Tuesday, April 10, 2012
The Americanization Of Alto
There’s a mod for that—making the perfect plane, Ron-Corbi style
Alto's playroom is replete with thoughtful, handy features: glove box, easy-reach fuel selector, carb heat, cabin heat and parking brake, just for starters. There's excellent airflow ventilation, good all-around visibility, a one-piece forward-sliding canopy, and don't forget that air-conditioner (see sidebar).
The flap and trim controls show off Corbi's attention to fine-tuning. Push and hold the electrical flap toggle down for a second for automatic full flaps, great during hands-full landings. Or just tap it, and flaps go automatically to the next incremental setting.
Push the electric trim buttons on top of the comfortable foam-padded stick (both pitch and aileron trim come standard—unusual for S-LSA) for a damped, smooth, analog-feeling trim change, rather than the hair-trigger, supersensitive trim setup I've flown on several other LSA.
|Aluminum Vs. Composite|
|Traditional GA airplanes, until just a few decades ago, were generally made of aluminum. The silver metal has many ideal properties for airframe construction. Composite technology, the revolutionary development utilizing fiberglass/foam sandwich techniques, is quite the rage due to its high strength-to-weight ratio and the flowing design it brings to creative designers. There are criticisms and rebuttals from proponents of both systems. Here's a short list:
Aluminum Pros: Decades of refinement in application and tooling; light yet strong; quantifiable, predictable strength and fatigue data; recognized lightning-strike properties and protection capability; minimized UV degradation from sunlight; flexes and transmits loads without failure; warns of impending failure; relatively easy to work with.
Aluminum Cons: After contour forming, needs heat treating to regain strength; expensive to produce complex airframes in low numbers; complex tooling jigs required; limited in aerodynamic shaping capability.
Composite Pros: Can be built economically in small quantities, such as by LSA makers and homebuilders; minimal complex tooling required; compound curve, flowing yet strong, aerodynamic shapes possible; not electrically conductive—antennas can be streamlined into the airframe; smoother inherent drag profile (no rivets, etc.).
Composite Cons: Voids (air pockets) and varying strength of identical parts during construction possible—requires tighter quality controls in production; two-wire electrical system required—composites have no common ground; more vulnerable to lightning strikes; UV degradation is a common challenge—must be well maintained; can delaminate with exposure to weather; can fail at full loads without warning; limited airframe life compared to aluminum.
Composite technology, such as the more recent addition of carbon fiber and Kevlar to airframes, continues to improve and be more thoroughly tested and understood. Airliners increasingly incorporate composites into all areas of airframe construction.
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