456
P. Liu
Fig. 7.12 Aircraft invented by the Wright brothers
Fig. 7.13 Swan and Boeing 747–400 (a, b)
air, such as balloons and airships. Another category is aircraft that generates
lift through wings, which are heavier than air. In the second category, fixedwing aircraft (such as gliders and civil aircraft) and non-fixed-wing aircraft are
further divisions. Non-fixed-wing aircraft further includes three types, one
is gyroplane, such as helicopter; the other is tilt-rotor aircraft currently in
service in Okinawa, Japan and the U. S; the other is flapping-wing aircraft
that people have now begun to manufacture, as shown in Fig. 7.14.
P. Liu
Fig. 7.12 Aircraft invented by the Wright brothers
Fig. 7.13 Swan and Boeing 747–400 (a, b)
air, such as balloons and airships. Another category is aircraft that generates
lift through wings, which are heavier than air. In the second category, fixedwing aircraft (such as gliders and civil aircraft) and non-fixed-wing aircraft are
further divisions. Non-fixed-wing aircraft further includes three types, one
is gyroplane, such as helicopter; the other is tilt-rotor aircraft currently in
service in Okinawa, Japan and the U. S; the other is flapping-wing aircraft
that people have now begun to manufacture, as shown in Fig. 7.14.