PT20J

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PT20J last won the day on December 8 2019

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About PT20J

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    0S9
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    N355DT
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    1994 M20J

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  1. To log the time for currency requires a Advanced Aviation Training Device (AATD) that is FAA approved. A Letter of Authorization (LOA) will stipulate the approved uses and limitations. https://www.faa.gov/about/office_org/headquarters_offices/avs/offices/afx/afs/afs800/afs810/media/FAA_Approved_Airplane_ATDs.pdf Bottom line is that you won’t find an affordable personal device for logging time. Your best bet is to find a flight school with an approved AATD to use. As noted, under the latest rules an instructor is no longer required for logging any currency time in an AATD since this is not considered training. If you just want to maintain proficiency, there are lots of relatively inexpensive flight controls that when coupled with a PC running MS Flight Simulator or X-plane can provide useful practice. An intriguing idea is to couple this with PilotEdge https://www.pilotedge.net I’ve heard favorable reviews of PilotEdge but have never tried it and would be interested in the experiences of any MSers that have used it. Skip
  2. During a tour of NORCAL TRACON a few years ago I asked what they do about inadvertent incursions of the class B - someone squawking 1200 that they're not talking to cutting a corner for instance. The manager said that if it doesn't cause a conflict they don't care and they are busy and don't need any extra paperwork...BUT there is a quality control group off somewhere that has a video feed and watches over the controllers and if they notice it, TRACON gets a call and they have to follow up.
  3. Now you got me curious. Where does the ff sensor go on a 231? I assumed it had a fuel return line And if not, how does it account for the return fuel?
  4. In my professional life, I have worked for seven tech companies, some large, some small, some public, some privately held. The only statement about morality I ever heard was a CEO saying, "We have a moral obligation to maximize the shareholder's return on investment." Employees know when the company is cutting corners; it's not a secret internally and the priorities are communicated from the top down.
  5. It depends. An ideal engine would fire the spark plugs at top dead center (TDC) and the mixture would ignite all at once and expand and push the piston down. But in a real engine the mixture takes time to burn. The flame fronts begin at the spark plugs and progress to meet in the middle. During this time the piston is moving -- first up toward TDC and then down again. This means that the size of the combustion chamber is shrinking and then expanding while the mixture is burning. Together these effects result in the combustion chamber pressure rising to a peak and then dropping off. It's the overall average pressure (engineers call it brake mean effective pressure, BMEP) that does the work of pushing the piston, not just the peak pressure. But where in the cycle the peak is located and the height of the peak have a lot to do with efficiency and engine stresses. There is an optimum point for the peak which is generally somewhere in the vicinity of 15 degrees after TDC where the engine generates the most torque and this will be the most efficient place to operate (maximum torque for a given amount of fuel). Generally higher peaks transfer more heat to the cylinder heads. Also, if the peak is too high and especially when combined with high CHTs, the anti-knock value of the gasoline will be exceeded and detonation may occur. Since magento timing is fixed and propeller efficiency considerations limit our range of rpm, our primary means of affecting peak pressure is the mixture control. Leaner mixtures burn slower and move the peak later in the cycle. This has the effect of lowering the peak and making the engine more efficient. It also reduces power output because the BMEP is reduced. At low power settings (let's say 65% and below) the heat load on the engine is less and you can run the mixture wherever you want. At full power, full rich is required. In between, your best proxy to determine that your peak pressure is not too high is CHT. High CHT weakens the metal in the cylinder heads, stresses the valves and decreases their life and also (and more importantly) reduces the detonation margin. So what about 50 ROP? Well, on the good side, when you want more power, it provides a compromise between best power and best economy (usually peak or leaner) mixtures. On the bad side it is the mixture that produces the highest peak pressure and the highest CHT. Is this really bad? Well, it depends on the power demanded from the engine. At 65%, no problem. At higher powers, it's OK if the CHTs stay in check (Lycoming's long-standing recommendation has been 435 for high performance cruise and 400 for economy cruise. I'd go with 400F max). If the CHTs get too high, you have to reduce power or adjust the mixture richer or leaner. High CHT and high power is what you really want to avoid. Remember, back when all the engine and airplane operator manuals were written we didn't have such good instrumentation and gas was cheap. Simple rules were created to make engine operation simple and safe for us amateur pilots (The professionals had gads of engine instruments and a flight engineer to keep things in check). Now we have better instrumentation, gas and engines are expensive and we know more. This has opened up a whole range of possibilities. The best advice from those that have a lot of experience is to understand what happens when you move the red knob and then make up your own simple rules based on what you want to accomplish. Mike Busch for instance clearly states that he is more interested in longevity than speed and he runs his engines at 65% or less and LOP. His engines typically make it well past TBO. Others have discovered that they can cruise at 80%+ power when well LOP and still have cool CHTs. Hope this helps. Skip
  6. Here's an interesting article, especially the part about the effect on the jet's autopilot. Seems like more and more avionics includes GPS-aided AHRS -- kind of makes one wonder... https://www.ctsys.com/blog/entry/how-interference-testing-affect-gps-navigation.html Skip
  7. This is the Mooney factory mounting for the Floscan (now owned by JPI) transducer on the IO-360. The bracket mounts to a couple of studs on the top of the sump non the left side of the engine. ing In this scheme, the transducer is actually mounted upside down. The reason its supposed to be mounted with the wires up is that there is a little vent on the top that way to vent any vapor that may get into it. I talked to a tech rep at JPI and he said it's not all that important. I was trying to improve the accuracy of my system and I went to some trouble to mount it in the same position but right side up (had to make a new bracket with some standoffs) and it made absolutely no difference. Skip
  8. Naw, a gallon per side every five or six hours is all the R-985s burn. But they drip some. They are fun to fly, but can be a bear in a cross wind. You wheel land them and keep the tail up as long as possible, then get it down as fast as you can. Those twin rudders lose effectiveness as the tail descends and they are blanked out behind the wing and directional control is nil until the tail wheel bites the ground. If a crosswind gust catches you when the tail is midway down differential power is all that will save you. Skip
  9. I was looking at the specs in the M20J service manual and noticed something I never noticed before. In addition to changing the airfoil from root to tip, there is also a geometric twist of -1.5 deg. BTW, I know aerodynamicists are just making educated guesses when they design some of these parameters because I never see something like -1.387 degrees Cessna singles have relatively longer span, shorter chord ailerons than Mooneys. How does that affect roll control at and near stall? Skip
  10. I think LOP is a lot more useful in a turbo, certainly out west where the MEAs are high and the power output from a NA engine is already so low that LOP just makes it go slow especially with only 200 HP. It’s useful down low when not in a hurry. Or, if you have one of the BIG engine models, you can think of it as derating. You go slower, but you mpg goes up and it’s not a bad tradeoff. Skip
  11. I loved the few hours I got in the museum C-45 before another pilot ran off the runway in a crosswind and hit a runway distance remaining sign. We patched it up and the ferry pilot ground looped it on landing and killed it (but luckily not himself). It’s a great airplane and was Olive Beech’s favorite.
  12. Check with Mid Continent. They are a Bendix King repair station and may have better parts access. I’ve found them very knowledgable and reasonable on pricing. Skip
  13. I appreciate everyone's comments and experience! I agree that trimming nose up during the flare would improve the nose wheel drop, but as has been pointed out it would make a go around more challenging. One thing to keep in mind is that the trim bungees add a lot of force to the yoke during the flare. We all learned full stall landings in trainers. I don't believe they are necessary or particularly desirable in high performance airplanes. Certainly it's not the way to land a multi-engine airplane or a jet, so why land a Mooney that way? All that's necessary is an attitude at touch down that permits landing on the mains with the nose wheel slightly above the runway. A Mooney can land shorter that way because it floats less. I've seen a lot of bad landings (mine included) result from trying to wrestle the airplane down to the ground solely with the elevators. It's best to remember that sometimes a little bit of power can save the day. A good landing requires coordination of ailerons, rudder, elevator and throttle. "Chop and drop" on short final works -- sometimes -- but it's not the best way to do it. Just my $.02 Skip
  14. I’d call Autopilots Central, Executive Autopilots or Mid-Continent. Also, should figure out what caused it. Skip