Designer's Notebook

Airplanes are surprisingly flexible, and changes in their shape can affect aerodynamic characteristics. Barnaby Wainfan explains how the two are coupled.

Aerodynamic flutter has been a recent concern in the homebuilt world. What exactly is flutter? What causes it? Barnaby Wainfan clarifies an often misunderstood and potentially dangerous phenomenon.

Barnaby Wainfan offers an explanation of how tail surfaces can be subject to flutter and how to avoid the potentially disastrous result.

Stall flutter is the result of the elastic axis of a wings surface being aft of the aerodynamic center, resulting in instability. A vicious cycle of lift, twist, stall and lift may ensue.

This month well look at another complex interaction between aerodynamics and aircraft structures that can cause structures to fail: fabric flutter.

When the airflow separates from a surface, the result can be unsteady forces or turbulent wake shedding, neither of which is desirable.

Sometimes adding accoutrements, paint, interior embellishments and other must-haves can result in a weight penalty that is difficult to overcome.

Increasing the weight of an aircraft will affect its performance in all phases of flight.

An ill-fitting joint where the wing joins the fuselage doesn't leap to mind as a foremost source of induced drag, but the effects can be significant.

Although we often consider maximizing airflow over the exterior of an aircraft, we sometimes neglect internal airflow design that can cause significant drag.