Pietenpol for Thailand.

Builders,

The following letter came from Cy Mao in Thailand. It caught my eye because many years of my childhood were spent in Thailand, where my father led the US work on infrastructure projects like Airbases and Hospitals. They were golden years for my family. We had the utmost respect for the nation that welcomed us. 

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Hello

I hope this is the right place to ask this. I apologize if your “comments” are not where you want this. If you prefer an email address to be used just tell me.

I want to build a Pietenpol in Thailand where a two seat ultralight can weigh 550 pounds empty. “Real airplanes” are very restricted in flight, sort of like flying IFR in the USA. Not so much fun. Ultralights can fly without being in constant radio contact with “our ATC”.

I saw in the 1932 Flying and Glider manual that a Piet weighs 625 pounds with water with a Model A of 244 pounds and radiator of 21. Take away 265 and add back an A65 of about 170 and it weighs 530 pounds which is legal by 20 pounds. This is my plan. Then I research this plane on the forum and see that this plane usually weighs over 700 pounds and I think it is due to a lot of changes by builders since 1932 likes batteries and brakes and such.

So I ask if you can help me build the lightest Pietenpol and if you think it can weigh 550 pounds or less. Then of course we will talk about CG – I watched your video about this too.

I prefer build wood fuselage. Is the metal version lighter? I can build steel if necessary.
What is lightest gear? I think old wooden gear looks lighter.
My place to build is not 30′ so I must build 3 piece wing. But if this adds too much weight I can look for a bigger place to build if this is important.

I plan only Airspeed indicator and oil pressure gauge.
No brakes, no battery, no radio. No upholstery, Only seatbelts.
You say always best to build long fuselage. Is this true even if empty weight is critical?
I like to have steerable tailwheel but can change to skid when finished if I need to lose a pound or two (but skid vs tailwheel may affect where I should have put the axle a bit to handle on the ground, and will move CG a bit also.)

I read about Oratex fabric that needs no heavy paint. I can use this. Some people say paint of airplane can weigh 30 pounds.

Do you think 550 pounds is possible?

If you think this is not possible by the plans then I wonder more:

Looking at other airplane plans I always see ribs built from 1/4 x 1/4. Piet uses 1/4 x 1/2. Is this important or only overbuilt? 1/4 x 1/4 can save almost half the weight of ribs (gussets still weigh the same of course) Rib spacing is close as any other plane and wing loading is very light. Do ribs need to be 1/2″ for some other reason? I don’t see much compression struts in Piet wing and wonder if they also serve this function and best to leave at 1/4″ x 1/2″

Also I notice fuselage longerons are 1″ x 1″ but many plans I look at make 3/4″ x 3/4″ much more common. Is this an example of rough landing areas in 1932 and not important anymore or is this not a good idea to make these smaller? Of course I don’t want a plane that will break apart.

Thank you

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Above, my father speaking with HRH, the King of Thailand, in 1974. Being born in Massachusetts and educated in Switzerland, The king understood both western and eastern worlds. To read the story, click here: Real moral power: HRH, the King of Thailand passes from this life

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Friend,

Your letter is an interesting challenge. Lets look at some numbers I’m sure of to see what can be planned:

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Lightest 65 Continental powered plane I have weighed was 590.  It was very lightly built, no brakes, hand prop, etc. I don’t think it is close enough to 550. The 170 pound weight for the engine is for the bare motor, its flying weight is closer to 190. The average 65 Continental Piet weighs over 700 pounds.

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Lightest Ford powered plane I have weighed is 677.  The average is 720 or so. These guys put more effort into saving weight than Continental builders. The numbers in the Flying and Glider manuals are optimistic guesses, not data. There is no way you could look at the 677 pound plane I weighed and see 50 spare pounds just sitting on it.  Im reasonably sure the 625 pound number is a myth.

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There is a lot of talk about steel tubing being lighter, but after the floorboards, tabs and mounting points are on it, the weight advantage of the steel tube plane largely evaporates.  I would still build a long fuselage unless you are your passengers are less than 1.7 meters tall. The weight difference is small. Plan on building the fuselage out of 3/4 x 3/4, it is plenty strong and BHP built some of his later planes that way. Make sure you use Spruce, or some wood that is that light. Fir is significantly more dense.

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The wooden gear and straight axle are much heavier than later J-3 style gear. The 590 pound plane used spun aluminum go cart wheels and very light tires, no brakes, and lightly built J-3 gear. I can show you how to make very light bungeeing gear that uses  about 600 #8 rubber bands on each side. Don’t laugh, it flew on my Piet for 25 years before I got it.

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Oratech fabric is a very real weight savings, perhaps 20-25 pounds on a Piet. It is not as expensive as people make it sound.  1/4 x 1/4 for cap strips is fine, that is actually the size in a Pitts Special. The Spars in some of BHP’s later planes were only 3/4″ wide. Consider this is the same as many Cubs. There is talk that the British built up spars are lighter, but routed 3/4″ spars would likely beat them.  I can show you how to make a two piece wing with a very light joint in the middle. A one peice wing is clumsy to build and cover. There are steel fittings that could be replaced by aluminum in certain places. Aluminum lift struts are very light by comparison to other options.

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With all this done, I still think you would have a very hard time getting into the 550 pound weight for sure. You could build the airframe and see if it could be Continental powered, but keep this as a back up: You could always use a Rotax 582 or  a UL-260 on a long mount for the lowest possible engine weight. People will say that they can’t power a Piet, but that you are speaking of building is several hundred pounds lighter than a typical Piet.  A 535 pound Piet with a 582 on the front would out climb almost any Pietenpol in the US.

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Send me your address and I will mail you a copy of my weight and Balance manual as a gift.  – this could be an interesting Project of International cooperation. ขอขอบคุณ.

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Billy from Philly, 3.3L Corvair engine run video

Builders:

Billy Kerchner, a Sonex plans builder from Philadelphia, was one of the other builders who came to my hangar for the finishing school.  He also elected to build an SPA 3.3L Corvair from an “Engine in a Box” kit.  We caught this short video after the run, when he was packing unto head home.  Not technical, just capturing the spirit of the moment. Word of caution to viewers under 13 and the easily offended, video does contain an accurate expression of happiness in the true Philly vernacular.

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We just reached 1,000 subscribers to my Youtube channel yesterday, but your participation is still important, if you have not yet subscribed, please take a moment to do so. Thank You,

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Ken Killian, 3.3L Corvair Run Video.

Builders:

Last week, several builders came to my hangar for a finishing school. Ken Killian, who is building a Zenith 650, Selected to build an SPA 3.3L Corvair from an “Engine in a Box” kit.  We caught this short video right after the run. Not technical, just capturing the spirit of the moment.

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We just reached 1,000 subscribers to my Youtube channel yesterday, but your participation is still important, if you have not yet subscribed, please take a moment to do so. Thank You,

WW.

A word of caution or being a kill joy?

Builders;

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The sign above, is pictured Thursday night at our airport in Florida.  It is normally stored on my back porch, hopefully never to be used. It’s only purpose is to keep unethical TV reporters in search of ratings, out of our neighborhood after an accident.  On Thursday afternoon, one of our neighbors went for a short flight in his RV-4, and never returned. Our little community only has 119 people here, the man was known and liked, friend to both myself and the Weseman’s.  This was the second fatal accident this year. The circumstances are unknown, and not important. He was a highly skilled guy, flying a good plane, and we will not see him in this life again.

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2020 will make my 31st season in aviation. Plenty of people have been around longer, but I most have them have spent their seasons in far more benign parts of aviation. Experimentals, antiques and aerobatics and other riskier parts of general aviation are arguably more dangerous than flying in the military.

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Salesmen in our industry understand that any discussion of accidents and risk management makes people who might dabble in homebuilding nervous. Conversely, I’m not a salesman, and I’ve long said that homebuilding is the wrong place to dabble. If you are interested in devoting your attention and ambitions in homebuilding, then I have some perspectives and experience to share with you, to give you understanding and tools to effectively minimize and manage your risks.

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This approach is not always welcome. A week ago, a new second owner of an experimental openly said on a discussion group that he couldn’t wait to get his plane because he wanted to take his kids flying in it. If that attitude doesn’t unsettle you, maybe you don’t know this fact: The first flights of the second owner of an experimental are statistically proven by the FAA to be the highest risk events in general aviation, several times more likely to result in a fatality than even the original flights of the aircraft. This is solely because of the second owner, and his rush to use the plane without transition training, often without a Pilot’s Operating Handbook, and without studying issues like Weight and Balance, loading and systems configuration specific to that particular plane.  These issues are not new, read 20 year old NTSB reports on John Denver’s accident, the circumstances never change.

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When I suggested to the new second owner that he might look into training, a POH and alerted him that his plane might have a very limited useful load, his public response was to openly say he had flown the plane over gross, had done his flight training over gross weight, and he thought it was “No big deal”. He directly said he just wanted to ‘spread some joy’ and took my comments as being a know it all.

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His reaction isn’t unusual today; twenty years ago, the majority of people were willing to listen to experience, today, people, particularly second owners, are very quick to take offense to nearly any comment that doesn’t validate and endorse their conception of how things work, often based on the ‘its no big deal’ perspective.  This summer I pointed out a Pietenpol with a structural issue about to be flown. The owners response was to demand I remove from my website, a picture he himself had put on the internet. He took no action of the items I referenced, and 45 days later the plane crashed on rotation on its first flight, and was completely destroyed. By an absolute miracle, the pilot survived. He later told an observer that he might have listened to me, but I wasn’t nice enough to him in my comments. I’ll leave it to you to decide if you believe him.

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TO BE ABSOLUTELY CLEAR: This story is not making a comment in any way about my neighbor’s accident. The point is only that I have known and been fairly close friends with more than two dozen men and women killed in light planes.  They were good people, and the real tragedy is that more than half of accidents were easily preventable.  Each loss offered some wisdom, if you were willing to learn. I share the  stories like these: Risk Management reference page with people willing to gain some understanding to improve their own risk management. On the other hand, it can all be dismissed as me just being a kill joy.

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2019 Midwest tour video

Builders:

Your Sunday morning: You could either watch Meet the Press and see the same old talking heads rehash the same old alarmist arguments, or you can spend the same amount of time watching our 2019 midwest tour video.  I guarantee our video will put you in a better mood to get stuff done on your Airplane today.

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The video above is the work of Ken Pavlou, aka “Kamal Mustafa” . He put nearly 18 hours of editing into it. So if you are tempted to turn the sound off to avoid hearing my low caffeine induced speech impediment of connecting all the sentences with the phrase “and-uh” , just imagine how Ken’s brain has been damaged by editing this for you. A human sacrifice on behalf of advancing the world of Corvairs.

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WW.

Deland Showcase, CC #45, Nov. 14.

Builders,

Here is the video notice for Corvair College #45. Please note that this College is an “Operations College” Where the focus of the event is learning the subjects in the New – M.O.P. Manual, a required technical document.

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The event is open to the public, you only need to buy a gate pass for the whole Showcase event, you can learn all about this great hands on, aviation event, based on participation, not on spectating. Here is their info:

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https://www.sportaviationshowcase.com/event-info/index

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Above, the intro Video: Notice I’m wearing spiffy new “Polo Mafia” shirt provided by Larry Nelson.

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In addition to all of the “M.O.P.” information at CC #45, you can:

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Come and see Corvair Powered planes like Phil Maxson’s 601XL and The SPA Panther.

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Meet Corvair Builder/Pilots like Phil Maxson,   Ken Pavlou, and Paul Salter (You can even see verbal sparing matches between Ford Man and ‘Old Hairy Guy’. )

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You can bring all your core parts or assemblies, and I will carefully inspect them. If you like I can bring them back to my hangar or SPA’s shop for reconditioning.

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You can study a running 3,000cc Corvair on my run stand, learn regular maintenance items like distributor installation and prop pitch setting. We will also be demonstrating “Corvair Fast Burn” Ignition timing settings and how air-fuel meters work.

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Have any question answered in a friendly setting, were we will have the resources right on hand to make sure you really understand your power plant.

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Make plans today, It will great event, we are planning on packing a lot into the day, don’t miss it.

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PS, if you have further questions about the event, please ask them here in the comments section, or call me direct at 904-806-8143.

 

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Something Funny- Oshkosh 2019

Builders,

Here is something funny from Oshkosh 2019. I am making fun of the square edge of top of Randy Bush’s Pietenpol cowling; this is done in jest, as I love Randy and he knows it, he is the person laughing in the background.

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Randy is part of our Oshkosh crew every year. There is no explanation for it, but some some reason Ken Pavlou, nick named him “Pot Roast”, and the name has stuck ever since.

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If you want to read more about Randy, get a look at these stories:

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Randy Bush’s Pietenpol hits 500 hours.

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Oshkosh 2019

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Above, Randy stands beside his 3,000cc Cleanex at Oshkosh 2017. Yes, “Pot Roast” has two Corvair Powered planes, and they have more than 1,000 hours between them.

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New – M.O.P. Manual, a required technical document.

Builders,

Below is a quick look and a video introduction to our new “Maintenance, Operations and Procedures manual

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Above, the cover: If you ar building or flying a Corvair powered plane, you need to own one of these. It is made up from data pulled together from my experience and that of Dan Weseman. Once or twice a month, we have a builder who calls us who has completely missed missed critical technical data we have previously presented in many formats. Here we have gathered critical information into a single, easily followed location. This is thousands of hours of testing, hundreds of hours writing, and all we ask of builders is to spend one hour reading it, and keep it on hand at all times, and follow it.

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Above, a look at the table of contents.

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Above, Three of the people who made the greatest contribution to getting this document into print.

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Above, a video explaining the content of the new MOP manual, and what its different about it.

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You can get your copy here:

http://shop.flycorvair.com/product-category/manuals/

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Thank you, William.

4201-B “STOL BOWL” nose bowls

Builders,

Just a 12 hours to go before departure for Corvair College #44 At the Zenith Aircraft Factory, but we are still prepping regular parts to be shipped by SPA while we are on the road.

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Above, two STOL bowl, production parts. One is for Florida Zenith builder Ramesh Nori, the other one is yet to be adopted. If you would like to be the new owner, all you have to do is call Lisa at SPA: 904-626-7777, place the order, and it will be shipped on Thursday.  Care and feeding is easier than adopting a puppy, plus, your STOL bowl will not ruin your carpet nor chew shoes.

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Looking forward to seeing many of you at the College.

WW.

Night Run: Carb and Intake testing

Builders,

A quick look at Sunday night, outside my hangar. Dan Weseman was looking for an intake design and a Carb orientation and model, specifically for Corvair powered Panthers with tricycle gear. Tonight was the test run, and it turned out amazingly good.

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Above, a look at the back of my test stand; Notice it is now sporting two lab grade 5 wire O2 driven Air/Fuel meters.  The test question was essentially this: If a Rotec TBI is turned 90 decrees, will it still have excellent mixture distribution to both sides of the engine. The answer is yes. This was the largest spread under power, .3 on the air/fuel ration. That is as good as carbureted engines get.

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Above, Dan runs the controls.

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Above, a look at the Rotec on the manifold. It started and ran exceptionally well.

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After tests, Dan Rachel and I ate dinner at their place and talked about a lot of stuff, ranging from airport business to the new “Ford vs Ferrari” movie. It was a real nice end to a productive weekend.

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For more info on carbs, look at this: Corvair Carb Reference page for 2020.

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