0
philh

nil winds

Recommended Posts

I am wondering if there is any statistics on incident rates for zero wind conditions. Im thinking there may be reason to expect them to be higher than normal due to 2 factors 1) More likely confusion over landing direction 2) faster landings . On the other hand nil winds does make it easier to get back from a bad spot. 

Does anyone know if there is such data and whether it shows any effect or not? 

Share this post


Link to post
Share on other sites

This doesn't answer your question, but I can't figure out for the life of me why some dropzones don't have a plan for no wind landings. I've always been fed bs about "the winds could change once we're at altitude" or whatever, but at the follow-the-flag or land-with-the-arrow dropzones, more than half the time you get cross traffic. It always feels like I spend 80% of my canopy flight setting up for the current wind direction, and it changes right as I enter my landing pattern, and no matter how many times I go through it I ask the question (while flying the now incorrect pattern), should I commit to this, or make an adjustment? I would rather take a thousand 3mph downwinders than ever have to ask myself that question again. Rant over.

Share this post


Link to post
Share on other sites

There is ‘way’ too much emphasis on landing into the wind. Landing into the wind is not a landing priority. The number one priority is avoiding canopy collisions and having to do a crosswind landing so that no one crosses paths is by far the preferable option. So your consideration should not be which way sets me up to land into the wind. It should be which way sets me up to not run into someone and die. 

  • Like 1

Share this post


Link to post
Share on other sites
9 hours ago, philh said:

Does anyone know if there is such data and whether it shows any effect or not? 

I don't know where you would find an incident database with surface wind speed as a searchable value. I think most of what you will get in this thread are anecdotes and educated guesses.

My educated guess is that fatalities don't correlate well with light to nil surface wind conditions.

 

Share this post


Link to post
Share on other sites

Better DZs have well-established no-wind landing patterns.

For example: land parallel to the runway.

Similar, do not cross the runway below 1,000’ AGL. This follows from the prohibition against interfering with airplane traffic patterns.

Since prevailing winds are from the west, the default landing pattern is to the west.

Since there are lots of obstacles (houses, trees, fences, wires, ditches, roads, guard dogs, etc.) to the east of the landing field, the default landing direction is to the west. When winds are light, you are far more likely to miss by over-shooting .... please overshot into an open area.

At some DZs, the ground radio instructor, DZSO holds the (landing direction) arrow to prevent it from swinging in light winds, “advising” everyone to land in the same direction as the arrow.

Anyone ignoring the DZSO’s advice about landing direction will get advice about pulling his head out of his ass and if the problem persists will be followed by more advice about alternate sports (e.g. bowling)!

Hah!

Hah!

Share this post


Link to post
Share on other sites

My current DZ sets the landing direction in the loading area. It's repeated on the plane. Jumpers are told that if they can't handle a 5 knot tailwind on landing, take a canopy course or get a different canopy. 

Anyone landing against the pattern will end up in a 'discussion' with the S&T A.

Share this post


Link to post
Share on other sites
On 4/20/2019 at 3:40 PM, wolfriverjoe said:

My current DZ sets the landing direction in the loading area. It's repeated on the plane. Jumpers are told that if they can't handle a 5 knot tailwind on landing, take a canopy course or get a different canopy. 

Anyone landing against the pattern will end up in a 'discussion' with the S&T A.

The last DZ I jumped at had the first part of that. We would all agree on a landing direction at the loading area, but once everyone started looking at the stupid spinning arrow all bets were off. 

Share this post


Link to post
Share on other sites

My DZ has an arrow, which can be rotated up until exit. As soon as the pilot gives the 2 minutes call, the CTL will no longer move the arrow.

Our landing site is split in 2 halves (with a 20m buffer in the center) and you can choose left or right-handed circuits, but everyone lands in the same direction.

There's a sign with the current landing direction at the boarding area, but everyone is advised this can change while in the plane, especially since the landing site is roughly 3km away from the actual landing site...

Share this post


Link to post
Share on other sites
4 hours ago, massis said:

My DZ has an arrow, which can be rotated up until exit. As soon as the pilot gives the 2 minutes call, the CTL will no longer move the arrow.

Our landing site is split in 2 halves (with a 20m buffer in the center) and you can choose left or right-handed circuits, but everyone lands in the same direction.

There's a sign with the current landing direction at the boarding area, but everyone is advised this can change while in the plane, especially since the landing site is roughly 3km away from the actual landing site...

thats a good idea

Share this post


Link to post
Share on other sites
(edited)
9 hours ago, dpreguy said:

massis.  What is a CTL? 

So, at your dropzone,  there is someone standing next to the arrow all day, every day,  manually moving the arrow and holding it in the desired direction?  

center leader, the guy in charge of the DZ that day (he communicates with the pilot, decides on jump limits, counts jumpers after they open, ... ).

And basicly, yes. DZ only operates on weekends, and there's always someone in charge of the arrow. He's not "holding" it , as it's a flat piece of vinyl 6+ft long and pretty damn heavy.

It is put in the center of the landing zone (which is split into 2 sections, so both left & righthanded circuits are possible without collision risk) pointing in the landing direction based on prevalent winds.
They generally stick to one of 4 directions (~NESW) so a bit of crosswind is pretty usual at our DZ. 

If the winds change, the arrow can be moved into the new direction as required. In nil winds or very low and changing winds, it is often left in one landing direction all day to avoid confusion.

It used to be by the side of the DZ, with a bullseye in the middle marking the center of the landing zone, but earlier this season they removed the bullseye and put the arrow in the center. You can see the arrow on google maps even :-) https://goo.gl/maps/Q1V4BCMEZurjh4UK9

Edited by massis

Share this post


Link to post
Share on other sites

For convenience I'm lumping all wind conditions in the landing pattern together.

I'm guessing that the 'incident' rate wouldn't correlate so much with wind conditions in general as with what the jumper themselves are used to.

If you're used to landing in low winds, you're more likely to bollix up at high winds and vice versa.

If the winds are high, then there is little to no chance to overshoot on final, but there is more risk of being blown off course on your base leg, or turning too late from your downwind leg.

Or you might have to land while backing up - stressful for most jumpers.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's free!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
0