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Mike Koerner

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About Mike Koerner

  • Rank
    Senior Crew Member

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  • Location
    Palos Verdes, CA
  • Interests
    flying, soaring, sailing, climbing
  • Gender
  1. 406 ELT Antenna Installation

    Hatter, 1) The instruments in the panel are not really in a cage. The signal is probably coming in from under the panel. 2) Testing the GPS receiver in the fuselage is a neat idea. You might need to roll the plane around a bit though, to make sure it is really tracking and not just accepting the last known position as good enough. 3) Putting a transmitter in the fuselage is a really great idea (again, transmission is much more challenging than recieving). 4) I would also be interested in hearing what you learn from the ELT manufacturer. 5) Yes, 121.5 is no longer used at all as an indication of an emergency. The FAA has made this very clear for years. But it is still used by the search and rescue folks to pinpoint your location as they close in on you. This may be significant if you don’t have the GPS interface to the 406 MHz signal - which is a more effect pinpointing system. 6) A more touching story than that of the MKS man you mention is that of young Carla Corbus who survived 54 days after a plane crash in mountains of Northern California. She kept a diary detailing the eventual deaths of her father and mother and her anguish and anger that no one had come to rescue her. Her remains were found by a hunter 6 months later. Her story, widely published in 1967, resulted in the FAA mandate for ELTs. Mike Koerner
  2. 406 ELT Antenna Installation

    Hatter, I believe the carbon fiber composite will act as a faraday cage and greatly reduce the ELT signal propagation if the ELT antenna is placed inside the fuselage. You are correct that some carbon composites have a metal mesh impregnated into them and that ours does not, but the intent there is lightening protection. The carbon fibers can't carry as high a current as copper, but I don't think they need to to effectively attenuate your transmissions. As for your experience with the GPS signals getting through to the instrument panel, I think there may be several factors at play which do not fully apply to the ELT: 1) There is a big hole in the carbon fiber structure for the windscreen, which lets radiation into the cockpit. Not so much for an antenna placed behind the rear cabin bulkhead, which is also carbon fiber. Yes, there are a couple holes in the bulkhead too, but they are mostly blocked by carbon-fiber seats - not much help there. 2) I believe it's a lot easier to get reasonable reception with a partially shielded antenna than it is to transmit with it. Receiving is all about signal-to-noise ratio. Transmission is about pumping out power. 3) Modern GPS receivers are adept at using very weak signals. We are able to use them in are cars (which also have holes in the faraday cage) and houses. Part of this is that they are digital which allows them to use algorithms to fill in missing bits of data. The 406 MHz portion of the ELT signal is digital too, but not the 121.5 MHz portion. Still, I think you would get much better GPS reception, and at least quicker initial fixes, if you use a remote GPS antenna placed on top of the glare shield (which is also carbon fiber) rather than under it. The disclaimer here is that I do not have a degree in antenna design… but I know someone who does (my brother) so if any of this sounds intolerable wrong or in need of further clarification, I’ll forward the issues to him. Bill, As the ELT manufacturers recommend, the best place for the antenna is on top of the fuselage. In the scenario you describe, activating the unit while coming down under chute, you need the signal to be propagate upward. If it does the MEOSAR Satellites will instantaneous detect you 406 MHZ signal and establish your location, even without the GPS output data (which further refines the location). They will know where you are and that you intend to crash before you ever reach the ground. Not so much if the antenna is underneath the plane. Also, though many of our off-field landings and runway excursions end with the aircraft flipped on its back, these seldom result in serious injury. I think you will be more in need of rescue after a steeper angle impact, such a stall-spin accident, where I think the plane is more likely to end up with its top side more or less up. Having said this, I must also admit that I recently installed a 406 MHz ELT myself and have not yet gotten around to relocating the antenna. However, it is on my seemingly infinite list of things to do, all of which I would like to finish before I crash. Mike Koerner
  3. Door Lever Guide Plate

    ib, Please post photos of the finished part and let us know how it holds up after a few cycles. I'm real interested in how it turns out. Thanks, Mike Koerner
  4. Flaps and stab question.

    Cap, My CT2k flaps creak a bit if I lower them toward the upper end of their allowable speed range. If I slow down a bit more first they're quiet. I don't use them to adjust the approach. I decide on downwind how much flap I'm going to use and adjust the approach with a forward slip if needed. Mike Koerner
  5. Tail tie down strap

    Doug, Tying down the wings is not an option for me. I don't have a hard point on the wings and FD wouldn't let me add them. Tying to the control hinges is a no-no. Throwing a strap over the top of the wing would surely damage the tailing edge control surfaces. I considered feeding an over-wing strap into the slot in front of the control surfaces, but it's not a straight path and would still load the control hinges. I could rig something to the tip but it's not structural. That leaves building a padded rigid frame that fits over the wing which would be hard to carry. Yes, a very strong crosswind can lift a tip. I try to tie the plane into the wind. If the winds sift I am hopeful they do so gradually and believe that in such strong winds the plane will weathervane about the nose tiedown, scuffing the tires as rocks from main to main. Again, assuming no obstructions within my turning radius. This is all still theoretical. I haven't had it out in a hurricane yet... though the FBO at Elmira claimed the winds got to 50 knots last weekend before they decided to move my plane into their hangar. Mike Koerner
  6. EGT question for the experts?

    Another use for EGT is to indicate when the pilot has done something incredibly stupid. Starting off on a trip to New York last week I had less than 150 rpm drop on either side during the "Mag" check. However, incredibly, I left the ignition switch in the "Left" position instead of returning it to "Both" after the run-up. It is difficult even for me to believe that I did this. Normally I count the switch clicks back and forth and never take my hand off the key until its back on "Both". Lame as it sounds, the only excuse I have is the distraction of a P-51 in the runup area. I was rushing to take a couple pictures and still get out in front of it so as to avoid getting blown over when he turned toward the active. Anyway, the first indication was rough idle performance. I had to nudge the throttle forward to keep the engine running at the runway hold line. Any reasonably prudent pilot would consider this reason enough to abort but I had just successfully completed the run-up, demonstrating takeoff power, and so was on my way. 18 minutes later the "Caution" light started blinking along with one of the four EGT readings on my FlyDat (an old-style engine instrumentation system). I pulled the power back and returned to my home field. It wasn't until I shut the engine off that a realized the problem. The highest EGT temperature I saw was 1660F right before I pulled the power. Though this is above the 1616F limit the engine was still operating normally and sounded fine so I started it back up, repeated the run-up and headed on my way again with no further anomalies for the duration of the trip. Mike Koerner
  7. iFly 740b Install

    So.. It wasn't a virtual ramp check then huh? Mike Koerner
  8. Tail tie down strap

    The CTSW and CTLS have wing tiedowns. My CT2k doesn't. I didn't get the tail strap either. I asked about adding wing tiedowns after that fact (I think I could have come up with a fine set) but my LOA request was rejected by Flight Design. Since then I've come to appreciate what I have. With a light wing loading like ours, the important thing is to keep the nose down. Wing tiedowns do a poor job of that, especially if they are tied straight down. The ground end is too close to the axis of rotation about the main gear - they have no leverage. Chain the wings down tight and then have a couple big guys straddle the narrow part of the tail and you'll probably snap the wing tiedowns off. Instead I carry short nylon sling with a carabiner in my foot locker. I park with my nose over one of the ground rings. I wrap the sling around the lower cross bar on the frame that holds the engine mount and nose gear to the fire wall and clip the biner directly to the ground ring. My strap and biner can carry many times the weight of my aircraft; and that cross bar probably can too. I think my setup up can survive with any two members of this forum on riding the tail... but I wouldn't want to try. The goal is not to come up with a new rodeo game. Its to keep the angle of attack of the wing as low as possible, which keeps the plane firmly planted on the ground. I think my setup can ride out a hurricane - as long as there are no obstructions within my turning radius and no trees, mobile homes, hangars or other aircraft upwind of me - but again, I wouldn't want to try. Mike Koerner
  9. Never seen these before, comma clouds?, sperm clouds?

    It has a roof pendant (different color rock on top) like Split Mountain but its not spiky enough (no split) and the background is all wrong.
  10. Never seen these before, comma clouds?, sperm clouds?

    Wow Ed. This is one of your best pictures. The clouds make it all the more interesting. Another neat thing is the way the sunbeams (shadows actually) converge in the distance, even though the sun is behind you. I've seen this before. Its hard to wrap your head around: sunbeams radiating from the sun and also toward a point on the horizon 180 degrees away. I've spent a couple hours now trying to figure out where this it. It looks familiar, but I can't put my finger on it. The valleys or canyons both to the right and left of the peak are confusing. Mike Koerner
  11. John,

    I'm sending this to you privately (I think) since my plane is still S-LSA.

    I put flap fences similar to what's on the CTLS on my CT2k. I cut them out of a plate of aluminum.

    I did it to improve performance during negative flap operation. Even though I have no way of measuring the results, it seems obvious it would help. Sailplanes have been doing this for 50 years.

    It may have also reduced the elevator bumping, but I'm not sure. I don't notice it now... but I really hadn't notice it recently either. Maybe I had just got used to it.

    I just realized I don't have a photo, but they look just like the ones on a CTLS. 

    Mike Koerner

  12. What I've done is a bit more rudimentary: Set a cinder block (or some such similar sized object) behind the main gear stub, lift up on the underside of the wing by hand (preferable along the spar and well outboard), walk back a step such as to pivot the plane around the other main gear (and drag the nose) until the axle gear stub is over the block, then set it down. Mike Koerner
  13. Grand Canyon Corridors

    I fly allows you to pick the chart you want to use too. It's this button: along the lower left side in the image provided by rtk above. Normally, iFly picks the chart that makes the most sense for the zoom setting you have selected. If you are zoomed way out it picks the World Aeronautic Chart (WAC - 1:1,000,000 scale). If you are zoomed way in it chooses the Terminal Area Chart (TAC - 1:250.000 scale). In between. of course. It picks sectional charts (1:500,000 scale). This insures the text is not too small to read or absurdly large. But to a limited degree, it also allows you to override its selection. That's where the chart selection button shown above comes in. This button also allows you to see the legends on the charts, if desired, or the VFR routing on the back of some terminal area charts. Note that the Grand Canyon Special Flight Rules Area chart is labeled as a TAC chart even though it does not include a class Bravo air terminal. It just happens to be the same scale so iFly calls it a TAC for convenience. Mike Koerner
  14. Drip Tray and the new cylinderheads

    To my admittedly untrained ear that does not sound like its coming from a gearbox. It sounds like the spinner or prop flange is catching on the edge of the cowl. Mike Koerner
  15. Foot rest

    Exactly the same with my 2004 CT2k - I notched the inside edge to clear the heater vent. But all of my non-flying passengers love this foot rest. Thanks Al. Mike Koerner