Thanks for the Spins Rich

Kevin Horton wrote in message ...
On Sat, 11 Oct 2003 20:00:31 -0700, David B. Cole wrote:


After takeoff we
climbed to about 4000' to do some dutch rolls. Initially I was a little
timid with the ailerons, but eventually got it together although my feet
were still slower than I would have liked. After the dutch rolls we
moved on to a few power-off stalls. Again, you have to be on your toes
as the nose has more of a tendency than the 172 to drop off to either
side if you're too slow on the rudder.

Great write up.

One very small nit to pick - I know a lot of people think a dutch roll is
a manoeuvre where the pilot it actively making the aircraft roll back
and forth around a point. But the term properly means a combined yawing
and rolling oscillation that the aircraft does all by itself.

It is hard to have clear communication when we have words that
mean different things to different people.

For a rant on the mis-use of the term dutch roll, see:
http://www.douglasdc3.com/sohn/41.htm

For what Bill Kershner thinks about it:
http://pulsar.westmont.edu/aeronca/d...ques/0080.html

For descriptions of what dutch roll is:
http://www.rmcs.cranfield.ac.uk/aeroxtra/dtcstab7.htm
http://www.av8n.com/how/htm/equilib.html

And to show that dutch roll is not just an issue with swept-wing jets:
http://www.berkutengineering.com/pag...rtav898-3.html


Hi Kevin,

Pilots picking nits? Who would have guessed ; )

The English language is very colorful, and many terms have multiple
meanings depending on the context. In the context of the aerobatic
environment, Dutch Roll (note the capitalization, which is customary
in this context) is well understood by aerobatic pilots to describe a
specific coordination maneuver as opposed to the inherent instability
dutch roll common in swept wing aircraft.

While it is true that sometimes the use of certain terms can lead to
confusion, we nevertheless frequently use terminology that has
multiple meanings. For example, ask the airline pilot who is strapping
into his aerobatic mount on his day off from his flying job to explain
and perform a Dutch Roll, and he will know exactly what is being asked
of him. However, ask him to define dutch roll while he's at 35,000
feet in the left seat of his airliner, and he'll likely delve into the
aerodynamic issues involved with dutch roll instability.

Yes, context is important; but to imply that a particlar phrase or
word can and must have one and only one meaning might be a fruitless
exercise indeed! Consider the following:

We'd have to find another word for "stall" since it means something
totally different to me when I'm in my car versus when I'm in my
airplane (and there are far more drivers than pilots, so we'd probably
lose the battle for exclusive use of that term);

We'd have to find another name for "flaps" because, frankly, they
don't;

The "elevator" does not elevate;

"Adding more throttle" or "increasing throttle" doesn't throttle
anything;

"Snap Rolls" have nothing to do with the roll control.

Anyone want to add to this list?

Rich
http://www.richstowell.com