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Mike Koerner

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About Mike Koerner

  • Rank
    Senior Crew Member

Profile Information

  • Location
    Palos Verdes, CA
  • Interests
    flying, soaring, sailing, climbing
  • Gender
    Male
  1. DYNON 120 EMS WANTED

    Great. Thanks for figuring this out Paulo. I have one of these voltage stabilizers on order. Mike Koerner
  2. DYNON 120 EMS WANTED

    Paulo, Thank you for your post and message! It is wonderful that you no longer have the Flydat shutdown during engine cranking and restart afterwards. Your automotive solution is ingenious. But just to make sure I understand... After the engine starts how long does the "Service" warning stay on? Is it still on for 30 seconds? Or can you reduce this to zero by turning the switch on, waiting the 30 seconds until the "Service " warning goes off, and then starting the engine? In that case do you still see the "Service" warning after engine startup? Mike Koerner
  3. GRS Parachute Failure

    This video is instructive. I assume the BRS in our CTs works similarly. Prior to deployment the aircraft is in forward flight, with its weight on its wings, at an altitude of perhaps 200 feet. The chute deploys directly behind the aircraft. Forward flight ends abruptly. The plane stalls... and falls. It accelerates quickly with the nose aimed straight down at one point and very little vertical restraint from the chute as it swings from a position in front of the chute to underneath it. It takes time for the chute to subsequently decelerate and stabilize the plane. In fact, though there was no injury here, it looks like from a slightly lower altitude there certainly would have been. The chute manufacturer points out that he is below the safe deployment altitude. Yet my CT manual says: "In an emergency, the parachute system should be activated even if at a very low altitude." I guess it's a question of the nature of the emergency. If its catastrophic, you might as well pull even at 100 feet, though I wouldn't necessarily expect a better outcome. Certainly the guy in this video, who used the chute out of concern over the integrity of his nose gear, should have pulled from at least a couple hundred feet higher... if at all. Even flipping over on landing would have been less traumatic than this. And there is always the potential for the parachute to fail to open completely. A streamer, in jumper parlance, with no way to cut away would be the worst of all worlds. Mike Koerner
  4. CTLS landing for beginners

    Tim, Try this: Push the plane onto a taxiway so its lined up with and on the center line. Get in and position yourself so you are sitting normally in the pilot seat. Find the spot on the windshield which, from your eye position, lines up with the point where the center line would meet the horizon. Put a small piece of colored masking tape on the inside of the windshield at that position. The next time land, during your flair, try to keep that piece of tape just above the the far end of the runway. You'll be lined straight and at a reasonable attitude as well. Mike Koerner
  5. Wingtip Repair

    Andy, Did you have your pipes wrapped at the time of failure? Mike Koerner
  6. Most of us on this side of the pond are probably going to miss this fly-in CT2k. Let us know how it goes... and good luck in the "Greatest Life Experience" competition (???). Mike Koerner
  7. -6 has best ANGLE of climb - debate resolved IMO

    Ed, It's not always aerodynamically "dirty" to have the flaps down at 15 degrees, and certainly not at zero. At low speeds those are the lowest drag (best L/D) flap positions. To climb steeply, you need low speed. Please do not construe my lack of further discourse on this subject as concession. I'm merely trying to budget my time so as to concentrate my efforts on more constructive activities. In this case, cleaning out the cat box is the obvious choice. Mike Koerner
  8. Climbing at -6 degrees vs 0 degrees?

    Ed, I never said flaps change the cord. Our flaps don't. Fowler flaps do. If you leave the flaps up at low speed you are generating additional lift, so as to equal weight as you say, by increasing the angle of attack. That's not the optimum wing profile. Furthermore, the fuselage will not be faired optimally. Mike Koerner
  9. Climbing at -6 degrees vs 0 degrees?

    Ed, Doug, I think there's a simpler way of looking at this (I certainly hope there is): For every indicated airspeed there is an optimum flap setting. If you flying around 90 knots or faster, you ought to have the flaps up. Slower than about 65, lower them a notch. In between, leave them faired at the zero setting. (These are just approximate speeds. The actual optimum flap position transition speeds vary a little with aircraft model and gross weight.) So, if your cruise climbing at high speed you should have the flaps up. If your're trying to climb steeper, at a lower speed, set the flaps accordingly. Remember too, that drag goes up as the square of speed. Your engine has to work hard to make you go fast. At the limits of aircraft performance (high speed, high gross weight, high altitude, etc.) you will have to slow down to climb. When you do, set the flaps accordingly. Mike Koerner .
  10. Oil Temperature runs high on climb out . . .

    The wrap inhibits convective and radiant heat transfer from the metal outer surface of the pipes to the surrounding air and the surrounding structure respectively. Those are the results you wanted. But as a result of reduced heat transfer from the pipes, the pipes themselves get hotter. that means more heat is conducted back through the mounting flange to the head. That is a result you don't want. So, the question is, which effect wins. The heat transfer coefficients for convection and radiation are much lower than that for conduction... favoring unwrapped. However, delta-T plays an equal role. The temperature difference between the pipes and the surrounding structures is much lower with wrap than without, while the temperature difference between the pipe mounting flanges and the heads will only be slightly greater with the wrap... favoring wrapped. There is insufficient data for a definitive answer, and testing would be both easier and more accurate than a thorough analysis. However, I am swayed, slightly, toward unwrapped pipes by the fact that there is, I believe, significant air flow through the cowling. This forced convection will essentially negate the convective heat transfer from the pipes to the surrounding structures, leaving only the radiant effects to counter conduction. As I said, I would expect (maybe guess would be a better word) that the difference is probably not a significant, or even measurable. Mike Koerner
  11. Back to Yosemite - smoky morning - normal lens

    I don't think the smoke hurt these at all! It doesn't look like smog. It's just an added interesting effect. Mike Koerner
  12. Oil Temperature runs high on climb out . . .

    I would expect an increase in oil temperature... though probably not a significant or even measurable amount. Mike Koerner
  13. Let's talk about grounds. Again.

    Corey, Thank you for explaining this. Mike Koerner
  14. So long Flight Design......

    Ed, The LSA market is about more than just relaxed medical requirements. The manufacturers don't have to certify the aircraft to normal FAA standards. That saves millions of dollars on each model and makes the planes affordable. If a manufacturer abandons the LSA rules - either with greater than 120 knot cruise speed capability, constant speed props, or max gross weights over 1320 lbs. - they will have to certify their planes... Which drives up the cost... and reduces the market. It's up to us, instead, to convince the FAA: 1) That 145 knots is no less safe... because we get where we are going faster and thus arrive with less fatigue and better mental acuity??? 2) That constant speed props are no less safe... because they are more efficient and thus produce fewer polluting emissions which will eventually kill us all??? 3) That higher gross weights are no less safe... because they make it easier to land safely in gusty wind conditions??? Good luck with that. Mike Koerner
  15. 10th Annual Page CT and Light Sport Fly-in

    Tim, You're going to scare people away from the fly-in. That's a thunderstorm. It happens all over the country - no more common out west than in the south. Mike Koerner
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