As Mike and
John have said, Reichmann’s method definitely works.
A common fault
in most early pilots is to turn as soon as there is any indication of lift,
usually with the result that they turn too early, an end up half in and half
our of the entrained air around a thermal, rather than the core itself.
An extension of
Reichmann’s technique is, when you first encounter a thermal, as long as the
lift is increasing, you should carry on flying in a straight line until the
lift is constant, and then bank. This is assuming that you meet the thermal
head on of course; if one wing lifts you should make an initial turn towards the
rising wing.
Another way of
looking at the same technique is to use the lowest point in the circle; when the
vario indicates you are at the weakest (even sink) point of the circle, look in
the direction of the ‘down; wing and pick a point on the horizon; a
quarter of a turn later, when you are pointing in the same direction as your picked
point, straighten up for 2 or 3 seconds, then recommence the bank. This has the
effect of moving the circle towards the centre of the thermal.
-----Original Message-----
From:
[EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf Of Todd Sandercock
Sent: Tuesday, 19 September 2006
7:16 AM
To: Discussion
of issues relating to Soaring in Australia.
Subject: Re: [Aus-soaring]
Reichmann
Thank you
That makes more sense now. its just that i use a technique where as you hit the
strong lift you tighten up for about 3/4 of a circle and then go back to
normal and that seems to work quite well.
Todd
John Wharington
<[EMAIL PROTECTED]> wrote:
Hi Todd,
Reichmann's technique as described in his book does indeed work. I
think you may be misunderstanding it slightly because of what might be a
translation error or oversimplified use of language.
To be more formal (and correct), his technique is:
- 1) While the climb is improving, flatten the circle
- 2) While the climb is deteriorating, steepen the circle
The effect of 1 is to tend to head toward the core, and the effect of 2
is to turn away from sink. Overall this results in the center of the
spiral to gradually drift towards the core.
So, you see the distinction is not "flatten out when at the strongest
lift" but rather "flatten out as the lift is increasing" etc.
In my PhD thesis I used this technique in an auto-thermalling control
system for an unmanned aircraft and it works quite well.
Hope this clarifies things.
Johnny
On Mon, 2006-09-18 at 22:56 +1000, Todd Sandercock wrote:
> hi all
>
> I was just reading the bible (Reichmann's "cross country
soaring") and
> came accross the thermaling technique described by reichmann. the
> technique to me seams wrong. i'm guessing if it is, then it has
> already been discused on this list but here it is anyway:
> - as climb improves, flatten the circle (15-20 degrees)
> - as climb deteriorates, steepen the circle (50 degrees)
> - if climb remains constant, keep bank constant (25-30 degrees)
>
> in the book it describes keeping the same bank angle for half a
> circle. so i have attached a couple of my drawings of the situation.
> the first is of the method above. the second picture is the opposite
> (as climb improves, steepen the circle. as climb deteriorates, flatten
> the circle).
>
> these drawings are my interpritations of the method so feel free to
> tell me what im doing wrong.
>
> Todd
>
>
>
> ______________________________________________________________________
> On Yahoo!7
> Fuel Price Watch - Find and map the cheapest petrol prices in
> Australia
> _______________________________________________
> Aus-soaring mailing list
> Aus-soaring@lists.internode.on.net
> To check or change subscription details, visit:
> http://lists.internode.on.net/mailman/listinfo/aus-soaring
_______________________________________________
Aus-soaring mailing list
Aus-soaring@lists.internode.on.net
To check or change subscription details, visit:
http://lists.internode.on.net/mailman/listinfo/aus-soaring
On Yahoo!7
Answers:
25 million answers and counting. Learn something new today
