Setback

Helicopters, often touted as the best hope of timid commuters, had a bad fortnight. Three of the windmill aircraft cracked up like any common airplane. A Bell helicopter broke up in the air and fell into Lake Union in Seattle, killing the pilot and a Civil Aeronautics Administration man. Two days later, Coast Guard Pilot David Gershowitz was showing off his Sikorsky HO51 before 250 high-school kids at Floyd Bennett Field, New York, when he swooped too low, pulled up too quickly. The tail rotor hit the ground and broke off. The helicopter belly-crashed in orange flames as Pilot Gershowitz rolled to safety.

Near Providence, R.I., another Bell 47B came apart like its Seattle sister ship. It fell 300 feet in flames, killing an instructor and his student. The Bell Aircraft Corp. last week hastily wired all owners of its models 47/B and 47B-3 not to fly their helicopters until the accidents had been investigated.

All this was shocking and surprising to enthusiasts who believe that helicopters are extra safe and extra easy to fly. Helicopter experts know better.

Tricky Craft. One leading test pilot has said flatly that helicopters are hard to fly. They have the basic advantage of being able to rise and descend vertically, avoiding the high-speed take-offs and landings which are the cause of many airplane accidents. But they have special hazards and problems of their own. There are four factors (thrust, weight, drag and lift) which must be kept in proper balance. A helicopter has two sticks controlling the main rotor. There are also the throttle and rudder pedals. All these must be managed with perfect coordination. A helicopter cannot be stalled like an airplane, but if the power is cut too much, the rotor blades can be stalled--with the same results.

Proper loading is critically important. If the center of gravity is off a few inches, the whole craft is out of balance. The pilot must be extra alert, for helicopters can and do fly both backwards and sideways.

A helicopter can "throw" a rotor blade, with immediately disastrous results. (This may have been what happened at Seattle and Providence.) The small tail rotor can and sometimes does come off, or get damaged. Engine failure by itself is not too serious, since a helicopter with a dead rotor acts like an autogiro and windmills down to earth.

Helicopter manufacturers were not too much disheartened by the accidents. President Larry Bell of Bell Aircraft pointed out that airplanes are 43 years old; helicopters are only nine. They are already useful for "specialized assignments such as crop dusting, mapping, rescue. . . ." Better design and accumulating experience, Bell believes, "will hasten the time of wide public use."

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