I had decided to make use of a prospective paramotor pilot's offer to drive for
me. We drove out to Watts Bridge airstrip near Toogoolawah and I flew the 83km
home, landed on the beach and walked the last few hundred metres.
I reverse launched into nil general wind but thermic conditions, where the breeze was
coming from every possible direction, depending on where a thermal was breaking off. After buzzing my friend a few times (who wanted some good video footage) and flying around the hangars, I thermalled up to 2000ft then headed off over the Mt Brisbane range to Lake Somerset. The thermals were not too rough but were sometimes peaking at up to 6m/sec but averaging more like 3m/sec (600ft/min). Not bad for mid July. I was mostly thermalling with cruise throttle as I didn’t want to waste too much time hanging around just to gain height. I had planned to drop down and play around the edges of the lake but I kept hitting thermals that made me offers that I couldn't refuse. The highest I got to was 1200m (4000ft). I could have gone higher but there was no need.
Going past the Woodford folk festival site I was flying at 100-200ft with my
chase driver right under me. My ground speeds were varying from 35kph to
45kph depending on altitude. My chase driver rarely had to wait for me as I
was taking the shorter route.
After taking up another offer of a free ride up, I flew thru a couple of kilometres of sink. Paramotoring thru sink is weird. The engine is racing, the canopy is sitting back due to your high throttle setting but you’re still going down. Next I went thru a couple of kilometres of good lift. (1-2m/sec). Convergence! What is causing that? I asked my driver if there was sea breeze on the ground, but no there wasn’t. I could see from smoke in the distance that there was sea breeze closer to the coast. On the other side of the “convergence” the wind seemed exactly the same. So what caused the “convergence”? I think it was a wave effect (caused by the sea breeze), that was propagating a bit faster than the sea breeze itself (it was late in the day and the sea breeze would have been backing off). The big area of sink in front of it seemed like how the water goes out before a Tsunami (tidal wave) comes in.
Sea breezes seem to behave very similarly to water. In the last couple of years of paramotoring I have noticed three main sea breeze effects. Firstly the initial tidal flow type that builds up very slowly. As it pushes inland the first parts of it are slowed down (can even be stopped) by having to displace the inland air. So the follow up flow tends to catch up with the leading flow and the result can be a sea breeze front. This is when you can get good convergence above and behind this front. Sometimes, and at certain times of the year, the sea breeze gust front can be like a fist that splashes the air in front of it to many times the height of the seabreeze flow itself. This type of sea breeze convergence can be very rough.
The third effect I’ve noticed is wave effects. Have you ever watched waves in the ocean running over a sandbank? A broken wave rushing over a sand bank is like a gust front with a follow up flow. If it then runs into deeper water the front turns back into a green wave, which will later break again onto the beach. The energy of the wave can be transferred backwards and forwards between the broken type of wave with follow up flow and the green type of wave (without much flow), depending on the depth of water. Sometimes seabreezes can even produce multiple waves in a similar way that a river running down an incline develops waves.
At Peachester I buzzed my mate Buchy's place where he was working in his macadamia orchard. I was posing, flying around his big eucalypt tree when a too tiny cable tie let go and allowed my airbox (carburettor inlet silencer) to start lightly touching the prop near the hub. As a consequence I landed for a cup of coffee and a new & bigger cable tie. The prop wasn’t appreciably damaged.
We threw the motor into the van and went back to a little grassy knoll where
I forward launched, trying out my idea for using A's & B's held low. (it’s an idea to make forward launching high attachment point paramotors easier) It worked fine but I'll have to make the effort to do more forward launches to further refine & test the idea.
Approaching the coast I could see smoke moving in opposite directions. I climbed to get above the sea breeze and was rewarded with 50kph ground speeds at 3000ft. At one point I flew thru a convergence with up to 3m/sec lift (with cruising throttle). It was a strong but narrow convergence. I think this would have corresponded to the splash type of convergence. However there is still much to learn about seabreeze effects.
I landed on the beach just after watching a glorious sunset from 2000ft. My driver was there to meet me, and home was only five minutes walk away. I had ten minutes of fuel left in the tank.
Life is great. I wouldn’t be dead for quids.