I can only agree with Harry and Pam. We should not try to set a height limit
below cloudbase; for all the reasons already put it would be irresponsible to
do so. But a limit some small height above cloudbase solves all the problems.
What height? Remember that we are attempting to quell any perception of
unfairness. My feeling is that 2000 feet above convection height is still
enough for an advantage if the first leg is downwind. However, if the height
allowed above cloudbase was small enough, then there is really no possibility
for advantage, and everyone will probably stay below base. Can we use reports
from airborne gliders to ascertain an accurate figure for the highest cloudbase
in the area?
There are more issues to be worked through, such as requirements for
calibration on loggers, (something we have managed to live without so far) and
penalties for indiscretions. The consequences of going over height need to be
sufficient to discourage, but not to cause irreparable damage in the
competition for that pilot.
Some questions to answer, but I favour this option wholeheartedly.
BT
----- Original Message -----
From: Pam Kurstjens
To: [EMAIL PROTECTED] ; 'Discussion of issues relating to Soaring in
Australia.'
Sent: Saturday, June 07, 2008 11:18 AM
Subject: Re: [Aus-soaring] FW: Starting Procedure
Harry
Very nicely put.
The really dangerous thing to do is to limit start height to a level at or
below cloudbase that can result in EVERYONE being at the top of the same
thermal waiting to start. In some circumstances they wait a long time after the
start has opened. This can happen even when no height limit has been imposed,
but a height limit will make it more likely.
Without a height limit, it is perceived that pilots gain an unfair advantage
by climbing several thousand feet higher than those who launch at the back of
the grid. This situation is made much worse when the announcement that the
start line will open in 15 minutes is made while the last two gliders in the
class are still ON TOW, as happened at Temora this year, and added weight to
the discussion at the pilots meeting.
>>
I would invite comments on the following:
The sensible compromise would be to have a maximum start height which is
above cloudbase, and therefore any gaggling in a very limited space (top of a
single thermal) is avoided. This would mean people can climb, let's say, 2000
feet above cloudbase, a compromise between getting everyone out of everyone's
way, and not allowing them to go up several thousand feet if they have an extra
hour in which to do so.
I'm suggesting 2000, rather than 500 ft above cloudbase, because when
transitioning into thermal wave, the first few hundred feet involve being close
to the wisps, and we wouldn't want everyone held in that layer. Also, the
prediction of cloudbase within 500ft is difficult, and cloudbase may well rise
500 ft during the launch.
Pam Kurstjens
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Dave Shorter
Sent: Saturday, 7 June 2008 10:46 AM
To: [email protected]
Subject: [Aus-soaring] FW: Starting Procedure
-----Original Message-----
From: harry medlicott [mailto:[EMAIL PROTECTED]
Sent: Saturday, 7 June 2008 9:54 AM
To: Dave Shorter
Subject:
Dave,
For reasons I am unable to sort out in the short term, am able to receive
aus-soaring postings but not send them.
Was hoping you could submit the following on my behalf,
Thanks,
Harry
Hi All,
The opinions by very experienced pilots as to the risks associated with the
proposal to introduce competition starting
requirements involving a defined maximum height and speed coupled with severe
penalties for infringements must surely result in this proposal being
reconsidered.
Despite this, the reasons behind this proposal deserve consideration. These
appears to be to provide all competitors a fair start, irrespective of
launching time. Implicit and explicit in the current rules is the provision
that the opening of the start gate be delayed on days when convection is high
to allow the last gliders to launch sufficient time to be in a position to
start at the same time as earlier launches. Hard to argue with this. An
advantageous start when others are still climbing to launch height can have a
profound effect on a daily score, particularly on days when an early start is
desirable for meteorological reasons.
So on days when shear wave or wave generally is available, what should be the
time delay before the start gate is opened? Allow for a pilot to find his first
reasonable thermal, climb and then travel perhaps 10 km to a start point, find
a suitable active cloud, climb to cloud base, accelerate to achieve a high
speed without entering the cloud, dive upwind through the skirt of the cloud,
hopefully connect with the shear wave and then climb 1/4,000ft at a lesser rate
of climb.Do it in less than 40 minutes and you are very fortunate.
Particularly in club/sports class the time to launch a class can run to 30/40
minutes. Add enough time for the last launched gliders to contact and climb in
wave and we have the early launched pilots perhaps loitering in the start area
for much too long and the potential to set a longer task or fit one in on an
indifferent or storm threatened day greatly compromised.
The answer assuming the aim is to ensure a fair start for all and not unduly
lengthen the start process?
Set a maximum allowed start height on the basis of about 500 ft above
predicted cloud base with the provision to vary this height at the time the
start gate is opened if the first estimate is incorrect. No pilot is going to
bother seeking out an extra 500 feet or thereabouts. An easier solution would
be to have a rule prohibiting starting above cloud base. Not ideal and subject
to argument but it would probably be effective in preventing major advantage
being taken of pilots accessing wave, if that is the aim of the exercise,
Harry Medlicott
------------------------------------------------------------------------------
_______________________________________________
Aus-soaring mailing list
[email protected]
To check or change subscription details, visit:
http://lists.internode.on.net/mailman/listinfo/aus-soaring
_______________________________________________
Aus-soaring mailing list
[email protected]
To check or change subscription details, visit:
http://lists.internode.on.net/mailman/listinfo/aus-soaring
