Art of the Soft Release
A soft release when performed on a Schweitzer hook prevents the release arm from slamming into the stop. It also puts less wear on the latch on both the male and female sides. It also keeps the rope from tying itself into a huge knot. The knot gets dragged on the runway and quickly wears it out as it’s now has a single point dragging across the pavement.
If done correctly, it’s less wear and tear on the hook and the rope.
What a soft release is not.
A 3 G pull-up while still on tow, followed by a -1G pushover.
When you “pull up,” you slow down, putting more tension on the rope. Many of use polypropylene rope which has some elasticity to it. Pulling up just stretches the rope, when you let the nose down to accelerate the rope is still stretched. You always end up with a hard release, a loud bang from the hook, and a good knot in the rope.
What should a soft release look like?
Reduce the tension on the rope, not making a large slackline. A gentle rise behind the towplane. Even better if it’s well before release. Let’s say you are planning on releasing in lift. You don’t release at the first bump of lift you need to feel out of it is wide enough. Five seconds with students is what I use a lot of the time. So as you hit the lift and start counting one, one thousand... you slowly climb behind the towplane — about 5-10 feet. Three one thousand, you are clearing both left and right. By four one thousand you gently let the nose down, accelerating back into position, 5 one thousand you pull the release turn right. If you are out of the lift you just slowly settle back into position.
Because you let the nose down for the soft release, you will need to bring the nose back up. Bringing the nose up stops chasing the rope after release, I can only imagine the damage the rope would do to you. But the other part is you probably want to slow down to thermalling speed. Even if there is no lift, I want to slow down to the minimum sink.
Before you turn, you want to make sure that you have released. You do not want to get that out of order. For the sake of the towpilot, please release before turning. Also, you have to release before raising the nose. When you do that out of order you defeat the whole purpose of the soft release and end up releasing under a lot more tension than you would have had you skipped all of the above and just pulled the release.
One note with the TOST release if you are going to use the manual recommendation and pull multiple times it would be best to hold it completely open for more than 1/100th of a second. I’ve had pilots that pull multiples times what seemed like five cycles in 1 second.
From the TOST Manual:
If the tow cable is under a reduced load, or no load at all (if the glider over-runs or overshoots the cable), the tow ring pair, along with the cable, will be released and dropped only when the release mechanism has been fully actuated. To be 100% sure the cable has been released, you should actuate the release completely several times.
Banner Photo by Mandi Ireland Photography
Garret Willat holds a flight instructor rating with over 8000 hours in sailplanes. His parents have owned Sky Sailing Inc. since 1979. He started instructing the day after his 18th birthday. Since then, Garret has represented the US Junior team in 2003 and 2005. He graduated from Embry-Riddle with a bachelor's degree in Professional Aeronautics. Garret represented the US Open Class team in 2008 and 2010 and the Club Class team in 2014. Garret has won 3 US National Championships.
