Ah-1 Cobra Pilot

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About Ah-1 Cobra Pilot

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    Full Member

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  • Gender
    Male
  • Location
    Lincoln NE
  • Interests
    Flying, duh!
  • Reg #
    N468W
  • Model
    M20J

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  1. Ah-1 Cobra Pilot

    FASTEST?

    The closest data I could find, (C-182), had a 2-blade prop at 46 lb, a 3-blade prop at 56 lb. That small a difference will be negligible. The drag of a 2 vs. 3-blade system? It depends on the blades.
  2. Ah-1 Cobra Pilot

    FASTEST?

    That paper is actually sophomore-level Aero E. Even without going through the Math, you can see a number of things. For instance, look at this table. Table 11.2: Propeller Parameters and their Units Parameter Symbol Units propeller diameter D m propeller speed n rev/s torque Q Nm thrust T N fluid density kg/m3 fluid viscosity m2/s fluid bulk elasticity modulus K N/m2 flight velocity m/s What is most applicable to our discussion is what is missing. Do you see "number of blades" anywhere? If not, ask yourself "Why?" Admittedly, this is Actuator Disk Theory. Also take a look at the graphs at the bottom of the page. What do they tell you? What I want to kill is the idea that 2 blades = ..., while 3 blades = ... As I said earlier, it is not good to generalize. There is a lot more that goes into deciding on a prop, and perhaps the most important factor is outside of calculating the greatest efficiency, which is $. Imagine this scenario: Engineer #1: "I have designed the perfect prop for this airplane in its present configuration. The prop companies want $1,000,000 to begin producing it." Engineer #2: "We can put an 'on-the-shelf' prop on it for a 3% drag penalty." Boss: "Will we sell more planes to make enough money with the perfect prop to pay that extra $1,000,000?" Hence the real dilemma.
  3. Ah-1 Cobra Pilot

    FASTEST?

    I will tell you what...Read this page, then get back to me. http://web.mit.edu/16.unified/www/FALL/thermodynamics/notes/node86.html
  4. Ah-1 Cobra Pilot

    FASTEST?

    The power required to turn a prop has nothing to do with the prop's mass, (except during acceleration), it is all about drag. Induced drag is dependent upon lift, so 2 vs. 3 blades is moot in that regard. Parasite drag depends on surface area, so which has more area, 2 or 3 blades?...It depends. Think of a prop as an airfoil, and it becomes more clear. You want maximum lift/drag, the tip speed must never go sonic, it has to be strong enough to survive predicted sustained and transient loads, you want to do all of this within the engine rpm limits, you want minimum weight, etc. Also, throw in such factors as engine configuration, physical limits of landing gear length, blade material/cost, and it gets more complicated. The number of blades is optimized over numerous criteria, and it is not good to generalize.
  5. Ah-1 Cobra Pilot

    Coming soon...1976 F equipped to your specs

    Their web site is somewhat convoluted. How much would it cost to for a 100%, full install, including autopilot?
  6. Ah-1 Cobra Pilot

    231 cowl flaps

    At my first annual, my mechanic suggested I replace the baffling as it was loose and floppy. I did not pay super close attention to the CHT before that, but as I recall, it seemed to drop at least 10o afterwards.
  7. Ah-1 Cobra Pilot

    I've started a Business! Its called WingSwap

    Would Ferrari or Porsche be a 'popular' brand, or would Ford and Chevy?
  8. Ah-1 Cobra Pilot

    Century III Autopilot

    I just returned from a trip to Texas. On the way down, my autopilot functioned flawlessly. On the way back, it would go in the correct direction and hold altitude properly, but it would constantly swing back and forth through the course, sometimes using over 30o of bank. There was a heavy rain on Friday with the plane outside, so I wondered if that contributed. I also just talked to my favorite avionics technician who said the pins in the C-III loosen a bit too often. He suggested I unplug and replug the pins, as that can produce a better contact, and that the connections from the VG are the most likely culprits. Has anyone else had experienced the same malady? What is the most efficacious fix?
  9. I hate to tell you, I am out. I made more than I thought people would want so I could have a spare set, but I do not even have that anymore. I guess I should make another batch.
  10. That sure is a beautiful panel, except for those ugly-ass switch covers!
  11. Ah-1 Cobra Pilot

    Weekend commercial pilot courses

    I started training in a Piper Arrow. The Power-Off 180os were easy; pull power, count to three, and start your turn. I finished training in a C-172, which I had a hell of a hard time getting right. Hitting a 200' touch down spot is not all that easy without practicing it...lots. I have never tried in my Mooney, because I do not want to cut the power so abruptly.
  12. Ah-1 Cobra Pilot

    Weekend commercial pilot courses

    Is closing the throttle from a power-on condition in flight bad for an engine, especially one with a turbocharger?
  13. Ah-1 Cobra Pilot

    Weekend commercial pilot courses

    One of the required Commercial maneuvers is the Power-Off 180o. I was always told that was a bad thing to do to turbocharged engines.(?)
  14. Ah-1 Cobra Pilot

    Weekend commercial pilot courses

    A long time ago, I went to a weekend course to get my multi-engine private and instrument add-ons. Last year, I added my single-engine Commercial to my multi-engine ATP rating. I used a semi-local flight school, and it took me about a dozen flights to finish it. Since it had been so long since I went through VFR-type training, I felt it was a GREAT refresher! I have routinely trained in instrument operations for decades, but practicing the VFR maneuvers has increased my skills more than I thought it could. I doubt I would feel that way if I had got my SE COMM through a short course.
  15. Ah-1 Cobra Pilot

    Flying with guns?

    It might be where I live...I often see people carrying soft-sided shotgun cases at airports, (during hunting season, at least), including ones with limited ramp access. They are often wearing hunter orange, too. I have never seen anyone care, other than to ask what they are hunting.