Technology will catch up and pass your definitions. I'm quite sure is it technically possible, and even practical, to install an autopilot and modest AI computer that would thermal better than the best competition pilot. It has not been done only because there is no economic incentive. Again there are parallels in yacht racing: in the 2014 A-Cup races, computers were not allowed to directly control sails or foils - so instead, a computer moved a needle on a dial to indicate its desired setpoint, a second needle indicated the current position of the foils and a crewman was assigned to turn a knob to keep the needles aligned, satisfying the rules.

In physics, the storage of energy in potential (altitude), kinetic (speed) or chemical (batteries) is equivalent and the distinction in this context arbitrary. Gravity isn't "absorbed" but the potential energy from it certainly is. In F1 racing, hybrid technology captures excess energy from braking which is used to accelerate out of the corner. What is different about using excess energy at cloud base to improve speed or distance to the next cloud? We already do this by diving away from the cloud.

I'm not advocating all or any of this. But you better start thinking about it now as some of it at least is inevitable. The line is in fact *very* fuzzy if it can be defined at all. It is possible (but not trivial*) to define potential energy at beginning of task = potential energy at end of task. The storage and retrieval of energy during the task is a very slippery subject.

*example of complexity: we are currently allowed to tow aloft and start with 500 or more lbs of water ballast. We are not required to bring that home. That represents quite a lot of watts of stored energy left on the course. By your definition, this should be illegal.

On Sunday, December 24, 2017 at 7:28:37 AM UTC-8, Bob Whelan wrote:[i]
I'll admit to not understanding their concept. If it involves storing
energy while flying, to be used in the weak spots then I would say the
physics is the same, only the details of execution are different...

And in details lie devils. Not only does the in-flight storing of solar energy
require no piloting skill (quite unlike thermalling or orographically-induced
energy storing, i.e. the very essences of soaring flight), how the stored
energy is subsequently used cuts to the same issue.

Using electrical energy to make noisy variometers and display pretty maps in
no way adds directly to the sailplane's energy state relative to the earth or
atmosphere, while using it to rotate a propeller, or otherwise muscle air
around, does. Just a "...detail of execution..." or the termination of soaring
flight?

For me the line is crossed when you finish with less energy than you
started with. That line has already been crossed in a modest way with
instrument batteries, but that is trivial. If I built solar panels into the
wings and used the energy stored during the task to cross a blue hole, is
that subverting soaring?

Whether the question posed immediately above is "subverting soaring flight" is
entirely up to the individual pilot to decide in my view...but it certainly
isn't *soaring* flight...and no IGC ruling will ever make it so.

I guess if we define soaring as only the direct
use of variations in air mass movement, then it is. How about if I deploy
the prop rather than the spoilers racing along under a cloud street,
charging the batteries to later use to cross a blue hole? It gets pretty
hard to draw a line. Loading up the energy on the ground to expend in the
air though is well down a slippery cliff.
We disagree that, "t gets pretty hard to draw a line." In my view it's
simple to draw the line between soaring flight and "some other kind of
flight," as the above paragraph's first sentence easily does. When all the
"usable energy" (following launch, of course) is drawn *directly* from the
atmosphere (not indirectly, from the sun, or from dinosaurs), *and* when zero
of the plane's absorbed energies come from other sources (e.g. propellers,
expelled dinosaur-juice motivated/modified atmosphere, etc.), then it is
soaring flight. Gravity - nothing else - is soaring's engine. And gravity
isn't "absorbed" but rather "inherently positional" and in constant exchange
with the atmosphere. Gravity in conjunction with a non-quiescent atmosphere
makes soaring possible.

Consider what we presently call "dynamic soaring." All of the energy to be
extracted and put into the plane are directly derived from the atmosphere.. All
the deriving and stored energy increase comes about directly from the pilot's
skill and control inputs. All the dissipation of that energy is
gravitationally driven. Qualifies as "soaring flight" to me!

And *that* seems to be the question posed by the O.P. (and perhaps by the
IGC). In my view it has zero to do with personal enjoyment vis-a-vis landouts
(averted or not), competition participation, or anything else. Because (in my
view) all flight is good, but not all flight is soaring flight, the sport of
soaring and its Powers that Be ought not to be attempting to fob off
non-soaring flight as soaring flight.


Bob - believes first principles matter - W.

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