jlunseth

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jlunseth last won the day on July 6 2015

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About jlunseth

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  • Gender
    Male
  • Location
    KFCM
  • Reg #
    N381SP
  • Model
    M20K 231
  1. Happy Thanksgiving

    My favorite holiday, because my family comes to my house. Our house and our hearts will be full today. I hope that is so for everyone of you.
  2. mixture issue

    The other possibility to check out is your fuel control. It is not common, but the controls have been known to fail or jam.
  3. mixture issue

    Hi Aaron. "tit hottest cyl" doesn't make sense. There is only one TIT and it is not measured at any cylinder, it is Turbine Inlet Termp., its measured at the turbo. I believe you are thinking of Engine Gas Temp, EGT can be measured at each cylinder, so you can have a "hottest" and "coolest" EGT. The engine driven fuel pump is a very good possibility for your problem.
  4. PS the other sort of weird oil issue is when did you check it. I can't tell you how many guys have expressed concern to me about their oil usage, they checked it before they flew, did a short flight, then check it after and it is down a quart and a half!! What do I do??? Well duh. For those who don't understand what I just said, and I hope there aren't any, the oil settles out of the engine when it sits, and your highest oil level will be before the engine is started. It only takes seconds for that "extra" oil to get pushed into the engine and voila, you are "down" a quart. Patience with new owners, we were all one once.
  5. Well here's my story. When I first got my 231 it consumed a fair amount of oil. Let's say 1 qt. in 10 hours, although it has been so long that I don't really remember with exactitude. I asked the same question, what is normal. I heard all the normal explanations, its a Continental, the cylinder seal is not very tight, its normal etc. It got to the point where I would use a quart for a long trip, say 4.5 - 5 hours, still was told that's just normal. We had some small leaks, mostly rocker covers. Then I had an incident which I have written about here, where we blew almost all the oil out, resulting in an emergency descent to landing in Can. A small piece of plastic had gotten lodged in the quick drain, there was virtually no evidence on the ground, but in the air with the engine running and pressurized, we were blowing oil out. Within a couple of years I had the engine IRAN'd, and all the small leaks were fixed. It used to be normal to have a number of chafe leaks at the top of the cowling. I still get one occasionally, but not much and not big. Now it is normal to go through an oil change cycle of 20-30 hours without adding oil, and if I am flying alot and go 40-50 hours between oil changes, I might need to add a quart. Now, during that cycle the oil level will have dropped a quart or so. That's about what I use now, 1 qt. per 20 hours. I have heard all that "stuff" about oil usage, and certainly the old radial engines burned through alot. But I no longer buy the idea that a quart in 6 or 8 hours, or even 10 hours, is normal. Maybe on a different type engine than my TSIO360LB it is normal, but if I get to that level again I will be looking for the problem in the engine.
  6. mixture issue

    Also would help to know your power setting (MP, RPM and fuel flow), and what the TITs actually were.
  7. What is this device in the tail?

    If you re-weigh, I guarantee the little things will add up to 250 lbs.
  8. Low oil Temperature

    My thought is the one mentioned earlier - that the engine runs too cool to heat the oil up much. The giveaway is CHTs in the 300 range. Just to be clear, I take it that means what it says, the CHTs are around 300 and not up around 350-380. If your OATs are in the 20-30 range, not of it seems abnormal to me, except you might have some trouble when winter gets really cold. I have a K, there is no minimum redline OT, but there are warnings in the POH to keep OT above 100. Our problem is different though, we need oil thin and warm enough to cool the turbo bearings. The oil cooler block several people have mentioned has always been the best solution for me, my A&P made up one from pieces of open cell foam taped together which is then stuffed in the cooler. Works good, and you actuallly get some heat off the heater to keep the cabin warm during the winter. Unless of course you fly in the flight levels and the OAT is -50 F. That is a different story. I just don't think you have anything wrong except a very cool running engine.
  9. What is this device in the tail?

    Oh that thing. It's your flux capacitor.
  10. On the subject of a legal requirement for the bottom of the white arc, I found CAR 3.82: 3.82 Definition of stalling speeds. (a) Vso denotes the true indicated stalling speed, if obtainable, or the minimum steady flight speed at which the airplane is controllable, in miles per hour, with: (1) Engines idling, throttles closed (or not more than sufficient power for zero thrust), (2) Propellers in position normally used for take-off, (3) Landing gear extended, (4) Wing flaps in the landing position, (5) Cowl flaps closed, (6) Center of gravity in the most unfavorable position within the allowable landing range, (7) The weight of the airplane equal to the weight in connection with which Vso is being used as a factor to determine a required performance. Then CAR 3.757 says: (4) The flap operating range—a white arc with the lower limit at Vso as determined in § 3.82 at the maximum weight, and the upper limit at the flaps-extended speed in § 3.742. I can't be certain I have the exactly right version of the CARs, just not possible to figure that out with what I have.
  11. M20K Fuel Flow

    Yes, and the last Mooney instructor I flew with worried about whether the engine was going to die in the air, if I was leaning it so far it would quit on the ground without more fuel. No, it doesn't. I suppose you could pull it far enough to cut off all fuel, don't do that. Pull it out far enough to smooth the engine.
  12. M20K Fuel Flow

    Yes, I have an intercooler. The 34" is with an intercooler. I use 36-37" for a takeoff setting, so it is a little less than takeoff. You could go even leaner of peak if you set the MP higher, like 36, but I just think that would work the turbo too hard.
  13. There is one. I just don't know if it is the one that applies to your aircraft, or mine too for that matter. They were born under the CARs, but I don't think the CAR's are significantly different than the FARs in these areas. I noticed that someone posted part of the CARs earlier, perhaps someone has them who can verify whether they are the same as the FARs. FAR 1.2 defines Vso as: "the stalling speed or the minimum steady flight speed in the landing configuration." I think that shoots down the issue about minimum steady flight speed that was discussed earlier, I think the reg. says they are the same. FAR 23.1545 says the ASI must be marked: (4) For the flap operating range, a white arc with the lower limit at VS0 at the maximum weight, and the upper limit at the flaps-extended speed VFE established under §23.1511. The landing configuration is going to be defined in the AFM, in mine it is gear down, full flaps. I don't know if that is in a table, it is in the "Normal Procedures" section that describes landing. So the bottom of the white arc is stall speed in the landing configuration. Now, there is a provision that says that the instrument must be accurate +/- 3% or 5 knots, whichever is greater. (23.1323) That would be 1.8 kts at 60kts, so perhaps that is part of the explanation. But I still think it is the fact that landing configuration requires the gear to be deployed, which is different from the bank angle table, which does not say that.
  14. I was taught that years ago during PP training - that gear down lowers stall speed. I will have to go find it in a book for you.
  15. I think I have an answer for you. Bear in mind I am not an aeronautical engineer, I am a damn lawyer, which only means I can maybe think and read, which is what I did. Also, I only read the first couple of pages of this thread, so maybe someone gave this answer in the third or fourth page, if so I apologize for being redundant. I went to three sources: Jeppesen's Commercial/Instrument textbook (big, thick hardcover), Gardner's The Complete Advanced Pilot, and Ecklabar's Flying High Performance Singles and Twins. Jeppesen and Gardner say the same interesting thing. KIAS and KCAS are virtually identical at higher aircraft speeds such as cruise, but separate in high angle of attack, low speed regimes of flight. The pitot tube is measuring pressure, of course, not speed. Ecklabar says this is: "dynamic pressure," i.e. the difference between static pressure and the total pressure the pitot sees. What the pitot sees is essentially what a calibrated pitot measuring device sees ( a tube on an extended boom to avoid interference and compression effects near the airframe) at high speeds. But at lower speeds, because the pitot is fixed, it also is moving through the air at a higher angle of attack, which I surmise reduces the cross section of the orifice in relation to the airflow, and therefore the pitot reads a lower pressure than if it we flat and away from the airframe. So in low speed/high angle of attack situations, CAS becomes more important and IAS becomes less accurate. IAS inaccurately reads the dynamic pressure as lower than it actually would be if the airplane were flat instead of at a high angle. This should tell you a couple of things. One is that you cannot assume that at low speeds the difference between CAS and IAS is a fixed number, like "5 knots." This is the regime of flight in which IAS is becoming less accurate and CAS is becoming more important and the difference is changing. Now, the rest of this is my own thinking, so take it for what it is worth. It is clear from my POH (I have a 231) that all of the arc speeds are KCAS, not KIAS. We also know that the pitot can only measure what it "sees," in other words, knots indicated, and the ASI can only display what the pitot sees. So my thinking is that the manufacturer, in creating a marked ASI, displays the arc speeds in KCAS, translated to KIAS, because that is the only thing the pitot can read and the ASI can show. The manufacturer wants the pilot to be able to directly read from the arc markings, where the aircraft is in relation to the speed at which the aircraft is going to stall, so the CAS adjustment is made and the arc is marked so that at lower speeds, what you see on the airspeed indicator (an indicated airspeed) corresponds to the KCAS at which stall will occur. In other words, to figure out stall the manufacturer goes out with the long boom and finds the KCAS at which the aircraft stalls in a specific configuration. The knots indicated is, lets say, 2 knots lower, and that goes on the ASI, so that is part of the answer as to why the ASI arcs are marked as they are. The other part is my own thinking also, so if you are really particular you should verify with the manufacturer. My POH, and I gather those of others, has a stall speed table that shows stall speed for a given angle of bank, gross weight, and C.G., for a given flap angle. My Airspeed Limitation chart has a "bottom of the white arc" which does not exactly correspond to any of the chart speeds. Why would that be? I think the answer is in the aircraft configuration. The speeds in the table are for given flap angles only, they do not specify "landing configuration." The arc table specifies "landing configuration." What's the difference, if landing at full flaps then the number on the arc should be the same as the number for 33 degrees of flaps in the table. The answer is that "landing configuration" as set out in the POH means THE GEAR IS DOWN, and I think the Stall/bank angle tables does not include the gear down. The gear being down will change the stall speed from the gear up stall speed, same flaps angle. So the bottom line is that the bottom of the white arc assumes full flaps, gear down, and is KCAS translated to what the ASI can display, which is an indicated airspeed. This was interesting, I knew there was a difference between these things but like everyone else, I just fly the plane. YMMV