Warren

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About Warren

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    Advanced Member

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  • Location
    Denver, CO
  • Reg #
    5808T
  • Model
    M20K 231

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  1. Warren

    CDT-Gauge dead ...

    The intercooloer should resolve any issues with the inlet charge temperature. Ultimately the CDT will be reduced across the intercooler to a much lower inlet charge temperature. In my 231, the intercooler reduces the temperature 70-90 C. My intercooler STC reuires a temperature sensor that measures the CDT and Inlet Charge Temperture as well as the difference between the two. This decrease in temperature is used to adjust the maximum manifold pressure. Detonation can be caused by high inlet temperatures but with your intercooler this should not be the issue. General guidance for remaining clear of detonation are the following: More fuel - under full power, make sure there is plenty of fuel. In our engines, 23-25 gph gives good margin. If you aren’t seeing this much fuel, have it adjusted. Excess fuel is important for cooling and slowing the combustion burn rate under full power. Higher rpm - moves the peak cylinder pressure later in the cycle. Lower risk at 2700 rpm. Not too much MP - make sure you are accounting for the intercooler and reducing the MP appropriately. You can’t run 40” with this setup because the intercooler increases the density of the air and at 40” you are making more than rated power. Good luck.
  2. Warren

    Too soon to move on to a Mooney 231? 130TT

    I bought a 231 with only 70 hours all in a 172. With good transition training it is not hard to learn to fly. Just take the time to slowly build experience. A careless moment or a careless pilot can get you in trouble much more quicky in a Mooney than a 172. Higher performance requries a little more precision when flying. I think it is finacially much less expensive to buy a longer term airplane than take an intermediate step and upgrade later. The biggest challenge is learning to deal with the speed during descent and landing. Flying at altitude, on oxygen and in the flight levels can wait until you have more experience. Lower cost is the 231. Make sure you get one with an intercooler and upper deck pressure controller or plan to make this upgrade. This closes the performance gap to the 252 significantly. Still need to manage MP but this quickly becomes second nature and is only critical when applying takeoff power — about 15 sec on a normal flight and during a ‘go around.’ I was really comfortable with everything after about 30 hours of flying. I then did my IR and that also made a huge difference in my piloting ability and general comfort with the airplane. Better yet is the 252. Costs more money and if you can afford it, it is the better plane and worth the extra money. For the extra money you get better MP control, larger turbo, 24V, dual alternators, infinitely adjustable cowl flaps and more speed (5-10 knots at altitude). Probably a few more things but this gives you a general idea. And one more is the Encore upgrade — big increase in useful load if you can find one. The other obvious question is level of avionic upgrades and maintenance. There are huge upgrade costs and/or maintenance costs that will overshadow the purchase price considerably. Good luck.
  3. As I read through this it is still hard to understand. I question the failure mode. If it failed in tension it would have broken while retracting the gear. How does a failed link then properly extend and lock the gear? Buckling failure seems far more likely under the compression load. It seems like the gear extended fully and the force caused the threaded section to buckle and fail after full extension. I can see a slightly buckled joint still fully extending the gear then getting pulled in tension during retraction and continually cycled until failure. However, this should cause cracking and an obvious pattern in the failed part. It sounds like this is not supported by the failure analysis but it is hard to believe that a full tension failure would allow the gear to extend. If a partial tension failure with necking was followed by a buckling failure on extension, there should be obvious signs of bending prior to full failure. Just random thoughts from my failure analysis experience. Still hard to understand based on the failure analysis vs. the description of the operation during failure.
  4. Warren

    Garmin acquisition of Fltplan.com

    Garmin seems really good at extracting maximum dollars from the marketplace. The Fltplan.com has been a free app and has all the maps and procedures available for free. The owners figured out how to make money by selling to Garmin. I am sure Garmin invested in the purchase to get rid of one of their biggest competitors to GP. I would be shocked if we don't start to see user fees or some other way to recover the investment. Likely will eventually get rolled into the Garmin product or obsoleted and disappear as a free option. Remember the Apollo acquisition (is GNS480)? Purchased a big competitor and eventually obsoleted the product. Now they dominate the GPS market.
  5. Warren

    M20K Power Settings..?

    I don't have access to Aviation Consumer but my engine development experience and engineering background disagree completely. When running stoichiometric or ROP, an engine's power output is based on air consumption. Air consumption in aviation is primarily determined by MP and RPM. However volume is only one part of the picture as the combustion process cares about the molecules of O2 available for combustion. At lower manifold temperatures and similar MP, the same volume of air has a higher density, thus has more oxygen available and can produce more power. It is true that an intercooler reduces pressure and temperature causing the turbocharger to work a little harder to create the same manifold pressure at a lower temperature. This is because there is more air being compressed due to the change in density. More air equals more power. If you take engine operating parameters from an non-intercooled engine running 150 ROP and add an intercooler while keeping MP constant you have added more air with the same fuel. You now are closer to peak temperature and risk getting into the "Red Box". At high power settings this is a risk as you are increasing the engine output and running nearer to peak temperatures. The intercooler manufacturer guidance or a 252 manual will provide good reference to adjust for the intercooler. It is critical to make adjustments and not rely on the original 231 settings. Stoichiometric or ROP, engine power is based on air consumption (density is important) as all the oxygen is consumed which limits the power. LOP power is based in fuel consumption as all the fuel is consumed and here the fuel limits power.
  6. My bad connection was on the wiring from the backup AI. About 1 foot away (middle of the panel on the pilots side). In my case it was a DB9 connector that had been wired in. However, the shells were not installed on the connector and thus the wires had no strain relief. Thin wires, no strain relief -- it was only a matter of time before failure. It was a quick fix to replace the pin on the broken wire. I ordered DB9 shells and added them to the connector. These are readily available and pretty simple to install - search DB9 connectors and you can find lots of options.
  7. After my GTN650 upgrade I had similar issues — I learned a lot about how things work. The Aspen only provides heading references to the autopilot as a direct heading from the Aspen heading or a passthrough when in GPSS mode. The non-Aspen attitude indicator is responsible for the analog attitude indications which the autopilot uses to make corrections to course. With these analog signals and the autopilot there is no error indication except the autopilot appears to lose its mind. During my install/upgrade one of the wires was broken (poor previous install with a DB9 connector and no strain relief) between the attitude indicator and the autopilot — of course it was intermittent, adding to the challenge. After chasing it for a long time I repaired the wire, added a shell for strain relief and it has worked flawlessly since. There are only 4 wires, so relatively easy to trace and confirm good connections. Edit (added after I realized this was not accurate in all cases): This does not apply if you have the EA100 adapter. That can provide attitude information from the Aspen to the autopilot.
  8. Warren

    Seat Rollers

    My 1985 K model has the adjustable height seats. To get the seat to move forward and aft enough to release from the rails the seat needs to be all the way down in one direction and all the way up on the other end. I can’t remember which but it took a little head scratching the first time.
  9. Warren

    G1000 WAAS Upgrade Cost?

    Don Maxwell (@Oldguy) made a post about this a couple of months ago. I can’t find a way to copy the link but here is the copy of the post title. G1000 WAAS upgrade parts availability ending It sounded like Don was trying to round up as many parts as he could to be able to offer the upgrades. If you want it done it sounds like soon may be the only option and is still pretty expensive.
  10. Warren

    Full Fuel Tanks

    I have an 85 K model and have run each side dry multiple times (on separate flights) to get an accurate measurement. When I refill to the flapper seat I get 33.8-34 gallons in the tank. I know this doesn’t count legally useable fuel but I know pretty close to when the actual level flight fuel exhaustion will happen. I can get more in by being patient but have the extended tanks and have never filled right to the top as I can easily get the fuel I need with the extended tanks. I have also checked my low fuel level and I run out in the 2.5-3 gal range after the light comes on.
  11. Warren

    Vacuum Pump replacement

    This might be a silly question...but. What if you called the G5 primary and the G500 the backup? Would that get past the paperwork challenge?
  12. Thanks for sharing your experience. My research and experience is a little different than yours. Quote from "Continuous Flow Fuel Injection Systems," Aircraft Maintenance Technology, November 1998: "All TCM pumps rely on a “by-pass valve” which serves to purge vapors from the lines when the boost pump is engaged prior to engine start up." This article reviews fuel setup on the various variants of TCM engines from naturally aspirated through fuel injected. It also has an interesting side bar about the complexity of setting up a TSIO-360 with aftermarket intercoolers and the Merlin wastegate controller. If you are seeing excessive fuel being dumped when running the boost pump while at ICO on your mixture, something is not correct. I would be worried that there is some damage/scoring/seals allowing leakage or you are not adjusted to get full cut-off. I run the boost pump frequently for cold and hot starts and have never observed excess fuel during this process. I looked at my setup in an -LB engine and there is a vapor line returning to the tanks from the top of the fuel pump. SID97-3G also has coverage of the full range of pumps. All these pumps also show a vapor return line. Just sharing my experience and research. Use your own judgement and make your decisions about safe operation. But, always good advice to be aware to look for fuel leakage. If you are going to try the boost pump operations it would be good practice to try this where you can make a good inspection for any excess fuel in and around the engine. It is definitely not a good idea to have lots of excess fuel pooling and try to start an engine. Good luck and be safe.
  13. I think there is still some misunderstanding of the various options with the TSIO-360 and the prime vs. boost function. 1. All low boost, high boost and prime use the same electric fuel pump. Low boost has a resistor inline which reduces the pump output, high boost and prime use the pump at full power/capacity. 2. High boost and low boost simply turn on the pump and provide backup/replacement for the mechanical fuel pump. Boost provides fuel to the injection system. How much fuel flow is dependent on the mixture, throttle and whether high/low boost are selected. 3. Prime also turns on the pump and energizes a valve that shuttles fuel to the intake manifold. 4. Summary -- Low/high boost puts fuel through the injectors and prime sprays fuel into the intake manifold. Prime Starting - Starting per the user manual and prime function dumps fuel into the intake. When the engine starts rotating, the mechanical pump starts to fill the fuel lines to the injectors. It takes some time to fill the fuel/injector lines and the manual recommends prime pump to keep the engine running while this happens and the engine eventually starts to run from fuel in the injectors. Boost Starting - The alternate many recommend is to use the high boost pump to load the main injection system and supply starting fuel to the cylinders directly. Most recommend xx seconds or wait until the fuel flow comes up indicating there is fuel flowing in the system. There is some risk with this process as it is possible to put too much fuel in the cylinders if you leave the pump on too long. No problem if you are careful not to run the pump too long but be careful. Hot Start - Many recommend throttle closed and mixture at cut-off. Use the high boost for up to 60 sec to circulate cool fuel from the tanks through the system and back to the tank effectively removing fuel vapor from the lines and cooling the lines with fresh fuel. Then start per your normal procedure. Hopefully this helps. Just a summary of what I have learned and read as I have researched operating my 231. I have tried all the above and they seem to work well. What I have found works best for me and almost never leads to a missed start. 1. Prime per table in manual. 2. Throttle to 1/4, mixture full rich. 3. High boost until FF comes up. 4. Start and pull throttle back as it catches. Hot Start - 60 sec high boost with closed throttle and mixture at cut-off. I have tried with and without the high boost and both work well. It just seems that with the high boost it starts quicker and does not require additional shots of prime to keep it running. Random thoughts from another rookie pilot. Good luck.
  14. Warren

    201/231/252 for family/commute

    I have a 231 with the upper deck pressure controller and an intercooler (similar to gxsrpilot with a little smaller turbo and not quite as good coolling). I always run lean of peak except for during the climb (full rich for this) and am limited by TIT at high power settings. My GAMI spread is about 0.5gph and all the cylinder heads run <360 (at 16-18k altitude, approx. 0C, near 75% power LOP). I am limited by the TIT. 75% power for me is 11.5 gph (I use 2500 rpm and about 33” MP). Usually at 11.5 gph I will run too high on TIT (it usually puts me really close to 1650 TIT) so I choose to back off a little. I lean until I get under 1625 to have a little margin. Using this limit I can usually find a good cruise at 11.0-11.3 gph making almost 75% power (much smaller number for me than a rocket) and this results in about 175-180 TAS at 16-18k. As you apporach 75% power, TIT is the limiting factor (in a TSIO-360). When LOP, TIT will be approx. 100F higher than in EGT. Under lean conditions the flame front is burning so much slower so there is residual combustion happening in the exhaust which continues to raise the temperature afther the EGT sensors.
  15. Warren

    Gpsmap 696

    Good news. The recent releases of FltPlan Go now link with the Garmin Flightstream products. So now there is a free option.