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Mike Koerner

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Everything posted by Mike Koerner

  1. Mike Koerner

    Altimeter Check

    Middle Pal and Norman again, from north of Big Pine Creek. Mike Koerner
  2. Mike Koerner

    ELSA possible fuel flow fix???

    Once again, I agree with everyone… except Ed flying around with one tank empty. I can't conscience that (Did I use that word right?). In a 172; sure, but not in a CT. But other than that: Yes, we have plenty of fuel capacity (unless you want to go really, really far). Yes, prolonged (as in a few minutes) porting of the tank with fuel is the issue (if the other tank has no fuel or has been shut off). Yes, you can just fly coordinated all the time. (I certainly try to... to the degree that it’s not an encumbrance on my flying enjoyment. But that doesn’t necessarily mean your wings will drain evenly. Apparently, differences in total pressure recovery by the tank vents and fuel plumbing restrictions tend to favor one wing over the other.Variations in the mounting of the slip indicator instrument, the ball, may also play a role.) Yes, rocking your wings every so often will address the issue if one of the sight gauges is showing empty in coordinated flight (but make it an uncoordinated rock, just using the stick for example. Better yet, just keep some fuel in both sides, then you don’t have to worry). Yes, you can rock the wings in the pattern (but with the power back there should be more than enough fuel in the lines to get you around the pattern. And again, there is no need to worry as long as there’s fuel showing in both sides. Also, the fact that the pattern turns are all the same direction doesn’t matter as long as the turns are coordinated. In a coordinated turn the fuel thinks you’re flying straight and level, just like the ball.) Yes, we are overthinking this (It only matters if you’re trying to eek out the last bit of distance with nearly empty tanks). Yes, that should not happen with 34 gallon capacity (and any semblance of planning). Which reminds me of a fuel stop at Northway in 2006. They didn’t have any, and apparently they hadn't in a long time. Of course, the neat thing about a CT is that I could just have someone drive me into town with my jugs to get auto fuel at the gas station. Only, it was getting kind of late in the afternoon and I wanted to get to Fairbanks. I don’t remember what calculations I made or what incantations I uttered, but I took off from a planned fuel stop with no added fuel anyway. It’s amazing how remote and completely unlandable that stretch is (except for the highway), especially when your watching your sight tubes every few seconds. I hated balancing out the fuel because it meant flying uncoordinated and I really wanted to fly as efficiently as possible. I made it anyway, with plenty of fuel still showing in both sides. Mike Koerner
  3. Mike Koerner

    CTSW flying @ 22 below zero!

    Thanks Ed. I would never have guessed any of those. I'm glad I didn't spend more time trying. Mike Koerner
  4. Mike Koerner

    ELSA possible fuel flow fix???

    My post made it sound like I don't like alerion and rudder trim or autopilots. That's not the case. My CT didn't come with these features, but I wish it had. And though they could exacerbate the fuel starvation due to uncoordinated flight condition, they could also make it a lot easier to hold the ball over to one side for a while. Mike Koerner
  5. Mike Koerner

    500fpm, 60 knots, 15 degrees flaps

    "Most of the time, with just a little rear wind (on downwind), it takes a long time to start losing altitude." Let's change this to, "...it takes a long distance to start losing altitude". The wind doesn't hold you up. It just pushes you further along. Mike Koerner
  6. Mike Koerner

    CTSW flying @ 22 below zero!

    I don't know any of these.
  7. Mike Koerner

    Mactan Cebu to Sicogon Is

    Maybe if we all got together, bought an old derelict freighter, put a level deck and a weather station on it, and parked it half way to Hawaii... I think that would open up the rest of the world to us… Hawaii, the South Pacific, the Philippines, New Zealand, Australia, and beyond… And Cdarza could visit us here. Mike Koerner
  8. Mike Koerner

    ELSA possible fuel flow fix???

    Indiana, I agree with everything said here... but I don't think anyone mentioned the most important thing (or directly answered your question): Unless your aircraft has a header tank with a low fuel level alarm, shutting off one of the tanks in flight is unsafe because of the risk of fuel starvation resulting from subsequent, sustained, uncoordinated flight with the ball toward the active wing. This applies whether the shutoff device is at the wing root or is a right-left-both fuel selector valve in the console. This issue is somewhat unique to CTs in that their wings have very little dihedral (this is not an issue at all in a Cessna, for example). As a result, the amount of miscoordination involved is relatively minor. Momentary miscoordination, such as in turbulence, or short duration miscoordination, such as in a distracted turn, is not an issue as the fuel system plumbing between the tanks and engine has some significant fuel capacity. But the issue is exasperated in cruise during calm conditions in an aircraft that has rudder and alerion trims, or an autopilot, in that these devices may allow a sustained uncoordinated condition. Hand flying or turbulent conditions mitigate the risk by adding a degree of randomness which may intermittently interrupt the sustained uncoordinated condition and refill the fuel lines from the wing toward the ball. Shutting off one of the tanks is just like letting one run dry. Unless you conscientiously keep fuel at the wing root of the other wing, you risk fuel starvation. The best approach, of course, is to keep at least a little fuel showing in each wing when the ball is centered. This is not much of an inconvenience. After 4 or so hours of flight you center the ball a check the amount of fuel in each wing. If one is low, move the ball a little bit (Roger says half a ball) toward that wing and fly like that for a while, returning the ball to the center to check your progress every few minutes. Once both wings show sufficient fuel, go back to flying as you were and check them again in another hour or so. In this manner you can run both tanks down to where just a tiny bit of fuel is showing in each sight tube when the ball is centered. In my plane I think this still leaves a least a gallon and a half in each side. If l don't see fuel in both sight tubes with the ball centered, I am already on the ground (I have never let this happen). Mike Koerner
  9. Mike Koerner

    3 Sierra Nevada Images from my CTSW

    Awesome indeed! You must have taken off at first light to get down there before the sun rose over the Inyo’s. Backup and pan right a little on the second photo and you might convince the new McCoys to change the background on their ski map. And the last is Middle Pal and Norman Clyde? Mike Koerner
  10. Sport, You may be thinking of 14 CFR 91.327 (a) which prohibits aircraft having a special airworthiness certificate in the light-sport category (S-LSA) from operating for compensation or hire except to tow a glider or an unpowered ultralight or to conduct flight training. Or you may be thinking of 14 CFR 91.319 (e) which prohibits aircraft issued an experimental certificate from operating for compensation or hire except to tow an LSA glider or to conduct flight training. Or you may be thinking of 14 CFR 61.315 (c) which prohibits a Sport Pilot (the person - not the aircraft) from operating an aircraft for compensation or hire, or in furtherance of a business. This last is a bit more restrictive. Mike Koerner
  11. Mike Koerner

    ADS-B out / TailBeacon installed

    Bozo, I don't think your Garmin transponder is sending either a Blue Tooth or wi-fi signal to your uAvionix's unit. Most legacy transponders don't have such capability. Instead, uAvionix uses its power lead to "read" the transponder transmissions. The 978 MHz UAT system uses a digital radio signal. It's a sequence of pulses, each of which causes a slight, but detectable, dip in the aircraft's bus voltage. This was uAvionix's brilliant way around a Garmin patent which prevents other ADS-B manufactures from using transponder transmissions. Mike Koerner
  12. Mike Koerner

    Kona, Hawaii fly in

    Duane, When you say Barbers Point do you mean Kalaeloa (Rogers) (JRF)? Are you based there? Why do Hawaiian airports have both 3 and 4 letter identifers? How many CT's are based on the islands? Mike Koerner
  13. Mike Koerner

    Page Fly-In 2019 - check out this place...Bar 10 Ranch

    I carry empty 6-gal and a 5-gal plastic gas jugs (together they actually hold 12 gallons), a light-weight folding dolly and a light-weight folding step stool whenever I go cross-country. Mike Koerner
  14. Mike Koerner

    Page Fly-In 2019 - check out this place...Bar 10 Ranch

    Olav, If you let them know in advance, I think the Bar 10 Ranch would make you a real fine breakfast or lunch, though it might be a bit expensive. I've flown into the Bar 10 airstrip, but I have not been up to the ranch house. My reason for landing there was based on the wording of the Grand Canyon special flight rules. As long as you're landing or taking off from an airport within the area you have permission to transition through it. You get nice canyon views from areas that would otherwise be prohibited. Amazing how poor my climb performance was on the way out. I have landed at Marble Canyon after each of my Page outings for the same reason, but also because there's unleaded fuel available across the street. Mike Koerner
  15. Mike Koerner

    A Good Day

    Congratulations to your son. I think starting out in sailplanes is a real good approach. It emphasizes stick and rudder skills and provides insights into airmass motion and aircraft performance that I think some power-only pilots lack. And of course, it reduces the sense of dependence on the engine. Aircraft fly perfectly fine without them. If yours goes out you don't crash and burn like in the movies, or even panic. You just land on what’s available, like Buckaroo’s alfalfa field. Or, in the rare case where the terrain within gliding distance is unlandable, pull the chute. Mike Koerner
  16. Mike Koerner

    No Cabin Heat-SOLVED!

    Thanks Roger! Nice photo Ed!
  17. Mike Koerner

    No Cabin Heat-SOLVED!

    I flew to Denver a couple weeks ago with my wife and nearly froze some of her parts off. The outside air temp over Wolf Creek Pass was in the teens. the cockpit temperature couldn't have been much warmer as, all of the sudden, the heater was not providing its usual warming for the sides of our ankles closest to the pedestal. Incidents like this make it ever harder to get my wife to go with me. So when we I got home, I took a close look at it. The diverter plate in the heater valve box (officially called the "cabin heater choke") was only swinging forward a tiny bit from the closed position. Long story short; one of the fasteners that hold the box in place had loosened enough that the head was standing proud from the bottom of the box. The edge of the diverter plate was catching on it. I could have saved a lot of work by just sticking a small Allen wrench down into the box and tightening it, instead of taking the whole thing apart. Keep this in mind if you suspect you may have the same problem. Mike Koerner
  18. Mike Koerner


  19. Mike Koerner

    What triggers a "Generator" warning light

    Mechanical generators are alternators at heart - they first convert rotation into an alternating current. Generators then "rectify" that ac current into direct current with diodes that block out the reverse pulses (or, more recently, by active switching). If the rectifier is integrated in the same package as alternator, that device should certainly be referred to as a "generator". Ours is not. The Rotax 912 engines have an internal “magneto ring” of permanent magnets rotating around a stator assembly with electrical coils. The electrical pulses from these coils are used to charge capacitors in our ignition units, to time the ignition pulses to our spark plugs and to provide power to our electrical systems via our voltage regulators, which are also rectifiers. The pulses from the electrical coils are alternating current and magnetos are considered a type of alternator. So, you’re right, we have an “alternator”. However, the Rotax Operator’s Manual refers to it as an “integrated generator” and certainly when referring to the overall circuit, including the rectifier, it should be called a generator. As Corey explained, our GEN warning light indicates if the dc output voltage from the voltage regulator is lower than the battery voltage. It doesn't know if the problem is with the alternator, the voltage regulator / rectifier, or the wiring in between. In this case, I think it's appropriate to call in a “generator” warning light. Mike Koerner
  20. Mike Koerner

    Handiflight around the world with 2 CTLS

    Thanks Cluemeister. The 4 in the foreground normally means there's 4000 feet of runway remaining in that direction. It sure looks like he's closer than that. The camera is zoomed in though, so maybe it's an illusion resulting from that. Obviously I"m wrong anyway. There's no arguing with broken wires. Mike Koerner
  21. Mike Koerner

    Handiflight around the world with 2 CTLS

    I share the sadness expressed by others here and add my condolences to family and friends. Duane, Cluemeister; I don't see this as a problem with wires. From the video the approach looks steep enough to avoid them. It looks like the aircraft may have crossed over the end of the field before departing from a stable approach. At that point he is certainly well inside the high-tension power lines and probably inside the railway wires as well. Mike Koerner
  22. Mike Koerner

    Power percentages

    Warning: Long and unnecessesary I would like to take this opportunity to apologize to my junior high math class. I sat in the back corner of the room and every time the teacher asked a question I jumped up and shouted out the answer. The teacher would say, "Mike, let's give someone else a chance to answer". But I kept doing it anyway. I don't think that was particularly helpful for my teacher, or for the other students in the class for that matter, some of whom were probably struggling with the subject and may have decided right then and there to avoid math forever after. But I couldn't stop myself. And I can't now either. Sorry Monkey. To say something is proportional to something else only indicates that there is some constant which when multiplied by the one will generate the other. It says the two curves have the same shape. It makes no claim that the absolute values are the same. You shouldn't worry that the cube of engine rpm is a big number. That doesn't affect proportionality. In fact, if delivered power is proportional to the cube of rpm it is also proportional to the cube of rps (revolutions per second). You can divide all the rpms by 60 before cubing them and have much smaller numbers to deal with if you like. A cube curve looks something like an aerobatic pilot pulling up into a hammerhead stall. 2 becomes 8. But increase it by just one more and 3 becomes 27, then 4 becomes 64 and so on. It’s climbing ever quicker. A cubed root looks something like instrument pilot approaching his assigned altitude. 125 becomes 5. Increase it by 1 and 126 is still almost 5. In fact, you have to increase it by 91 just to get up to 6, and then by another 127 to get to 7. It’s leveling off. When you double your rpm do you expect 8 times the delivered power (2 cubed), or just 26% more power (the cubed root of 2)? The cube curve makes more sense (though personally, I would have expected delivered power to be proportional to the square of rpm, just as the lift or drag of our wing is proportional to the square of airspeed). To determine the proportionality constant you need only look at the value at one point. For example, we expect our props to deliver (absorb) about 100 hp at 5800 rpm. So we cube 5800 and then ask what constant we can multiply that by to give 100. The answer is 100 divided by the cube of 5800, which is 5.13E-10 or .000000000513: 100/5800^3 = .000000000513 Cube any rpm Roger gave and then multiple that by this coefficient and you get the delivered power he gave: 5800^3 x .000000000513 = 100 5000^3 x .000000000513 = 64.1 Alternately, you can just take the new rpm, divide it by 5800, cube the quotient then multiple that by 100. (5000/5800)^3 x 100 = 64.1 This is doing the same thing with the proportionality constant built in so you never have to see any big numbers. Mike Koerner
  23. Mike Koerner

    Power percentages

    Roger, This is useful information. Thanks. One small correction: The word "root" should be stricken from the 5th and 6th lines. The calculations shown are based on delivered power being proportional to the "cube" of rpm, not the "cube root". Cube root doesn't make any sense - we would get almost the same power at any rpm. By the way, I think you're right that the ROTAX power curves assume a wide open throttle and an engine loaded to achieve the specified speeds. As you point out, if you pull the prop off it certainly won't generate anything close to 100 hp at 5800 rpm. Mike Koerner
  24. Mike Koerner

    Both tanks (sight tubes) dry - 12 miles from field

    Dick, I did a test something like yours as part of a sight tube calibration years ago. I believe my engine idled for 20 minutes on the ground after the last fuel was visible. Warning: Your mileage may vary. My idle is only about 1600 rpm. 20 min at idle is very little time at power. You should not depend on this as a fuel reserve. I am always on the ground before either tank shows empty in straight and level flight. I don't believe anyone else should be flying around with an empty tank either (though Ed can do whatever he wants). Mike Koerner
  25. Mike Koerner

    uAvionix skyBeacon for ADS-B Out

    Andy, Sorry to respond so late to this... You don't use wire nuts on a aircraft. you need to crip the wires together. Mike Koerner