Launch Post
Crosswind foot launch towing tool
Foot launching in a crosswind can be a lot easier with the Launch Post. You take off directly into the wind, the towline pops off the post, you then turn to follow the vehicle and continue the tow as normal.
I made this one from a rear section of keel that gets double staked to the ground, to allow the towline to "bend" so a pilot can launch more directly into the wind. The concept has been tried in various forms in the past, sometimes with spectacular results (not good). This particular design, however, has been tested with much better success.
Parts:
– Fairly wide tube like a keel or leading edge (A- below). This tube
should be about 4-5 feet long and have a sleeve/bushing through the tube
about halfway.
– Piece of batten (B) about two feet long (crossbar that keeps the
towline from sliding down onto the holding rope and/or under the tube).
Drill a hole through A-tube ABOVE the through-bolt to snugly fit the batten.
– 2 Large ground stakes (C and D) – 1st one, inside the tube,
should be wrapped with leather or rubber to prevent the A-tube from flopping
around. The 2nd stake (D) should be placed to split the
difference between direction of glider movement and towline direction
to the car.
– Perlon or other rope to hook from the bushing to the 2nd stake
Set 1st stake (C), set tube on top the stake, set 2nd stake, tie together. Insert the crossbar batten (B) and lay the towline ABOVE the crossbar (B). Tube should be vertical or slightly slanted away from the pilot. Pull on it to make sure it doesn't move when tow force is applied.
Side View showing padded 1st stake (A + C),
batten (B), 2nd stake (D) and holding rope
Dec 14, 2003 - part B above should be a flexible plastic or rubber rod/tube so that if the towline is placed underneath, it'll flex to not trap the towline.
Set up the post so it's downwind from the glider.
Driver gives the pilot his end of the line, drives to the post and loops towline over post, making sure the towline won't snag on the post or the crossbrace, then continues driving the line out.
Pilot launches directly towards the post (it's at least 50 yards away) and the line pops off the top of the post, straightens out, and the pilot continues flying.
It's a real non-event for an experienced pilot. Gotta make sure you don't turn before the towline comes off the post or the towline will "twang" and go slack. This is a regular piece of equipment in my towing stuff now since trying out this variation last Sept and Oct 99 with about 10 other pilots. Everyone did well even in a 90 cross. It will ease the crosswind jitters but won't prevent dust devils from wreaking their devilish havoc.
Make sure the ground stakes are firmly planted in dry ground. Soft or newly plowed ground will let the stakes shift, which causes the post to lean towards the pilot, which means the towline will pop off too soon.
May 2001: I attempted a Launch Post takeoff but the ground was too soft from winter's percolation, making the soil quite loose. I aborted the launch as soon as I saw it coming off the post while I was still on the ground. I think it may have been due to too steep an angle of the towline at the post. Seems the second anchor stake should be oriented favoring the car's pulling direction, not exactly evenly split.
PeterB
DISCLAIMER: As with all aviation endeavors, your choice and use of equipment is totally up to you. It is assumed you are an experienced HG or PG tow pilot who is intimately familiar with the style of towing you will be doing. As such, YOU ASSUME ALL RISK AND LIABILITY in the use of the Linknife, as well as all other parts, functions and personnel involved in the towing and flight operations. If you do not have experience in towing, please contact an instructor for expert training. Trying to learn on your own can, and probably will, result in your injury and even death. Many pilots have paid the ultimate price so we may now tow as safely as never before possible. Please learn from their lessons.
Reel
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Last update January 25, 2008