Only the very ardent aviation enthusiasts will want to read this but those who do will find a gratifying amount of information about whirly birds. Mr. Gablehouse gives a complete history going all the way back to 4th century B.C. and the Chinese flying tops. Leonardo Da Vinci was an experimenter, so was Thomas Edison but things didn't really get off the ground until the late 1700's when two Frenchmen shot straight up in the air for a breathtaking 30 seconds. Credit for new improvements then hopscotched back and forth across the English Channel with Britisher Sir George Cayley trying out valid techniques and Frenchman Louis Breguet making the first sustained flight. The author writes with precision detailing events, discussing military and peacetime uses, defining aeronautical terms, explaining basic principles of flight, future possibilities--extensive heliports etc. The most interesting chapter records some of the more daring rescue missions performed by this versatile craft. But the book may prove a trifle dry to the layman who doesn't know a VTOL from a STOL.