints?

36 The center of gravity of a completed RC airplane is behind the recommended range. Which correction is most appropriate?

37 A control horn is being installed on a balsa elevator. Where should the pushrod hole be positioned relative to the hinge line?

38 A thin balsa fuselage side cracks repeatedly near the wing mount. Which modification best addresses the local stress?

39 When heat-shrink film is applied unevenly to a light balsa wing, the wing becomes twisted. What is the best correction?

40 The motor firewall loosens during a ground power test. What is the safest fabrication response?

41 A powered glider climbs steadily at . Its aerodynamic drag consumes of mechanical power, and the complete propulsion system is efficient. Approximately what electrical input power is required? Use .

42 An RC airplane has wing area , mass , and . A payload is added without changing the aerodynamics. At sea level, where , what is the new stall speed?

43 A model has its center of gravity behind a datum. A camera is installed behind the same datum. Where is the new center of gravity?

44 A model stalls at in level flight. Assuming altitude is maintained and compressibility is negligible, approximately what stall speed applies during a coordinated banked turn?

45 A simulator predicts at full throttle from a 3-cell battery. The battery measures at rest and has total internal resistance . The ESC low-voltage cutoff is . Which outcome is most likely near the predicted current?

46 During a calm-air, motor-off simulation test, a powered glider has a horizontal speed of and a steady sink rate of . Neglecting the small difference between horizontal and air-path speed, what is its approximate glide ratio?

47 A geometrically half-scale simulated model is flown at the same speed and in the same air as the full-scale reference. Which similarity parameter becomes approximately half its reference value and can significantly change stall behavior?

48 A real RC airplane has a roll time constant of about , but the simulator adds of command latency. Pilots repeatedly overcorrect in simulation even though the modeled steady roll rate matches flight data. What is the best correction?

49 A simulator predicts a noticeably better motor-off glide than flight tests. The simulated propeller folds immediately, while video shows the real fixed propeller windmilling throughout the descent. Which model change most directly addresses the discrepancy?

50 The real aircraft approaches stall with a stable root-first buffet, but its simulator abruptly drops a wingtip. Overall , center of gravity, and control calibration already match measured data. Which refinement is most appropriate?

51 A built-up balsa wing must resist high positive bending loads with minimal mass. Which spar-cap arrangement uses balsa most effectively?

52 A polypropylene fuselage shell repeatedly releases a conventionally bonded balsa equipment tray. Which joint redesign is most reliable?

53 A balsa wing has adequate vertical bending strength but twists excessively under aileron load. Which modification gives the greatest torsional-stiffness improvement for a modest mass increase?

54 In a built-up wing, thin balsa shear webs are installed between upper and lower spar caps. For the usual arrangement, how should the balsa grain primarily be oriented?

55 A removable plastic wing is secured by bolts passing through thin plastic skin. Flight loads have begun elongating the holes. What is the best structural correction?

56 A cracked balsa longeron must be repaired without creating a severe stiffness discontinuity. Which repair is preferable?

57 After heat-shrinking film on only the upper surface of a lightweight balsa stabilizer, the structure develops a permanent bow. Which fabrication practice best prevents this problem?

58 High-speed tests reveal intermittent aileron oscillation. Inspection finds of free play at the control horn while the wing and servo mounts remain rigid. What should be corrected first?

59 A tractor-configured powered glider tracks straight with the motor off but yaws left immediately when high power is applied. The fin and rudder are aligned, and lateral balance is correct. Which fabrication adjustment most directly counters this power-dependent yaw?

60 A airframe has its center of gravity behind a datum. During tail fabrication, of excess epoxy is added at behind the datum. Approximately how far does the center of gravity shift aft?