The Backyard Flyer_GeneSmith Interview

just outside Kansas City is a town called Gardner Kansas they have a general aviation Airport and every year host an event featuring World War one type aircraft & militaria it has proven to be quite a draw for about a year prior to this show I had been corresponding with Larry Smith of Bally engineering in Missouri over the years Larry's dad Gene Smith has designed and flown a number of small airplanes through their business valley engineering they market light airplanes engine reduction drives and the Culver line of wooden propellers they also market a firewall forward power system for light aircraft that incorporates a modified Generac engine their reduction drive and their large culver props my interest in this father-son team is genes newest creation which combines all the aforementioned products into a flying machine an ultralight called the backyard flyer given the 254 pounds ma r103 weight limit we ultralight flyers are limited as to our engine choices most four-stroke motors of the 40 to 50 horsepower needed for light flight are too heavy and would not leave enough allowance for sufficiently strong structure because of this ever since I've been flying ultralights we have been limited to using two-stroke motors because of their superior power-to-weight ratios while they are powerful for their sides they are also somewhat cantankerous they have to run at high rpms to generate the power required and this causes them to run fairly hot also for their horsepower output they burn in an ordinate amount of fuel compared to four strokes thus limiting the air time one can achieve with the five gallons of gas we are allowed they require consistent and constant attention and care my experience has been that flying with two strokes requires one to balance art and science to keep them running well because of this I was greatly intrigued by the announcement that Gene Smith had designed a legal ultralight backyard flyer with a four-stroke motor in addition the engine has an electric starter the craft has full three axis controls differential braking and a number of other innovations I will let him tell you about anyway we all finally got together at the Gardner airshow so I could learn more about the backyard flyer see it fly and show it to you at times during my interview with Jean our field was strafed by biplanes threading their way through withering anti-aircraft fire sporadically aerial combat would break out also so occasionally you will hear the sounds of genteel warfare in the background while Jean tells us about the back yard flyer oh it's a backyard flyer ultra light on Gaston backyard UL I went through the University of Missouri at Rolla yeah actually with this Missouri School of Mines when I started in University of Missouri Rolla when I graduated I do have a degree in mechanical engineering I have cropped this crop dusted for 21 years and been an AMT I don't know how many years quite a quite a few years been an EMP I guess that's mainly the qualifications for I know how they ought to fly I know how they gotta fly if you wanna survive crop dusting the primary thing is to to build an actual legal heart 103 ultralight with four-stroke power and electric starting those those are the those are the main things we wanted we wanted an electric starting a four-stroke with an adequate horsepower to do a good job of flying the Indian Court has the reduction drive on him it allows us to run a 72 inch diameter prop and that's allows us to get a lot of thrust out of those out of our limited to 40 horsepower it is electric starting also had just charging the system left out of 20 24 amp alternator built into the flywheel there's some people love the two strokes and get along with them very well a lot of people say it's not when they will quit on it's not not if they'll quit it's when they will quit and I don't know I never flew them that much to really have any trouble to the two-stroke but for one thing the four strokes for more efficient visceral fly on just over a gallon an hour got I mean you can cruise around all day at a gallon an hour a normal cruise would be about a gallon in the court about five about five course an hour therefore is why we chose this engine it's american-made made in Wisconsin although we do we modify it's quite a lot of these we put the Weber carburetors on it because Weber carburetors or designs were totally tunable they have for many many selections of jets the air bleeds and millicent tubes everything is adjustable and we can tune those engines these engines can be tuned for the aircraft use we also have is this automatic carburetor heat and that's very important also I think they all everybody ought to have that automatic carburetor heat on the engine we do have the our own belt reduction Drive the purpose course is to allow you to run a much larger diameter propeller which gives you far more efficiency this is our Series three and it has the feature that meant the main feature is it has a built-in overrunning clutch action it's not an over running clutch but it's a it's a belt with a slack side idler and the slack side idler is being spring-loaded so that the propeller cannot power the engine if the engine can power the prop but the propeller can't power the engine and this in effect then cancels one half of your resinous and if the engine and prop try to resonate the the slack side idler releases one one-half of that cycle and you can't have resonance without both both phases the bottom line is it that stops them breaking the Rif belts and breaking the crankshaft we bought out cover prompts a few years ago and big bill of course build our own props and it's a it's a big advantage being able to experiment with a lot of different diameters and pitches and of course where we we build a reduction Drive is with many different ratios so there's a lot of different combinations you can put together with different ratios different propeller speeds different propeller diameters and we've learned a lot we will tell you all of our secrets but we learn pretty well how to get the performance out of these low horsepower power plants with aluminum because it's light but aluminum also has a lot of springiness it has more flexibility than steel so because of that I use the large diameters as large diameter as I can and then you have to use the wall thickness we have to keep it fairly thin because of the weight limitation we've got to stay within our 254 can be welded very very well it's harder sure it's not easy but the we've designed the structure so that none of the wells are in in critical tension we'll try to put the wells non critical either in compression or in shear but as much as possible try not to put any any critical will in tension and that's just the way I designed them and then we weld them of course to eliminate all of the disconnects I just don't like all of the cables and pins and disconnects that have potential potential problems to either forget one or lose one or something like that we try to eliminate all of those that we can because it's a design for very highly if it's very lightweight it has internally it has a triangle trust trust or core strength it's it's tapered both in cord and in thickness vest that is all for the benefit of getting it light developing us lift and keeping it light enough that and strong this is designed and withstanding 6 G's and and then the main feature of it I guess the unique feature is that this wing swings we have four attach points here these little hand wheels spend these little hand wheels out and the wing rotates 90 degrees into position and be the tie-down point over here on the left wing attaches to the t-bar on top of the tail and at that point the airplane is 7 7 feet wide and 25 feet long or whatever the wingspan is this one's 27 but 25 to 27 foot and all you have to have is a long box trailer takes about two minutes to transfer it from one to the other we can be in the trailer in a couple of minutes we're back out ready to fly in a couple of minutes for flight the wing is attached to the airframe in four points these two points here the rear spar the varus Barnes test here and the main spar has to attach points here only one of which is used during transport which it's it's in transport position now only one of them is used but when you swing it back around for flight and both of these will be used as along with these rear ones so has four points that suspend it during during flight and then only the one here and two at the tail tail post for transport that's why we build it this way that so that the one-piece wing can stay intact no disconnects no cables no pins no braces all fully cantilevered folded like there or rotated like this it's ready to go in and standard the standard box trailer and of course you see there are no stress no braces no wires the wing is entirely cantilevered and all one piece all welded chose the the junker style or that they displaced a LaRon from the wind from one primary cause and that is in a full stall the ailerons are still fully effective because they're down here below the wing in the in the air that is not stalled the stall of course goals only it happens on the top of the wing and and even though you might be in a full stall we have full roll control didn't pull this from back all the way back full stall and then rock the wings rock the wings as it's falling through the stall you still have full roll control if those Junkers tile aileron are any additional drag and I'm not sure they are they might be a little additional drag but that's okay with it most time we we are more concerned with being able to meet the speed limit the that we're held to on the part of--part 103 and so there might be a benefit in that that respect tail draggers really need to have individual brakes which we do have but it looks like we I mean we won't have one pedal here just just one set of pedals but they're hooked to the brake and the wrecker through a pulley a pulley on the on the rudder pedal and when I step on it it pulls both of them but there's a very strong return spring on the brake so I'll get tail wheel steering and Reder before I get brake action but if I need braking action push a little harder and I get breakouts and also and that works course in either direction as far as straight ahead if you're just like light pedaling you'll get steering if you push hard you get both brakes it's just as simple as that on the landing gear it it's pretty much old standard j-3 type of a construction with one exception instead of using a set of bungee cords or or whatever for the shock absorption I for two reasons for saving in weight and for simplicity I just use a piece of curved tubing and the piece of curved tubing can act as your as your bungee we we prefer to operate under the part 103 because two things the light sport is so expensive and the regulations are far more than could have been necessary it seems to me but at any rate we don't feel like we as a small operator we can't afford to go with the light sport you have to stay with the part 103 yeah we'd all like have a little more weight it's hard to keep them light enough to meet that requirement but but yes I'll I'm being happy to keep it as it is very valuable yes if they should do away with part 103 I think that would be really a terrible blow to thee to the average man to the people that can't afford these $100,000 even $50,000 light sports a well designed to alter light I think is just a safe not as fast when that's one of the good points with youth when you have a landing speed of 25 or 30 miles an hour not a whole lot can go wrong done not if not nearly not nearly as serious that it is at 50 or 60 miles an hour like this airplane here we'll take off the land at 25 miles an hour and anything would happen at those speeds as far less likely to give you injury there's a 50 or 60 mile an hour takeoff and landing well if it flies about the easiest of any any airplane I believe I've ever flown it's just extremely easy on the landing it's so it's so forgiving you can even land a little faster a little slower it doesn't care you can set it down you know you can set it down at 35 or 30 over 2 or 25 it just floats whatever it it glides glides off in there and it's just it's just a such a pleasure to fly you you you you

Channel: Brian FitzGerald

Views: 736,634

Keywords: Quicksilver Ultralights, yt:quality=high:, ThePrairiePrince, Powered Parachutes, Backyard Flyer, Flying Movie, Aviation, Powered Paragliders, TrikeBuggy, Aviation Heros, Mosquito Helicopter, Kolb Firefly, Ultralight Flying

Id: uaUe8uT-CtM

Length: 19min 30sec (1170 seconds)

Published: Thu Apr 09 2015