376 FORMS OF ENERGY 14. What causes an airplane to stall? 15. \\ hat factors most affect the speed of an airplane? 16. What are the advantages of cambered wings over flat wings? What factors determine the maximum amount of camber that can be used? 17. What is meant by the term camber? 18. Explain the thrust produced by the propeller. 19. Explain the lift of an airplane. 20. Name the three axes of an airplane and describe the controls which the pilot uses to determine the rotation about each axis. 21. What would a pilot have to do to make a left turn? 22. Name the airfoils which give control to each axis. 2,S. Why should an airplane always be taken off into the wind? 24. Why should an airplane be landed against the wind? 25. Name three ways of correcting nose-heaviness. 26. Why is streamlining so important, especially at high speeds? 27. What are the advantages of metal propellers over wood propellers? 28. What is a tractor airplane? 29. What forces oppose the forces of gravity and thrust in an airplane in flight? 30. State Newton's third law of motion and apply it to airplane flight. 31. What factors determine the lift of an airplane? 32. What is meant by the burble point? 2>i. What is meant by the stability of an airplane? 34. Mention several important safety rules for student pilots to keep in mind.
UNIT V SECTION 9 AVIGATION IS THE SCIENCE OF CONDUCTING AN AIRCRAFT FROM A POINT OF DEPARTURE TO THE DESTINATION Introduction. The science of directing an aircraft from here to there is much different from that of traveling over well-marked highways by automobile. Familiar landmarks do not look the same from an airplane as they do from the ground. In bad weather and at night even familiar landmarks are often lost to view. battle has been won. When one has once learned to fly, only half the The next problem is that of learning how to navigate an aircraft. The navigation of an aircraft is often spoken of as avigation to distinguish it from the navigation of watercraft. There are four recognized methods of navigating aircraft: (1) navigation by celestial observation, (2) navigation by terrestrial observation (pilotage), (3) navigation by dead reckoning, and (4) navigation by use of the radio beam. 1. Navigation by Celestial Observation Depends upon the Frequent Determination of the Position of an Airplane by Observation of the Sun or Stars. Navigation by celestial observation is the most advanced and most scientific of all of the methods, but it can be used only when the sun or selected stars are visible and thus permit the determination of their angle of elevation with the sextant. The observations and computations require more attention than a pilot can spare, so that celestial navigation is only possible when a navigator can accompany the pilot. Celestial navigation is practical either day or night provided one can fly above the clouds, and efficient operation demands that long flights be made at high altitudes. Celestial navigation is especially valuable for flying across oceans where there are no landmarks and when flying in the substratosphere above an overcast because often radio signals are affected unfavorably at these altitudes. 377