New Yorker IV (oz535)

About this Plan

New Yorker IV (Stout Outdoor Record Holder). 1939 contest rubber model by Frank Zaic.

Note this is a not a full size plan, this is a scan of the drawings as originally printed in the magazine, along with article text.

Quote: "The Stout Outdoor Record Holder. How This Remarkable Plane Made Its Record Flight - Plans With Complete Details of How You Can Build It. By Frank Zaic.

IT IS about time - was all I could say when the New Yorker IV caught a thermal over Wayne County Airport during the 1938 Nationals. It had been a long time since one of my ships got sucked up into the clouds. Of course there was considerable luck attached to it as it is with most thermal flights. However, the flight was prede-termined after a fashion and a great deal of credit belongs to Dick Everett.

I'll never forget the way he timed our walk with the timer from the check-in table to the take-off runway. He was constantly watching two billowy clouds which were drifting over the field. At the same time he kept an eye on the models taking off. As soon as he saw one of them caught by the first thermal he hurried us into preparation and it was a matter of minutes before the New Yorker IV was spiralling upward. The thirty-four inch pitch prop under the stress of tightly wound eighteen strands of 1/4 pulled the ship quite high. Over a minute passed before we noticed that the model managed to keep its altitude, and then it began a slow upward spiral. The model which showed us the initial thermal was already a speck under the cloud.

Well, it seems that we caught the fringe of the passing thermal. The model first drifted at right angle to the ground breeze; very likely due to the circulation of the thermal. Getting ready to follow it, we noted that the drift was now in the opposite di-rection, and that the second cloud was coming up. Could it be possible that the circulation of the second thermal was doing this lucky thing? At any rate, minutes ticked off and it looked worthwhile losing the model. But 'Luck' stayed on. Instead of being drawn into the center of the coming cloud, the model persisted in staying in the fringe so that when the cloud passed by the model began its long spiral glide which landed it in-side the field after 17 minutes 6.2 seconds of mixed emotions. Might men-tion that the other model was lost into the cloud with official time of less than ten minutes. Such is Fate!

The Design: The general design follows a definite predetermined theory. A high pitch prop was used to get every bit of possible altitude. Eighteen strands of 1/4 flat rubber in determined hands has quite a kick in it and it could handle well the 34 inch pitch on 17 inches diameter. Of course the torque is greater than on smaller pitches, but the generous and poly-shaped dihedral of the wing was adequate for its control.

The wing was set at a comparatively high angle of incidence of five degrees to keep the fuselage close to being parallel with the airstream, as well as to obtain higher lift. The airfoil was specifically designed to present a good entry at angles between six and twelve degrees. Twin rudders were used to give the stabilizer a better lift efficiency. The initial rudders were too small and at the contest tabs had to he added.

The fuselage was designed to have the mini-mum of material on the stressed members ; hence, the square type of basic structure with stringers and cabin to provide the needed cross section area. All these considerations proved of value in the final accounting.

The Construction: Before any attempt is made to duplicate the model, be sure that you have a good idea of every part. Drawings were pre-pared to show up the doubtful points. To some of you the construction might seem complicated, but if you just follow the suggestions and stick to the job you will be wiser in many construction points. The (#) marks indicate the poundage of balsa used. Color coded balsa was used for just this purpose. 'C' indicates that quarter grain was used.

Fuselage: The fuselage is composed of square cross section basic structure, and is a straightforward job. The only deviation from the square is the tail portion which supports the stabilizer to zero degree incidence. It was found that the best method for cementing the two sides into a square is to first cement the bulkhead 'A' and the sides at the tail end. The cross braces can then be positioned with assurance..."

Supplementary file notes

Planfile includes article.

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