IBob

Blue, if the blade height is 1100mm, then 1 deg of pitch is about 20mm of laser spot movement. Actually a bit more, but not hugely so: 1100 x 2 x 3.14 = 6908 Divide by 360 = 19.2

After that, I think smooth running comes down to carb synchronisation. That starts with the standard Rotax adjustment of the idle throttle stops and idle jets, which is a quick and simple job. I took particular care installing my throttle linkages and routing the cables, then adjusted the cables so that both carbs come off the full throttle stop at the same time when when throttling back. Since much of flying is done at higher engine speeds, this seemed to me to be the most important end of the range. I do check at the other end of the range...that both carbs come off the idle throttle stops simultaneously, and in my case they do that too. I made minor adjustments to maintain the synchronisation over the first 50hrs. Since then I have checked periodically but no further adjustment has been necessary. I also fitted a simple idle position stop to the throttle bar that runs across the firewall: without this, if the pilot pulls back hard on the throttle, the load goes onto the carb throttle arms, and once they hit the carb idle stops, the arms will flex or distort.

Marty, for the stick with clamp, I just hold it vertical to start with and put a masking tape marker on the floor where it lands. I then position the stick on that marker for each blade. I also use masking tape on the floor where the laser hits, so I can make precise marks with a pen. As for tracking, I can't remember clearly how I did it. I think I had the aircraft facing a wall, brought each blade round onto the stick then measured to the wall. Or something like that. I certainly didn't go to the bother of removing the prop. I'm not sure if you have measured and marked in from the tips for the laser location on the blade. If not, I would definitely recommend that too. I guess it all sounds like a lot of mucking around, but I have found it simple and not a long job once you have the tools and method sorted. An additional check as to how well you've done can be made in flight: at certain sun angles, the sun flashes off the back of the blade and all the flashes will look the same if the pitching is accurate.

Marty......much tidier than the thing I cobbled up! Apart from very accurate measurements from floor to blade (I use a stick with a clamp on it, bring the each blade down onto the clamp) and very accurate measurement from blade tip to laser position (I use a sliding square and mark the location with masking tape).........there is one other thing to watch for using this method, and that is blade tracking: One of my blades tracks about 2mm further forward at the tip than the other two, so I factor that in. If I were using a similar method, but with an inclinometer on the blade, I wouldn't have to be concerned with the tracking. The only proviso then would to be sure I was using a good quality inclinometer, as they are not all born equal........ For myself, I will carry on with what I've got: done with care it does get very accurate results. PS I tighten all bolts fully then check all blades again, as sometimes the tightening does shift the pitch a bit.

Skippy, I have to disagree with 'completely ineffective'. For instance, you don't think landing light/s make an approaching aircraft more obvious when you are waiting to enter a runway??? What I would agree with is that typical/traditional wingtip and beacon lights are very poor in bright sunlight. Having said that, I have seen, a beacon so bright in daylight that I walked the 700M across the airfield to see what it was. That was on the ground. I'm pretty sure it was one of the Aveo products. And you may have noticed that cautionary lights on road maintenance and emergency vehicles are now a whole lot more visible at distance than they used to be? The technology is getting better and brighter, and that will percolate through to aviation kit.

Hi Lyndon, I can't answer as to what is mandatory......but I'm sure others here will know. What I would say is that, now we are better understanding the limitations of the eye in 'see and be seen', they are definitely not something I would skimp on.

I guess they probably do that fine at the factory......where they've had the practise, have worked out their methods, and will have jigs and tools to expedite everything. So they'll be on the tools and building all the time. Whereas, on a first build, there is probably a great deal of time spent figuring things out, getting things right, and generally proceeding cautiously. I have struck the same thing with house renovations/modifications: a builder mate of mine would drop by and do more in 3 hours than I got done in a day. It puzzled me a bit, so I began watching myself......and realised just how much time I was spending trying to think things out etc, while he knew just what he was doing and his 3hrs was on the tools full time.

sfG I can't speak for the Ventura, but for the Savannah I've come across two numbers: 400hrs and 700hrs. It would be really interesting to know where they came from, as an ex-airforce sheetmetal worker here took about 1700hrs on his. And while I did not log the hours, mine would easily have taken that long too.

Welcome, Joe. This is a very big site, with a huge historical wealth of information and discussion. And opinions.......we're rarely short of those.........)

Pretty tough winters up there: I spent part of one on Paramushir, just off the end of the peninsula. The houses of the one village....about 2000 people......disappeared entirely under the depth of packed snow, with only raised escape doors sticking up above the surface enabling the inhabitants to come and go. And the weight of that same snow, which just builds up and progressively compresses to ice, completely bowed in the roof of one of our containers........

While I can't claim to know about fuel systems on other types, it seems to me the 701/Savannah setup is well thought out and functions very nicely: The 6L receiver tank with level switch buffers any momentary unporting of the wing tanks, while giving 15minutes of early warning of fuel exhaustion. And the fuel return (via orifice) addresses the problem of vapour lock.

Marty, that seems very comprehensive. Just some notes: 1. My receiver tank developed a leak from one of the upper fittings: the tank came with fittings in place and I had omitted to check they were tight. The leak did not occur initially and required removal of some plastic round the fitting to remedy. Almost certainly a one-off, but I suggest checking for any dampness on or round the tank during initial trials. 2. The electrical aux fuel pump should give you at least 2PSI once the carbs are full. I did my initial engine runs without wings, with the fuel return line blanked off. Since the pump has a non-return valve, the system maintained the 2+PSI with the engine off when the pump was run then turned off. With wings on and the return line connected, engine off, the aux pump should still give you 2+PSI but this will drop to 0PSI once the pump is turned off: this indicates that your return orifice and pipe are clear and functioning correctly. I did not top my tanks off, just used enough fuel to to flood the receiver tank etc and test for adequate flow. The aux pump delivered 1.2L/min. Assuming you have the Savannah receiver tank (?), the early Savs had no tank vent there. The result was that small amounts of air could become trapped in the upper tank and would give false 'tank low' indications. Typically this would occur when climbing to altitude, as the trapped bubble expanded. Later Savs fixed this by running a vent line from the tank top to the upper LH wing tank.

Skippy, the Savannah has a pronounced lip at the front of air outlet, to provide negative pressure there. It also has an airbox, but mounted to the rear engine mount, so not hanging off the carbs. For combustion air intake it has a NACA scoop......but I discovered that doesn't work so well at high angles of attack, was also pulling air from under the cowl. Was able to fix that by extending the airbox inlet to almost reach the scoop....while still leaving a small gap for drainage on the ground. Also: where specifically are you measuring the temperatures? Air temperatures tend to be very location specific, by which I mean there will be quite different temperatures in various places under the cowl.

Do I detect a degree of disrespect for the glorious future leader of the most heavily armed paranoid nation in the world..........?????

wrong thread..(

With the 912 standard throttle cable setup, throttling back is pulling the cables, but throttling up is pushing the cables, and relying on the springs on the carb throttle arms to pull the arms and cable at the other end. So it may be worth checking that the cables and linkages etc are all moving freely on both carbs.

It almost has a DC3 front end..........

Bryan, now I think back: the pilot who test flew my Savannah taped over a small hole where the root fairings meets the wing skin LE. The fairings are non-standard, I wanted them to turn in more towards the screen and give me a wider field of vision. So that edge of the fairing (which tucks in behind the wing skin) has a series of cuts in it, resulting in small holes when they were fitted, one on each side out in the airflow enough to make noise. That tape is still there: two round silver dots of it.

The wing root fairings on my Savannah are aluminium, with a rubber edging where they meet the screen. At something over 95kts, I get a noise like someone blowing a high pressure raspberry. However, since you have to point at the ground to reach those sort of velocities, it doesn't happen during 'normal' flight. Though I do get the occasional quick blast at cruise in turbulence.

Assuming that you sealed where the bottom of the windscreen meets the fuselage......the next most likely place is where the wing root fairings meet the windscreen at the sides and top.

It seems to me that aircraft are like cars, in that certain models look good in certain colours or colour schemes. I do think that some homebuilts are let down by poor choice of colours/schemes, which is doubly unfortunate given the amount of time and care that goes into them. One approach to choosing a scheme is to colour in a profile of the aircraft, but I found this not useful at all, actually quite deceptive as the aircraft rarely appears in straight profile. I found it far more helpful to view the numerous shots of real aircraft online.

Once upon time I flew (as passenger, Olympic Airways) from Athens to Crete and back monthly to service some gear there. Sometimes they took forever doing their mag checks and warming up before taking to the skies. And shortly after takeoff the hostess would run from the back to the cockpit with 2 little paper cups: rumour had it this was ouzo. The USAF also used them at that time for airevac and routine hospital runs, as different hospitals specialised. So, for instance, maternity was in Frankfurt, and expectant military wives were all gathered up and shipped to Frankfurt when the time came. Sometimes it was possible to get on those runs, space available, but you could also get bumped and end up somewhere other than you thought you were going. On one such from Turkey, we got diverted to Tripoli to pick up an injured sailor. He had been hit by a broken cable, had brain damage and was strapped to his stretcher from where he screamed obscenities and called for his mother all the way to Athens. I was very glad to get off and felt sorry for all the mums-to-be sharing that flight.........

I'm pretty sure someone commented here a while back on the latency or delay in some of these data sources. As an example: where 90kts is about 150ft/sec, a 10sec delay will result in a 1500ft error in position reporting. 120kts and a delay of 30sec and the error is 6000ft, or 1 nautical mile.

Moving this over here to try and get away from the thread drift. I use a Ping and had similar position issues relative to my tablet, ended up moving the Ping to the brow of the windshield. Also mounted it properly rather than relying on suckering it to the screen. Works fine now.