1.   At the time of writing, however, the ideal design of the main rotor blade was still to be established.

2.   I have found it to be a great help if the main rotor blades are covered with a glossy white material.

3.   If this attitude can be maintained throughout the roll, then the model will be continuously pulled forward by the main rotor.

4.   Some models will drop very rapidly during the early part of the descent while the main rotor winds up to a suitable speed.

5.   This means rolling to the right with a clockwise main rotor or to the left if the rotor rotates anticlockwise.

6.   Turning to the right-with the torque-would make more power avail-able to the main rotors.

7.   The helicopter warning horn then sounded advising that the main rotor blades were too slow.

8.   A stream of air released through vents on an enlarged tail boom counters the torque produced by the main rotors.

9.   But the first prototype has been plagued by frozen computer displays, a faulty clutch and a badly designed main rotor.