Re: Steering

["James R. Cunningham" <jrccea@bellsouth.net>]

Pat,  my local library doesn't have this.  What's the chance of mooching a xerox
by snail-mail?  Other comments follow within the body of your post.

Patrick Norton wrote:

> My friend JimC, w said:
>
> >For the most part, modern birds (like airplanes), don't generally use their
> tails for "steering".<
>
> I'd be interested in Jim's (and others) thoughts about Adrian Thomas'
> findings (Bioscience, 4/97) that: "Bird tails confer stability and control

Yes, both.  But more control than stability. Modern birds tend to be unstable
for increased mobility and efficiency, as do modern fighter planes.

> and provide a means of augmenting the lift of the wings to reduce the cost
> of low-speed flight

Yes, but the drag goes up substantially when the tail is lifting, and the
mechanical efficiency tends to go down.  However, efficiency aside, at low
speed, a lifting tail can mean the difference between flying and not flying.
They can also be used to create a download to combat the pitching moment of the
wings without having to sweep the wings forward (this is the usual function of
an aircraft's horizontal stabilizer).

> and increase turning performance".

I never said it didn't enhance turning performance.  It does.  But not by
'steering'.  It does so by 'coordinating' the turn. In aircraft terms, by
'keeping the ball centered'.  Most general aviation aircraft are well enough
coordinated that the rudder isn't really needed to turn, and as often as not
during a turn the rudder is pointed opposite the turn.  One of my friends, an
instrument flight instructor, often flies his plane with his feet flat on the
floor, never touching the rudder, even in turns.

>  Lots of other
> interesting stuff in Thomas' article as well.

Sounds like it.

Jim