Dolphin (oz2291)

About this Plan

Dolphin (Dolfin). Free flight gas model. 1937 gas free flight, 9 ft span, eliptical wings, streamline fuse. June 1939 MAN.

Quote: "How You Can Build an Efficient Contest Gas Model That Flew Out of Sight in Nine Minutes - Part No.1

Scene: Wayne County Airport, Detroit. Time: July 9, 1937, about 10 am. Suddenly a huge blue and orange winged teardrop roars off the snowy white runway into the azure, glistening in the suit and nosing upward on its maiden flight. Up, up, up it goes till after nine minutes it is only a speck in the sky.

This is what took place on the morning of the Texaco Event, The model had been adjusted the night before by its builder, Petrides, and when given its first trial flight, it disappeared into the blue. This spoke well for the design and the construction of the ship, but it was disappointing to knoiw that the plane could not be entered in the event because of an abrupt leave of absence.

Three days after the contest, when the model had been given up for lost, an airplane pilot phoned the hotel in accordance with a notice in the paper, and stated that he had sighted the model from his airplane. The Dolphin had landed in a soft wheat field, and was exactly 24 miles from the point of launching, however, two automobile trips had to be made before the model was located. The car followed under the plane to the approximate spot, while the big ship circled around the vicinity in which the little one had landed. The total gas bill involved in retrieving the plane amounted to $9. If that aviator hadn't sighted the gas job, the latter may never have been retrieved. You know how some of those farmers are.

A streamliner model of this type, due to its high lift and high efficiency is easily adaptable to weight lifting and radio control work. The monocoque fuselage provides a high strength safety factor enabling the model to carry a great deal of weight with the assurance that it remain intact. Of course for this type of work it is essential to maintain the correct center of gravity placement and this must be taken into consideration when making any adaptation. If the builder does happen to be interested in using the model for the above purpose, he is referred to the article on the 'Payload Gas Model' in the August, 1938 issue of MAN. The original model had a projected wing area of nine square feet with a weight of 5,3 pounds. This made the wing loading 9.3 ounces per square foot.

Although a Brown Jr motor was used in the plane with a great deal of success, it is advisable to use a 1/3 horsepower motor in the model. The reason for this is that in previous Nationals, the models were 'gassed' according to their weight. The heavier a model, the more gas allotted to it; this gave them all an equal chance. Of course, this system is not now in effect. All motors run for twenty seconds, large or small. We thus see that a model just meeting the weight rule with a maximum of power will stand the best chance.

By following the instructions given here, the Dolphin may be made to meet the adequate requirements.

Thus on completion of the model the builder will find that he has a gas job outstanding in performance, appearance, and we might add, dimensions.

Construction: In this first installment the building of the wing and tail surfaces will be fully described. Always keep in mind that the accuracy of the structure and its alignment determine the Success of the performance of the ship.

A full size drawing of the wing half is required. This is easily accomplished by following the dimensions on Plate 1. Note the slight sweep back in the wing..."

Supplementary file notes

Article.

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