Altitude Change and downsizing

[lippy 773]

I'm not the most articulate person in the world, so bear with me...

I'm currently jumping a stilleto 135 loaded at about 1.5. I had been getting a little bored under it until I discovered the joys of downwinders, and although that's entertaining, I'm looking to step down to a 120 that, unlike my 135, isn't out of trim and a little baffed. I'd be loading the 120 at about 1.67.

I'm currently jumping at DZs around 700-900' MSL. It's looking like I may soon be transferring to an area around 3000'.

Obviously the 120 is gonna go faster, and with the altitude change + downsize at the same time, I'm a little concerned. OTOH, when I demoed the 120 last weekend I noticed a dramatic increase in the bottom end, and my ability to get the thing stopped, which was one of the major reasons I liked it so much. I attributed this to the fact that my 135 is a little baffed.


So I'm asking for some advice on the situation. And on swooping at higher altitudes in general. Thinner air means less lift, but it also means higher speed. Can this higher speed be converted to more lift? Was the increase in bottom end I found on the 120 purely a factor of the newer material, or is it somehow related to a higher wing-loading?

I got nuthin

[CanuckInUSA 0]

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Thinner air means less lift, but it also means higher speed. Can this higher speed be converted to more lift?

Unfortunately the answer is no. Your approach speeds will be faster, but since the air is thinner, you will lose your lift faster. That is why it is imperative that people who jump smallish canopies here at altitude know how to complete their flare.

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Was the increase in bottom end I found on the 120 purely a factor of the newer material, or is it somehow related to a higher wing-loading?

I'm thinking that is was a result of the higher wing loading. But a more qualified person may correct me.

This is a good time of year to downsize if that is what you plan on doing. The temperatures are cool (if not cold) and the density altitude will not be as bad as in the summer months. In a week or so I will be taking delivery of a canopy 8 square feet smaller than what I jump and more importantly it will be my first (beer) cross-braced canopy. I could have choosen to wait until the fall or decided to jump it now (I know where the canopy nazis will chime in). But I would absolutely be asking for trouble if I chose to start flying this canopy for the first time during the hot summer months. And since I want to compete on the CPC with a cross-braced canopy, now is the time for me to take the leap. If I crater, I only have myself to blame.

Try not to worry about the things you have no control over

[Spizzzarko 0]

TRy your 135 up at your new dz. You may find that the altitude gives you the speed you want. More airspeed up at the higher altitude doesn't equal more lift. If you are having problems shutting your 135 down then land it into the wind. Doing downwinders is probably not a really good habit to get into. You end up being one of those assholes that the rest of the jumpers doesn't like, but they don't say anything to your face. Doing downwinders at a higher dz altitude is doubly not smart. If landing into the wind isn't helping you out then get your canopy relined. A fresh lineset will do wonders for a canopy. ZP can last upwards to 3,000+ jumps if well taken care of. Line sets usually start wearing out around 500+ jumps. When people say that you need to downsize to get a good landing, it is about the most assignine thing I have ever heard. Also I think the stilletto's optimal wingloading for distacne is about 1.7 or less, so if you downsize to the 120 it will almost bring you up to that. Now add the higher elevation, and it will act as if you have gone beyond that wing loading. Think about these things. That is all.