"Eric Greenwell" wrote in message
news:XygLg.26301$CL6.23010@trnddc06...
W.J. (Bill) Dean (U.K.) wrote:
After two or three days, with his ship not going as well compared with
the others as he expected, he removed it. The difference was immediate
and obvious, he described to me the difference with it fitted as turning
the ASW27 into an ASW20! Remember, he had been flying with the antenna
for some time, it was only in contest against other similar gliders with
good pilots that he saw the difference.
I remain sceptical: I sure didn't see any difference at all when I fitted
a transponder antenna to my ASH 26 E, flying against gliders I'd flown
with for years, nor have I heard of anyone else noticing a difference.
Perhaps something unusual was occurring in his case.
He was flying in a very competitive Nationals (entry of 35) against 11 other
gliders of identical type. Some 5 of the competitors have represented the
UK in Worlds, including one current world champion. See
http://www.cotswoldgliding.co.uk/com...ts/15m2006.htm . The antenna
was fitted on the port side underneath, close to the wheel door. It was
the type with a short wire and a sphere on the end.
Please do not talk as if flying in UK contests involves the same
collision risk with CAT as flying in the high skies around Minden (I have
never done that, alas!).
I won't, and I didn't. My remarks were directed at a Std Cirrus pilot
who felt he needed every crumb of performance, and that was why he
wouldn't consider a transponder. My belief the drag increase is
insignificant, so it shouldn't be a factor in his decision. The need for
it and the cost are the most important factors, I think.
To anyone buying a new modern machine from Schleicher, Schempp or the
others, the cost of fitting a transponder is only a small percentage of
the total cost, but would still involve finding panel space, and
sufficient power (particularly if the transponder is to be on whenever
airborne). But there are still a lot of low value gliders in use in
the UK, and a lot of gliding being done where the actual collision risk
where a transponder would make a difference is very small.
Also the situation in much of the USA. Though, I don't think the value
of the glider should be a factor in the decision to install a transponder.
I realize you are using the glider value as a proxy for the spare cash the
owner has, but I'd rather the focus was on the collision risk, the value
of reducing it, and the cost of installing a transponder.
It is the cost of the instrument, of the cabling and antenna, of the extra
battery power, and of the installation. It is not only the cost in cash,
but also the cost in space needed, and in loss of disposable weight.
It also has to do with how the glider will be flown. Fitting a transponder
would do hardly anything to reduce collision risk for most gliding in the
UK. It will only help those who can and want to fly high in wave. From
the posts I have been reading the situation is quite different in the Minden
area, though even there it seems that the routeing of CAT into and out of
airfields could be improved.
In the USA, I wonder how many of the 1-26 fleet are fitted?
I don't know, but some do have them in the Minden area.
Are you allowed to fly in airways in the UK (as we do in the US), and
would having a transponder give you greater access to them?
For UK ATS Airspace Classifications see
http://www.caa.co.uk/docs/64/ATS_Classifications.pdf , one page.
For the CAA publication "Guide to Visual Flight Rules in the UK" see
http://www.caa.co.uk/docs/64/DAP_ACD_VFR_Guide.pdf 40 pages.
The section "Gliders" is on page 23.
Note that nowhere is there any mention of transponders. In class A and B
airspace the controller will be helped if a transponder is fitted and used,
which is why some UK pilots are carrying them. Obviously a controller is
more likely to help if the glider can squawk.
Note: email address new as of 9/4/2006
Change "netto" to "net" to email me directly
Eric Greenwell - Washington State, USA
"Transponders in Sailplanes" on the Soaring Safety Foundation website
www.soaringsafety.org/prevention/articles.html
"A Guide to Self-launching Sailplane Operation" at www.motorglider.org
W.J. (Bill) Dean (U.K.).
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