Unusual conditions

[ezza]

Just got back from an unusual days flying.

Left home, wind NE about 10-15kn. Get to Powerlines wind seems strong one second and absolutely still the next. Flying ranges from sinking out, to booming thermals, as high as you like. Shared a nice thermal with 5 Pelicans. They were only happy if they were above me. I couldn't thermal nearly as well as them with the JW.

Decide to head for Lennox assuming the wind would be steady down at the beach. Get there and the hangliders are all sitting around. I hear one of them shout 'This will be interesting'. One of them walks over to the slope with me. He said when you get up about 100m the wind is coming from the West. On the water, it shows strong NE at the end of the point and almost glassy towards the beach at Lennox. I throw out in almost no wind where I am standing and fly, eastwards, up for the end of the point. Sure enough there is good lift and I start working higher and higher until I realise I have never flown this high at a beach cliff. Then it starts REALLY goin up. Wow!! The JW was tiny and sure enough it was slow at working back towards my self, which means it is flying into a stiff Westerly!! The wind is clearly NE down on the slope, where I am standing. Eventually it went up until I basically could hardly see it, easily as high as I had ever flown it. It was easy to stay up there with huge lift. Then I come down for a landing and the wind at sea level has gone around to the west. I tried to do it again but nothing at all.

I have heard of convergent zones but had not experienced one until today. One of the hanglider pilots said he had once reached an altitude of over 1000m at Lennox on a similar day.

If you look at todays windguages at www.seabreeze.com.au/graphs/nsw3.asp you can see that the wind is Northerly at Byron Bay and Westerly at Ballina about 25k's south.

Wierd, but fun day.

Eric

[ding]

I'm posting here to remind myself to tell a full size gliding story here. One of only two times I was ever worried in a glider.....

[ezza]

Cool, looking forward to it Ding.

I have yet to try any full size stuff. Not sure, might woose out after this story of yours.

The hang glider guys were trying to talk me into having a go. Maybe one day.

[atmosteve]

I would like to experience that ezza, sounds like lots to think about!!

I had a weird days flying too, everywhere i went today i saw a huge variety of birds; Black thingyy's here at home, three thermaling Wedgetails at Nickenbah, a trio of Brolga's at Toogoom. Probably all very hungry after our recent bad weather and needing food.

When i got to the coast slope at PV north the breeze was only moderate, but dead steady north.
Threw up my dads little glider and it just went up and up, to the point where i could back around over the houses behind, interesting to say the least!

Got it down again and it was joined by one of two juvenile Ospreys, there is a monitered nest on a pole on the point only 3-400 metres away. This young bird showed a real interest in the wobbly glider, so i gave it a bit of dive and chase, only to find the bird quickly return the gesture!!
We did this for a minute, diving close to each other, then i settled down and flew straight, the bird was never more than 5 metres from my wing, often a lot closer.
Get this though, twice the bird reached out with its talons and put them gently around the tail boom of the little glider in flight! but it let go when it saw the plane get a little out of shape, i was totally stunned, we were playing in the air together!

When i did a loop, roll or sharp turn the bird would quickly follow suit to stay close, amazing to see it do something approaching a roll and an Imelman turn.

It only went on for 5 minutes, then we parted. Later Brahminy kites, whistling kites and a pelican visited, but all the birds wheren't keen on the combat wing, just the young osprey with the smaller more conventional glider.

I think this young, curious Osprey was just being playful, will never forget our airbourne fun. Just amazing.

[thevon]

Wow, Ezza that's a super-amazing and very rare experience! Never heard of 2 different wind directions so close to the ground. A bit scary if you think about landing a real plane in that!!

It really reinforces the complex and chaotic nature of air movement. The air is invisible and we tend to think of it as a single mass of air all moving in one direction. But at our flying sites, if we we had those multi - coloured smoke streams like they use in wind tunnel experiments, we'd be pretty amazed. It's really complex.

One thing that gave me an inkling of it was reading about slope thermals. When you're flying on an inland slope such as Mt Mee, there's slope lift but there are also thermals, the big columns of lift that we love to circle in and gain height. Thermals really suck air in strongly around their base, sort of like a vacuum nozzle held just above the ground.

The thermals don't stay still - they move downwind with the air mass, and over the slope. As the thermal gets close to the slope, the wind on the slope will drop because the air is getting "sucked" towards the thermal, so everyone starts yelling "hey the lift's dropped out!". Then as it goes over the top and behind the hill, the air is getting sucked the other way so the wind on the slope gets stronger and slope lift gets strong.

And obviously if the thermal goes to the side of you, the air gets pulled to that side. All this partly explains those weird wind shifts you get on a hot day with moderate breeze.

[skyboyken]

Hey Ding,

I'll tell mine if you'll tell yours .

[ezza]

I have been having all sorts of fun with thermals recently. I seem to be addicted to flying in circles! I learned alot after attending the Armidale sailplane expo. Watching all the best guys working the thermals. It is definately a real skill.

I have been experimenting alot lately. Catching thernals on the slope and then travelling out behind the slope with the thermal. One of my main slopes has a valley behind it and it is amazing to go over the backside of a slope and keep gaining height. One afternoon I took a thermal downwind until I was getting really uncomfortable with the distance, I think I was starting to get slope lift from the other side of the valley. Then as I would work back up wind towards myself, I would hit another thermal and go back down wind. I had flight times of more than 25 minutes on the down wind side of the slope. Good fun.

Eric

[atmosteve]

Hi Eric, yep using thermal lift can become a very addictive art if you let it, combining it to assist slope soaring activity is another real challenge, would like to learn more about it combined with sloping.
Once, I was totally dedicated to F3A while also field flying all sorts models, pylon racing and some frontside sloping, but F3A was it for me.
Then i got talked into doing F3J competitions, and also the duration ones. My love for this silent flight quickly overtook the F3A, and glider folk have so much more comraderie than powered competitions, the converstaion was more relaxed.
I found it more mentally stimulating than just pulling off the best choreography over a strip by heaps.

Your description there sounds good, the slope gliding topography must be a lot better than around here. Would like to visit the area sometime if all goes well.
Steve.

[ding]

Ok here we go. I'm flying at my home club at Boonah in a Club Libelle. This is a light little fibreglass single seater that was based around the standard Libelle.

It's late in the afternoon and I'm slope soaring on our home ridge just off the end of the runway. This ridge never gets all that much lift... maybe 1200 but occasionally 1500 with carefull flying. It was about 800 ft high. Anyway, I popped up to see if I could get a last few minutes flying for the day.

I started working the ridge and all was good for a few minutes. I started running wider at each end but the lift was still there. After a couple of goes I just cruised off the hill to see what was doing and there was lift everywhere! I just started blasting around in this excellent lift. I think it was 400/500 ft per minute. That's pretty reasonable. Before long I was doing high speed laps over the valley having a wail. I looked down and saw they were turning the cars lights on the strip. This is a sign saying "it might be light where you are but it's dark down here". By this time I'm at 6.5k feet!

So, with a heavy heart I glanced at my watch and popped the breaks. I descended for about a minute and then all hell broke loose! The airspeed just dropped and it got crazy bumpy. I can remember seeing the asi gusting between 30 and 50 knots while I had the nose pointed down at 45 deg. I pulled the breaks away to try and get speed and remember hearing "kawaka kaawaka" and looking out at the wings bending up and down. About then I got rolled over! Somewhere in here I remember seeing the clubs 2 seal ask-14 (??) in the same sort of bother.

Anway, I got the thing back up right and I was still heading for the deck. I was getting seriously concerned. Then, at about 1200 everything got normal again. This was just in time to pop into circuit and land.

From the time I glanced at my watch at 2 thousand metres to stationary on the ground it was 6 minutes! Boy that got my attention.

The relevance of all this is while talking to the instructor (in the trainer) about what had happened over a beer or three he reckoned that it was a seabreeze front coming through. The cold air wedges under the warmer air. So, you can have two different directions. The bit where they are merging is very turbulent. Yeah right!

[skyboyken]

Great story Ding!

OK, as promised, here's mine.

I was flying a Junior, a glass club single-seater with not very good penetration. It was at an away weekend at Khancoban, near Mt Kosciosko. The club I was in at the time had a week there every year. The guys in high performance gliders used to soar to Kozzy and then ridge-soar around there.

I went off for a thermal flight for a hour or so, and the longer I was up the patchier became the lift. I got down to 700' once, in fact I had already started an outlanding approach to a field when I picked up a small bubble, so I circled with sweaty palms for 5 or 6 minutes until it thankfully strengthened and away I went.

After that I headed back toward the airfield, intending to call it a day. However, I flew past a beautiful ridge line (really the edge of the Great Dividing Range) off to my left. I could see the wind was blowing onto it and as I had never done full size ridge soaring I decided to have a go.

It was sensational!

For about 15 minutes I flew past a sheer rock wall, slowly gaining height as it gained altitude. I was so close I could see the blue and green lichen growing in cracks in the rock. It was totally smooth - no turbulence at all. Then quite shockingly suddenly I lifted above the ridge and found myself looking out over the high alpine plain - no trees (too high), only tundra (low scrub).

A few minutes later I was at about 8,000 feet and it was cold. Really cold. So cold that I made a really bad decision which very nearly killed me.

As I said, the glider I was in didn't penetrate very well. Instead of simply turning around and flying fast along the ridge back to the airfield I decided to fly into the now stronger wind to get to a lower ridge about a mile upwind of me, and then take it home. As I sat there shivering the thought of losing height quickly and getting warmer was what I most wanted.

So I turned into wind, put the nose down and away I went. Except I kept having to put the nose down further and further and I still wasn't making much progress towards my goal. I sure was losing a lot of height though. The only thing I had going for me was that I had 2 small cleared fields pretty much below me that I thought I could land in at the worst.

Not long after overflying them I finally admitted there was no way I was going to reach the ridge I had been aiming for, so I turned and started heading downwind back to the main ridge. I was now much lower, but I could still reach the 2 outlanding fields so I had a safety fallback. I overflew them again, and not far past them there was a steep-sided valley across my flightpath, with a promising-looking ridge the other side of it which looked like I could use to make some ground toward home and gain height at the same time. So I kept going toward it, and then all hell broke loose.

The valley I was about to cross had sides at about 70 degree pitch, covered with mature pine trees, all the way down to a tiny stream. No flat or open ground anywhere. The sort of territory that gives you no option at all but to crash into it.

As I flew over the upwind edge it was like the hand of God reached out and pushed me down, such was the downdraft I hit. In the space of about 15 seconds I lost over 2,000 feet of altitude. I went from looking down at my safety fields to looking up at the steep sides of this valley I was now trapped in. I couldn't believe it, but I had no time to think about it because my situation was now critical.

I flew as close as I could to the downwind side of the valley, but all I achieved was to reduce my descent rate. As I flew along I could see that the valley turned a sharp corner to face upwind, and I was about to arrive at it. As I did so, flying close to the downwind wall, finally I got a small amount of lift. But the wall ran out only 10 seconds ahead as it turned the corner. So there I found myself, desperately flying what amounted to figure-8's across this tiny area that was keeping me aloft, unable to climb high enough to escape - and I tried several times to cross to somewhere more promising, but each time I lost so much height I was forced back to my tiny safe spot.

That went on for about 20 minutes. I tried calling on the radio so someone would at least know where I was but I had no replies. The terrain was blocking the signal.

I knew I was in dire straits so I went through all my options, including bailing out over the middle of the valley (too low) or a controlled landing against the side of the hill (which I thought was the most likely outcome). The only option which involved not crash-landing was to fly up the valley (upwind) to safety. However that option had 2 things against it: First I had already experienced my lack of upwind performance, and second there were 2 cross-ridges on the way out which, although lower than me, effectively blocked the exit.

By now it was getting quite late in the day, and of all things the wind which I was now depending on for survival started to drop, and I started to go further down into the valley. As I said, I had already reviewed my options and I knew immediately that my only chance was to go for it up the valley now before I lost any height, and crash land if it didn't work out. My heart was pounding fast and hard as I turned into wind and put the nose down I can tell you!

As I headed toward the first cross ridge I stayed really close to the left hand wall, and whenever I got a little lift I'd yank the nose up and make the most of it, and then stuff the nose down to go fast through the sink spots. It was the best I had ever flown, and it seemed to be working. I was losing less height than the slope of the valley. It looked like I would clear the first and highest ridge by about 100 feet.

And then I hit the downdraft in the lee of the ridge.

Even though I was losing height at a terrifying rate, and I could see the trees rushing up at me, I stuffed the nose further down to accelerate. Speed was my only hope. I aimed as far up the back of the ridge as I could and held the nose down till I could see the individual pine needles. Then when I dared hold my course no longer, I pulled the nose up and aimed to just clear the ridge, and hoped. I knew I'd either just make it, or I'd be landing in the treetops in about 5 seconds.

As it happened, I cleared the ridge by about 20 feet, at stall speed as I pushed over the top and went as far left as I could again to work the wall for lift as before. I couldn't afford even a moment to relax as the second ridge was now looking tougher to get to than the first had been.

I went through pretty much the same scenario with the second ridge, including the terrifying dive at the back of the ridge through the downdraft. Pushing the nose down at the trees was the hardest thing I've ever done.

I really don't know how I got over that second ridge. As I pushed the nose over the top I was at tree height and below stall speed. The only thing that saved me was that the ridge had a steep back side so I could keep holding full down elevator and get the nose down without stalling.

And then I was free! I was at 50 feet and the valley ended only about 100 metres in front of me. I could see a cow paddock and I had the height and speed to get there. So I flew out of the valley and saw a bigger field to my left which would be easier to do an aerotow retrieve out of. I turned toward it and allowed the glider to descend to below fence height as I covered the (lovely, flat, open) ground, then pulled up over the fence, popped the airbrakes and landed.

When I had rolled to a stop, I got out of the glider and stood next to it with my hands on the co-ckpit side. I was totally overcome by a fit of shaking which went on for probably a couple of minutes until it finally subsided and I had control of my limbs again.

A few minutes later a curious farmer arrived with 2 of his kids. He took me back to his place where I called the club. They relayed a message to the away group who came and got me. We returned early the next morning and another pilot flew the aerotow retrieve. The tug pilot said I'd picked the only field in the entire valley he could have retrieved from, and if I hadn't landed there we would have had to completely tear the glider down to get it out in pieces, because there was no way to get a proper retrieval trailer in or out.

Is there a moral to this story? Probably, but I'll leave that to others. The lesson I learned is that it's easy to make a bad decision when you're not warm, dry and comfortable, and an expedient decision can easily be the last one you make.

[callun]

Wow Ken, that's an amazing story! As the boy scouts say, be prepared! Take a jacket

[ding]

WOW Ken thanks for sharing. That is a great story and scarier than mine! We'll have to swap some more gliding stories at the next fish and chips

BTW I flew juniors too. I was being rated on them and they told me to go up and do an "observed" spin, which I did. In fact I was having a great old time and did a couple of loops and chandelles for good measure. After I landed and was sitting around at the pie cart one of the instructors casually told me that the junior isn't rated for aerobatics other than spins. I wish they had placarded that

You're right, they were a wussy plane too.

[thevon]

Wow Ken, I've got sweaty palms just from reading your story! Thanks for that, really well written - wouldn't be out of place in the Readers Digest and it (unfortunately) makes you feel like you're there!

Makes my favourite story seem fairly tame by comparison ... crossing from Bamaga to Thursday Island in my halfcabin tinny in big SE winds, finding it getting swamped on the way from a rip in the hull, finding the bilge pump not working, then 2 UHF's not working, 14 knot currents heading downwind towards Indonesia, etc etc ....

[ezza]

Wow great stories!!!

Close call Ken!!!!!

I'll stick to RC. For now....

All the full size gliders down this way have little fold out spinny things on them for close calls. I have seen them used a couple of times. Nice to have a backup.

Eric