The Ross-Stephens 1 sailplane went through many changes in its long history. Over the next few weeks I am going to try to make sense of these and develop a time-line for this history, with drawings and photos to support how the ship evolved from 1937 until its present-day arrangement and configuration.
Here is the first. The photo below is a very early image, probably taken in 1937 or early 1938 by Howard Burr and from his son's Chip's private collection. As far as I know the photo has never been published and may be the only one that shows the entire airframe without other ships or cropping obscuring part of the aircraft in this earliest general arrangement.
This is the unpainted RS-1 which clearly shows a dolly under the ship, no landing gear or wheel, a simple skid with no standoffs or shock absorbers, and the early canopy and horizontal tail. Images at this site both historic and contemporary would seem to corroborate that this photo was taken at Harris Hill in the period when Howard was living and working in New York state.
The October 1937 issue of SOARING shows the aircraft in framed but uncovered condition shortly before the photo above was taken, but unfortunately I only have a poor copy. These photos tell me much more about the original airframe which I can then compare to those I have from the 1960s and 70s after all of the modifications were complete. Its my hope to initially release a 1:3.5 scale kit (same scale as the Augustine build which Joe Holtzman owns) and to then offer parts and diagrams to produce a model depicting any of the variations one chooses.
Another telling image from the late 30s of the aircraft at the Arvin, CA flying site show that the early arrangement of the wing joining was much different than after later modifications to clean up the ship were made by John Robinson to increase its L/D. The two photos below clearly show this difference. What is not known from the early image is whether the root fairings leading and trailing the carry through spar in the fuselage were separate structures put in place after the wings were mated or if they remained as part of the wing assembly, and where access was permitted to pin or bolt the wings in place.
Photo courtesy Dr. Gary Fogel and the Soaring Society of America.
Photos courtesy Andy Page and Paul Gibson.
What is clearly seen in the image above is that their were significant changes to the lower fuselage in the cockpit area and nose to accommodate a large and robust landing skid with shock absorbing capabilities.
Photos that I've just received tell more about the early days of the ship. The first two photos below were likely taken just outside the building where the RS-1 was constructed and possibly upon its first rollout and assembly. The canopy framing is installed but appears to be without glazing. The fuselage appears complete with pitot tube, skid, etc. but the covered surfaces of the wings and tails are without fabric.
The next photo, although not the best angle, (another exists taken from the side this same day that is published in the October/November 1937 issue of Soaring magazine which I have yet to find in original print), shows that the additional upper surface ribs, three per bay shown in the next photo, must have been installed later when the ship was rebuilt some years later by John Robinson. John took the sailplane from a 30:1 glide ratio to become the world's first sailplane to have 40:1 L/D and the most record setting sailplane in history.
Besides generally cleaning up the aircraft's drag, he apparently also modified the wings to increase airfoil fidelity across the critical upper aft sections by adding these improvements shown in the image below taken in the 1970's when owned by Paul Gibson.
The fabric would have been adhered to these points to prevent it ballooning up and changing the airfoil and so inducing more drag at high speed and reducing lift. Its clear however, that I will need to research every writing about the aircraft in order to discern exactly when these changes may have been made and resultant changes in empty weight and wing and span loading.
What is known from the early photographs that I now have in high resolution and without the detriment of moires caused by scanning photos from magazines, is a better picture of Harlan Ross' initial design. One includes a good image of the early instruments to compare with those taken later on in the 1970s.
Suprising to me is that the original cockpit featured a wheel much like the Bowlus designs rather than the later simple stick attached to the control yoke. I believe there may be enough detail in the first photo below to make out the instrument placement.
A parting shot for now.... more later.
The Ross-Stephens 1 being assembled on a dry lake bed in California's Desert. Notice the sheeting of the wing root area. It appears that the design allowed a single sheet of plywood between each fuselage bulkhead former to be cold-molded into position with minimal compound curving of each surface, yielding a very streamlined and low-drag surface at this critical juncture. Such farings help to smooth the airflow around the root, allowing the wing to provide more lift in the inboard section than would be possible without this treatment.
I find the shot of the original cockpit very interesting. A wheel vs a stick, given the normal lack of space in sailplanes. And since the original configuration is what I would like to build, thanks for the insight.
Posted by: Gergory Yanz | January 04, 2010 at 05:30 PM