2,700 cc / 100 hp Zenith engine of Jim Barber 

Builders, 

Another running Corvair, test run outside the SPA/ Panther factory. Jim came down for Finishing School #2, but his progress was halted buy the failure of Chinese head studs, which were installed in his case by another Corvair shop, when he was torquing his heads. 

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Above, Jim’s engine running today on my stand in Florida.

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The shop that installed the Chinese head studs didn’t test them, because they would have known they were less than 50% of required strength. I have been called everything from xenophobic to racist for speaking out against Chinese products, but the material doesn’t lie, these studs were expensive garbage without heat treatment.  

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The manufacturer didn’t replace them for Jim, The importer didn’t, and neither did the person who installed them. They just made their buck and washed their hands. Who fixed this? Dan and I did, and it required a lot of work, but we happen to be in the business of solving problems, not creating them.

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We asked Jim to leave the engine and pick it up when he came back to Florida on vacation, next week. One more engine done right. If you are getting started on Corvairs this year, learn two lessons; pick the right people to work with the first time, and if the right people don’t use parts from Chairman Mao’s workers paradise, it isn’t because their racist, it just because your engine has to work.

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-WW.

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Short video of the engine running.

Competing for 2nd place

Builders,

 In previous posts, we have had some fun  comparing some people’s applications for the Darwin awards. As long as we are learning the underlying lessons, there is no harm, but I wish to be clear on one point: They are all competing for 2nd place, because I already know who the biggest idiot I have ever met is, and unfortunately, he looks a lot like me.

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Above, a 2005 photo of yours truly standing on a stepladder working on the Vagabond. This was taken at our old Edgewater hangar, the day I made the dumbest mistake I have ever made turning wrenches on planes. Notice the dual point distributor is removed from the engine.

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The task of the day was to determine the ideal jetting on Stromberg Carbs. The NAS-3 comes with several venturi sizes and jetting combinations, and we wanted to nail down the best one for Corvair builders. This involved a lot of wrenching, with each iteration being test flown by our resident test pilot, Gus Warren.

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Everything was going smoothly, and after replacing the distributor  I decided to base line the ignition timing with a strobe light at 30 degrees. After doing this, we buttoned up the cowl and Gus went to the runway. He took off on the 4,000′ runway, and the engine sounded great, but abruptly at 250′ Gus cut the throttle, slipped the plane and landed straight on the runway. He couldn’t say what was wrong, nothing on the instruments, but he thought he felt a slight reduction in rpm, so he aborted the climb out. ( See: Critical Understanding #4, ANY loss of RPM is Detonation. ) He wasn’t going to sit there and see what happened next while his option to land straight ahead evaporated.

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We brought the plane back, and went over it with a fine tooth comb, including rechecking the timing with a strobe light. It was all right. After an hour of this, Gus went back to the runway, everything was great, but again he aborted the climb out at 2 or 3 hundred feet, and landed straight ahead. Back at the hangar, nothing can be found. Gus is not pleased, suggests another check. Looking very carefully, I see what I had missed both times before: The white line on the harmonic damper has been erroneously painted on at 15 degrees not zero. I have been setting the timing to 45 degrees total, not 30. The sag in rpm Gus has felt is the engine reaching full temperature in climb, and beginning to detonate, even though the plane was fuelled with 100LL. I had just sent my friend to the runway with an in-airworthy plane, twice in the same morning.

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If anyone cares to hear my full set of credentials on my first class imbecility during my 28 years in aviation, come find me after hours at Oshkosh, be forewarned to bring a cooler and a lawn chair, it’s going to be a long night. I have not made many errors doing maintenance, and I don’t count all the holes drilled in the wrong spot, the thousand or so tubes, carefully measured and then cut too short. That is stuff everyone does, I am talking about real mistakes.

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 Try this: When I graduated from Embry Riddle, the world famous Kosola global aircraft salvage firm showed up to hire just two people. Just 105 graduates met the criterion for an interview, and three days later this was whittled to 3 people, and I was one of them. At dinner that night, which was supposed to be casual, but I understood it was part of the process, I let another candidate bait me into showing my sharp tongue.  It cost me the job.

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I went on to spend several years building Lancair IVP’s, every hour of which I now consider a mistake. Read it’s harsh lessons here: 2,500 words about levels of aircraft finish……

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  Try this: On 7/14/01, Grace called me and said not to go flying, the one and only time she had said this. I didn’t listen, and that was the day my Pietenpol crashed.

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I quit being an instructor at Embry Riddle because I thought advancement was to slow; one of my class mates who told me I was making a mistake is now a department Chairman.

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In 2009, a guy who really understands economics and finance, took an entire evening to explain that my customer base, the working middle class, was never going to recover their confidence in the economy. I said people would scale back planes, but if flying was in you, you don’t quit. Today, after 8 years of effort,  I can admit he was more right that myself.

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  I could fill an evening with stories of employees and subcontractors I never should have hired. I read the Maya Angelou quote “When people show you who they are, believe them, the first time.” 30 years ago, yet I gave 40 idiot builders the second chance they needed to really defame our work with Corvairs.

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None of this even touches on the errors which affected other people, like this : Thinking of Mike Holey, an Aviator and a friend.

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This story has two simple morals:

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Never trust anyone in aviation who tells you he doesn’t make mistakes. He is either a liar, or he is delusional, and over the years I have certainly met plenty of both working in aviation. Take note that the delusional ones feel there is no need to them critically examine their own thinking or work, and they will not even do so when presented with plain evidence. Stay away from these people. If I have a single redeeming feature, it is being willing to listen to others and be swayed by evidence. I have no fear of changing my mind. I have long said I would rather be successful and be called a hypocrite, than be an unchanging zealot and a failure.

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Second, no builder should repeat the tests I have done or the mistake I have made. I have spent an awful lot of years learning this stuff, and it is really wasted if people feel the need to argue the basics or are determined to try things that our testing conclusively showed not to work, 10,15 or even 20 years ago. Seems obvious, but just today, I got a note from a guy essentially saying I don’t know where to put an oil cooler on an engine.  Never mind that I have tried 10 coolers and six locations, I am sure he will need to prove me wrong. I accept that such people will always be there, but if you wish to get much out of my work, don’t be one of them.

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-ww.

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Engine Ground Cable

Builders,

In 2016, we had two different Zenith builders fly in to the same event. They had never met each other. I studied both of their engine installations, which has cumulatively about 500 hours of flight time. They were different, but both airworthy. They had an odd thing in common;  They both ad an engine ground cable that was 3 feet too long, and it terminated at the same points, the center of the firewall and the starter mounting brackets on each plane. Most people would not have noticed this commonality, but it told me something important: Both of these guys who had never met each other were listening to the same idiot on the internet, rather than following examples we show or even common sense. Somewhere out there in cyberville was a moron gleefully dispensing poor advice on ground cables. While this particular error just added weight and looked dumb, I am sure the same expert had doled out plenty of other electrical advice that was far more dangerous.

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Above, the ground strap location for a Corvair engine. This is the aft end of the co-pilots side head. The head has a  3/8″-16 tapped hole, perfect for grounding, the cable is 9 inches long, it is #2 wire. You can even use wire without insulation, ( it is a ground) or go to your auto parts store and buy a premade cable, and it can even be one of the ones that look like bare woven metal, a ‘bonding jumper’.  Yes, the powder coating has to be scraped off where the 5/16″ bolt goes through, and it does have to have a metal lock nut.  Every motor mount I have ever made has a tab or a corner brace at this intersection for a ground cable.  If anyone suggests that a 4130 motor mount or an aluminum fuselage don’t conduct electricity, they are not just wrong, they are probably mentally ill, just nod politely, smile and back away slowly.

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Your Vote Counts:  In the comments section, please vote for one of three following examples from my experience:

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 A) “Led Zenith”  10 years ago I went to inspect a Zenith. The builder had placed a group 24 lead acid truck battery in the tail cone, (because he had made an error doing his weight and balance on a set of $10 bathroom scales.)  but he also insisted that he needed to run a 00 copper battery ground cable all the way from the battery, 12 feet to the motor, and insisted that it also had to have insulation on it. A very nice gentleman, had been a pilot for 35 years, built a number of planes, and had a long and lucrative career as a mechanical engineer.

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B) “Ungrounded Claims” A second owner of a Corvair powered plane called both Dan and Myself, because his “Starter was burned out”. He was on a cross country, far from home, the starter had previously worked without a hint of a problem for years. Dan tells him to directly put the jumper cables on the starter, to isolate the starter to test it. Guy claims he did this, no dice. His solution was to rent a motel and a car, drive 200 miles to a city where he paid a guy several hundred bucks to hand rebuild the starter on a Sunday, in spite of the fact the guy said there was nothing wrong with it. About $1,000 later, the starter is back on the plane, and it still doesn’t work. Local EAA chapter experts say the issue is because it is a Corvair. After another day, he discovers that the ground cable to the motor has become disconnected, something he would have known had he actually put the jumper cables on the motor as instructed.

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C) “The sticky throttle cable and $7,000 worth of starters” Back in the 1990s, when I had a lapse of moral judgement and built Lancair IVPs for rich guys, we has a guy with a flying plane call the shop asking if we could install a new starter on his TSIO-550B Continental, which, on, by the way also needed a new throttle cable every 25 hours. He had spend thousands of dollars with other shops, but he was now willing to pay our “Overpriced labor for A&Ps” ($50/hr in 1996). He initially didn’t want to use A&Ps because technically experimental didn’t require it. We solved his problem in 10 minutes: he never had an engine ground strap, and the throttle cable by default was functioning as a high resistance one. He has instead purchased one rebuilt starter for $2,500 and had later purchased a factory new starter from TCM, and it was about $4,500. The logs showed the throttle cable had been replaced 4 times. Good thing he didn’t get ripped off by trained mechanics.

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-ww.

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” 2 / 2 ” – EGT sender location

Builders,

I use the short hand ” 2 / 2 “ to note a Corvair motor which is set up with 2 CHT’s and 2 EGT senders.  My own personal aircraft is set this way, with one CHT on the bottom of each head in the stock location, and one EGT sender on each other the exhaust pipes. This is pictured below.

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Above is the pilots side exhaust pipe from my aircraft. The single EGT sending unit comes just after the #2 cylinder exhaust port. It is on the inboard side of the pipe to have a cleaner appearance and simplify wiring. This particular sending unit is an Auto Meter 5249, which can be used either as a clamp on or (as pictured) a welded on installation. I chose to put one of these in each side of the exhaust, but I run a DPDT switch under the Auto Meter gage allowing the one instrument to be fed by either sending unit.

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Many Corvairs flying today use Dynon or GRT glass cockpits to effectively monitor “6/6”, for traditional instrumentation, “2/2” makes sense to me and provides effective coverage, information for leaning, and an opportunity to look at right/left comparisons. Because this takes just 2 more probes 2 switches, it makes a lot more sense that a “1/1” system. One of the things that I find ironic is when a low time pilot tells me he “must” have a “6/6” system. I’ll ask him what he did his flight training in, and it is often a Cessna 150, and I will ask him how many CHT’s and EGT’s that plane had. Very few of these people remember that their training was done in a plane with a “0/0” system.

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I strongly recommend against anyone even thinking of flying a Corvair with a “0/0” system. We had a guy try this 3 years ago. He had also designed his own cowl and cooling system and was at an airport with a base elevation over 5,000′. The 2 questions that should come to your mind are “How would he know if the cooling system worked without a CHT gage?”  and “how does one lean a Corvair if you have no EGT information?”  I don’t have answers for those questions, and neither did the builder. First flight was 25 seconds long, landing was upside down in a farm field. No serious injuries, but it did make TV news, where the builders buddy took the opportunity to blame the motor right away.

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If you are thinking of a “2/2” system, read the stories below. If you are thinking about Glass Cockpit stuff, and want to speak with the most experienced people on Corvair/glass 6/6 arrangements, Call Rachel and Dan at 904-626-7777 , ext. #1. They mostly sell GRT stuff, but they do have experience with all of the systems.

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Inexpensive Panel……..part one.

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Inexpensive panel…….part two.

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Thought For The Day: Mechanical Instruments

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-ww.

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Rule of thumb in evaluating gear mesh 

Builders

A quick guide on gear tooth clearance;

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No blood = too loose.

Aircraft Mechanic passes out = too tight.

Moderate bleeding = acceptable clearance.

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Note to builders: When turning engine over by gripping flywheel, avoid the 10 and 2 O’clock grip because it puts the right thumb very close to the point where the starter and ring gear mesh. Proper mesh clearance is set with a 1/16″ drill in in a separate operation, thumb is not an accepted substitute for 1/16″ drill.

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-ww.
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Critical Understanding #9 -Percent of Power and fuel flow.

Builders:

Three things come from article #9 in this series:

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You know  what 100% power is and the fuel burn at that setting

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You know what conditions produce 75% power, and the fuel burn at that setting.

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You know when the engine is at “Substantially reduced power” and understand that Carb heat is required for operation at these settings. (This will be covered in detail in part #10 )

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Piston engines inhale air and fuel, and burn it to make power. If you know the displacement of the motor, the RPM it is running at, and the density of air it is inhaling, you can make a pretty accurate calculation on which setting will produce a given power output and commiserate fuel flow. If you cross reference this with several very accurate dynamometer runs, your calculations will be within a few percentage points of your flight experience.

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Mass Flow:

The number you need to know is How many pounds of air are inhaled by the engine in an hour? Let’s look at an example from a 3,000 cc Corvair:

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3,000cc = 183 cubic inches = .106 cubic feet.

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3,200 RPM is 1600 inhalations on a 4 stroke motor, 1600 x .106 = 170 cubic feet of air per minute.

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170 cubic Ft./Min.= 10,200 Cubic feet per hour.

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At seal level on a standard day, air weighs .08 pounds per cubic foot.  10,200 x .08 = 816 pounds of air per hour.

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Engines without turbos or superchargers don’t inhale with perfect efficiency, the Volumetric Efficiency or VE of a Corvair head is .95 so… 816 pounds x VE of .95 = 775 pounds of air per hour going through the motor at wide open throttle and full RPM on a standard day.

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Engines make their best power at 12 to 1, air to fuel ratio by weight so …

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2,775 cc Corvair – 716 pounds of air per hour + 60 pounds of Gasoline = 100% power

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3,000 cc Corvair – 775 pounds of air per hour + 65 pounds of Gasoline = 100% power

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3,300 cc Corvair – 848 pounds of air per hour +  71 pounds of Gasoline = 100% power

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What is 75% Power?

It is any condition that results in the engine burning 3/4 of weight of air and fuel as the 100% power rating above.

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2,775 cc Corvair – 537 pounds of air per hour + 45 pounds of Gasoline = 75% power

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3,000 cc Corvair – 581 pounds of air per hour + 48 pounds of Gasoline = 75% power

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3,300 cc Corvair – 636 pounds of air per hour +  53 pounds of Gasoline = 75% power

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Any combination of throttle opening and rpm that results in the engine inhaling the 75% weight of air and fuel per hour will yield 75% of the rated power.

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Sea level standard pressure is 29.92″ of mercury.  3/4 of this pressure is 22.5″ If you had an Manifold air pressure gauge ( MAP ) in your plane and took off at SL on a standard day, it would read damn near 29.92″. If you left the throttle wide open and climbed to 8,000 ft. it would then read 22.5″ MAP, and if you leaned the mixture so the fuel flow dropped by 25% to match the reduction in the weight of air, you would now be at 75% power.

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If you were in Denver on an 85 degree day, with a bit of humidity in the air, you are now at 8,000′ Density Altitude (DA) and guess what? you now have a motor that only makes 75% of its rated power. In cruse flight, the plane will not loose 25% of its speed because it is flying through thinner air, but it will have reduced take off  and climb performance, but the people who build airports know this and tend to build longer runways in high places. Denver’s Runway 16R/34L is 16,000′ long, the longest commercial runway in North America.

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You can get a calculator and use the values in the first part of this article, along with an on line  DA calculator, (http://wahiduddin.net/calc/calc_da.htm) and work a great number of examples about your size engine at airports and climate conditions you may flight plan for. Note that your engine will likely not turn 3,200 RPM static, so realize that planes with fixed pitch props don’t start their take off roll at 100% power.

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Rich mixture for wide open throttle, leaned for cruise, a fuel flow variable.

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Aircraft carbs are designed to automatically run rich at wide open throttle. Please read this story to learn :Air / Fuel ratios on Corvair carbs.. They can go as far as a 10.5 to 1 air fuel ratio by weight. That mean our 3,000 cc Corvair  example above could go from 65 pounds of fuel per hour to 74 pounds per hour at a wide open seal level take off on a cool day and hitting 3200 rpm.

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Aircraft carbs are designed to be leaned at cruse if desired. The Corvair at low power settings can be leaned to 14 to 1 air / fuel ratio by weight. On the chart above, a 3,000 cc Corvair cruising at 75% power can possibly be leaned from 48 pounds of fuel per hour to 42.

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How much gas is that?

If you don’t know that gasoline weighs six pounds per gallon right off the top of your head, call up your flight instructor and tell him you want your money back, and he needs to mail his CFI ticket back to Oklahoma City. Seriously, if your instructor didn’t drill that into you, how do you know how much weight you are adding to the plane at the gas pump?  How does one do a weight and balance? These are the kind of skills that have been allowed to degrade in the modern era of  the “CFI Lite”  The man who taught me how to fly got his CFI in the USAF in 1952, when the standard response to a student asking “Is this going to be on the test?” was punching the student in the mouth. ( Sensitive CFI’s with progressive attitudes just slapped people.) Be your own hard core, old school CFI, and that way you will never look stupid around planes.

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If you don’t know this stuff, it’s ok, you are on team Corvair, and I am going to make it my business that you have a fresh chance to really learn it, because I want every moron in experimental aviation to know that Corvair builders know their shit. Being a dopey moron about aircraft operations is why they make Rotax engines and Bing carbs. Set your goal in aviation that just in case Chuck Yeager shows up at your airport on his 100th birthday and says to you “Hey, somebody want to take me flying for an hour?”  and he points at a in a PA-18 super cub on the ramp, you won’t have to be like all the pilots trained on Rotax’s who will have to say “Sorry, I can’t. I don’t know how a mixture control works.”  Besides, Yeager is old school, and he is going to punch those people in the mouth. -ww.

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Note Book Section:

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Make line 9.1 in your Hand book a hand written entry, stating what displacement your Corvair Engine is in both CC’s and Cubic inches.

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Make line 9.2 in your Hand book a calculation for your engine showing the fuel flow in Gallons per hour for your engine, at full rated power,  both at 12 to 1   air fuel ratio and at the auto rich setting of 10.5 to 1. Make a note in CAPITAL letters stating the maximum fuel flow the engine is capable of, and right under that figure out how many gallons it would take for your plane to climb to 5,000′ with a 600′ per minute rate of climb, to learn just how much fuel your plane could potentially use.

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Make line 9.3 in your Hand book a calculations of the DA of your home airport on a standard day, a 25F day, a 75F day and a 100F day. 

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Make line 9.4 in your Hand Book a notation of the fuel flow in Gallons per hour for your engine at a 75% power setting both at sea level and at 5,000′ These will be numbers you use frequently to flight plan.

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Make line 9.5 in your Hand Book a notation for the actual mass flow rate through your engine at it’s static rpm. Express this as a percentage of the mass flow rate of your engine at its rated RPM. This number will be your percent of rated HP available on take off.

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‘Your Moral Purpose’

Builders:

The following story was inspired by seeing one too many internet memes about “relationships and love” and reading one too many stories about flying centered on “electronics and regulations.” I have no particularly profound insight into love and flight, but good God, we can all do better than the trash that is littered into our lives as alleged wisdom.

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A man is scattering seeds in a ploughed field. The figure is represented as small, and is set in the upper right and walking out of the picture. He carries a bag of seed over one shoulder. The ploughed soil is grey, and behind it rises a standing crop, and in the left distance, a farmhouse. In the centre of the horizon is a giant yellow rising sun with emanating yellow rays. A path leads into the picture, and birds are swooping down.

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Above, Vincent Van Gogh’s  The sower, painted in Arles France in June of 1888. He wrote his brother Theo to express the great difficulty, and the emotional cost of his pursuit of cutting edge art: “You risk your life on it.” Van Gogh’s life took place at the intersection of extreme creativity and insanity. If he could have been offered a cure, he would not have accepted it, for art was his Moral Purpose. In the year and a half he spent in Arles he painted perhaps 500 pieces. When it was over, he shot himself. He was 37.

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OK, as simply as I can express it: Your Moral Purpose could be an Art, a Passion, a Cause, a Service, anything that will pass this simple test: There is nothing anyone could offer you to have your fidelity to it end. Van Gogh wasn’t going to stop painting, Gandhi wasn’t going to leave India a colony, and Lindbergh wasn’t going to stop flying. When you discover your Moral Purpose, you will have simultaneously found something worth living for, and worth risking your life on.

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The desire to have a Moral Purpose is internal to humans. On the outside, powerful forces are opposed to your search for individual meaning. In past centuries, society needed slaves, and today it demands consumers. No one ever discovered their Moral Purpose while accepting either of those functions. Flight itself, has the capacity to be one’s Moral Purpose, pursued as an art form, something you could both seek to master and be in awe of it’s beauty at the same moment. You are doing this when you learn a new skill or develop a deeper understanding, when you effortlessly fly a perfect power off pattern at sunset. A guy looking for a bargain on avionics or debating ADSB crap isn’t finding a meaning, he is just being a consumer. He will find flying to be an expensive hobby or pass time. This is why you should always approach flight as a calling, it is the only hope of finding a real reward in  it.

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If you find a moral purpose, and live with fidelity to it, people may not agree with it nor even understand it, but inherently individuals will respect you. If they have their own purpose, it need not be the same for this to happen. Charles Lindbergh and Miles Davis probably wouldn’t have been friends, but they would have had something more valuable: mutual respect. Notice how people wallowing in consumerism have only the uber wealthy to envy and worship. An individual with a Moral Purpose respects and admires a human like John Glenn, because to Glenn, being an American wasn’t a matter of birth, it was his Moral Purpose, one which “Meant more than life itself.” 

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On the topic of Love, There is only one thing that matters, Respect. I see memes about ‘relationships’ and I want to vomit, because that is a condition two consumers without Moral Purpose might find themselves in, and a ‘successful relationship’ isn’t Love, it is just a negotiated position of perks for compromise, another consumer product. I have a young friend who would essentially give anything to be in a ‘successful relationship.’ I advised her to spend time alone until she discovered something about herself, something she would not abandon for anyone, her Moral Purpose. Only then would she know respect, the vital component in  A love beyond this life.

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This isn’t new-age BS nor weak words, it’s basic 2,500 year old Stoic Greek Philosophy. If you question its value, It was the creed of James Stockdale – Philosophy strong enough to allow him to resist 2,700 consecutive days as a POW being tortured. His Moral Purpose was his service and shipmates, and eventually even his captors and tormentors understood that he could not be ‘purchased’ at any price. Beaten, starved and dressed in rags, he had more dignity and serenity, and deserved more respect than any billionaire who is merely the king of consumers.

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There is a false temptation to look at this as “all or nothing” to give in to lesser company and smaller ideas and a diminished life, because you are not willing to discard every comfort to pursue a passion. Because Van Gogh’s path in Arles was to spend 465 days on the absolute cutting edge of his potential as a human being, doesn’t make the only other option spending the next 40 or 50 years as a pure consumer.

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The actual question is how many of the remaining hours in 2017 can you invest in treating your passion for creating and flying as your Moral Purpose?  If at any point in this year you catch yourself thinking “homebuilding sure costs a lot” the reaction that should spring from your mind is to question; Why you are accepting so little in return for your investment? To change the equation, stop looking at flight as just another hobby or consumer experience. Start treating it as your Calling, a worthy Moral Purpose, something which expresses the value of your life as an individual.

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-ww.

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