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jetjr

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Posts posted by jetjr

  1. Any report is better than none, even a rough assessment of what make and model and was it mechanical/pilot /other causes does help

     

    They shouldn't alter whats submitted.

     

    Previously there was near nothing being submitted and some looong assumptions being drawn on reliability and CASA acted on it. This had massive cost to RAA aircraft owners and had a part in manufacturers closing

     

    Not perfect for sure but better

     

    People may be prone to providing unclear detail when insurance will end up being involved

     

     

  2. Engine - which one/version , full history, 2011 puts it at a sensitive age with Jabiru engines not being at their best BUT flight schools have good arrangements to exchange engines regularly at good rates I believe.

     

    Plenty would look to having some top end work at 500hrs - don't see this too much as bad thing, pretty cheap comparably.

     

     

  3. Thanks jetjr, yes I did that sb years ago. They supplied a moulding which replaced part of the front lower cowl leaving more room for the oil cooler and actually lowering the drag.

     

    Yes, not that one, theres one regarding rear exit of cowl. they have system for estimating how bad overheating is and then 2 or three different cowel exit mouldings

     

    https://jabiru.net.au/wp-content/uploads/2018/05/Engine-Cooling-JSB016-1.pdf

     

    Theres a similar one for J230 that discussed Gull wing baffles removal and theres pics of std ram ducts going deep into cylinders like pictured before

     

    The plates joining heads on the outside - preventing air leaks, were also tried by CAE and crack after a short time. Cylinders must move independently it seems

     

     

    • Like 1
  4. Don't think you can modify, have to be certificated. Experimentals stay as they are

     

    CASA indicated there are a few hundred aircraft that can fit into new catagory

     

    Appears targeted to GA aircraft dropping into RAA regs rather than RAA moving heavier - hence the original comment for this thread and the thought why are RAA spending energy on it.

     

     

  5. The term "dark art" comes to mind.

     

    Sure is, and in terms of air flow through cowl, (and fuel flow from inlet) it seems no to Jabs are the same

     

    The big difference is made by sucking more air out - lower cowl lips,

     

    then controlling the path that air takes - duct deflectors

     

    I think sealing gaps etc is essentially playing around the edges.

     

    There is a point where lower lip modifications can result in less flow and can cause exhaust to enter cockpit

     

    When modifying older Jabiru heads, be careful as you cant easily get them anymore unless something has changed

     

     

  6. Id not be able to work all that out in the few seconds decision time you had, by the time you worked out they weren't working could be too late anyway

     

    If you had been a slow approach and everything going well, try to stop or run off somewhere safe

     

    If things a bit fast, go around, think a bit and try again with more options prepared, grass etc is a good idea

     

    Older Jabs not reknown for effective brakes, often loose performance on a hard brake/fast landing, not to be totally relied upon.

     

    Pays to get good at slow approaches and have some options available for higher speed exit

     

     

  7. Jabiru and CAE worked with "gull wing deflectors", they sat in valley between cylinders, Jabiru placed on top to shift more air to rear cylinders on 6 cyl, they were later deleted (actually was a direction to remove)

     

    I fitted these under cylinders and it stabilised temps but no reduction

     

    CAE supplied larger versions under cylinders std.

     

    They also fitted shields to CHT temp probes to preventing air blast cooling and some high quality probes to try to sort out erroneous readings. CAE reads hotter (125 -137 in cruise, 150 on take off) but I think its just closer to reality, Previous Jab setup read probably 10-15 deg cooler and moved around much more in phases of flight.

     

    Which is a worry when you consider some 150+ temps being seen with std Jab supplied probes

     

     

    • Like 1
    • Agree 1
  8. Yeah 100 deg cht is a low number, you need higher than this to get oil temps up Id have thought

     

    But number isn't that critical so long as they are even and you have some idea what variation from actual cht

     

    Two now talked about good results but none saying what was done?

     

     

  9. Only if the airframe can handle it and manufacturer will support it

     

    To measure that an aircraft is compliant with 45 kt stall, what should RAA or CASA do?

     

    Measuring accuracy to 2-3 kts takes some smart gear and/or a significant flight program

     

     

  10. Might be wrong but reckon Bruce is talking about water mist on outside of cylinders, not water /meth injection

     

    Gets used in some road vehicles but dust turns to mud, bakes on and clogs things up. Aircraft dont really have water proof electricals etc

     

     

    • Like 1
  11. The stall speed increase required is around 2-3 kts

     

    Don't think much thought went into LSA numbers as US and AU are different

     

    The whole minimum stall speed needs review as measuring accurately is difficult, especially to 2-3 kts

     

     

  12. be aware of air blast onto sensors

     

    Fitting CAE wind shields around probes raised temps a bit

     

    A slight block to cool side will help more get sucked into warm side,

     

    Id prefer slightly high temps and even under limits of course

     

     

    • Like 1
  13. Why does a pilot need a PPL? Why does a pilot need a medical? These are just BS excuses. A CTR endorsement & transponder is in reality the only difference. Works fine elsewhere in the world but for some reason it can't possibly work here.

     

    It can work here except there isn't a CTA endorsement for PCert nor system to offer training - all can be sorted out.

     

    My point was in reference to an indication an RA aircraft cant fly in CTA - they can, normal RA pilot cannot

     

     

  14. Fuel level shouldn't be that hard to setup but there has been problems with needle and seats not sealing over the years, some pumps can push past seat/needle.

     

    Mech fuel pump, bing is sensitive to pump pressure, spring in pump adjusts this and they can corrode  - not sure how being vented to case.

     

    getting it back together is delicate as plunger can bind once warm, close fit and easy to misalign

     

     

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