THE HISTORY OF V.A.R.M.S The Annual Diary 1990 - 2009

65
contest of piloting skills.
What the 1-26 needs for good performance in the model is a clean moderate-lift airfoil
pirated from an Aquila Grande (Bravo) or a Bird of Time (Bravo again). Or, if you have the
ordinates, an Eppler 174, 176 or 178, unless you're a heavy handed builder and plan on a 12 to 16
ounce wing loading. Then you'll want a high lift/high drag section to slow her down a bit. Don't go
to undercamber ... the situation isn't that desperate ... Just grab a good old Clark Y.
Another one of my favourites among the Schweizer series is the 1-29 (in factory language, it
means "single place, design number 29.") The 1-29 came about in the mid-fifties, when Schweizer
first began experimenting with laminar-flow airfoils. They stuck a constant-chord wing with a
15.75 aspect ratio onto a stock 1-23G fuselage and tailfeathers, and it sure does make the plane
easier to model than the stock 1-23 ... no more wings that taper down to nothing! If you ever
encounter a real 1-23, you'll be struck by how tiny the fuselage is in cross-section, especially when
sitting alongside the 1-26. This is another bonus to the modeller who's interested in performance.
Once I Built a 90-inch 1-29 and, bored with its flat bottom performance, put together a set of
wings with a laminar airfoil to fit the ship. After all, the real one has laminar wings, no? I don't
remember what airfoil I used ... one of the Wortmanns recommended for modelling ... but I
distinctly remember the results! It was the only airplane I ever owned that would fly with its nose
down! To make it fly well at all I had to was increase the wing loading from a stock eight to over
twelve. Then it would stroke across the sky (this was at the slope) at nifty speeds. But manoeuvres
of any kind were out, because the instant the airspeed fell slightly below Fast, the whole airplane
fell out of the sky! Stalls were absolutely without warning, and recovery depended on having
LOTS of altitude. Mr Wortmann and his 16% wing sections haven't had much of my business
since.
Incidentally, the 1-29 was a "one-off" design, and as far as I know the Schweizer factory at
Elmira still owns her. Please don't pester them for pictures, as their PR department isn't set up to
promote a twenty-year-old design. The 1974 Sailplane Directory put out by Soaring magazine and
the SSA has a picture of the 1-29, as well as all the other Schweizers. (Ever wondered what a
Bowlus Bumblebee or a Slingsby Kirby Gull look like? This directory has them all, including a
wealth of homebuilds. No three views, however). The very best info available on Schweizer
sailplanes, including three views of everything from the Schweizer 1-1 (1929) to the 2-32 is Air
Progress for Oct./Nov. 1964. It's going to take a good library, or a very good friend, to locate the
book, but it's worth it. Twenty-five pages of photos, drawings, company history. The lovely old
TF-2 military training glider from WW-II. The Schweizer 1-6, world's first all-metal sailplane,
build in 1937. The 1-6 looks for all the world like a Baby Bowlus in a suit of armour; waiting for
her turn at the winch, just in front of an old Franklin Utility. I flew a 72-inch 1-6 off the slopes in
New Mexico for years ... the wing is still hanging in a rack over my head as I write this. Talk about
ugly!
Now a word about drawing number three. There's a shape only a Thornburg could love! It's
the old "Wolf" sailplane, designed by that German Chap who invented the idea of circling in lift,
Wolf Hirth. About 52 Wolfs were build, but don't look for one at your local gliderport; the only one
in the U.S. was back in ol ' Virginny when the 1974 Soaring directory came out. The Wolf has one
of those lovely bird-like undercambered airfoils from the '30's and '40's. Don't use it! If you must
build undercamber for authenticity; try the Eppler 387, or a nice clean NAAC 4409.
The final drawing is my only concession to fiberglass, a Glasfugel "Club Libelle."
No see-through surfaces on the bird! To duplicate, you need a lot of block balsa and white
Monokote. The full-scale airfoil is a laminar, of course, and again I'd recommend something
thinner and more nearly flat-bottomed, such as the Eppler 176.
Would I recommend your trying to build from the drawings shown here? You bet!
(Drawings actually not included in the History, but they are in Aspectivity 296, or try other
sources). I've build dozens of models from just such thumbnail sketches. What you want is a plane
that captures the essence of a particular full-scale machine, not a museum piece. All you need to
scale up the drawings is a straightedge, a ruler marked to at least sixteenths of an inch, and a very