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IBob

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Posts posted by IBob

  1. But certainly reminiscent of them good ol' days when, to add to the excitement, the pilot wasn't allowed to see where he was actually going.

    Or where he'd been: just where he might have been if he was travelling parallel to his actual current path.............(

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  2. Whatever floats your boat, Kyle.

    I would comment that the 912 ULS as fitted in the Savannah and with an appropriately pitched prop runs very nicely and does not suffer any high or marginal temperature problems: quite the opposite in our temperate climate, where we blank off part of the oil radiator for a good part of the year in order to see recommended oil temperatures. The Savannah kit includes a wiring harness and steam gauges that pick up the 2 head coolant temperatures (or CHTs in older engines) plus oil temp and pressure, which are fitted standard to the 912.

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  3. I made my own skin extensions, as I wanted them to turn in like the 701, rather than be an inboard extension of the leading edge shape which I think also intrudes some on the field of vision. I count myself as a reasonably competent pattern maker, but it turned out to be quite a mission, and while i am happy enough with the result, it is certainly not perfect. If it is any consolation, this is a challenging area on most high winged aircraft. And on the Savannah, since the windscreen is not predrilled, the shape there will vary some from build to build, so you will quite probably need to trim to get a good fit.

     

    For the roof panel, the manual says to fit it on top, but I copied another local builder and fitted it under the wing skins, using those fastening strips to secure it underneath rather than on top. You have to trim a bit off the sides to get it under there. I think it does a much neater job, if potentially a bit less weatherproof. I can't recall if I put silicone sealer in there.

  4. Kyle, I have a Savannah S, but have also enjoyed quite a few flights in Pete's (fallowdeer) VG, which has the original bed mount. And I can't say I noticed any particular difference in smoothness. Be aware also that on XL and the S, for which the ring mount was introduced, the firewall sits at a slightly different angle than the VG. So there would likely be some packing involved. Marty_d may be able to comment on that, as he has fitted a ring mount on his 701 build.

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  5. 12 hours ago, Marty_d said:

    The point of the reserve is so you don't go down.

    FYI Marty, 2 possible shortcomings of the receiver tank alarm system:
    1. In the kits it comes with an incandescent bulb indicator. We swap that for a flashing red LED, which we also mount on the LH side of the panel (where the standard indicator is on the RH side).
    2. Unless you have a way to valve off the main tanks, you have no easy way of testing the level switch, which is a simple magnetically operated reed switch and can fail.
    We put in a 4 valve system for the 4 tanks, following Mark Kyle's early example, and this does allow easy routine testing of the entire alarm circuit.

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  6. Surely, in light singles and microlights, a small receiver tank with level switch in the top is an excellent innovation?
    In the Zenith 701 and and the Savannah this is a 6L tank, kept flooded by the main tanks.

    At cruise with a 912, the low level alarm comes on 150secs after the main tank/s stop delivering, leaving the pilot with approx 20minutes of fuel to sort out the problem or find a suitable landing spot.
    It seems to me this addresses all sorts of scenarios, including momentary unporting, which have brought other aircraft down.

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  7. Facthutnter, if BC0979 is referring to the standard Savannah park brake, it is simply a pair of ganged shutoff valves in circuit between the pedals and the wheels: the pilot closes the valves while standing on the brakes.
    In the Savannah, these valves are situated just under the LH end of the instrument panel. So the brake lines go up from pedals to valves, then back down to the wheels. However, this will not result in fluid flowing back down to the pedals, unless an air leak at the valves allows air in there to replace the falling fluid.
    And you are right, such a brake should not be relied on for any extended period. But it does allow time for the pilot to find a rock or chocks as required.

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  8. BC0979 I just printed out the 06/23 version of the Savannah S Maintenance Manual....which has grown from just 16 pages in 2014 to 132 pages in this latest version. It includes a section on the brakes including bleeding that states the oil level should not be higher than half of the (upper) tank level, or approx 20mm down from the top.

     

    Onetrack, unless there have been changes (I have yet to read all of this new manual) ICP specifically call for mineral based oil.......and that is what is in my S.

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  9. Hi Bryan, I have no detailed pics.
    The J struts mount as you describe:

    The upper bracket is riveted to the underside of the wing as shown Ch2 Pages 34 & 35.
    The lower bracket is wrapped round the wingstrut and riveted under the trailing edge of that. In my manual this is shown Ch 26 Pages 6 & 7.
     

    You do have to work out just where on the wingstrut:
    I fastened the upper bracket, the position of this is clear from the manual.
    I then had to trim the Jstrut to fit between wing and strut: I trimmed the top, cutting it off at an angle to match the wing underside. As I recall I did this initial trimming with a hacksaw, as it required a lot of material to be removed.
    With this done I lodged the J strut top at the wing fastening and used a square on the strut while moving the Jstrut bottom, to establish where it should fall (as the Jstrut needs to be perpendicular to the wing strut).
    With that position marked, I was able to wrap, drill and rivet the lower bracket to the wing strut.
    And with the two brackets in place, I was then able to make final adjustments to the trimming of the Jstrut, and drill it for fastening.

    For fastening I just used the rivnuts, with star washers as per the manual. I assume the thinking is that it requires very little force to hold the strut from bowing while it is in a straight condition. And that explains the light fastenings used.

    Other notes:
    As mentioned, a lot of the upper Jstrut had to be removed to make it fit.
    The bottom of the Jstrut is already cut to a curve, but this does not match the shape of the Wingstrut very well. You may want to remove a little of the front of the curve.
    With both brackets in place and while lodging the Jstrut for final fitting/drilling, I found I was at risk of pushing the wingstrut out of straight. To reduce the risk of this I worked the Jstrut shape to be a looser fit on the brackets, and also ran a stringline up the length of the Wingstrut.
    The bottom bracket is SS, so not at risk of corrosion. However, since my struts are painted white, I ran white heatshrink onto it to neaten the appearance.

     

    I hope this helps. It is a fitting job, rather than just straight assembly. But not difficult. It's just the manual..................(

  10. 28 minutes ago, facthunter said:

    IF the mainwheels are back too far it requires a lot of elevator downforce  to raise the nose and that adds to the weight on the mains and doesn't work as you slow up. It also affects the way the plane lifts off.   Nev

    Yep, same problem if the C of G is too far forward: once the main wheels are down, the elevator won't keep the nose up as the aircraft slows.
    I have this with my Savannah, which I often fly solo and quite light: I recently added 10kG of (removable) ballast in the baggage area and it is now a completely different aircraft to land.
    The main difference I notice in liftoff is more rudder to hold her straight during initial acceleration, presumably as the nosewheel is effectively lighter.

  11. 17 hours ago, 3rd harmonic said:

    Against what may be considered sensible or advisable, i decided that the buying a repairable wreck of a Morgan Sierra might a challenging and satisfying project!?

     

    As a brief history: The aircraft was built from kit supplied by Morgan Aeroworks and unfortunately after only a couple of flight hours, ended up suffering a loss-of-control on landing accident.
    Insurance was claimed for the value of the expected repairs which were substantial and although it wasn't considered a total loss, the salvage value of the wreck was not very high compared to the cost of the original build.

     

    The accident damage mostly confined to the nose of the A/C.
    nose wheel folded under and snapped off
    damage to the firewall and floor.
    Prop strike, prop destroyed.
    Engine mount cracked/bent/broken.
    Very minor damage to the winglets and wing leading edges right at the tip.

    IMG_7435.thumb.JPG.c86fdc3d957dbf574cf15dab148fb12d.JPGIMG_7419.thumb.JPG.f2bba399df17279bc8c4ddcc80774019.JPG


    The wreck was sold to a guy who trailered it to Melbourne, where it sat in a storage unit for about a year.
    I brought it off him and trailered him back to SA in an epic 2 day road trip.
    As pictured on a very large car trailer.

    IMG_7445.thumb.JPG.8ff498eda96d70f90b0055239a8202fb.JPG

     

    With quad nosewheel mod???????

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  12. I used a small cheap greenhouse pump sprayer with neoprene tube attached, but most of them leak at the screwon top, so test if buying.

     

    However, I like the idea of the pump oilcan above much better: the pumped up sprayer delivers the fluid at an uncertain rate, and needs to be shut off real quick at the end of the fill.
     

  13. Assuming you have the flight recorder enabled in Ozrunways, it generates a data file for each flight.
    By dumping that out you can access the altitude data, which is what I did following a near miss at the start of a flight a while ago.
    I then corrected the data for QNH on the day, and found the corrected GPS data to be very accurate: I know this because, following the near miss I flew a return trip at very precise altitudes (as displayed by my altimeter).

    There are various comments about GPS altitude not being very accurate. There are also comments about it being less accurate near ground level.
    It would be nice to get a fix on the actual degrees of inaccuracy:
    Are we talking about tens, or hundreds of feet?
    And how close to ground level should we expect additional inaccuracy?
    Anyone???????

     

    • Like 1
  14. Maybe check the size of your mudwasps, Skippy? And take note of where they nest in your area. Remember they have to be able to get in and also turn round in order to lay eggs etc. So if the hole is round it has to be a reasonable diameter to allow that.
    Here they will get in a dowel sized hole  or a keyhole (which allows turning). I haven't seen them in anything round much smaller than that.
    They also nest between flat surfaces and in curtain or hung clothing folds, but that's not relevant here..........

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  15. FWIW Savannahs traditionally have a 3mm nylon breather line for each tank. These poke out under the wind and are cut off at 45deg into wind to give a degree of positive pressure. It's not the tidiest setup, but seems to work though it can be difficult to get equal pressure in all tanks as the pipes do not sit straight or perpendicular to the underwing due to the natural curve of the pipe itself.
    At one stage I had very uneven L/R fuel feed, and was able to partly correct this by adjusting the angle of the pipe cutoffs. If I were  building again, I would run and anchor solid pipes down through the wings, rather than flexible line, allowing the cutoff angles to be precisely adjusted.

     

    I did try converting to (much tidier) forward facing underwing vents, using tiny 90deg garden irrigation fitting, but changed back after just one short flight that saw massive crossfeeding. Part of the problem there was a poorly moulded integral fuel tank filler point, that allowed that tank to 'blow'. However, it does not do this with the standard setup, so clearly the forward facing vents were delivering a lot more pressure.
     

    Mason bees/mud wasps are a whole class of critters: over here they are just a little smaller than a german wasp, but far too large to enter or nest in a 3mm pipe. They may be different where you are.

    Part of my preflight is to visually check the ends of the breather lines. This is easy as the the nylon is semi transparent. To date I have never found anything in there.

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