IBob

I doubt there's a pilot here who hasn't had his moments. Learn what you can from it. Then put it behind you and push on, I say.

Hughes/MD500s were also famously used for deer shooting, then later for live capture by wrangling, net guns and tranquilizer darts. There's a fair bit of exciting footage on Youtube, if anyone wants to look at it. And in some locations it got territorial: a pilot friend of mine gave it away after a bullet hole appeared in his canopy during a deer recovery flight.

Yep, they didn't fly up and down, Nev: just hovered in place until moved to another spot. And it wasn't a 5 minute job, sometimes they were up for hours. This was in one of NZs principal fruit growing areas, principally for export. But I moved out of the area 20 years ago, I have no idea if they still do it.

In NZ they are sometimes used to prevent overnight frost damage in orchards at key points in the growth cycle. Or they used to be. Very expensive and very boring for the pilot, hovering in place over a marker light. Other frost protection methods include: Windmills, like small wind generators, permanently installed at various points. Either electrically powered or diesel/petrol. Though the petrol ones went out of fashion after it was discovered the engines were perfect for jet boats, and a few orchardists went out on frosty nights to discover nothing attached to their windmills........... Spraying water on the foliage. And smoke pots used to be used a lot, but around towns they are only allowed them a few times each year.

Yep, I would like to have read that, but am not on Facebook, and prefer not to be. Is there an alternative source?

Admin, congratulations on building and maintaining this most excellent resource. The rest of us must go where it goes if we wish to continue accessing that. My only concern is that we not lose the huge accumulated wealth of detailed knowledge and information here. Otherwise, all power to you!

Kbstone, nice looking build! While mine is an S, the Drawing 14 you have posted above appears to be exactly the same as for the S, where the profile of the 2 sections are as shown (though my part numbers are different): The outer part (your SF029-15) is an uneven channel with the long side turned in to meet the outer screen. The inner part (your SF029-16) is an oblique L section, turned in to meet the inner screen. Neither of the sections in your pics look like those, so I would suggest that either Drawing 14 for your build is not correct, or you have pulled the wrong parts?

If increasing tyre size, I'd say that's the way to go. I was talking with a very experienced and capable Savannah owner a while back, and he was remarking on how you have to rotate the aircraft off the ground. It doesn't take much at all, but it won't lift off at lower speeds (in steady conditions) while on all wheels. Which is very handy for choosing your desired liftoff speed and point. Also very handy for getting the thing to stay on the ground on landing, especially if lightly loaded.

Cutting to the chase: The problem isn't the prop size, it's that it's attached to the aircraft lower than with a 912. Note this will also result in a different thrust line. Also, unfortunately, just jacking up the front (which would need a much bigger tyre and the forks to take it etc.) is likely to result in less than ideal takeoff and landing behaviours: On takeoff, the aircraft is rotated from the go, so will lift off at a low speed, whether you want that or not. On landing, gusty weather may result in multiple touchdowns, as once all wheels are on, those high lift wings are sitting in a rotated attitude.

70" is usual here. There is a 68" I think but if you visit the Stolspeed website, he's done a lot of prop comparisons, and the 68" performs less well.

So, 26 were built for lendlease to WW2 Russia.....of which 7 were lost on the N Arctic delivery route...and just 10 of the remaining 19 were accepted into service???

A significant number of builds report the same problem: fuel pressure shows okay on the ground, but appears to diminish with altitude. There is generally nothing wrong with either the gauge or the fuel pressure. The problem is that the gauge needs a static port, so that air pressure inside the gauge is able to change with changes in altitude. The top of the gauge body, behind the panel, has a little rubber bung in it, and the quick fix is to just pop this out. A better fix would be to then install some sort of filter in it's place, to prevent the ingress of dust & bugs.

Our jump club, about 20 people, managed to get a session in the Airforce (de) pressure chamber in Auckland years ago. They took us all to 18,000ft, had us take off our masks, and the result was very pleasant, like being tipsy. Everyone was happy but lots of us couldn't now recall details from the simple briefing we had previously attended. They then took us to 25,000ft and had us remove our masks, 2 at a time, while the rest of the group watched. The unmasked had to do simple repetitive subtractions (300 minus 7, minus 7 again etc), with regular physical checks that involved pausing the calculations and repeatedly touching their own nose then touching a finger held up in front of them (we had a couple of instructors in there with us). Most had trouble physically locating their own nose, and then accurately touching the finger. One got target fixation, insisted on continuing with this exercise and holding the instructor's wrist when he tried to take his finger away. For the most part we were told to put masks back on as our performance worsened after about 2 minutes of this. A couple didn't want to do this despite repeated commands (we all had on headsets), had to have their masks forcibly applied. And on the way back down, while the recovery is very rapid for most (with a sudden return of colour vision we hadn't noticed had faded) one continued into hypoxia, requiring oxygen and a lie down. There was also one, and a smoker at that, who had no trouble with the required exercises at 25,000ft and after a full 5 minutes was apparently entirely functional. What came out of this for me is that our bodies generate absolutely no warning signs as hypoxia sets in...if anything, there is a sense that it's all going wonderfully well. So if in doubt, trim for descent (I believe that's right, but stand to be corrected). And different people can be affected quite differently.

Works fine for me.

Continuing to follow (and enjoy) your Sonex voyage of discoveries here, Skippy. It continues to raise interesting stuff I'd never thought about. I know where there's as Sonex parked at the back of a hangar...it almost makes me want to look at tinkering...........)

What Nev says feels right: stiffen it up and you increase the loads elsewhere. My first thought was to try and limit movement with smooth running, including starts and stops, hence the the question about prop weight which seems to make a big difference in that respect.

FWIW: My idle jet and idle throttle stop settings are as per the Rotax manual. (I checked them at new and one of them was a bit out from the factory, can't remember which one but it's a very quick setup, and evidently worth doing). With those settings, the tacho drops towards 1400 when pulled to the stop, and I switch off the ignitions almost simultaneously as it is getting there.

Skippy, what weight of prop do you have? And what are your engine starts and stops like? I ask because I have a reasonably light Bolly 70" prop, and that coupled with the improved Rotax ignition retard, plus a bit of practise and understanding gives me very smoothe starts and stops. Our club Tecnams, however, have the much heavier prop mandated by the manufacturer and engine start/stops can be quite ugly, no doubt resulting in considerable engine movement.

FWIW kbstone, my kit came with the skin holes and blowout panels for a parachute setup. Since I have no parachute, rather than mess around with those panels (which go under the skin), I just blanked the holes off with a simple capping panel. This I made with an offcut from the kit, specifically the cut out piece in the lower wing skins where the tanks go in. If someone wants to fit a parachute in future, that is simple enough. In the meantime it is a tidy and weatherproof solution in a place nobody ever looks anyway.

I don't know kbstone. What the kits have now is a round pattern of drilled holes in the top skin, that fit under the cover you have there. I would add a skin over that big hole, with a circular pattern of round holes, then mount your cover over that. We put the cover on late, as we like to apply silicone between skin and cover, also a lip of silicone round the holes to keep out rain both in the air and on the ground.

Pat, what I meant by 'the arrangement' is the individual air filters on the carbs, taking air always from under the cowl, which should be warmer than outside air. And my suggestion about sustained low power settings (usually on long descents) was because the engine will be producing much less heat in that mode of flight, so the air under the cowl and entering the carbs will be cooler. I cannot say if your engine compartment is warm enough to avoid ice. That depends very much on how the air circulates there. I suggest your best source of information would be from pilots operating similar aircraft in your climate.

Yep, that's the arrangement on at least one of our club Tecnams, and I'm not aware that they have icing problems, apart from one possible incident some years ago. How effective it is will depend on what sort of temperatures you get at the air intakes under the cowl. Probably best to avoid long descents at low power settings?

Yes, absolutely, carb ice can be a problem. Some Rotax equipped aircraft do not have carb heat, but instead take air from under the cowls all the time. A VG on our airfield does have carb heat, and the XL and S Savannahs all do too. It's probably easiest to post a pic of what you have under the cowl, Pat?

Strictly speaking, that aint a float bowl vent....it's not for venting, it's for pressure balancing in the float bowl....but I'm sure we've had this conversation already........)