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cliffy last won the day on December 16 2017

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About cliffy

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    M20 D/C
  1. Forgot to add (its late) Gary He's referring to the "knee" of the main gear forward of and above the main wheel. Please get some training the first time you change a tire. If you do it wrong, it can literally kill you in the hangar as you disassemble the wheel. I saved an owner just a couple of years ago from just that by seconds on his first tire change. In Australia, pilots are specifically restricted from jacking all 3 wheels off the ground Just interesting FYI
  2. Attached is a manual from the FAA on what you as the owner/pilot can do to your airplane. Most everything is "inspection". The only "maintenance " allowed is contained in Part 43 Appendix A Part C All those items require you to sign off the "maintenance' in the a/c log book as specified in the FARs. You'll notice "gear retraction" is not included in any list. But, just to retract the gear and observe you're on your own. Nothing requires a sign off to do that. if you remove a gear door (or unhook it) and do a retract to verify that it clears that is "maintenance" that requires an A&P to sign off. As a pilot you can remove "fairings" I could stretch that to "wheel fairings" to change a tire as you are allowed to do in PM work. Jacking an aircraft is inherently dangerous . If you haven't been trained on how to do it safely, don't do it. I've seen Boeings fall off the jacks. FAA P-8740-15 Maintenance Aspects of Owning Your Own Aircraft [hi-res] branded.pdf
  3. Icing encounter

    On the early flat windshield Boeings (727, 737, 707) your first indication of icing would be on the axle nut of the windshield wiper. Ice would start to build there and it was visible right in front of your eyes. I've seen it 3" out into space from there. Actually one thing most of you will never get a chance of seeing is St. Elmo's Fire. Quite an experience at night up high. Actually used to bring the FAs up front to see it. Oh, wait, I'm day VFR now and enjoying it!! :-)
  4. C Model Fuel Burn Rate

    The economizer doesn't carry any additional fuel t all. What it does is "inject" air from above the float in the float chamber into the fuel nozzle after the main metering jet and before the nozzle outlet in the throat of the carb. It only does this when the throttle is pulled back from WOT and the spring pushes the needle open allowing the air to flow. The "extra " fuel used at WOT comes from the very low pressure in the throat of the carb "drawing" fuel from the higher pressure float chamber. Once the WOT is pulled and the economizer allows air to flow, the air "leans" out the amount of fuel being drawn from the float bowl in the main nozzle. In affect, it allows a higher bowl pressure to be put against the lower venturi pressure thereby lessening the fuel pushed through the main nozzle from the float chamber. The accelerator pump has a separate nozzle in the throat of the carb for discharge. If too many pumps are pushed without cranking the engine (thus not sucking the fuel UP into the cylinders) the extra fuel will drain out of the throat of the carb and drop into the carb heat box right behind the air filter. The only screen needing attention is the fuel inlet screen. The bowl vent screen is never pulled. If you check the inlet fuel screen, one should have another special lock washer available to use when it is replaced. We all remember that we don't reuse lock washers, safety wire, locking tabs, etc. This really is a big item (lock washers) especially on our mags. NEVER LOOSEN A MAG MOUNTING NUT WITHOUT REPLACING THE LOCK WASHER.
  5. C Model Fuel Burn Rate

    DXB I don't think there is any valid reason to "try" to adjust this item except on a flow bench during overhaul to set it to its called for setting per its flow number on its ID tag. This is not a field adjustable parameter as far as I know. I can't imagine a time I would want to mess with the flow settings of any particular carb except for idle mixture and idle speed. There is reference somewhere I saw that has the settings of the pin (turns in or out) to match the flow rating but again its not something we want to do in the field. Its set for the model carb and doesn't need fiddling with.
  6. C Model Fuel Burn Rate

    Hank- Winds? Was the flight time the same? Temp the same? Altitude was different? Route exactly the same? Winds at lower altitudes during climb or decent? Your flying technique ? Turbulence? Weight? Any number of things can cause it.
  7. C Model Fuel Burn Rate

    Oscar Here it is copied from the Mooney C TCDS- IV. Model M20C, 4 PCLM (Normal Category); Approved October 20, 1961 Engine Textron-Lycoming O-360-A1D or O-360-A1A (Carburetor MA4-5, Flow Setting P/N 10-3878, 10-3878-M, or 10-4164-1).
  8. C Model Fuel Burn Rate

    No idea on the amount of enrichment but I am sure it varies from one dash number carb to another by the size of the precise hole. It's either open or closed. Nothing in between. Like I mentioned, unless one is down low and running wide open this system has no meaning to the total operation. Once the mixture control is pulled this system is out of its control range and has no effect. You can leave the throttle wide open and lean it at altitude with this system having no effect on the fuel flow (leaned) what so ever.
  9. C Model Fuel Burn Rate

    We really don't have 2 fuel jets in our carburetors - Let's begin with basics. On any carb'd engine the main fuel flow comes from the float bowl, through the main metering jet (this is the main way of limiting maximum fuel flow to the engine) and out the main fuel nozzle located in the throat of the carb. Fuel flows through the nozzle to the engine anytime intake air is flowing through the throat of the carb. It is being "pushed" through the nozzle by the difference between the air pressure (pushing) on/in the top of the float chamber ( higher pressure) and the lower air pressure in the throat of the carb due to the flow of air speeding up (Bernoulli's Principle) through the carb throat. The faster the air (more throttle) the more fuel is "pushed" by the higher pressure air in the float chamber through the fuel nozzle. WOT = max fuel flow, governed by the main metering jet. On air cooled engines like we have, the air cooling is not enough to keep the engine within heat parameters without the use of "extra" fuel for cooling at WOT and low altitude. Governed again by the main metering jet size called for by the engine maker. When looking at the "mechanical" fuel enrichment system (economizer system) in the 180 HP Lycoming MA4-5 carb, the system really doesn't have 2 fuel jets. What happens is that as the power comes up (with WOT) the throttle arm is pushing on a spring loaded pin valve, holding it closed. Once we pull back off of WOT a little this spring loaded pin valve opens. This valve ports air from the top of the float chamber (higher ambient air pressure) through a precisely sized hole and into the main fuel nozzle after the main metering jet for the carb (a lower pressure area as we said before). More air after the main jet means less fuel so the mixture "leans" a little, as we don't need the extra fuel for cooling like we did at WOT. All done "automatically by Lycoming design. Thus, as Lycoming calls it, the "economizer" system. Once we get high enough and want/need to lean the mixture for altitude the leaning of the economizer system has no effect as we take the FF below the amount the economizer system can do by using the use of the mixture control. Remember, the economizer has a very limited effect because of the highly precise hole that it uses for leaning. Some who have cylinder head temp problems may want to check another item to try and cure the issue. Every airplane is certified with a very precisely calibrated carb. Each carb for each airframe installation has a very specific fuel flow design even though they are all MA4-5 carbs. These carbs are specified in the TCDS for each airplane. Sometimes 2 or more are allowed, each with maybe a different fuel flow specific (higher or lower). If you can't seem to get a handle on your temps you might check very carefully to see if you have the correct SPECIFIC carb for your airplane.
  10. I wonder if it was the application process used? Maybe aluminum instead of steel? Failure of the undercoat/primer? Have a good friend with a high end body shop who really likes water based paints.
  11. There are $5000 paint jobs and there are $15000 paint jobs. Its all in the detail taken and the repairs needed when stripped. There is still a wide spectrum of paint jobs but, by and large, the cost has escalated so that there are very few bottom end shops any more. I think one can still find a scratch and spray job if one looks far enough. I'm willing to bet that good automotive stuff would far exceed any testing parameters if it was done. The only barrier? $$$$$$$$$$$$ Water based auto paints are really good now a days. They can last forever even in direct sun every day.
  12. IIRC on Cirrus aircraft part of the paints job is to provide UV protection for the composite structure underneath so that sunlight exposure doesn't compromise the strength of the plastic airplane. Proper paint is vital to jets and high performance airplanes because (as mentioned, the environment they operate in and the chemicals they carry and use (Skydrol is a killer if you've never used it. Great paint stripper on shoe sole disolver. They say it causes "mild eye irritation- BS, you're blind for 30 mins!, BTDT). This has been a very enlightening thread. Learn something new every day. It seems that as time has marched on over the last 50 years since our airplanes were first made that paint selection has been more focused and restricted as regulations have been modified and interpreted by not only the Feds but the manufacturers themselves. Just look at the 1964 Pilot's Handbook and the current POH on Mooneys. Same basic airplane, 5 decades difference in time and regulations. Dan, thanks for all the effort in your postings.
  13. C Model Fuel Burn Rate

    I'll take EM data like you state as "empirical data" as it is from a digital readout source. I have no way of verifying what is said as I am old school panel equipped and have no 4 point EGT read out.
  14. C Model Fuel Burn Rate

    I asked the question for a reason- just because we all "do something" for a long time doesn't necessarily make it correct. Without empirical data it's all just supposition and OWTs. Fuel distribution by moving the fly plate is not something noted in any Lycoming data that I have ever read. It may very well be there, I just haven't seen it in my 50+ years reading this stuff. And, it might very well work but data is needed to verify. Not just, "we've done it this way for years". Let's find someone willing to gather the data on 4 cylinder carb'd engines. (Likewise, not many really understand the mechanical mixture enrichment system in our carb'd engines. It's not what many think. And, it plays no part once we lean the mixture for cruise. ) Most of the LOP and adding carb heat to improve distribution came from radial engines. P&W R-985s are ones that respond well to carb heat to improve cylinder to cylinder fuel flows but an intake temp gauge is needed to do it properly. Anyone with a 4 probe EGT can do it and write down the numbers. I have factory original 1 probe type stuff. "Flying on step" Oh boy, here come the flaming arrows- Transition to cruise flight from climb speed is all we are trying to do. How long that takes depends on several factors. One can climb above cruise altitude and trade altitude for speed or one can leave climb power on, level at cruise altitude and let the speed accelerate to normal cruise before reducing to cruise power (this is this way I was taught in both DC-3s and 727s) in addition to Navajos, Citations and Cessna 150s. Both ways will get you to the proper ATTITUDE for cruise. If one levels at cruise altitude and immediately pulls back to cruise power then the time to accelerate to cruise speed will be drawn out and (depending on weight and altitude) you may never get there. Take a jet above its optimum cruise altitude for the weight and all it does is mush along. Same with us in our bug smashers. Don't get it up to speed first and it just mushes along at a higher angle of attack (due to low speed), at a higher drag regime (due to the high angle of attack and higher induced drag). If one wants to call flying in cruise condition at the optimum angle of attack being "on step" I no real problem with that moniker.
  15. C Model Fuel Burn Rate

    I should add 4 cylinder engine.