BROKEN STABILO LINE

Had a good scare the other day. Doing a tandem for a pilots friend. During

the breifing and simulation "excited pilot friend" kept interrupting and was

trying to be helpful by setting up my glider. I asked him on three separate

occasions to not do anything with my gear, after he had already taken my

glider out of the bag. Long story short, After layout and hook in, we pulled

up the glider, checked the lines, it was all good. We began to

launch--loading the glider. At that point the left main stabilo line snapped

as we left the ground. The cosmic rider flies like shit without that line,

by the way. Had some control, but it was very difficult to manage. Tried

ears to stabilize, but couldn't hold em in while trying to counter the turn.

I didn't think of it at the time, but I could have had my passenger hold

them in. As we flew over the LZ I contemplated throwing the reserve. I

thought the glider was still manageable, so we continued to set up for the

normal approach to the LZ. As I felt the brakes on the left, it felt really

stally-mushy weird. Ran into a little bit of textured air on final and ended

up full stalling the glider into the ditch on the west end of the LZ and fell

into the stream. Had to stall it so we didn't run into the other side of

ditchbank. We landed very softly with him landing on top of me and me laying

in the stream. No injuries and the only damage was to the line. After we

looked at it, it appears that someone stepped on it while it was laying over

a sharp rock. The cut is about 18 inches from the quick link, so it wasn't

like it was a snag.

Hindsight being 20/20, Here are some lessons learned:

Excited pilot friends who want to show off how much they know to their

friends are a real pain in the ass and need to be told politely but firmly to

give us a little space.

I never let other people touch my gear. In this case "excited pilot friend"

already had my glider yanked out of the bag while I wasn't looking.

Over the LZ, I considered using a larger, alternate LZ, but decided I had

enough control of the glider to use the normal LZ. Looking back, the bigger

LZ would have been a better option.

Letting the passenger help out by holding ears may work, but it would depend

on the passengers state of mind and ablity. They might freak and pull to

much--you never know.

Ross Rob

TWO RESERVES

I've had some smokejumper paracargo experience using parachute clusters (two or more 'chutes on the same load) and the mention of two solo 'chutes for a tandem emergency system piqued my interest. At first it's easy to think of some disadvantages. Assuming both of the solo 'chutes are non-steerable (unmodified) and that they are configured to each deploy without entangling with the other, possible disadvantages might include: Weight and bulk-- Each parachute in a cluster should be able to individually handle the maximum load (during opening shock) because even well-timed cluster deployments rarely see individual 'chutes opening at exactly the same time. Are solo emergency parachutes that are proven to be capable of handling a tandem maximum loading much smaller than tandem emergency 'chutes? Descent rate-- According to T.W. Knacke (1992) in Parachute Recovery Systems Design Manual, "Parachute clusters experience a reduction in drag because of interference and systems geometry." That is, none of the individual parachutes in a cluster is vertically centered over the load providing its best drag. It appears from his figures that in a two solo emergency canopy cluster each 'chute's drag coefficient may be reduced by about 10%. This suggests to me that two canopies each certified to provide an acceptable descent rate for a 100 kg load will probably not, when used together, provide the same descent rate for a 200 kg load.

Possible advantages to the two parachute system still make it interesting though: Stability-- Clustering parachutes pretty much eliminates canopy oscillations during descent. Opening times-- Smaller canopies have generally shorter filling times during deployment. Redundant emergency system possibilities-- Two independent emergency 'chute systems from the harness attachments on up decrease the chance that failure of a single sub-system would be catastrophic.

Anyhow my wife says the above is a bunch of gobbly-gook and what's it all mean? From my experience and limited research I'd say I'd rather find myself and passenger descending under an appropriately-sized and attached emergency 'chute cluster if I had to deploy. Given that I'd probably have to carry the extra weight and bulk up the hill for years for that one (if any) emergency ride though, it's my inclination at this point to stick with my single tandem-sized emergency 'chute for my situation. It's an interesting possibility depending on one's situation/requirements.

-Todd Onken

HOOKING IN(in response to my <Chris> preachings about hooking passenger to pilot and then to the glider)

The loops on the spreaders being too tight creates a long hook in fight with the

bieners that can be quite discouraging to rehooking equipment to the glider for

each flight, particularly in cold weather.

Ken Hudonjorgensen

HOOKING IN(in response to my <Chris> preachings about hooking passenger to pilot and then to the glider)

Hi there ya'll. I'd make only one comment. The passenger is always hooked up

after I've done my thing. If I must re-arrange my glider, I make a mental

note that I miss-judged my alloted time for prep and launch. This

happens to every pilot. So, I simply start over. This is very important.

Will guarantee that any pro with a perpensity to strive for excellence, can

feel that each tandem he does will be his best ever. Best in terms of how well

he or she performed the basics, not how long, high or whatever you flew. In wind,

if the glider is disturbed, or in light wind with trigger-temp, which often lifts

the trailing edge even when your body position and line tension is relatively correct,

just unhook the passenger, link up with the cycles and build a wall. If the cycles are far

apart and you must redo the forward launch layout, consider that if your

schedule allows, it might be better to delay for a few minutes until the flow

either gets established or until you get in time with the conditions allowing you

time to hook up again. I cannot place myself relative to the glider hooked to the

passenger. When I'm perfectly positioned, I hook my student to me.

Just my grandpa approach!

Thanks,

Monte Bell

CARABINERS

During a recent T2/T3 course, we did some kiting exercises in which we ran across a twist gate carabiner that came open on its own. To combat this sort of thing, we have been encouraging pilots to do the following check once the glider is up and above head, in addition to their pre-inflation check;

-no sticks/tangles

-brakes working

-main biners good

-passenger still has three points on the harness

-passenger biners good

-passenger has three points on the harness

-pilot biners good

-no reserve on the ground

This can typically be done in one smooth, quick, visual scan with some practice... It is often best to practice this when solo flying in and attempt to master the "scan" for tandem flying. Clearly, flat slope launches offer more time to make this check and are much easier than the steep and especially the windy and steep launches where there is little time or opportunity to abort. Either way, it is possible to derive some better peace of mind from doing this scan.

TANDEM BRIDLES

We have some tandem y-bridles in stock, if you have been wanting to run your bridles to the spreader bar, now is the time. A pilot who once suffered an inadvertent deployment off launch recently commented that the first thing that crossed his mind once the reserve started to tug was how happy he was that they were hanging from the spreader. They had a nice landing and walked away.

TECHNIQUE TIDBIT

During a recent T2/T3 course, Scott Horton showed me a trick that you all may know allready, but I somehow missed out on it. When it is time to get the passengers arms behind the spreader bars, tell the passenger to cross his/her arms, then lean back. This way, the hands end up behind the spreaders, presto magico! Thanks for the tip Scott! Anyone have another?

ZIP IT

Firebird has a new tandem that can be either 38 or 42 M. Pardon the shameless plug, but this could just make tandem flying safer...

  http://www.superflychris.com/choice.htm

TANDEM FORUM

Message past, present and future can be found at  http://www.superflychris.com/Tandem%20Forum.htm  Also, please note that there some new links on the tandem forum page entitled; T3 Test, Briefing, Subjects etc. They might be interesting to you. As always, let me know if you want to be taken off my list. Please contribute. Also, feel free to disagree with me or anyone else involved. Let's keep things interesting...

Chris Santacroce