Cirrus aircraft and spins

[EDR]

One of the things I looked at when this whole debate started were the
aircraft dimensions.
The SR-22 is 26 feet long and 38 feet (38.3) wide (wingspan).
One of my books (STALLS, SPINS, AND SAFETY/Sammy Mason) discusses the
moment about the wings and moment about the fuselage and the ability to
recover from spins and the necessary inputs.
The ailerons are roll devices and have no effect on resisting yaw,
necessary to stop a spin.
This raises the question, do the Cirrus aircraft have sufficient
horizontal and vertical surfaces?
Is there a way to increase the tail surfaces without increasing
additional drag?

[Dieter Kleinschmidt]

EDR wrote:

> One of the things I looked at when this whole debate started were the
> aircraft dimensions.
> The SR-22 is 26 feet long and 38 feet (38.3) wide (wingspan).
> One of my books (STALLS, SPINS, AND SAFETY/Sammy Mason) discusses the
> moment about the wings and moment about the fuselage and the ability to
> recover from spins and the necessary inputs.
A usual sailplane (one seat) is 22ft long and has a wingspan of 49ft
and has no trouble to recover from a spin. IMHO the overall length of
the fuselage is of minor interest here. The arm of the vertical
surface relativ to the neutral point of the wing is the more
interesting parameter. Multiply that arm with the vertical surface
area and you'll get the so called 'vertical tail volume' ( which is
often used in sailplane design ).
> The ailerons are roll devices and have no effect on resisting yaw,
> necessary to stop a spin.
> This raises the question, do the Cirrus aircraft have sufficient
> horizontal and vertical surfaces?
Don't know.
> Is there a way to increase the tail surfaces without increasing
> additional drag?
This will always increase drag.

Greetings
Dieter