Sparrow (oz3091)

About this Plan

Sparrow. Unorthodox glider design.

Quote: "This interesting and unorthodox post-war German design is the second of its type to be produced by Reinhard Roeser. Basically the same as that which we now present, the prototype was of all-ply construction, rib capping-strips being of drawing paper. As would be expected, this model was considerably heavier than the balsa version and its gliding capabilities were less. Designed primarily for slope-soaring, the first Sparrow had a fast sinking speed.

On a normal tow-line, instability was somewhat marked, but towing became practicable by the use of the LSARA Rolling Bobbin and tow-hooks at the wing tips. For those readers who are not familiar with this method, it should be explained that the tow-line terminates in a bobbin through which runs another line with ring at either end. These rings attach to the tow-hooks on each wing of the glider aml, should it slew to either side when being towed up, the bobbin runs along the line and the tow pull has the effect of righting the model in its flight-path.

The designer warns intending builders that a .few test flights may be necessary before the handling of this type of glider becomes familiar. Glider exponents will, no doubt, be surprised to discover that Sparrow has the NACA 0012 symmetrical wing section, with its 12 percent thickness ratio, more usually found on control line stunt models.

Many readers will remember another interesting tailless of this type, although considerably larger than either of the above, which was featured in the 'Operation Research' article in May, 1950. This was the scale XFGI of 13 ft 6 in span by the Dynamic Model Unit of Dayton, Ohio. Dropped from a full-size aircraft, it was radio-controlled and carried a safety parachute for landing. From the data obtained, a full-size glider of similar layout was built and flown.

Complete instructions for building are issued with each full size reproduction of the 1/5th scale plan opposite, price 6/- post free from the Aeromodeller Plans Service. "

Quote: "Sparrow. A design for a tailless glider designed by one Reinhard Roeser. It is a large glider with a pod fuselage (one could hide radio in there). The drawings are presented in two because I have duplicated the opposite wing and the intermediate ribs, features that were often missing but which are really handy. Hands up all those that ruined a plan by putting oil on it to see through, oh the joys of childhood. As always with my plans please take care if you are going to use them." This is a modern redrawn plan in PDFvector format.

Supplementary file notes

Article thanks to Pit.

CAD file

This plan is available for download in CAD format.

Corrections?

Did we get something wrong with these details about this plan (especially the datafile)? That happens sometimes. You can help us fix it.
Add a correction