View Full Version : Johnson Flight Tests have been updated
Greg Arnold
April 27th 05, 06:44 PM
Thanks to the efforts of several Region 12 pilots, the last 7 years of
Johnson Flight Tests have been added to the SSA site. Log in as a
member, then click on Johnson Articles.
Per
April 27th 05, 08:07 PM
Very nice.
Is there a way in which us european non SSA pilots can log in to the site?
Regards
Per Givskov
"Greg Arnold" > skrev i en meddelelse
news:SfQbe.50$Tg3.43@fed1read03...
> Thanks to the efforts of several Region 12 pilots, the last 7 years of
> Johnson Flight Tests have been added to the SSA site. Log in as a member,
> then click on Johnson Articles.
>
Bob Kuykendall
April 27th 05, 08:33 PM
Earlier, Per wrote:
> Is there a way in which us european non
> SSA pilots can log in to the site?
I imagine that joining the SSA oughta do it.
Per
April 27th 05, 09:33 PM
Thanks, right.
$64 per year seems a little steap considering I don't wan't the magazine or
any other members benefit.
Per
"Bob Kuykendall" > skrev i en meddelelse
oups.com...
> Earlier, Per wrote:
>
>> Is there a way in which us european non
>> SSA pilots can log in to the site?
>
> I imagine that joining the SSA oughta do it.
>
Stewart Kissel
April 28th 05, 02:04 AM
>$64 per year seems a little steap considering I don't
>wan't the magazine or
>any other members benefit.
>
Hmm, I guess you could do your own tests...pardon wise-ass
remark.
Yes, his reports are excellent...and unfortunately
for you I suspect most of us SSA dues payers probably
feel somewhat the same as you in regards to the magazine
and other benefits...but we still pay up :)
MC
April 28th 05, 03:10 AM
If you want to log on for the flight tests, there is a link to the tests at
the www.gliderforum.com
Mike
"Per" > wrote in message
. ..
> Very nice.
>
> Is there a way in which us european non SSA pilots can log in to the site?
>
> Regards
>
> Per Givskov
>
> "Greg Arnold" > skrev i en meddelelse
> news:SfQbe.50$Tg3.43@fed1read03...
> > Thanks to the efforts of several Region 12 pilots, the last 7 years of
> > Johnson Flight Tests have been added to the SSA site. Log in as a
member,
> > then click on Johnson Articles.
> >
>
>
Eric Greenwell
April 28th 05, 03:46 AM
Per wrote:
> Thanks, right.
>
> $64 per year seems a little steap considering I don't wan't the magazine or
> any other members benefit.
It might be possible for the SSA to make the reports available for sale
as printed copies. I'd be glad to inquire about this. There are about 77
reports, generally 4 or more pages each, from 1977 to the present.
What would you be willing to pay for one printed report, not including
postage?
What would you be willing to pay for one electronic copy, emailed to
you? They are about 800 kb each.
Of course, if you wanted all of them, the cheapest thing to do might be
to become a member for a year.
--
Change "netto" to "net" to email me directly
Eric Greenwell
Washington State
USA
Willie
April 28th 05, 03:46 PM
Not all of the reports are Dick Johnson's articles, some
are pilot reports.
Not to negate a fine article by Eric Greenwell, but it is purely
subjective. If someone loaned me a glider to fly, and happened
to live in my neck of the woods, I doubt I would have anything
negative to say about it either.
I am really interested in seeing the actual trails of the
Sparrowhawk. I want to see some hard data and polars
concerning minimum sink and L/D.
Before I get a bunch of flames about how unimportant
L/D is on this ship, a lot of people still use that number
as a basis for their purchasing decision.
I read on the Windward-Performance website a claim
of 36:1 L/D and I don't believe it. Ever since the SSA
convention there has been a rumor that this number
is highly inflated. The rumor is that the actual performance
is closer to 30:1.
I would be interested in hearing any counterclaims to this.
Willie
Greg Arnold
April 28th 05, 08:35 PM
Willie wrote:
> Not all of the reports are Dick Johnson's articles, some
> are pilot reports.
>
> Not to negate a fine article by Eric Greenwell, but it is purely
> subjective. If someone loaned me a glider to fly, and happened
> to live in my neck of the woods, I doubt I would have anything
> negative to say about it either.
I was the one who came up with the list of newer articles that were
recently placed on the SSA site. I included some articles not written
by Dick Johnson because information is good. All reports, whether by
Dick Johnson, Eric Greenwell, or someone else, are subjective. It is up
to the reader to decide what weight to place upon them.
John Galloway
April 28th 05, 09:19 PM
Well - there's a thing -as a non SSA UK pilot for years
until yesterday I could get straight to the Johnson
flight tests (including yesterday the newly posted
ones) and then today all of a sudden I can't.
http://www.ssa.org/Magazines/Johnson.asp
Anyone got a new link?
John Galloway
Willie
April 28th 05, 10:59 PM
Greg, you did a fine job of putting these articles up
and the effort is greatly appreciated. I read them all
and found useful information in all of them.
I was not putting down anyones pilot report.
But...
Give ten pilots the opportunity to fly a new ship and
you will get ten different pilot reports, each will have
his own opinion depending on a variety of things,
including experience, skill or ability, weight, etc.
All of these pilot reports are subjective, Wheras I
believe Dick Johnson's flight reports are more OBJECTIVE.
Backed up by flight tests with measured and recorded
results. They feature polars and numbers relating real
world results.
Over the years, manufacturers have consistantly given
their L/D numbers to be 1 or 2 points higher than was
revealed after Mr. Johnson tested a production craft.
Dick Johnson has established his credibility among
glider pilots by being very independant in his testing.
My issue is with the claimed L/D of the Sparrowhawk.
I was hoping to see an independent review of this
sailplane with polars.
Willie
Marc Ramsey
April 28th 05, 11:06 PM
Willie wrote:
> My issue is with the claimed L/D of the Sparrowhawk.
>
> I was hoping to see an independent review of this
> sailplane with polars.
The tests have been done, it was discussed at the SSA convention. It
hasn't been published in Soaring, yet, so it is no surprise it isn't online.
Bob Kuykendall
April 29th 05, 01:03 AM
Earlier, Marc Ramsey wrote:
> The tests have been done, it was discussed
> at the SSA convention. It hasn't been
> published in Soaring, yet, so it is no
> surprise it isn't online.
Hmmm. I was pretty sure I did see it in Soaring. Now I'd better go
check.
Eric Greenwell
May 1st 05, 06:50 PM
Willie wrote:
> All of these pilot reports are subjective, Wheras I
> believe Dick Johnson's flight reports are more OBJECTIVE.
> Backed up by flight tests with measured and recorded
> results. They feature polars and numbers relating real
> world results.
Even Dick will tell you that a flight test is not exactly "real world
results". How many contests or soaring flights are flown in dead calm
conditions at steady speeds? The early ASW 24 is an interesting example
of this, as it tested well, but did not climb well in mid-afternoon
turbulence. Later models changed the airfoil slightly, showing no change
in flight testing, but definitely improving the climb. Another example
back in the '80s from Schleicher is the ASW 20, which outdid the
Ventus in dolphin style flying, but not in straight steady glides. One
glide suffered separation in pull-ups, the other did not.
Even ensuring these "dead calm" conditions is a major problem, which is
why the Alafliegs use a very carefully tested comparison sailplane to
fly with the glider they are testing, instead of trying to measure
actual sink rates.
Also, as Dick has explained in the past, his results are not based
entirely on objective criteria, but involve some "educated guessing"
about which points to ignore and exactly where to draw the curve through
points that are kept. As you might expect, not all aerodynamicists or
sailplane designers agree with this approach!
The point I'm slowly making is it sounds like you may be giving too much
weight to Dick's flight tests, instead of considering it just one of a
number of ways of evaluating a glider's performance in the _real_ world.
This is definitely more difficult to do with a new glider whose small
numbers mean there isn't much real world flying you can examine.
The people at Windward Performance tell me they believe the calculated
value of 36:1 is reasonable, based on informal glide testing against
several other types of gliders in the 35+ L/D range. I don't know if
this practical for you, but if I were seriously interested in a
SparrowHawk, I'd try to arrange to fly one, or to fly along side one in
glider with the performance I'd want it to have (Std Cirrus? Std
Libelle?). Great Western Soaring might be the place to do this, since
they are a SparrowHak dealer and will have a SparrowHawk there, and
maybe other sailplanes to rent for the comparison. A couple days there
would be money well spent when considering the purchase of a new sailplane.
--
Change "netto" to "net" to email me directly
Eric Greenwell
Washington State
USA
Chris Rowland
May 2nd 05, 11:16 AM
On 28 Apr 2005 20:19:15 GMT, John Galloway
> wrote:
>Well - there's a thing -as a non SSA UK pilot for years
>until yesterday I could get straight to the Johnson
>flight tests (including yesterday the newly posted
>ones) and then today all of a sudden I can't.
>
>http://www.ssa.org/Magazines/Johnson.asp
>
>Anyone got a new link?
The wayback machine web site has som of them -
http://web.archive.org/web/20040214110551/http://www.ssa.org/Magazines/Johnson.asp
Chris
John Galloway
May 2nd 05, 05:29 PM
At 10:30 02 May 2005, Chris Rowland wrote:
>On 28 Apr 2005 20:19:15 GMT, John Galloway
> wrote:
>
>>Well - there's a thing -as a non SSA UK pilot for years
>>until yesterday I could get straight to the Johnson
>>flight tests (including yesterday the newly posted
>>ones) and then today all of a sudden I can't.
>>
>>http://www.ssa.org/Magazines/Johnson.asp
>>
>>Anyone got a new link?
>
>The wayback machine web site has som of them -
>http://web.archive.org/web/20040214110551/http://www.ssa.org/Magaz
>>ines/Johnson.asp
>
>Chris
>
Chris,
Thanks. That's a good archive site that I knew nothing
about - and it gets me back to what I could previously
access.
I still feel that it is a shame that the SSA have decided
to deny general web access to all of the Johnson tests
at the time they have posted some more recent ones.
The are a unique resource of independent data.
No polars are ever going to be totally true but Dick
Johnson has a record of picking up quite few valid
performance issues over the years. DFVLR polars are
surprisingly smooth, surprisingly better at higher
speeds than Johnson's, don't show individual flap polars,
and are available only by individual purchase 2 years
after measurement or in manufacturers manuals. I always
use Dick Johnson's data (if available) for glide computers.
John Galloway
Bert Willing
May 2nd 05, 05:53 PM
The Idaflieg/DLR measurement data is available only after 2 years (except
when a manufacturer agrees to an earlier date) because manufacturer do
actually trust these polars - and a bad polar for a particular glider could
make the company go belly up...
The Idaflieg measurement setup is much more sophisticated than any private
individual could afford, and I would always Idaflieg data if I had a choice.
BTW, my Idaflieg polar for the ASW20 does show individual flap settings...
--
Bert Willing
ASW20 "TW"
"John Galloway" > a écrit dans le message
de news: ...
> At 10:30 02 May 2005, Chris Rowland wrote:
>>On 28 Apr 2005 20:19:15 GMT, John Galloway
>> wrote:
> No polars are ever going to be totally true but Dick
> Johnson has a record of picking up quite few valid
> performance issues over the years. DFVLR polars are
> surprisingly smooth, surprisingly better at higher
> speeds than Johnson's, don't show individual flap polars,
> and are available only by individual purchase 2 years
> after measurement or in manufacturers manuals. I always
> use Dick Johnson's data (if available) for glide computers.
>
> John Galloway
>
>
Bill Daniels
May 2nd 05, 06:01 PM
I've been watching Dick Johnson's reports for several decades. The usual
pattern is for a new glider to be produced with a claimed L/D that is
significantly higher than what results from Dick's testing. The
manufacturer will sometimes pick on dick's methodology and claim that it
doesn't show everything about the glider in question or is somehow unfair.
Much later, when the glider is no longer in production, the general opinion
will be that Dick was dead on with the original report.
Dick's methodology is the best there is given limited budgets. Even so, the
results are far better than what could be reasonably expected which is a
tribute to Dick's skill as an engineer and pilot. A great benefit is that
the same methodology has been consistently and meticulously applied to a
huge number of gliders over a very long time so there is a lot of data to
compare and consequently a lot of confidence in the results.
We all owe a great debt to Dick and the TSA for the years of work they have
done testing gliders.
Bill Daniels
"John Galloway" > wrote in message
...
> At 10:30 02 May 2005, Chris Rowland wrote:
> >On 28 Apr 2005 20:19:15 GMT, John Galloway
> > wrote:
> >
> >>Well - there's a thing -as a non SSA UK pilot for years
> >>until yesterday I could get straight to the Johnson
> >>flight tests (including yesterday the newly posted
> >>ones) and then today all of a sudden I can't.
> >>
> >>http://www.ssa.org/Magazines/Johnson.asp
> >>
> >>Anyone got a new link?
> >
> >The wayback machine web site has som of them -
> >http://web.archive.org/web/20040214110551/http://www.ssa.org/Magaz
> >>ines/Johnson.asp
> >
> >Chris
> >
> Chris,
>
> Thanks. That's a good archive site that I knew nothing
> about - and it gets me back to what I could previously
> access.
>
> I still feel that it is a shame that the SSA have decided
> to deny general web access to all of the Johnson tests
> at the time they have posted some more recent ones.
> The are a unique resource of independent data.
>
> No polars are ever going to be totally true but Dick
> Johnson has a record of picking up quite few valid
> performance issues over the years. DFVLR polars are
> surprisingly smooth, surprisingly better at higher
> speeds than Johnson's, don't show individual flap polars,
> and are available only by individual purchase 2 years
> after measurement or in manufacturers manuals. I always
> use Dick Johnson's data (if available) for glide computers.
>
> John Galloway
>
>
John Galloway
May 2nd 05, 10:09 PM
I agree.
At 17:30 02 May 2005, Bill Daniels wrote:
>I've been watching Dick Johnson's reports for several
>decades. The usual
>pattern is for a new glider to be produced with a claimed
>L/D that is
>significantly higher than what results from Dick's
>testing. The
>manufacturer will sometimes pick on dick's methodology
>and claim that it
>doesn't show everything about the glider in question
>or is somehow unfair.
>
>Much later, when the glider is no longer in production,
>the general opinion
>will be that Dick was dead on with the original report.
>
>Dick's methodology is the best there is given limited
>budgets. Even so, the
>results are far better than what could be reasonably
>expected which is a
>tribute to Dick's skill as an engineer and pilot.
>A great benefit is that
>the same methodology has been consistently and meticulously
>applied to a
>huge number of gliders over a very long time so there
>is a lot of data to
>compare and consequently a lot of confidence in the
>results.
>
>We all owe a great debt to Dick and the TSA for the
>years of work they have
>done testing gliders.
>
>Bill Daniels
>
>
>'John Galloway' wrote in message
...
>> At 10:30 02 May 2005, Chris Rowland wrote:
>> >On 28 Apr 2005 20:19:15 GMT, John Galloway
>> > wrote:
>> >
>> >>Well - there's a thing -as a non SSA UK pilot for
>>>>years
>> >>until yesterday I could get straight to the Johnson
>> >>flight tests (including yesterday the newly posted
>> >>ones) and then today all of a sudden I can't.
>> >>
>> >>http://www.ssa.org/Magazines/Johnson.asp
>> >>
>> >>Anyone got a new link?
>> >
>> >The wayback machine web site has som of them -
>> >http://web.archive.org/web/20040214110551/http://www.ssa.org/Maga
>>>>z
>> >>ines/Johnson.asp
>> >
>> >Chris
>> >
>> Chris,
>>
>> Thanks. That's a good archive site that I knew nothing
>> about - and it gets me back to what I could previously
>> access.
>>
>> I still feel that it is a shame that the SSA have
>>decided
>> to deny general web access to all of the Johnson tests
>> at the time they have posted some more recent ones.
>> The are a unique resource of independent data.
>>
>> No polars are ever going to be totally true but Dick
>> Johnson has a record of picking up quite few valid
>> performance issues over the years. DFVLR polars
>>are
>> surprisingly smooth, surprisingly better at higher
>> speeds than Johnson's, don't show individual flap
>>polars,
>> and are available only by individual purchase 2 years
>> after measurement or in manufacturers manuals. I
>>always
>> use Dick Johnson's data (if available) for glide computers.
>>
>> John Galloway
>>
>>
>
>
Is the Idaflieg/DLR measurement data available on the web somewhere?
I hear complaints about Dick's measurements but know of no other
sources of info.
at the moment I'd like to see the info for the Mosquito 303B
Chris
Bert Willing
May 4th 05, 08:18 AM
If you want an Idaflieg measurement, you need to ask them (p.e. by email).
If they have it, they will charge you a small fee for snail mailing it to
you.
--
Bert Willing
ASW20 "TW"
> a écrit dans le message de news:
. com...
> Is the Idaflieg/DLR measurement data available on the web somewhere?
>
> I hear complaints about Dick's measurements but know of no other
> sources of info.
>
> at the moment I'd like to see the info for the Mosquito 303B
>
> Chris
>
Henryk Birecki
May 4th 05, 05:23 PM
wrote:
>Is the Idaflieg/DLR measurement data available on the web somewhere?
>
>I hear complaints about Dick's measurements but know of no other
>sources of info.
>
>at the moment I'd like to see the info for the Mosquito 303B
>
>Chris
Go to http://www.gliderforum.com/thread-view.asp?threadid=484&posts=3
there is a link there to a spreadsheet for containing data for many
gliders.
Henryk Birecki
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