Glider definition (span^2/weight)

A while back I read an FAA definition of a glider (as
opposed to an airplane). I think it was an FAA document
that referenced JAR 22. One of the criteria was a
span squared over weight number (S^2/W). I can't find
this document. Does this sound familiar to anyone?

Bob C.

Bob,

Here is the reference:

http://mysite.verizon.net/engreenwel...teria_2004.pdf

You have it backward it is Weight / span ^ 2 0.62

Wayne
HP-14 "6F"
http://www.soaridaho.com/Schreder


"Bob C" wrote in message
...
A while back I read an FAA definition of a glider (as
opposed to an airplane). I think it was an FAA document
that referenced JAR 22. One of the criteria was a
span squared over weight number (S^2/W). I can't find
this document. Does this sound familiar to anyone?

Bob C.

Thanks. I found it online about two minutes after
I posted the question. Advisory Circular 21.17-2A

Bob C.



At 03:36 29 April 2007, Wayne Paul wrote:
Bob,

Here is the reference:

http://mysite.verizon.net/engreenwel...r_criteria_200
4.pdf

You have it backward it is Weight / span ^ 2 wrote
in message
...
A while back I read an FAA definition of a glider (as
opposed to an airplane). I think it was an FAA document
that referenced JAR 22. One of the criteria was a
span squared over weight number (S^2/W). I can't
find
this document. Does this sound familiar to anyone?

Bob C.

On Sat, 28 Apr 2007 21:32:47 -0600, "Wayne Paul"
wrote:

Bob,

Here is the reference:

http://mysite.verizon.net/engreenwel...teria_2004.pdf

You have it backward it is Weight / span ^ 2 0.62

In other words, it's the wing loading.

rj

"Ralph Jones" wrote in message
...
On Sat, 28 Apr 2007 21:32:47 -0600, "Wayne Paul"
wrote:

Bob,

Here is the reference:

http://mysite.verizon.net/engreenwel...teria_2004.pdf

You have it backward it is Weight / span ^ 2 0.62

In other words, it's the wing loading.

Ralph,

No, wing loading = weight / (span * MAC). Span loading does not consider
the wing's cord.

Wayne
HP-14 "6F"
http://www.soaridaho.com/Schreder
..

On Sun, 29 Apr 2007 12:25:49 -0600, "Wayne Paul"
wrote:


"Ralph Jones" wrote in message
.. .
On Sat, 28 Apr 2007 21:32:47 -0600, "Wayne Paul"
wrote:

Bob,

Here is the reference:

http://mysite.verizon.net/engreenwel...teria_2004.pdf

You have it backward it is Weight / span ^ 2 0.62

In other words, it's the wing loading.

Ralph,

No, wing loading = weight / (span * MAC). Span loading does not consider
the wing's cord.

Oops, my bad.

rj

Isn't a glider simply defined as an aircraft with no
motive power..?

Any aircraft can become a 'glider', whereas a sailplane
is a glider built specifically for soaring.

What a motorglider is, I have no idea...

;o)

At 03:24 29 April 2007, Bob C wrote:
A while back I read an FAA definition of a glider (as
opposed to an airplane). I think it was an FAA document
that referenced JAR 22. One of the criteria was a
span squared over weight number (S^2/W). I can't find
this document. Does this sound familiar to anyone?

Bob C.





There are only 10 types of people in the world. Those who understand Binary, and those who don't.

Al,

In the US formula is used to determine whether a fixed wing aircraft with an
engine is classified as a glider or as an airplane.

Wayne
HP-14 "6F"
http://www.soaridaho.com/


"Al Eddie" wrote in message
...
Isn't a glider simply defined as an aircraft with no
motive power..?

Any aircraft can become a 'glider', whereas a sailplane
is a glider built specifically for soaring.

What a motorglider is, I have no idea...

;o)

At 03:24 29 April 2007, Bob C wrote:
A while back I read an FAA definition of a glider (as
opposed to an airplane). I think it was an FAA document
that referenced JAR 22. One of the criteria was a
span squared over weight number (S^2/W). I can't find
this document. Does this sound familiar to anyone?

Bob C.





There are only 10 types of people in the world. Those who understand
Binary, and those who don't.

Boy, this is how years worth of misconceptions get started..

If you go to the FAA website http://www.FAA.gov and use the aircraft
certification site ... reference the FAR part 1 Definitions.
http://www.airweb.faa.gov/Regulatory...2572960077077A

page 8 states " Glider means a heavier - than - air aircraft, that is
supported in flight by the dynamic reaction of the air against its
lifting surfaces and whose free flight does not depend principally on
an engine."

The JAR 22 reference is a European reference.
CAR 3 is the old certification reference for the USA. I can't recall
any US gliders that have been certified recently. The Kansas City
Small Aircraft Directorate is in charge of that in the US. In fact,
when I started to register my ASW-20 they were going to register it as
an LSA (light Sport Aircraft) until I told then the top speed is
160K !

"Wing Loading"is Weight/Wing Area (typically ASW-20 is 110 sq ft
approx.)
"Span Loading" is the distribution of lift over the wing span, is
typically elliptical (ie. is the top part of an ellipse with the
greatest amount at the center, decreasing 'elliptically' to the tip).

At 12:42 30 April 2007, Wayne Paul wrote:
Al,

In the US formula is used to determine whether a fixed
wing aircraft with an
engine is classified as a glider or as an airplane.

Wayne
HP-14 '6F'
http://www.soaridaho.com/

All very well but, when the engine(s) fail(s), no number
of formulae will ever determine that aircraft to be
anything other than a glider...

;o)