Experimenter is a magazine created by EAA for people who build airplanes. We will report on amateur-built aircraft as well as ultralights and other other light aircraft.
Issue link: http://experimenter.epubxp.com/i/81495
words and simply stared in amazement at it, oftentimes requiring their own moment of silence. Jack's shop is lined with B-17 posters and memorabilia, so he is surrounded with documentation to help keep the airplane as accurate as possible. He is building this replica from a set of Don Smith 1/9-scale, radio-controlled (RC) airplane plans. Jack has many, many sets of RC B-17 plans, but the Don Smith plans were deemed to be the most accurate among the collection. He spent some time going over the pages and pages of plans with me, showing me a couple of places where even the most accurate plans had to be massaged a little bit. Fabricating parts from the drawings is something Jack is supremely comfortable with. Some of the more complex parts are some of the most beautifully crafted parts on the airplane…all made right there in Jack's shop. Having the right tooling is essential to building a scratchbuilt airplane of this magnitude, and Jack has them all: Mill, lathe, planner, jointer, all the big stuff we like to play with. Take, for example, the spinners for the propellers. To make them scale, Jack had to fi nd something that matched the size needed. His outside- of-the-box thinking comes into play here. Rather than looking for some sort of cup-shaped item, he noticed that a part of a home air-conditioner unit had the appropriately sized "bowl" to make into a spinner. However, that bowl wasn't actually a bowl; it was a cylinder with lots of stuff inside of it. "Why not just whack it in half, remove the insides, and toss it in the lathe to match the shape?" Jack said to himself. That's the kind of stuff that hooked me to every word Jack had to say. The engines on the airplane are four-cylinder, two- stroke Hirth F30s, good for about 85 hp each if they are allowed to turn up to their full-rated rpm of 5500. Jack doesn't plan to turn them that fast, but he plans to run them at an rpm that will net about 60 hp each, giving him 240 hp total to lift an airplane roughly the same size and weight as a Cessna 152. I sort of imagine an angry hornet's nest as the sound this airplane will make as it passes by going full tilt. These engines have provided plenty of head scratching for Jack as he makes T e spinner for the propellers is made from a home air conditioner part, sliced in half, and machined to fi t and look to scale. adjustments to them to fi t in a properly scaled cowl. The cylinder heads were turned 45 degrees to allow better clearance, and in doing so they had to be machined slightly to fi t. It makes for an interesting look, but still should provide adequate cooling. For air to fl ow properly to the carburetors (eight of them!), a custom intake had to be made, and that is what Jack was designing and testing during my visit. They had to be made so both carbs were getting the same amount of air at all times, but yet provide necessary clearance for the round cowl surrounding them. From custom intakes to propellers to hand-blown nose bowls, every piece of this airplane is custom made by one man. Jack's documentation and dedication to this project is pure homebuilder. Projects like Jack's are underway and more guys like Jack are out there; we just don't see them very much because they are constantly working away in the shop to bring a special airplane to light someday. I will visit Jack Bally and his 1/3-scale B-17 project again to provide yet another update on what is turning out to be one of the most fascinating projects any of us will come across. » Click here for a photo gallery of images with more details of construction. Each month we'll also feature another member's homebuilt project via a short video. Click here to learn about Steve Dentz's homebuilt Just Aircraft Highlander. EAA EXPERIMENTER 27