Forums: Skydiving: Gear and Rigging: Re: [rss_v] Are manufacturer canopy sizing recommendations quite conservative?: Edit Log


DrewEckhardt  (D 28461)

Aug 21, 2012, 12:55 PM

Views: 1071
Re: [rss_v] Are manufacturer canopy sizing recommendations quite conservative?

 
In reply to:
Thanks for the replies, all. I've looked into it a bit further, and talked in person with some people at my DZ. An important point has come up which is that focussing on size can be misleading because different canopies - according to their shape, material, age, etc. - behave very differently and a larger canopy is never necessarily a slower/safer/easier one. One option I have is a Fury 220 that's 23 years old, with 500 jumps.

No. You'd be jumping that canopy with a wing loading beyond its design goals and the age means it may not be flaring well.

In reply to:
It's been suggested that the 9-year-old Sabre 2 190 with 600 jumps would have a lot more flare in it and would generally be easier to control than the old, porous Fury.

That still doesn't make it the best first canopy because the size and wing-loading make unintentional over-control close to the ground more likely.

Follow Brian Germain's advice. Follow Bill's advice. Learn to land down-wind and cross-wind, up-hill and down-hill, making flat and flare turns down to ground level, and with some added speed from front risers. Learn to land flaring from at least half brakes. That'll be easier and safer with more square footage.

If you still want to go faster and turn quicker after getting things like that dialed in and accumulating an appropriate number of jumps according to Brian's chart get another used canopy, sell the one you had for about what you paid - $1/jump (assuming you got a decent price), and repeat the process. Your first container (unless it has the closing loop mounted on a main flap and assuming it was built for the canopy size you start with) will probably be good for two canopy sizes smaller which gets you to 250-400 jumps. With a good purchase price it too can be sold for what you paid - $1/jump. The observant reader would note that they may spend $2/jump on depreciation regardless of how many rigs they own on the journey.

In reply to:
What do you reckon to that general idea? It sure makes things trickier for an idiot like myself who knows nothing of different canopy characteristics.

Get a ZP main loaded at 1.0 pounds/square foot. Learn some survival skills which are also fun and exciting. Do not down-size to a smaller canopy which you are afraid to turn low - plenty of fatalities involve "not hook turn type people" who did not learn that and found themselves in situations (unseen power lines, did not quite make it back because winds picked up, etc.) where they had to and did. Do not down-size to a smaller canopy that you're unwilling to land down-wind because that leads to imprudent low turns (which can lead to mid-air collisions when executed correctly when you break the pattern and impacts with the ground when not). Do not down-size to a smaller canopy when you have not mastered the flat and flare turns which keep you from being an unguided meat-missile in the landing area which poses a danger to yourself and others. If you want to go faster it's safer to add some riser input to a large canopy when you're current and landing in a sunny wide open field than to get that speed from a smaller canopy where you're stuck with it when landing off the airport under less than ideal conditions.

At 200-210 pounds naked you're probably 230-240 geared up. 230/230 = 1.0. 240/230 = 1.04 which is close enough. 240/210 = 1.14 which is more like a 100-150 jump canopy and 240/190 = 1.26 which is more like 250 jump canopy. That's close to Brian's minimums; his recommended sizes are larger.

http://www.bigairsportz.com/pdf/bas-sizingchart.pdf


(This post was edited by DrewEckhardt on Aug 21, 2012, 5:26 PM)


Edit Log:
Post edited by DrewEckhardt () on Aug 21, 2012, 12:56 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 12:57 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 12:58 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:10 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:13 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:14 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:23 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:24 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:27 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:31 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 1:31 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 2:14 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 2:15 PM
Post edited by DrewEckhardt () on Aug 21, 2012, 5:26 PM


Search for (options)