PB100:  The Pete Bowers Centennial
Rebooting the Fly Baby
15 May 2018


Peter M. Bowers
May 15th, 1918 - April 27th, 2003

We're re-inventing the building process!

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Table of Contents

Introduction

In 1958, the Experimental Aircraft Association (EAA) announced a contest to design, build, and demonstrate a new homebuilt aircraft.  The winner would have to be simple and inexpensive to build in the home shops and garages of that era.  One of the stipulations of the contest was that the winning designer would have to completely document how to build that airplane within the pages of EAA's SPORT AVIATION magazine.

Peter M. Bowers and his "Fly Baby" won.  It was an inspired selection for a number of reasons.  Not only did the Fly Baby meet the buildability and flyability criteria of the contest, in Pete Bowers they had that rarities of rarities... an engineer/aircraft designer who would actually write.  

And so, in a 14-part series in EAA SPORT AVIATION starting in December 1962 (just four months after winning the contest), Pete wrote about how to build a Fly Baby.  Thousands of EAA members started construction.  Dozens, or even hundreds of them were completed and flown.

While he worked on the articles, Pete was assembling a stand-along set of plans for sale.  The plans used the same diagrams (drawn by Jim Morrow) as the magazine articles.   The diagrams printed in SPORT AVIATION even had the figure-numbering of the plans set, rather than relative to their position among the articles.  From 1963 to 2003, Pete ended up selling around 5,000 sets of plans.  About 500 airplanes were built, either from the magazine articles or from the plans.  As you can see from the above diagram most of the planes were completed in the '60s to early '70s.

Drew Fidoe's "Stringbag" was built from the EAA Magazine Articles

So, what's the problem?

It's the 100th anniversary of Pete Bowers' birth...but the plans for his most famous creation are no longer available. 

And, in any case, the plans were written in 1963.  While there were almost a dozen revisions, they all were technical in nature--correcting dimensions, etc.  The current planes don't really doesn't reflect the realities of the 21st Century.

Think about how much has else changed in the past 50+ years, just in the homebuilding world.  Epoxy glues.  Stits fabric.  Composites.  Computer-aided laser, plasma, and water-cutting of steel and aluminum.  The latest edition of Pete's plans says you can buy a freshly overhauled Continental A65 for $500.  That'll hardly buy the overhaul gasket kit, now. 

Finally, people are different now from back then.  Back in the '60s, high school kids took shop classes, and practically anyone with a house had a table saw and did some minor woodworking.  It's just not the case, anymore.  The classic argument for a Fly Baby is that it's built just like a balsa-and-tissue model.  But how many people are actually building those, nowadays?

Safety Issues

Another aspect is safety.  Over fifty years of Fly Baby flying has revealed some problems with the design.  For the most part, nothing major... but the Fly Baby has the highest rate of in-flight structural failure among homebuilt aircraft in the US.  Almost a quarter of Fly Baby accidents involve wing failures. 

A Fly Baby properly built, properly maintained, and properly operated doesn't have a problem.  But Pietenpols are older than the Fly Baby, there are twice as many of them...but their wings don't break.  Why does the Fly Baby have such a problem?

I believe there are some changes that will provide pilots with a bit more design margin. And I'd like ensure builders know about them.

So What is "PB100" About?

We don't need band-aids to the existing instructions:  We need a REBOOT. So, to honor Pete Bowers' legacy, let's take things down to fundamentals, give the builder of the 21st century the kind of help that wasn't thought necessary in the '60s, and recommend modifications where experience shows it needs it.

Most homebuilt designs become lost to history when the plans go off the market.  But the Fly Baby has a unique advantage:  That 14-part building series in EAA SPORT AVIATION magazine.  No other homebuilt has had that level of detail published, free, for the use of the magazine's readers.  And if you're an EAA member, the entire series is available for you to download.  For free. 


That's what PB100 is all about:  Helping people build Fly Babies, whether they have an original set of plans or use the magazine articles.  PB100 support will be based on what can be downloaded for free from EAA.  For each of the 14 articles, I'm going to present information to help you understand them and know what kinds of changes are necessary or desired.  Each article will include a "Companion Guide."  These guides will provide additional information that'll greatly assist in your construction.  Each Guide will contain:
  1. Errata on what changes to the diagrams are needed.  Over the years, Pete did make some changes to the figures.
  2. Expanded detail to help you understand the tasks needed to be performed.  This will include new diagrams that illustrate aspects of the design to help you imagine how it goes together.
  3.  Key changes needed for safety
  4.  Warnings about components no longer being available, and potential alternatives
  5. Alternative approaches to some aspects of the design, as suggested by the builder community.
In addition, the section on each article will include links to key articles written by Fly Baby folks over the past twenty years.  They may not tie directly into the subject article, but they'll help with understanding it.

If you own plans...PB100 will make your building job easier.  But Pete intended that the magazine articles would be all a builder would need.

The Companion guides will be added gradually...probably one a month for the next year or so.  In addition, I'll be modifying them as suggestions are received, depending on the input from the community.  I've flown Fly Babies a lot, I've worked on them a lot, but I've never actually built a Fly Baby myself. I'm depending on the community for good info.  Each guide will include a version number to help identify when they've been updated.

Accessing the Building Series in EAA SPORT AVIATION

Construction instructions for the Fly Baby are available in the form of reprints of the original Fly Baby construction series, running from January 1963 to September 1964.  If you're an EAA member, you can download these articles FOR FREE from the EAA Archives.  If you're not an EAA Member, it costs just $40 to join, and you get a great monthly magazine.


The first step is to download the magazine articles.  Go to the EAA Sport Aviation Archive page and click the “View PDFs of Past Issues” section.  You'll need to log in to the site, using your EAA number.  The link here may not work all the way, because of the log-in requirement.  In any case, you'll need to access the "Education and Resources" tab, then select "Publications."  From there, just click the "SPORT AVIATION" link, and select "Archives" at the bottom of the page.  Hit the "Search For Articles" button, and you're ready to go.

Enter "Building Fly Baby" in the "Exact Phase" box, and turn off all the options except "Title."

Here’s a breakdown of the EAA magazine articles vs. the organization of the plans.  Note that the articles were not published in the same sequence as the plans. 

EAA Magazine Article Part

Date of Publication

Plans Topic

1

Jan 1963

Wing Construction

2

Feb 1963

Wing Assembly

3

March 1963

Fuselage

4

April 1963

Fuselage Secondary Structure

5

May 1963

Landing Gear

6

June 1963

Tail Surfaces

7

July 1963

Power Plant and Related Installations

8

Sept 1963

Controls

9

Nov 1963

Misc Systems 1

10

Dec 1963

Misc Systems 2

11

Jan 1964

Corrections

12

May 1964

Assembly

13

Aug 1964

Covering Tail and Wing

14

Sept 1964

Covering Fuselage

There's also an "Overview" in the December 1962 issue.  This is mostly history and background.

Making the EAA Articles More Usable

The complete building instructions for the Fly Baby were printed in EAA Sport Aviation magazine, but the articles are kind of hard to read. They're in PDF format, with pretty small print, and the text is huge monolithic blocks that are hard to wade through.

I have written a program that helps this. It allows you to select the text in the PDF articles and save it as an ordinary text file. What's more, it breaks up the blocks... it splits up each sentence into its own line, and individually numbers the sentences. You can save it as a ".txt" file, then load it into your word processor to increase the font size, select a different font, indent the sentences, go to double spacing, whatever. you can even re-combine some of the sentences.


Sadly, it only runs on Windows.

Download the ZIP File

To use the Fly Baby Converter:

1.  Open the ZIP file, and transfer the "Fly Baby Article Converter.exe" file to a convenient folder.
2.  Double-click to start. If problems occur, see below.
3.  Open one of the EAA Fly Baby Building series articles (PDF) file.
4.  Drag the mouse across all the text on the first page.  Don't worry if you get too much.
 - You could even just hit Control-A to highlight everything.
5.  Hit Control-C (copy to clipboard)
6.  Switch to the Article Converter
7.  Click the "Get Clipboard Data" button
8.  Go back to the EAA article, and select the next page with text
9.  Highlight the text you want to include.
10.  Go back to the Article Converter, and click the "Add More" button.
11.  Repeat steps 8-10 as necessary
12.  Go back to the Article Converter, and select the "Save" button.

The information saves as a Text file.  This can be loaded into any Word processor, and you can format it as you desire...make the font larger, increase line spacing, etc.  Do a "Save as" to preserve any features you add.

The conversion isn't perfect...there's some stuff that doesn't come across.  You may have to manually correct some fractional sizes, which PDF doesn't seem to handle well.  You'll also probably get some excess material (such as the magazine information) that can be easily deleted.

Potential Problems:

The file converter uses VisualBasic, and MalwareBytes tends to reject .exe files.  What's more, it will actually DELETE the Fly Baby Article Converter file!
Give it a try on your computer, but if you get a MalwareBytes issue, here's the fix:

1.  Copy the Article Converter file from the ZIP file to the folder again (assuming it had deleted it)
2.  Do NOT start it!
3.  Start MalwareBytes.
4.  Select "Settings" (menu on the left)
5.  Click "Exclusion"
6.  Select "Exclude file or folder"
7.  Click "Next"
8.  For the "specify file or folder," browse and select "Fly Baby Article Converter.exe"
9.  Select "Exclude from detection as malware or potentially unwanted item only"
10.  Click "OK"

Fly Baby Article Converter should now run.  Convert all the articles, save them to Word or as TXT files, then delete the MalwareBytes exemption and reboot your computer.


Finding Help

All this data is being compiled with the assistance of the Fly Baby community on Facebook and on the Fly Baby group on Yahoo.

If you have questions, feel free to ask them there.  As more information comes out, the supporting information will be upgraded.

Tony Bingelis articles

In addition to the Fly Baby articles, EAA Sport Aviation is chock-full of great information on building planes like the Fly Baby.  The late Tony Bingelis wrote many of them.  Here's a summary of useful articles in SPORT AVIATION

  • January 1972, Page 14, "Aircraft Metal Work"
  • December 1972, Page 36, "To Nail or not To Nail"
  • October 1981, Page 39, "Control System Cable Terminals and Connections"
  • September to November 1980, "Making Fittings" parts 1, 2, and 3
  • November 1979, Page 14, "You Can't Build an Airplane Without Nuts and Bolts"
  • September 1978, Page 34, "Aircraft Plywood...How to Use It"
If you're stumped about something, try searching the Sport Aviation archives.

Also, many of Bingelis' articles were re-published in book form.  "Sportplane Construction Techniques" and "The Sportplane Builder" can be purchases from the EAA.  For when you're ready to bolt on the powerplant, get "Firewall Forward" and "Tony Bingelis on Engines."

Fly Baby Bulletin

There was a newsletter for Fly Baby builders published in the 1960s.  I have received permission to include it for free download.  There's a lot of good information scattered throughout.

Templates for Steel Parts

Ted Cannaday put together a PDF file that contains templates for all the Fly Baby steel parts.  These are the same for both the EAA Articles and the formal plans.

Jim Katz generated these CAD files (.DWG format) for getting his steel AND wood parts cut by laser/water jet/plasma systems.  In an ideal world, you should be able to take these by a commercial vendor and have them cut out quickly at a fairly low cost

FAA Advisory Circular AC43.13-1B

This Advisory Circular provides the official guidance for aircraft construction and repair.  If covers everything, from wood, to metal, to hardware, to fabric, to electrical work, and far beyond.  It provides techniques, and it provides standards.  If you follow AC43.13, no FAA inspector or Designee will object to how your airplane is constructed.

Building Information

Updated 18 July 2018 (See Update Note Section)
  • Introduction
  • Wing Construction -- Article 1,  January 1963
    • Companion Guide
    • Rib templates
      • Nose Ribs
      • Middle Ribs
      • Trailing Edge Ribs
      • Note that it's VERY IMPORTANT that the templates be printed out accurately.  They each contain a scale showing a ruler.  Print one template out, and measure with a ruler to ensure it's printed to the correct scale.
    • Steel part templates
      • Ted Cannaday's Overall Steel-Part Templates.  
        • For Article 1, you will need all templates labeled "W402", "W403," "W404", "W405," and "W406"
        • Note that the templates show the center point for all holes to be added, not the diameter of the holes.  You'll have to cross-reference with the original figures in Article 1.
        • Also note that it's VERY IMPORTANT that the templates be printed out accurately.  They each contain a scale showing a ruler.  Print one template out, and measure with a ruler to ensure it's printed to the correct scale.  For my Epson 830 printer, I have to print these out at 94% scale.
    • Jim Katz' Autocad Templates
      • Jim Katz generated these CAD files (.DWG format) for getting his steel AND wood parts cut by laser/water jet/plasma systems.  In an ideal world, you should be able to take these by a commercial vendor and have them cut out quickly at a fairly low cost
      • However, it's important to CHECK the dimensions youself... there's no guarantee there aren't any errors in there, nor that the various computer systems haven't distorted some of the dimensions.
      • You may want to have the shop actually put in pilot holes, rather than the full-size holes shown in these drawings.  It gives you a bit more leeway.
    • Wing ordinates for the airfoil
    • Other Pertinent Information



Update Information

1 June 2018

  • Added the draft Companion Guide for Article 2.  This currently takes the builder through the initial wing assembly.
  • Updated the guide for Article 1

26 May 2018:

  • Updated the guide for Article 1
  • Added the DWG templates
10 June 2018
  • Completed Companion Guide for Article 2
  • Updated Article 1 Companion Guide, and the Preparations material.

22 June

  • Updated first two Companion Guides
  • Added Draft Guide for Fuselage Construction

25 June

  • Article 3 Companion Guide completed and placed online
18 July
  • Updated Article 3 Companion Guide
22 July
  • Added Draft version of Article 4 Companion Guide
  • Updated Article 3 Companion Guide

23 July

  • Replaced draft with Version 1.0 of Article 4 Companion Guide