Stairstepdocks

[morris 0]

Is it correct that the foot of the upper person catches the outside A-line "coming in" from the front/nose of the canopy, not from the side?
We had a nice entanglement yesterday...

[faulknerwn 36]

Yes. You normally catch the line from the front. What happened?

[morris 0]

The lower canopy collapsed on the side of the dock the moment the dock took place, don´t know what caused it. The other side of the canopy kept flying, resulting in ~two fast spins, the upper guys foot still docked. The moment the lower guy was about to cutaway the formation settled back to normal flight and flew pictureperfect - only to realise that the outside A-line had been winded up ~twice around the upper guys ankle. We couldn´t clear that and didn´t like the idea of landing it...

What could have caused the collapse?

Additional question:
Is it important for CRW to have no cascade in the outside A-line (just as the center A-line)?
It seems to me to be easier to catch the line if there isn´t a cascade as the angle of the line in relation to the canopy is a different one, closer to the nose of the canopy, easier to reach.
Opinions/informations?

Final question:
Anything special to take care about with stairstepdocks in general?

Thanks for any input!

[FreeFlyer2100 0]

I am by no mean a CRW expert but then again you are getting advice on the internet so I guess it doesn't matter. When taking a stairstep dock the lower canopy will lose lift or increase drag on the side that the dock is being taken. The other side of the canopy is still in full flight and now the other side will act as a pivot since it has increased drag. The way to combat this pivot or spin is to apply some front riser on the side of the canopy that is not docked. This will also act as a safety measure if things go wrong and the dock is lost. If you keep the pressure on the riser and lose the dock then the lower canopy will fly away from the formation instead of into it creating problems. Hope this helps

[morris 0]

Experts please confirm whether this is correct or not!
Outside frontinput will not only get tension "into the system" - which might be a good thing - but will also make the undocked side fly even faster...?? This could be a bad thing...?

[mrobiette 0]

OK, here's a few comments:

1. Stairstep docks are usually made from the front to give a stable formation, but in competition the point is also allowed if it is made from the side. Neither should cause an immediate wrap if made gently, but as previously mentioned the lower jumper should be ready to apply outside front riser if necessary to stabilise his canopy.

2. Outside front riser will actually tend to make the canopy turn down and away from the dock, therefore increasing tension and preventing the canopy rising up and turning in which is one of the causes of a wrap. Ideally it should just be used to stabilise the docking and then backed off, but this depends on the compatibility of the canopies and wing loadings

3. Yes, CRW canopies all have de-cascaded centre and corner A-lines to make dockings easier and safer, and also make it easier to get your foot out (as you've found!). What canopies are you using for these stairstep docks? If they are not specific CRW canopies, eg 9-cells, that might be the reason you got a sudden wrap as they will be much less stable for wing dockings.

4. Also with stairstep docks, the upper jumper has to take care to keep his body and canopy straight when taking the dock, it can be very easy to lean into the lower canopy without realising (especially if taking with a hand rather than foot takes), which can make the lower jumper think he has caused the wrap when in fact its not his fault. Video helps here! The golden rule for stairsteps (in addition to the points above) is to be gentle, lose your momentum before the docking, and don't manhandle the canopies around too much, especially if they are not proper CRW canopies. Also keep flying your canopy! Don't relax just because you have successfully docked - keep watching and evaluating how you are flying relative to the other canopy(ies)

Hope this all helps and makes sense,
Martin

[morris 0]

This helps a lot, thanks very much!

We are using Storms loaded about 1.6
Let me first point out that we are very(!) happy with the chutes!
We´ve chosen the regularversion, not the "full" CF-Version.
Instead we went for the CF-option with the rings on top for the retractable POD and PC.
This option comes with continous center A-lines and we´ve chosen dacron 600 for the lines.
This CF-option for casual CF however does not include continous outside A-lines.
Now we are going to install continous outside A-lines asap as it looks like we like CRW way too much to do it just on a casual basis.
As the linetrims for the regular Storm and the CF-version are different ones, we need to know the length for those lines.
For this reason I´ve contacted PD this very morning (on a Friday) by email, asking for help.
They´ve been answering within minutes and gonna get the needed information for us from the engineering-department.
THIS IS WHAT I CALL OUTSTANDING CUSTOMERSERVICE!

[mrobiette 0]

Great, glad I could help, and that you are enjoying CRW so much! Sounds like you are going about things the right way, just take it steady and as you get more experience you will get a better feel for what you can get away with and what you can't! And if you get the chance, try to get to one of the CRW camps to really get some good experience and coaching - the crwdog mailing list is the best place to hear about that stuff and also get advice (Wendy - have you got the details handy?)

Cheers,
Martin

[skyjumpenfool 2]

Where are you located? I'm betting there's a Crew Dawg nearby that would be glad to stop in and do some coaching.

Edited to add...

Another technique that you can try is to do Center Docks, and walk your way out to the outside line. This will give you experience flying a stairstep before you do offset docks.

Once in the stairstep, the low man should keep an eye on where his canopy is flying in relation to the upper mans leg. If it starts to creap up (go light) a little ouside front riser will compensate.

Once you're comfortable flying a stairstep, doing an offset dock will be less scarry.

Welcome to the dark side.

Birdshit & Fools Productions

"Son, only two things fall from the sky."

[chuckbrown 0]

My suspicion is that the top skin of the lower canopy got pulled down over the nose of the end cell causing the collapse.

[morris 0]

Quote

Welcome to the dark side.

:-)
Always been there, but thanks anyways!

We are located in Germany and will get input from one of the very best german CReWjumpers ten days from now.
I´m coming to the states on a regular basis for jumping for about a decade now but this was always just for RWteamtraining and CanopyPilotingCompetitions, never for doing CRW with the exception of a single jump doing outsidevideo for a 4way sequential team from Florida at Eloy.
Next time I´ll come over will likely be for the US CP-nationals. Any CRW events in August/September I should try to pass by?
We feel already quite ok flying the stairstep and the docks aren´t that scary either, just don´t wanna figure out anthing by trial and error...

Thanks for your input!

[morris 0]

Quote

My suspicion is that the top skin of the lower canopy got pulled down over the nose of the end cell causing the collapse.

I think you are right, this is how it looked like from my perspective, being the lower guy.

[skyjumpenfool 2]

Quote

Any CRW events in August/September I should try to pass by?

The Wisconsin Boogie has been great! CRW talent from all around the place, good coaching/training, great people. According to a recent e-mail the goal is to build the state record to 36. I haven't heard about a date yet, I think their looking for a bigger plane.

I'm sure it'll be posted here when they nail down the details.

Birdshit & Fools Productions

"Son, only two things fall from the sky."

[faulknerwn 36]

And any CREWdogs who aren't already members can go to groups.google.com and join the group crwdogs :-)