Silent Trikes

Meet the Silent family of sleek trikes
Most trikes (powered hang gliders) use fiberglass only for nose pods and wheelpants. The Silent brand of trikes from Germany is an exception as these machines use composite materials for much of the trike carriage or chassis. The Silent family includes four models, two of which are still in production.
Although the Silent trikes are well known to Germans and other Europeans, it took Australian light aviation pioneer Bill Moyes to introduce the stunning Silent Racer to American skies. I first came across this unusual machine at Florida’s Wallaby Ranch before the Sun ’n Fun airshow three years ago.
But I’ve had other contact with developer Helmut Grossklaus as he has, not once, but twice been saved by the same BRS parachute installed in his aircraft. I collected info about this in my role at BRS. Neither accident was the fault of the equipment but of flying circumstances. Grossklaus is a proponent of these emergency systems.
Less exciting but more interesting were my flights with Grossklaus to experience this unique aircraft. I know of nothing else that looks like the Silent Racer (although another interesting, somewhat-related ultralight may be at Sun ’n Fun in April this year).
Sitting in the cockpit of the Silent Racer, you note immediately that this machine has no forward support tube. Its absence has a dramatic effect, broadly expanding the view for the occupants.
Because he uses composites, Grossklaus needs no triangulated aluminum tubing structures like those that  dominate virtually all other trike designs. By careful design, the chassis is supported from the wing by the single main structure aft of the occupants.  
Unusual Features
After noting the unusual structure, I checked out the gorgeous four-blade folding prop. We rarely see these in the U.S., but they are fairly common in Europe where gliding and efficient flying are much more popular. This particular work of art is done in house at Grossklaus’ factory.
No part of the engine is visible, not even the exhaust and muffler. Because Europeans must use engine intake and exhaust silencers to stay within noise restrictions, Grossklaus’ hardware-hiding design also makes less drag. He has engineered cooling so the Silent Racer can cruise for 3 hours without overheating. The interior of the engine compartment also has thorough insulation, which helps this trike earn its name. Two occupants at cruise can talk without need of headsets (although you’ll want them for full-power flying).
You might also observe that the landing gear is different. Fashioning the aft fuselage has allowed the tricycle landing gear to be retracted into the body. Because the Silent Racer is relatively large and heavy, it needs substantial wheels, so these are not completely buried inside.
Because it was quite warm in Florida, I didn’t get a chance to photograph a Silent Racer with a full windscreen, but one can be fitted. It has openings in the sides to permit control bar movement as required in a weight-shift aircraft.
Put the whole package together and Silent Racer is the lowest-drag trike since the Cosmos C trike of the early 1990s.  
Silent Family
Like nearly all aviation designs, the Silent Racer followed earlier developments. Grossklaus started with a single-seater that had its gear tucked up close to the body; they did not retract. His first design looks like a sailplane fuselage but with a hang glider-type wing overhead.
The second in the series used a body more akin to the latest version, but it had fully retractable gear. Single-seater No. 2 was light. It featured a smaller engine and only a two-blade folding prop.
Today, Grossklaus offers two members of his Silent family. One is the microlight featured here, and the other is the Silent Flyer, a single-seater light enough to qualify for FAR Part 103, the U.S. ultralight regulation.
The Silent Flyer boasts many of the same qualities as the larger Silent Racer including composite structure needing no forward support member, a full windscreen, a folding two-blade prop, and a Hirth 2704 powerplant. The big difference is that to stay within the Part 103 weight limit (254 pounds), the gear is fixed. The Silent Flyer weighs only 198 pounds empty, so wings of various sizes can be chosen.  
Lots for Not Much
As with many trike chassis makers, Grossklaus’ designs can employ wings from several other producers. The Silent Racer trike minus a wing is about $10,000 in ready-to-fly mode, and a chassis kit is available for $5000.
The Part 103-capable Silent Flyer is offered either fully built ($5000) or as a kit ($3000).
You will have to add a wing and an engine for either model, but for this sophistication, the prices are reasonable.
For something truly different yet fully proven, check out the Silent trike line. The only reason to wait is to see what will come next from this prolific engineer. Grossklaus hinted at something new, and I’ll be watching.  
FOR MORE INFORMATION, contact Kenny Brown at Moyes America, 200 Hillcrest Drive, Auburn CA 95603; call 530/888-8622; fax 530/888-8708; e-mail flyamoyes@aol.com; web www.zip.com.au/~moyes.
German designer/manufacturer Helmut Grossklaus may be contacted by e-mail at ogrossklaus@metronet.de; web www.silentfamily.com.