Something I was thinking about the other day.....
How does a headwind effect the heading performance of an opening canopy compared to a tailwind? If you were jumping an S with no chance of an object strike would you ever choose to jump in to a headwind?
My gut instinct is that a headwind is more likely to turn the canopy but I really don't have any experience to back that up.
Gus
The more important effect is going to be opening speed (altitude required), not heading (with no chance of object strike, right?).
Tailwinds slow down your openings. Headwinds speed them up.
This is a noticeable effect. I know of people sustaining injuries from jumps at low altitudes in tailwinds, where the canopy never fully inflated. The difference is also _very_ noticeable on ultra low pulls. From "feel", it basically changes the inflation from a "slider not quite at the links" (in a tailwind) to a "barely enough time to get the toggles off" (in a headwind).
When it's very windy I like to open into the wind. I did some floaters but most of the time I jump cross and turn another 90 degrees. But this is all because of the low object here and I more like it to turn in freefall then under canopy with high groundspeed.
To me it feels like the heading performance is better as down wind, and that's because I believe if the pilot chute goes one way the opening will be the opposite. Most of the time when I jump cross wind the pilot will go downwind and the opening into the wind(yes, most of the time!)
So when jumping in the wind the pilot goes to the back and opening to the front, works for me. And they are faster!
Don't get scared now for jumping downwind...
I highly recommend ground launching, or at least some extended kiting time, to get a good understanding of how wind affects inflation and heading. I've justunder 60 hours of kiting now with several canopies (including a Fox 245). It's taught me a lot about canopies, wind, etc, that I can apply to ground launching, skydiving, and BASE.
My theories on how wind affects openings, based on kiting:
- With a tailwind, you have to rely entirely on your body's velocity to provide enough speed to get your canopy open.
- With a headwind, the speed of the wind (all or most of it) is added to your fall rate, thus speeding opening time/distance.
- A crosswind will affect heading -- The stronger the wind, the shorter your delay, and the more perpendicular the windline is to the cord of your canopy, the more the wind affects your heading performance.
IMO, strong winds can turn a perfect pack job into a ****ty opening or a ****ty pack job into a perfect opening, so long as you perform accordingly. Pick out the windline and execute the proper body position during deployment. Bottom skin vents, or anything else that helps inflate a canopy at lower airspeeds, should likely detract from the effects of winds.
That's my guess.
Do you want to expand on this theory? Are you talking about a headwind relative to the front of your body, or relative to the side of the antenna you're jumping off of?
Just want to make sure this information isn't misinterpreted by anyone causing them to jump an antenna in a headwind...
i usaly jump in some weired windsOriginally Posted by Ferry
hard winds down the wire has been jumpedbut the scary thing also happened once.
I do find the same that the canopy usaly will turn against the wind,BUT once i jumped off 400ft whith wind down the wire to my left.
It opened DOWNwind and i were absolutly happy that i in those times(wind down the wire9 usaly opens between 2 sets of wire,as i actuly flew through themi never touched the wire but i sure felt more than the groundrush on that one(i do have 2 kids but i still want to make sex
)
Oh, I'm not advising anyone on anything. I'm just saying that, at low airspeeds in strong winds, a headwind speeds up openings, a tailwind yields a slightly slower opening, and crosswinds may affect heading. I don't believe a tailwind will affect heading too much, so long as you're flying directly down the windline (as on an A).
This is all relative to the nose of the canopy. Your body position should dictate that, but a bad pack job can change that up.
Manbird
Triax was asking Crazy Thomas to clarify what he said in his post about needing a headwind if you want to do a floating exit off an Antenna, which does need clarifying cos potentially that could be misconstrued and lead to a very bad hair day. As Thomas is still alive and kicking (which he wouldn't be if he was doing what he seems to be suggesting) I can only assume he is referring to a headwind as the direction the wind is blowing towards the jumper's face during launch/freefall. This of course would be a tailwind to jumpers off the same object at the same time doing regular exits.
ian
Ah. Interweb.
Re: Heading performance: headwind vs tailwind
Yes, relevant to the jumper. The jumper is facing the tower, hence a head wind is splitting the wires behind him/her. The jumper will either turn in freefall, or shortly after opening, and be flying downwind splitting the wires, theoritically.
Nestea plunge off a tower is ideal looking into the wind.
Thomas
wait , wait ... your second clarification ?
You are saying :...The jumper is facing the tower (floater exit) and the wind is splitting the wires ( Behind ) Him / Her ???
So he is doing a floating exit with the wind at his back (tail wind) and will turn 180 in free-fall and have a head wind ?
.
And then this giant three-headed rabbit will appear from a tank and avenge his fallen comrades. What?
Manbird :
and then this giant three headed rabbit will appear from a tank and avenge his fallen comrades.
.........................
Hey.... you didnt tell him I was rabbit hunting yesterday, Did You ????
.
Pretty much.
So he is doing a floating exit with the wind at his back (tail wind) and will turn 180 in free-fall and have a head wind ?
.
No. I am facing the tower, and facing into the wind (head wind). As I exit, I am still facing into the wind. And after turning, I am now looking away from the tower, with a tail wind, which is usual Antenna protocol. Opening before or after turning is entirely up to the jumper.
Thomas
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