Glider definition (span^2/weight)

[Bob C]

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.

[Wayne Paul]

Bob,

Here is the reference:

http://mysite.verizon.net/engreenwell/ASA/Motorglider_criteria_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.
>
>
>

[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/engreenwell/ASA/Motorglider_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.
>>
>>
>>
>
>
>

[Ralph Jones[_2_]]

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

>Bob,
>
>Here is the reference:
>
>http://mysite.verizon.net/engreenwell/ASA/Motorglider_criteria_2004.pdf
>
>You have it backward it is Weight / span ^ 2 < 0.62
>
In other words, it's the wing loading.

rj

[Wayne Paul]

"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/engreenwell/ASA/Motorglider_criteria_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
..

[Ralph Jones[_2_]]

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/engreenwell/ASA/Motorglider_criteria_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

[Al Eddie]

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.

[Wayne Paul]

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.
>
>

[jettester]

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_and_Guidance_Library/rgFAR.nsf/0/BD73C51E9C7C3FE2862572960077077A

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).

[Al Eddie[_2_]]

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)

[Wayne Paul]

"Al Eddie" > wrote in message
...
> 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...
>

True; however, the formula is used to determine it is and therfore what type
rating you must have to fly it when the engine is running.

[Doug Hoffman]

Al Eddie wrote:
> 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...

One reason it can be important to know
the precise definition of a motorglider(and Wayne
has provided the correct definition),
is for pilot licensing. One can legally
pilot a "motorglider" with just a glider
certificate with a self-launch endorsement.

--
Doug via Treo handheld


--
Posted via a free Usenet account from http://www.teranews.com

[Andy[_1_]]

On Apr 30, 11:06 am, "Wayne Paul" > wrote:

> True; however, the formula is used to determine it is and therfore what type
> rating you must have to fly it when the engine is running.

That may explain why many airplane engine failure incidents turn out
badly. Airplane rated pilot flying an airplane loses engine. Pilot
is no longer rated to fly since it is now a glider. Pilot, in fear of
FAA reprisal, releases the controls and becomes a passenger.

If only he had known that the aircraft category had nothing to do with
whether the engine was running or not he might have survived.

Andy