There are two accepted approaches for engineering general aviation aircraft. One is analysis based (similar to the approach taken by transport category aircraft companies) using industry accepted analysis and modeling practices. The other, possibly more traditional in general aviation, is test-oriented: designing an airplane from experience and standard practices, appropriately over-building, and using tests to see that it meets FAA requirements.
Cirrus embraces the analytical approach where we understand the structural characteristics of materials and components and then build a computer model. We begin by predicting, using analysis, the characteristics of larger structures. Tests then check the computer models to validate what we believe we already know. While an expensive approach requiring more people, IT infrastructure and time, we believe this is the best approach.
This analytical approach has been refined at Cirrus to the extent that, when the SR22-G3 wing was tested to destruction, we remarkably achieved results nearly identical to our models. This occurred at several points along the wing more or less simultaneously and illustrates how well we understand our design. This is the objective: optimized structure, minimal unnecessary weight and predictable results. We don’t break test equipment because we know what the answers are going to be.
Compare a Cirrus’ empty weight (with comparable equipment) and gross weight to similar airplanes. Given that Cirrus airplanes all include CAPS (parachute system) in that base weight we think you’ll be impressed.
COMPUTER MODEL OF CIRRUS WING
At the end of day, what’s the difference?
Both engineering approaches can produce excellent airplanes. Design by analysis, though, tends to produce a lighter structure without any compromises in integrity. Other approaches tend to run on the heavy side since, almost by definition, they are less optimized.
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