Jump to content
  • Welcome to Recreational Flying!
    A compelling community experience for all aviators
    Intuitive, Social, Engaging...Registration is FREE.
    Register Log in


  • Content Count

  • Joined

  • Last visited

Community Reputation

4 Neutral

About vk3auu

  • Rank
    Well-known member
  • Birthday 28/05/1935
  1. vk3auu

    CH-701 or 750

    I would suggest that you have a good look at the Foxbat. Stol performance, 100 knot cruise. David
  2. vk3auu

    Sport Air

    That is real good. The sheila who was running the show before wasn't giving very good service. I'm sure Alan will do better. David
  3. vk3auu

    CH-701 or 750

    A couple of points. If you are larger than average go for the CH750. The 701, even with the bow in the doors would be a bit too squeezy. Don't even attempt to use a Jabiru engine. As previously mentioned, you need a big prop. The Rotax 912S is the ideal engine for the 750. The Subaru is too heavy, and unless you get one that really produces 100 HP, performance will not be very good. Also, don't put the leading edge slats on it. Use John Gilpin's vortex generators on the top of the wings and put a row of them on the underside of the elevator. David
  4. Sorry, it has taken a while for me to get back to the page. I have the extended baggage compartment and A friend of mine fabricated a 40 litre fuel tank to fit in the top of the front section. It is slightly behind the Centre of gravity so I have to make sure that I put heavier Items in the front of the baggage compartment or if no passenger, then on the seat. Also I need to use the fuel from the rear tank first to keep the C o G within the envelope. All that being said, If I was doing it all again, I would put the tanks in the wings and forget about the folding wing option, which I don't have. I thought it looked too cumbersome and anyway, I don't need it as I have my own hangar. Incidentally, I have taken off the leading edge slats and put on the vortex generators and one up it climbs out at 1700 feet per min with the 80 HP 912. The aircraft is now for sale if anyone wishes to make a reasonable offer. Email me direct at [email protected],net.au David
  5. Mandatory carriage of radio I think is is a good idea and should have been bought in years ago. It is a much better idea than the one about the carriage of ELT's. David
  6. Elevator authority Surely a lower "gearing" between the stick and the elevator would reduce the pitch sensitivity without reducing the effectiveness of the elevator at lower speeds. On my old 701 I had to put vortex generators underneath to increase the effectiveness of the elevator at low speeds as even at maximum deflection, I couldn't get the nose up with full flap at 45 knots or lower. David
  7. Bert Flood's funeral Further to the above, I believe the address is 10 McIntyre Lane Yering David
  8. Just a comment about rate of climb with VG's fitted. If for instance, the stall speed has been reduced from say 40 knots to 35 knots, then the safe approach speed which in my case is roughly equal to the best climb speed will be reduced by about 6.5 knots. (I said roughly) That will mean that the best rate of climb speed should drop from 52 to 45.5 knots. That will mean a drag reduction of about 30 percent which will mean some more power available to climb, if you adopt the lower speed. As to the best place to put them, forget about percentages, it depends on the wing upper surface profile and should approximately be right on the top when the wing is just starting to stall which will generally be at around 14 degrees depending on the washout. Finally, the CH701 has an all flying rudder but the elevator is separate from the stabiliser, although it has the unusual upside down profile. David
  9. Actually the underside of the elevator is the place to put them for maximum effectiveness. On my CH701 I have them placed right at the bottom when the elevator is at full up deflection. On the wing, the best place seems to be to place them right at the highest point when the angle of attack is about 15 degrees, which is where most wings usually stall. The earlier Jabs with their little rudders could probably also benefit from fitting them to the sides of the rudder, again at the extreme outside when at 15 degrees deflection. John Gilpin at Maleny is the bloke to get them from. David
  10. If you take an aircraft such as a Quicksilver GT400 which has a highly cambered wing with a flat bottom, it will fly quite well at about 50 knots at zero angle of attack. The lift is all due to Benouilli, Newton doesn't come into it at all. David
  11. vk3auu

    Exhaust Insulation Wrap

    Ross, I think we may be talking at cross purposes. My comments were regarding the air under the cowl where the pressure is not too much greater at the inlet than it is at the outlet, so that the P term can almost be ignored. There are some people who make the inlet hole larger than the outlet in the mistaken belief that this will increase the air flow, but at the end of the day it has to be the other way around. Just putting a lip under the exit hole can only be marginally effective too, if the ratio of outlet to inlet is not large enough, just creating drag, but no extra air flow. David
  12. vk3auu

    Exhaust Insulation Wrap

    Concerning the ratio of the size of the opening for outlet air compared to inlet air. The volume is proportional to the absolute temperatures in degrees K, not the degrees C, so that assuming a cold day with inlet temp of Zero degrees C and outlet temp of say 80 degrees C, the outlet would only need to be about 353/273 = 1.3 times the area of the inlet. Any bigger would just be causing unnecessary drag. David
  13. I don't quite know where this should go. The best Air Race Pilot ever? | chilloutzone.de - free games and free fun David
  14. What do you mean test page David
  15. Ian, I just got your TEST page again. David
  • Create New...