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New to using a Flysurfer for foiling...
Had a straight drop from a high mast MH Lift riding a FS Unity today.
Being that the center lines are attached to the leading edge it caused the kite to immediately invert and race to the water, game over.

I believe the Unity has a few years on it but Im wondering if all of the flysurfers have these front line attachments that pull the nose down with potential to invert or have some of the newer ones accounted for this somehow...never happened on a tube kite for me....

Not quite following you.
Did it front stall?

If it’s flying bad, check line lengths and do mixer test.

https://youtu.be/uryWF-NasQM

Did the mixer on bridle and all bar lines the same.

Flies great...until I drop straight down 4 feet to the water...nose dives...

I've had lots of flysurfers and owned a couple unitys and I had nothing but problems with them . I keep the 10m deluxe for a couple years waiting till I started foil boarding and it was even worse for that . The power was very on and off.

It sounds like a front stall to me. Did it collapse in the middle or at the wingtips. One side or both? Sometimes it helps to fly the kite in light wind on the beach and see if you can duplicate the behavior by putting the kite in extremis. Generally I find the foil kites recover better than tube kites if you violently pull the front lines in to create a front stall.

There are a couple of ways to reduce the tendency to front stall. Since any kite can have a crash, and its otherwise flying great, I might wait and see if it does it again before changing anything. Maybe with practice and by actively flying the kite to keep line tension in a crash or simply keeping the bar sheeted in you can live with it how it is.

The three remedies are:
Shortening B and C at the mixer, increasing reflex and decreasing camber.
Lengthening Z (same effect on profile shape but better for back-stall).
Changing profile momentum adjusters - the last resort. I'm curious to know if you find these in the Unity. Flysurfer spilled the beans on how they work just with the Soul Tech Talk video but I have found them in kites as old as 2013.

Unity is a 2011 kite. Very likely the Z lines have shrunk above the mixer, meaning the mixer test will get you close but not perfect. I have about a 4 cm pigtail added to the Z riser lines in my Speed 4 8m, just for reference. I like to tune the kite to have just a little front stall, too much reflex-stability dumbs them down.

Yea the Unity was kinda the bastard ginger stepchild. Heavy, over complicated bridle, and very on/off power. Sounds like your bridle is the problem. Time to print off the line sheet from FS and measure each and every line in the bridle to find the problem. Have fun with that.

=Jason-

I am not familier with Unity and it's flight behaviour. So I write in general some tasks you could do. On my experiences when line tension is lost most Flysurfers drift quite nicely if there is true wind. So I'd expect that from Unity as well.

Instead of (inaccurately) measuring and using hours of time you could just make a quick rig to stretch bridles for test if it helps on behavior. But if you decide to measure, remember to use 5kg load when measuring (with a rig described on next chapter).

Instead measuring my proposal would be..

Tie mixer top-lines (A,B,C and Z) to water canister via elevated pulley by using frontline or extension line. Put first 10l = 10kg water to canister. Then at kite's end at every LCL attachment point lift water canister to air on gentle steady pull. Insert screw driver through LCL-loop for easier pulling for your hands. After all done then ride & check if it changed anything. For thicker combolines you should increase canister weight. Check for dyneema strength first from line plans and remember dyneema weakens on use. So unless you want to replace bridle-lines use something like 50% of dyneema strength at line plan first to check if it helps. If bridle breaks at 50% of rated maybe it is time to replace it anyway. Stretching is not longlasting fix anymore if originally bridles were pre-stretched and heat treated etc.

The fact is that bridle shrinks and mixer test does not reveal it. But usually shrink should be that way that AoA increases so tendency to backstall increases. But there might be some introduced washout on uneven span-wise shrink which causes center of kite Hindenburg first. But if above stretching does not help, then by adjusting mixer test you could compensate more some shrinkage.

Or if kite is old and much used do porosity test. Try to breathe through kite fabric. You should not be able to do it. If you can then the kite is more or less end-of-life unless re-coated. So it does not hold pressure well for drifting. You could try to visually check also by looking leading edge while flying. Does it take any airfoil shape or is it just like creaters. But remember on static flying there is less pressure inside kite than active flying so don't miss-judge.

Likely need to keep the bar sheeted in when you drop suddenly.

We jump in from about the same height at our launch.

Invariably the uninitiated jump with the kite overhead. It usually shoots and drops. Worse in light wind as people are already light on the bar.

Might not be what your referring to, but we see it with both tubes and foils.

Fly the kite actively while jumping in to keep it in the air.

Great feedback folks. Thank you.
The experience flying this kite on a foil is unreal so will keep with it.

Definitely will try to remember to hold on to the bar to keep the canopy in proportion to prevent front stall....