weak links

[Tad Eareckson]

Correction for previous. Needs to read -

If tow line tension gets misdirected, reduced, or lost because:...

No, Brian, you read it right.

My 2007/08/01 response to Bacil was about the irrelevancy of everything in front of the parts which normally stay with the glider to its future resale value provided its pilot is doing things right.

My post from yesterday addressed situations in which the glider pilots had not met that condition and was a refutation of the philosophy that a dead tow line is invariably a good tow line.

In Example A the pilots allowed the glider to get too slow.

In B the pilot had failed to notice that the breeze wasn't blowing the right way on his starboard wingtip before he gave the thumb's up.

Need to clear up some definitions.

Yeah, the nose is higher when you're leaving the cart at Ridgely than when strolling into the breeze at Woodstock. But the angle of attack - and thus drag to lift ratio - isn't.

Let's see if we can round up enough asteroids to squash together and make a new planet 1.5 times the mass of this one - call it Thor (we'll have to leave one rock out there big enough to end the reign of Homo sapiens and give this planet a fighting chance).

You blindfold the glider and haul it up behind a Dragonfly. It's got gravity pulling it straight down and the tug pulling it, with about half the force, straight ahead. It doesn't know the forces are coming from two different sources so it averages their strengths and directions, figures that it's flying over planet Thor and straight down is thirty degrees forward of what it would be minus the blindfold, and trims accordingly. The pitch attitude is thus thirty degrees higher than normal but the AOA is fine. It's flying faster 'cause it thinks it's heavier.

Snip the tow line and the glider say's "Holy Shit! This isn't Thor - this is Earth! And down is way the hell back there!" and immediately adjusts accordingly. If the pilot wasn't holding enough extra speed to allow for an easy transition and Earth gets there before the adjustment is completed...

Neither your pitch attitude, AOA, nor combination of the two tells you anything about the relative positions of glider, tug, and runway.

You can be high on pitch, AOA, and position and nosing the tug into the ground.

You can be high on pitch, AOA, and low on position and nosing the tug into the sky. This was the scenario progressing in Example A.

You can be high on pitch, AOA, and in excellent position if you've just forced the glider off the cart. In those circumstances you really do not want to be off tow.