Talk:Spiral divergence

This article tries to state qualitatively how aircraft geometry influences the spiral mode, and is probably accessible to a wide readership. It could be used as an introduction to the quantitative analysis of the Flight dynamics article. It gives a good explanation of why an excessively stable Dutch Roll mode leads to an unstable spiral mode.

The objective of two articles appears to be the same - to relate the aircraft geometry to its behaviour, so they should be merged.

The explanation of pitch plane stability is probably fairly straightforward. This article suggests an approach which starts by treating the yaw plane directional stability in a similar manner to pitch, making the point that a consequence of concentrating on weathercock motion in yaw is this unstable spiral - that would give a more logical introduction to the need for dihedral, and its effect on directional stability. Gordon Vigurs 10:41, 2 September 2006 (UTC)