Glider Convergence Flying: The Dangers?!

Convergences are one the most awesome ways to fly hundreds of kilometres around New Zealand, and many other soaring sites around the world. We have a look at air mass convergences, lee convergences, and the dangers of flying convergences.
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00:00 Welcome to convergences
00:47 Lee Convergences
03:26 Airmass Convergences
05:56 Mountain Convergences
06:37 Dangers of flying Convergences

[@Nexus822]

Fantastic episode. and I don't even fly gliders, just normal single engine pistons. One can never have too much knowledge about weather.

[@PureGlide]

Use this knowledge to save a ton of fuel!

[@BillPalmer]

Another great addition to our KZbin glider pilot education collection. Thanks!

[@PureGlide]

Thanks Bill!

[@stephaniekent8483]

fascinating stuff, yes that warning light on the nose is fantastic, I was flying a cloud street once in the Ardmore valley toward Hunua ranges just merrily skooting along in my K6 when another K6 came head on at me out of nowhere, no time to do anything, just hung on and hoped we missed as we did, but only I would say about 50 feet clearance as they shot over me phew!

[@n176ldesperanza7]

Lights! What a great idea. Never seen that before.

[@PureGlide]

Yeah they are good!

[@naturarum]

awesome explanation, live in the glider! thanks so much for all the education you do, as a newbie I feel like I have all the tools to progress much faster than it was possible 20-30 years ago.

[@PureGlide]

Hey great to hear you think it's useful! Just shout if you have any questions, cheers

[@daszieher]

The FLARM flasher is super neat!

[@PureGlide]

Yeah they’re pretty cool, don’t cost too much, so why not!

[@alanward9521]

Hoping to start my adventure into glider flying next month in the UK. Your channel is invaluable to the lead up to me starting training. Quick question to all, how do you rate using a flight sim when you can't get out and fly for real? Cheers all and safe flying 😎

[@PureGlide]

Awesome to hear! Glad you're enjoying the videos. Yeah a flight sim is useful especially for practicing circuits, and your radio calls and checks. I made a video about it, look up gliding simulator on my channel

[@glider1157]

Challenging teaching - thank you very much. I had a conversion line in Spain (Fuentemilanos) when I did my Silver C distance flight. It was wonderfull - flying a plane with an engine without an engine... 🤠

[@PureGlide]

Awesome stuff :)

[@dennislyons3095]

I was watching the altimeter unwind as you approached the mountain. Just made it, close. Good info watching the conditions & able to see the instruments a bit too.

[@brushitoff503]

Ahh! Good Stuff & Thanks Tim! Got my butt into a Glider last weekend for the first time in 22 years! Freaking loved it! Man I missed that feeling so much! Cheers.

[@PureGlide]

oh awesome stuff, great to hear!! I assumed you were already doing it haha

[@brushitoff503]

@@PureGlide I wish! 22 years of "life" getting in the way, Not anymore!! Let's go Flying! ha ha

[@charlieirvin5898]

hell yeah more convergence videos!!

[@PureGlide]

That's the spirit! :)

[@dend8119]

This is something I've been strugging to understand by reading theory, but watching the vid really lays out a real world example very well. thanks and cheers!

[@PureGlide]

Glad I could help!

[@erikisberg3886]

Very educational, wonderful flying conditions!

[@PureGlide]

Glad you enjoyed it!

[@shelleyclow]

Very interesting. I have cousins in N.Z. One of them is involved in a gliding magazine. (I don't want to name drop.) Gliding fascinates me. How you read the skies to find the best 'roads' is amazing to me. Thanks for sharing.

[@PureGlide]

Hi I guess Jill! Glad you found it interesting, cheers :)

[@shelleyclow]

@@PureGlide Good guess. I'm her first cousin on the Barnes side. Would love to go gliding with her sometime. (Or you. 🙂) Or anyone who is willing to take me up to be honest.

[@PureGlide]

It was easy as she was the only editor haha

[@Will-ui7dv]

Nice one Tim, I liked how you shot the intro. Gave it a more pro-documentary feel :)

[@PureGlide]

Thanks!

[@ronaldglider]

Thanks mate! This is the 'convergence video' that many other and I have been waiting for... Great!

[@PureGlide]

Great to hear!

[@coldsamon]

Enjoy your videos. Very useful information here 👍

[@PureGlide]

Thanks!

[@Gianky640220]

Great explanation, as always!

[@PureGlide]

Thanks!

[@hedonzx822]

Again Tim, a great educational presentation 🙏🏻👍🏻💪🏻👍🏻🙏🏾👍🏾💪🏾

[@PureGlide]

Thank you!

[@palleh.jensen4648]

As usual, great, thanks Tim.

[@PureGlide]

Thanks!

[@miguelmedero3701]

Tim, great material, always!!

[@PureGlide]

Thank you Miguel!

[@walterlown6308]

Another excellent presentation thanks Tim!

[@PureGlide]

Thanks Walter!

[@JoarABTheflyingraven]

Thanks for this video.

[@PureGlide]

You're welcome

[@brenorates495]

Love your vids, Tim. I wonder if and how I could get instructions from you. Thanks in advance for your attention.

[@PureGlide]

Hi thank you! sorry I'm not available for instructing due to time and being a non-commercial instructor. Cheers

[@brenorates495]

Understood. Thanks. Any recommendations and directions for leaning mountain soaring in NZ?

[@Alpha-III]

thank you very much, I learned a lot! Always a pleasure to watch your Videos

[@PureGlide]

Glad to hear that!

[@Alpha-III]

When ever you come to Bavaria, give me a call, you will be very welcome! Alpha 3

[@PureGlide]

Thank you!

[@chrisj800]

Best video you have done. I am in Philippines mostly sailing but have just found Tuy here is an airstrip with winch and 4 or 5 gliders. Will go for a fly soon.

[@PureGlide]

Sounds great! enjoy yourself

[@averageflying]

My dream is to get a winch, launch stratford, and fly the Taranaki convergence in a SW across Whangamomona, Te kuiti, back to Kaimais

[@PureGlide]

Totally do-able!

[@carlitosiucci6510]

Awsome video!!! Just a question...why 2 yaw strings??? Never seen before. Thanks!

[@PureGlide]

Thanks! Questions answered here Two Yaw Strings? That's Crazy! kzbin.info/www/bejne/hYOcq32tmKyrpbM

[@TheSoaringChannel]

I'm surprised you didn't use the footage we caught of cloud formation in the daggy bits 🤪😂

[@PureGlide]

Crap I should have!

[@Rafael-nz6pp]

Great stuff. Thank you for the explanation and the videos. Quick question... on your final glide, do you aim for a straight in approach. At my club we practice ending the final at circuit height. Any concerns about safety marging? Thanks again.

[@PureGlide]

Hi we use a 3km finish circle ring with a min height, then I will usually land straight in. In one of those shots we had a mountain in the way so had to go around that :)

[@Rafael-nz6pp]

@@PureGlide Thanks for the explanation and for creating these great videos.

[@CarlosMoreno-dq3kg]

Awesome video, thanks for the explanation. Question, under the street or converging area, if you do the dolphin thecnic you will be able to increase the average speed or just flying straight below the street doesn't has much difference?

[@PureGlide]

Great question, I tend to slow down under convergences, because there's usually not much sink, and being slow in sink is the worst! Going slower let's you climb. In general I avoid giant big pull ups, partly because there might be someone above you, partly due to the drag created by big control movements. So a slow down to make the most of the lift is what I suggest. Unless you're already plenty high enough, in that case go fast!

[@CarlosMoreno-dq3kg]

@@PureGlide thank you very much for the answer!!!!!

[@Paul-vh6ul]

In the US, the FAA wants 2000 feet horizontal offset from cloud. We're not supposed to fly in the notch near the top of the step like you do at 6:20 . Lee convergences do not present this problem.

[@PureGlide]

Hi yes it's a problem in most countries. In New Zealand we have cloud flying procedures which do make flying up to cloud bases and edges legal. I made a video about our cloud flying rules here kzbin.info/www/bejne/gaHao5evq8-saa8

[@Johan-ex5yj]

The Lee Convergence is very interesting, Tim! At first it did not make sense to me that the same air mass colliding with itself will create lift? But when you said at 2:40 “trigger thermals in a line”, then it made sense! So we know that lee side thermals develop because air can heat up on the side of the mountain that is sheltered from the wind, but it needs a trigger to get it rising. Along comes the wind wrapping around the mountain and in a “pincer movement” forces the hot air to rise (almost like a DOUBLE convergence?). Does that make sense?

[@PureGlide]

Air colliding with itself after wrapping around a hill is exactly the same as two different air masses meeting. It doesn't know any different! And if two things collide the only place it can go is up. And yes definitely wind shadows can help cause thermals, but that depends on the shape of the terrain. A perfectly conical or round shape won't have a wind shadow, just like you can blow out a candle behind a wine bottle.

[@Johan-ex5yj]

@@PureGlide Sorry, I don’t agree. The same air colliding with itself (without any warmer less dense air in between) cannot produce the amount of lift that you are flying in there. (Maybe something of the order of ridge lift) As in a Sea Breeze front, you need colder (denser) air to cut in under warmer (less dense) air to produce lift that goes much higher than the mountains.

[@PureGlide]

You might well be right, maybe it's more about a lower wind speed where the two winds meet, that allows thermals to trigger. It's hard to imagine two masses of air meeting at different angles don't create some sort of up force. This has a nice diagram of how air can work around a isolated peak www.nwcg.gov/publications/pms437/weather/estimating-winds-for-fire-behavior

[@xistsixt]

Hi Do you have as well the phenomenon of alpine pumping?

[@PureGlide]

Never heard of it sorry! I’ll have to look it up. I wonder if it’s similar to catabatic and anabatic winds?

[@bagoistvan3182]

👍🍺🍺🍺🍺🍺 AWESOME !!! 😁😁😁

[@PureGlide]

Cheers!

[@ibraheemtalash5094]

What about frontal lifts?

[@LongTran-em6hc]

I see convergences, I think calculus lol Btw nice video, even people who are actual pilot doesn't know much about flying gliders.

[@PureGlide]

Cheers!

[@scheerlon]

why do you have two of those red strings attached? did you lost one in the past and then went for redundant instrumentation? ;)

[@PureGlide]

I made a video about them! kzbin.info/www/bejne/hYOcq32tmKyrpbM

[@scheerlon]

@@PureGlide I assumed that question was asked before. And you made a complete video, thanks! (Sry could have searched by my own, but wasn’t assuming you covered that in a video)

[@johnrobertson9945]

Extreme danger of high XC speed

[@PureGlide]

haha exactly

[@quitypop]

what glider have u got?

[@PureGlide]

Hi it's a Ventus cT, cheers for watching

[@JonathanStCloud-yo5oq]

Waist of time. It is just a sales video without any substance!

[@PureGlide]

Gotta pay the bills...