Baby Duration Trainer (oz3548)


Baby Duration Trainer (oz3548) by Felix Gilbert from Model Airplane News 1939 - plan thumbnail

About this Plan

Baby Duration Trainer. Rubber sport model.

Quote: "Complete Data From Which You Can Build a Duration Trainer of 100 Sq. In. Wing Area or Contest Models of Larger Size. The Baby Duration Trainer, by Felix Gilbert.

IT DIDN'T take this little job long to get used to the ozone. She flew 'right off the bat' and has been one of the writers most consistant fliers to date. A steep climb char-acterizes the ship and the glide couldn't be much more desirable. As an all-weather flyabout that can take a beating and put up a real performance, this is the ship to build; and its construction requires no super experience. The day this plane made its swell 5 minute flight it had rained slightly. The sky was overcast and the writer would not even have thought of flying it except that he promised to meet some friends at the field. At the time the plane was equipped with an experimental 10 in propeller, and 14 strands of 1/8 in rubber.

Without any testing, the plane was given 580 turns and released. A bit of extreme speed was expected and the plane didn't fail us. It shot up to 100 feet, did a complete and perfect loop whizzing down within 10 feet of the ground. The loop completed, it proceeded to spiral up to 300 feet at quite a rate. The sky had now cleared slightly and the plane caught a thermal over the field. With stop-watch in hand and head pointed skyward, the writer followed the plane by walking under it at a normal rate. The wind was negligible and the drift was only about 1,000 feet or less. After flying over a wooded area in the park, the plane finally glided down, being careful to miss every tree except one which it hit head-on about a foot over the ground and two feet from the highway, for which it was headed. Thus a perfect flight was made, a tree saved the model, though clumsily, and there was no damage.

The plane is very graceful in appearance with its taper wing, diamond body, and twin-tip tail which is a variation of the double-rudder type and has been found to work very well. The original was com-pletely covered with tissue, but it is suggested that the builder cover the body with 1/32 in sheet as well as the two center wing panels. This will not only improve the looks, but materially increase the strength. The original plane was designed just as a sport model. Those who want to build it as a contest model need merely build the small extra center section shown on the small plate, and glue it between the wing halves when assembling the model. This will give the wing the few needed square inches of area to bring the model within NAA specifications. The area will be slightly over 100 square inches.

Builders who would like a larger model may scale up the plans. The area will be 150 square inches, by increasing the dimensions shown on the plans by 25 percent. A very simple method of scaling up the plans is to use dividers or proportional dividers. Since the plans are 1/3 actual size, scaling up the reduced drawings four times will give a model with a wing area of 170 square inches..."

Quote: "Here is a full size PDF format plan and the accompanying constructruction article for the Baby Duration Trainer, a 30-inch wingspan, parasol type rubber-powered endurance model designed by Felix Gilbert and published in the October 1939 Model Airplane News. I employed the 'flat' wingspan, given at 30 inches, as a metric for scaling the full-size plan."

Supplementary file notes

Article text, 3 pages.


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Baby Duration Trainer (oz3548) by Felix Gilbert from Model Airplane News 1939 - model pic


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  • Baby Duration Trainer (oz3548)
  • Plan File Filesize: 1003KB Filename: Baby_Duration_Trainer_plan_oz3548.pdf
  • Supplement Filesize: 868KB Filename: Baby_Duration_Trainer_plan_oz3548_article.pdf
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