I was excited to find this article in the Newspaper Archives because it had clear sketches of Tesla's Helicopter/Airplane plans!
The Bee, Danville, Virginia. March 2, 1928.
It is a tiny combination plane which, its inventor asserts, will rise and descend vertically and fly horizontally at great speed, much faster than the speed of the planes of today. But despite the feats which he credits to his invention. Tesla says that it will sell for something less than $1,000.
When the plane rests on the ground the propeller will be overhead and the wings will be standing vertically. The motor is expected to generate a terrific power that will lift the plane into the air. This power can be sustained only a short while.
At the desired height, the aviator begins to tilt his plane. The wings gradually are brought into a horizontal position that puts the propeller in front of the machine. During this operation the engine power is decreased, and, at this lower power, the helicopter becomes an airplane and is operated as such.
The wings now are supporting surfaces, and, except when exceptional speed is wanted for a few moments, the engine will be run at a low rate.
Seats for the pilot and three or four passengers are suspended from trunnions on which they can turn through an angle of ninety degrees. This enables those in the plane to sit in a normal position at all times.
With two wheel bases at right angles, the helicopter-airplane is able to descend in a glide or vertically, landing easily either way. As a helicopter, it has a low landing velocity.
Tesla, for years one of the world's pioneer inventors, now is nearly seventy-two. He has attained his greatest fame, perhaps, through his work on wireless, in which he had made great progress even before the experiments of Marconi.
He designed an airplane when he was in college in 1876, and he says that a plane built from his design recently has been flown in France. In 1900 he claimed to have communicated with Mars, and since then he has dreamed of establishing communication with the planet.