Pilot statistics: SSA vs non-SSA

[DrJack]

John Roake, Chairman of the International Gliding Commission's
Membership Committee, has stated (see on-line Gliding Magazine at
http://www.glidingmagazine.com/FeatureArticle.asp?id=400) that based
on newly revised FAA statistics the SSA represents less than 50% of
sailplane pilots in the USA. So I found it interesting that in a
recent poll of BLIPMAP users, of the 430 respondents who listed
themselves as a "Sailplane" pilot the percentage who also said they
were SSA members was _91%_. Of course any statistic can be biased
and knowing how different statistics should be interpreted can be
tricky, but still 91% differs greatly from "less than 50%". I expect
that BLIPMAP users tend to be more active pilots and also more likely
to be XC/contest pilots than the "average" soaring pilot. It's also
possible that those BLIPMAP users who took the time to respond are
more "group" oriented than those who did not - but with a 30%
participation, there would have to be a huge opposing bias in the
non-participating pilots to get down to a 50% overall SSA-member
level. FWIW, my conclusion is that the number of _active_ soaring
pilots who are also SSA members is much greater than 50%, so the pool
of non-SSA soaring pilots which might be used to increase SSA
membership is not nearly so large as Roake's statement would suggest.

A summary of that survey is now available on-line at
http://www.drjack.info/BLIP/INFO/SURVEY/2003/survey2003.summary.html

Jack

--
Dr. John W. (Jack) Glendening Meteorologist

[Albert Gold]

Jack,

Great job!

Another interesting measure of the biases of the sample of respondents
is that while only about 5% of soaring pilots fly in contestes, 28% of
your respondents do.

Al
Discus B PG

DrJack wrote:

>
> John Roake, Chairman of the International Gliding Commission's
> Membership Committee, has stated (see on-line Gliding Magazine at
> http://www.glidingmagazine.com/FeatureArticle.asp?id=400) that based
> on newly revised FAA statistics the SSA represents less than 50% of
> sailplane pilots in the USA. So I found it interesting that in a
> recent poll of BLIPMAP users, of the 430 respondents who listed
> themselves as a "Sailplane" pilot the percentage who also said they
> were SSA members was _91%_. Of course any statistic can be biased
> and knowing how different statistics should be interpreted can be
> tricky, but still 91% differs greatly from "less than 50%". I expect
> that BLIPMAP users tend to be more active pilots and also more likely
> to be XC/contest pilots than the "average" soaring pilot. It's also
> possible that those BLIPMAP users who took the time to respond are
> more "group" oriented than those who did not - but with a 30%
> participation, there would have to be a huge opposing bias in the
> non-participating pilots to get down to a 50% overall SSA-member
> level. FWIW, my conclusion is that the number of _active_ soaring
> pilots who are also SSA members is much greater than 50%, so the pool
> of non-SSA soaring pilots which might be used to increase SSA
> membership is not nearly so large as Roake's statement would suggest.
>
> A summary of that survey is now available on-line at
> http://www.drjack.info/BLIP/INFO/SURVEY/2003/survey2003.summary.html
>
> Jack
>

[Mark James Boyd]

Albert Gold > wrote:
>Jack,
>
>Great job!
>
>Another interesting measure of the biases of the sample of respondents
>is that while only about 5% of soaring pilots fly in contestes, 28% of
>your respondents do.
>
>Al
>Discus B PG

How could one possibly succeed in any contest without
BLIPMAPS? ;)
--

------------+
Mark Boyd
Avenal, California, USA

[Eric Greenwell]

Mark James Boyd wrote:
> Albert Gold > wrote:
>
>>Jack,
>>
>>Great job!
>>
>>Another interesting measure of the biases of the sample of respondents
>>is that while only about 5% of soaring pilots fly in contestes, 28% of
>>your respondents do.
>>
>>Al
>>Discus B PG
>
>
> How could one possibly succeed in any contest without
> BLIPMAPS? ;)

This probably reflects the interest of "contest pilots" have in
cross-country flying, rather than any great value for the individual
pilot flying in a contest. The competition director and his advisors
certainly use them when planning the task for the day, but the entrants
don't get near value out them that a pilot planning a cross-country
flight gets, because they are told when to launch, and mostly where to
go. When you have a choice of where to go, it's generally done real-time
(you look as you fly!).

The entrants might actually look at the the Blipmaps that the Director
post, as trends are very important. This can affect the choice of start
time.
--
-----
change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

[Michael]

DrJack > wrote
> So I found it interesting that in a
> recent poll of BLIPMAP users, of the 430 respondents who listed
> themselves as a "Sailplane" pilot the percentage who also said they
> were SSA members was _91%_.

I think the main selection bias you are missing is the low
participation of power pilots. Less than 30% of the respondents were
power rated at all; given my experience with active soaring pilots who
are also power rated, I would guess that means that only about 10-20%
of the respondents are active in power flying.

Further, I think of the soaring pilots not represented by SSA, the
majority are primarily power pilots with limited soaring interest.
After all, if you're going to get badges, enter constests, or be in a
club, you generally have to join SSA.

> there would have to be a huge opposing bias in the
> non-participating pilots to get down to a 50% overall SSA-member
> level.

Actually, I think the real selection bias is being a BLIPMAP member in
the first place. I never even heard of it until now, and I'm
primarily a power pilot and occasional soaring pilot who is not an SSA
member.

> FWIW, my conclusion is that the number of _active_ soaring
> pilots who are also SSA members is much greater than 50%

Almost certainly, especially if by 'active' you mean those who soar
most weekends. An active power pilot is going to have other interests
(mainly power flying) and is unlikely to soar as much as someone whose
only flying is soaring.

> so the pool
> of non-SSA soaring pilots which might be used to increase SSA
> membership is not nearly so large as Roake's statement would suggest.

Actually, I suspect that those soaring pilots who are not SSA members
are mostly not available to increase SSA membership at all. Someone
whose primary interest is flying, and who considers soaring to be just
one aspect of it (and not the most important one at that) is much more
likely to give his money to AOPA or EAA.

My experience is that there are lots of inactive and sporadic soaring
pilots out there who are active in other kinds of flying. Some just
got the rating with no intent of ever using it (should they be called
gliding rather than soaring pilots?) but many others actually have
some XC experience, and don't soar much (or at all) because soaring is
so inconvenient compared to powered flying. Good luck trying to
convince those people that they should send money to SSA.

Michael

[John Cochrane]

DrJack > wrote in message >...
> John Roake, Chairman of the International Gliding Commission's
> Membership Committee, has stated (see on-line Gliding Magazine at
> http://www.glidingmagazine.com/FeatureArticle.asp?id=400) that based
> on newly revised FAA statistics the SSA represents less than 50% of
> sailplane pilots in the USA. So I found it interesting that in a
> recent poll of BLIPMAP users, of the 430 respondents who listed
> themselves as a "Sailplane" pilot the percentage who also said they
> were SSA members was _91%_.

At the bottom of the Roake report it explained where he got his
numbers. As I read it, 30,000 is the total number of glider licences
or ratings ever granted by the FAA. The vast majority are therefore
likely to be inactive (don't fly anymore) or power pilots with glider
ratings they don't use. This number is probably a gross overcount.
Alas.

John Cochrane BB

[Michael Stringfellow]

John is correct. We recently checked the FAA database of pilots holding
glider ratings in Arizona and it is much larger than you might imagine. We
concluded that most were inactive.

Mike



"John Cochrane" > wrote in message
om...
> DrJack > wrote in message
>...
> > John Roake, Chairman of the International Gliding Commission's
> > Membership Committee, has stated (see on-line Gliding Magazine at
> > http://www.glidingmagazine.com/FeatureArticle.asp?id=400) that based
> > on newly revised FAA statistics the SSA represents less than 50% of
> > sailplane pilots in the USA. So I found it interesting that in a
> > recent poll of BLIPMAP users, of the 430 respondents who listed
> > themselves as a "Sailplane" pilot the percentage who also said they
> > were SSA members was _91%_.
>
> At the bottom of the Roake report it explained where he got his
> numbers. As I read it, 30,000 is the total number of glider licences
> or ratings ever granted by the FAA. The vast majority are therefore
> likely to be inactive (don't fly anymore) or power pilots with glider
> ratings they don't use. This number is probably a gross overcount.
> Alas.
>
> John Cochrane BB