Tail Bounce on Front riser approach

[Hooknswoop 19]

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In a CReW dive there are many occasions other than landings during which the slack will be advantageous: during approach to a formation when using those front risers, for example. During these maneuvers a Lightning pilot will not want the slack to be removed from brake lines... But then at the end of this dive, when setting up for a landing, the goal is different: A lightning pilot now wants to be able to plane out the canopy completely and use evey bit of flare that is avaialble from those brake lines.

I see what you are saying the lighting (I have a Dragon 218 BTW) is set up for CReW, not landing. I find it odd that canopy that is set up for front risering makes the steering lines too long to be able to flare completely. My Dragon has a fairly short control range for the size of the canopy. It isn't set up for front riserr turns, but I could lengthen the steering lines quite a bit and still get the full flare (what there is of it anyway) out of the canopy. There are, of course, exceptions to every rule, and the Lighting is a very task-specific canopy. Maybe in order to correctly set the steering lines for front riser work, they have to be so long the pilot won't be able to finish the flare without ridiciously long risers. Now I want to jump a Lighting.

Hook

[flyhi 24]

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With the steering lines correctly set, your canopy will dive longer and faster, have lower front riser pressure, and you can get the most out of your canopy.

As a person with an engineering degree, let me make the standard engineering assumptions, i.e. assume 2-D and linearity. Having said that, am I correct in saying:

1) If we assume a semi-straight arm movement pattern, we have approx. 180 degrees of range of movement for our toggles from full up ( 0 degrees) to full down (180 degrees), and

2) If, when initially set up, the first 30 or so degrees of movement produces no input to the tail and the somewhere around the 170 degree point we induce a stall, then by increasing the brake line length, we make some larger arc, say 45 deg ineffective for input, but then also put ourselves in the position where not only can we no longer stall the canopy, but unless we have it set up perfectly, we have lost some control input.

I guess what I am asking here (after rewriting this about 6.02X10^23 times) is are we cutting off some of the control range to increase performance at the top of the maneuver and sacrificing performance (i.e. lift) at the bottom end? And of course I am not averse to doing this if it is the most efficient way to do the entire maneuver. It's kind of a snapshot of synergy, but definitely something to do consciously rather than unknowingly.

As an aside, if what I have captured is valid, I would make two observations:

1. This must be why the canopy nazi's have distain for us, or anyone who advocates stepping down from a 210' canopy. They know that the first downsizing is just leading you down the road to shortening your brakes and cutting into your safety margin.
2. Bill Booth there seems like the perfect opportunity for your genius to shine. Create a system/mechanism that will allow long enough brake lines prior to the turn which will not interfere with it and then automatically shorten or adjust them for maximum performance once the flare starts.

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"What can I say, I'm the idea guy. Feed the mayonnaise to the tuna fish."

Shit happens. And it usually happens because of physics.

[Hooknswoop 19]

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1) If we assume a semi-straight arm movement pattern, we have approx. 180 degrees of range of movement for our toggles from full up ( 0 degrees) to full down (180 degrees),

OK, I'm with ya here.

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2) If, when initially set up, the first 30 or so degrees of movement produces no input to the tail and the somewhere around the 170 degree point we induce a stall, then by increasing the brake line length, we make some larger arc, say 45 deg ineffective for input, but then also put ourselves in the position where not only can we no longer stall the canopy, but unless we have it set up perfectly, we have lost some control input.

I see what you are saying. It is possible that in order to have no tail deflection while pulling down the front risers, the steering lines have to be lengthened to the point that the pilot is no longer able to completely flare tha canopy. This is rare in my experience. The fix is longer risers, moving full up (0 degrees) up, which increases the amount of toggle input full flare (180 degrees) gives the pilot. If you run into this situation (lengthening your steering lines so that they no longer deflect the tail while in front risers) causes you to no longer ba able to flare the canopy completely, sacrifice the ideal setting for for the complete flare. In that situation, again I think it is rare, it would be a trade off. I would not recommend setting up your steering lines so that a complete flare is not possible.

I don't think that very many canopy/riser/arm length combinations create this situation. A lot of high performance canopy pilots finish their flare no where near full arms extension.

Thank you for bringing this up, it was an oversight I should have covered.

Hook

[flyhi 24]

Thanks. I appreciate the input. Again, I find this forum an incredible source of information.

Mahalo

Shit happens. And it usually happens because of physics.