FOR US THE LIVING BY ROBERT A. HEINLEIN

“Suppose the main motor stops while you’re in the helicopter?”

“It settles down on the rotor. The wheels snap out into place. They are held retracted magnetically by a field off the main motor. You settle down pretty hard—It’s about like falling ten meters at sea level, a little harder in this thin air. But the carriage takes most of the shock and this pneumatic upholstery soaks up the rest. It is pretty much of a jolt however. Anyone standing in the cabin should lie down quickly on the couch.”

“Suppose it fell over water.”

“The car will float. If you can start the rotor again, you can even take off again. I’ve done it with this one from Lake Tahoe. If you can’t take off, you can just sit there and wait to be rescued.”

“Now tell me how to maneuver this baby.”

“Turn the main control switch from ‘helix’ to ‘plane’. The wings come out,”—Sure enough, Perry saw them spread on each side—”and the screw starts. As it gathers speed, it drags more and more current, and the rotor slows down and stops and folds up. If you stop the screw by throwing the switch back, or if something happens to it, the rotor starts. The wings don’t retract until the rotor is maintaining lift. See, there goes the rotor.” The great vanes passed by, turning more slowly each revolution, finally stopped, folded back on each other like a Japanese fan, and disappeared. “We are flying now. If I pull back on the stick now the speed increases. When the air speed meter shows the speed I want I return the stick to vertical. If I pushed the stick forward the speed slows. If I slow to stalling speed before I reach it the rotor will start.”

“How do you change direction?”

“If you push the stick sideways, the car turns in the same direction. When you are on your new course you return the stick to vertical.”

“Does that both bank and handle the rudder? Say, I didn’t see a rudder nor any other control surfaces. Why should it turn?”

“There aren’t any control surfaces. The car is gyro stabilized. We rotate the car around the rigid reference frame of the gyros and let the screw push away in our new direction.”

Perry nodded slowly. “That seems all right, except that she must side slip like the very devil on a turn.”

“That’s right, Perry, but ordinarily it doesn’t matter. If you need to prevent it, you can turn past your new course and hold it there until the side slip is killed.”

Perry’s face cleared. “Yes, I suppose so, but I would hate to try to fly a tight military formation in her.”

“You couldn’t. This is a family model, for quiet people like me. It isn’t very fast and it’s as nearly foolproof and automatic as they can make it. They claim that if you can use a knife and fork you can fly a ‘Cloud House’.”

“What speed does she make?”

“I cruise her at about five hundred kilometers. I could make five hundred and fifty but there’s a nasty vibration at that speed. I may need a new propellor.”

Perry whistled. “If that is a moderate speed for a family car, what’s the record these days?”

“About three thousand. That is with rockets of course. But I don’t like a rocket ship. They make me nervous and they are devilish to handle. Give me my old-fashioned electric runabout. I’m in no hurry.”

“Which reminds me. I gather this baby must be electric drive, but how?”

“The rotor and the prop are driven by induction motors. The power comes from storage batteries. The gyros each have their own induction windings. They run all the time.”

“Storage batteries—I should think they would be too heavy.”

“These aren’t heavy for the power they store. They call ’em chlorophyll batteries because the principle involved is supposed to be similar to the photosynthesis of plants. But don’t ask me why. I’m a dancer, not a physicist. However there are some new models on the market that make their own electricity from coal.”

“Directly?”

“I don’t know. It doesn’t burn if that’s what you mean.”